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• 16301. [Image] The Endangered Species Act and the National Research Council's interim judgment in Klamath Basin

  	The controversial 2001 U.S. Fish and Wildlife Service water allocation decision in the Klamath Basin has been portrayed as an example of scientific guesswork operating under a flawed Endangered Species ...
  	Citation × Citation Citation Abstract Copy Title: The Endangered Species Act and the National Research Council's interim judgment in Klamath Basin Author: Cooperman, Michael S. ; Markle, Douglas F. Year: 2002, 2005 The controversial 2001 U.S. Fish and Wildlife Service water allocation decision in the Klamath Basin has been portrayed as an example of scientific guesswork operating under a flawed Endangered Species Act. This conclusion has been based on an interim National Research Council report, quickly prepared in late fall, 2001. We have reviewed several iterations of the NRC Interim Report as well as all Biological Opinions and management documents related to Klamath Basin suckers and provide an overview. The 2001 Biological Opinion and the Interim Report illustrate the lack of consensus typical of scientists in the early stages of exploring a complex system. Unfortunately, the decision created hardship for a small group of people and the lack of scientific consensus has politicized the debate. Politicians have assumed that the Interim Report has primacy in the scientific debate when, in fact, its speedy construction contributed to multiple errors that detract from its scientific usefulness. The NRC Interim Report has, instead, primarily served to deflect debate away from the needs of listed fishes to one about shortcomings in the Endangered Species Act. Although the process of science has been served by both the 2001 Biological Opinion and the Interim Report, both have shortcomings, and we see no justification for either side labeling the other's decisions or conclusions as "not sound science." Title: The Endangered Species Act and the National Research Council's interim judgment in Klamath Basin Author: Cooperman, Michael S. ; Markle, Douglas F. Year: 2002, 2005 The controversial 2001 U.S. Fish and Wildlife Service water allocation decision in the Klamath Basin has been portrayed as an example of scientific guesswork operating under a flawed Endangered Species Act. This conclusion has been based on an interim National Research Council report, quickly prepared in late fall, 2001. We have reviewed several iterations of the NRC Interim Report as well as all Biological Opinions and management documents related to Klamath Basin suckers and provide an overview. The 2001 Biological Opinion and the Interim Report illustrate the lack of consensus typical of scientists in the early stages of exploring a complex system. Unfortunately, the decision created hardship for a small group of people and the lack of scientific consensus has politicized the debate. Politicians have assumed that the Interim Report has primacy in the scientific debate when, in fact, its speedy construction contributed to multiple errors that detract from its scientific usefulness. The NRC Interim Report has, instead, primarily served to deflect debate away from the needs of listed fishes to one about shortcomings in the Endangered Species Act. Although the process of science has been served by both the 2001 Biological Opinion and the Interim Report, both have shortcomings, and we see no justification for either side labeling the other's decisions or conclusions as "not sound science." Close

• 16302. [Article] The influence of climate change and restoration on stream temperature

  Water temperature is an essential property of a stream. Temperature regulates physical and biochemical processes in aquatic habitats. Various factors related to climatic conditions, landscape characteristics, ...

  Citation × Citation Citation Abstract Copy Title: The influence of climate change and restoration on stream temperature Author: Diabat, Mousa Water temperature is an essential property of a stream. Temperature regulates physical and biochemical processes in aquatic habitats. Various factors related to climatic conditions, landscape characteristics, and channel structure directly influence stream temperature. Numerous studies indicate that increased average air temperature during the past century has led to stream warming across the world. The trend of stream warming was also present in spring-fed watersheds, where summer flow has decreased. In addition, anthropogenic practices that alter the natural landscape and channel structure, such as forest management, agriculture, and mining contributed to stream warming. For example, deforested and unshaded stream reaches or dredged channels were warmer than shaded reaches and meandering streams. Stream temperatures in North American lotic habitats are of a specific concern due to their significant economic, cultural, and ecological value. With climate projections indicating that air temperature will only continue to rise throughout the 21st century, cold- or cool-water organisms, especially fishes, will be affected. Therefore, there is a strong need to better understand the impacts of changing climate, riparian landscape, and channel structure on a stream's heat budget. This may assist in restoring the historic thermal regime in impacted sites and mitigating the impacts of future climate change. This study looks into the relative influences of the different factors on a stream's heat budget with three manuscripts: one on stream temperature response to diel timing of air warming, one on stream temperature response to changes in air temperature, flow, and riparian vegetation, and one on stream temperature response to air warming and channel reconstruction. I used the software Heat Source version 8.05 to simulate stream temperature for all three analyses along the Middle Fork John Day River, Oregon USA. Two of the manuscripts were applied to an upper 37 km section of the Middle Fork John Day River (presented in chapter 2 and 3), where the third manuscript was applied to a 1.5-km section. The sensitivity analysis of stream temperature response to diel timing of air warming (Chapter 2: Diel Timing of Warmer Air under Climate Change Affects Magnitude, Timing, and Duration of Stream Temperature Change) was based on scenarios representing uniform air warming over the diel period, daytime warming, and nighttime warming. Uniform warming of air temperature is a simple representation of increases in the average daily or monthly temperatures generated by the 'delta method'. The delta method relies on adding a constant value to the air temperature time-series data. This constant value is the difference (delta) between base case average air temperatures and the projected one. Scenarios of daytime or nighttime warming represent conditions under which most of the warming of the air occurs during the daytime or the nighttime, respectively. I simulated the stream temperature response to warmer air conditions of +2 °C and +4 °C in daily average for all three cases of air warming conditions. The three cases of different diel distributions of air warming generated 7-day average daily maximum stream temperature (7DADM) increases of approximately +1.8 °C ± 0.1 °C at the downstream end of the study section relative to the base case. In most parts of the reach, the three distributions of air warming generated different ranges of stream temperatures, different 7DADM values, different durations of stream temperature changes, and different average daily temperatures. Changes of stream temperature were out of phase with imposed changes of air temperature. Therefore, nighttime warming of air temperatures would cause the greatest increase in maximum daily stream temperature, which typically occurs during the daytime. The sensitivity analysis of the relative influences of changes in air temperature, stream flow, and riparian vegetation on stream temperature (Chapter 3: Assessing Stream Temperature Response to Cumulative Influence of Changing Air Temperature, Flow, and Riparian Vegetation). This study summarized stream temperature simulation in 36 scenarios representing possible manifestations of 21st century climate conditions and land management strategies. In addition to existing conditions (base case) of flow, air temperature, and riparian vegetation, scenarios consisted of: two air temperature increases of 2 °C and 4 °C, two stream flow variations of +30% and -30%, three spatially uniform riparian vegetation conditions that create averages of effective shade 7%, 34%, and 79%, in addition to 14% for base case conditions. Results suggest that variation in riparian vegetation was the dominant factor influencing stream temperature because it regulates incoming shortwave radiation, the largest heat input to the stream, while variation in stream flow has a negligible influence. Results indicated that increasing the effective shade along the study section, particularly in the currently unshaded sections, could mitigate the influence of increasing air temperature, and would reduce stream temperature maxima below current values even under future climate conditions of warmer air. With the small influence it had, increasing stream flow reduced the 7DADM under low shade conditions. However, increasing stream flow showed counterintuitive results as it contributed to increasing stream temperature maxima when the stream was heavily shaded. The applied study examined the stream temperature response to restoration practices and their potential to mitigate the influence of warmer air conditions (Chapter 4: Estimating Stream Temperature Response to Restoring Channel and Riparian Vegetation and the Potential to Mitigate Warmer Air Conditions). This study focused on a 1.5 km section along the upper part of the Middle Fork John Day River that was modified due to past anthropogenic activities of mining for gold and timber harvest. Currently, the riparian vegetation of the study site is mostly shrubs and stands of short trees. Restoration designs call for the restoration of both the channel structure and replanting the riparian vegetation. Simulation results showed that the 7DADM was higher in the restored channel than the existing channel with both conditions of low and high effective shade conditions. However, a combined restoration practice of channel reconstruction and medium effective shade conditions reduced stream temperature maxima more than restoring riparian vegetation alone. In addition, results showed that restoring riparian vegetation was sufficient to mitigate the influence of warmer air on stream temperature, while restoring the channel alone is not. Heat budget analysis showed that heat accumulation during the daytime increased in the restored channel, which was longer, narrower, and deeper than the existing channel. It is important to emphasize that stream temperature is one of many goals that restoration activities aim to improve. Furthermore, differences in 7DADM among the different scenarios of restoration are negligible. Such small differences could hardly be measure. While this study examined a short section of 1.5 km, longer stream sections may increase the differences in 7DADM. Primary conclusions of this study are: 1) daily maxima of stream temperature will increase in response to increased air temperature regardless of the distribution of air warming during the diel cycle; 2) nighttime air warming caused a greater increase in stream temperature maximum than daytime warming; 3) riparian vegetation was the dominant factor on stream's heat budget, more than air temperature or stream flow; 4) restoring riparian vegetation mitigated the influence of warmer air; 5) restoring channel structure alone was not sufficient to lower temperature maxima; and 6) restoration project was most successful in improving degraded stream temperature when combined with channel reconstruction and improved riparian shade. Title: The influence of climate change and restoration on stream temperature Author: Diabat, Mousa Water temperature is an essential property of a stream. Temperature regulates physical and biochemical processes in aquatic habitats. Various factors related to climatic conditions, landscape characteristics, and channel structure directly influence stream temperature. Numerous studies indicate that increased average air temperature during the past century has led to stream warming across the world. The trend of stream warming was also present in spring-fed watersheds, where summer flow has decreased. In addition, anthropogenic practices that alter the natural landscape and channel structure, such as forest management, agriculture, and mining contributed to stream warming. For example, deforested and unshaded stream reaches or dredged channels were warmer than shaded reaches and meandering streams. Stream temperatures in North American lotic habitats are of a specific concern due to their significant economic, cultural, and ecological value. With climate projections indicating that air temperature will only continue to rise throughout the 21st century, cold- or cool-water organisms, especially fishes, will be affected. Therefore, there is a strong need to better understand the impacts of changing climate, riparian landscape, and channel structure on a stream's heat budget. This may assist in restoring the historic thermal regime in impacted sites and mitigating the impacts of future climate change. This study looks into the relative influences of the different factors on a stream's heat budget with three manuscripts: one on stream temperature response to diel timing of air warming, one on stream temperature response to changes in air temperature, flow, and riparian vegetation, and one on stream temperature response to air warming and channel reconstruction. I used the software Heat Source version 8.05 to simulate stream temperature for all three analyses along the Middle Fork John Day River, Oregon USA. Two of the manuscripts were applied to an upper 37 km section of the Middle Fork John Day River (presented in chapter 2 and 3), where the third manuscript was applied to a 1.5-km section. The sensitivity analysis of stream temperature response to diel timing of air warming (Chapter 2: Diel Timing of Warmer Air under Climate Change Affects Magnitude, Timing, and Duration of Stream Temperature Change) was based on scenarios representing uniform air warming over the diel period, daytime warming, and nighttime warming. Uniform warming of air temperature is a simple representation of increases in the average daily or monthly temperatures generated by the 'delta method'. The delta method relies on adding a constant value to the air temperature time-series data. This constant value is the difference (delta) between base case average air temperatures and the projected one. Scenarios of daytime or nighttime warming represent conditions under which most of the warming of the air occurs during the daytime or the nighttime, respectively. I simulated the stream temperature response to warmer air conditions of +2 °C and +4 °C in daily average for all three cases of air warming conditions. The three cases of different diel distributions of air warming generated 7-day average daily maximum stream temperature (7DADM) increases of approximately +1.8 °C ± 0.1 °C at the downstream end of the study section relative to the base case. In most parts of the reach, the three distributions of air warming generated different ranges of stream temperatures, different 7DADM values, different durations of stream temperature changes, and different average daily temperatures. Changes of stream temperature were out of phase with imposed changes of air temperature. Therefore, nighttime warming of air temperatures would cause the greatest increase in maximum daily stream temperature, which typically occurs during the daytime. The sensitivity analysis of the relative influences of changes in air temperature, stream flow, and riparian vegetation on stream temperature (Chapter 3: Assessing Stream Temperature Response to Cumulative Influence of Changing Air Temperature, Flow, and Riparian Vegetation). This study summarized stream temperature simulation in 36 scenarios representing possible manifestations of 21st century climate conditions and land management strategies. In addition to existing conditions (base case) of flow, air temperature, and riparian vegetation, scenarios consisted of: two air temperature increases of 2 °C and 4 °C, two stream flow variations of +30% and -30%, three spatially uniform riparian vegetation conditions that create averages of effective shade 7%, 34%, and 79%, in addition to 14% for base case conditions. Results suggest that variation in riparian vegetation was the dominant factor influencing stream temperature because it regulates incoming shortwave radiation, the largest heat input to the stream, while variation in stream flow has a negligible influence. Results indicated that increasing the effective shade along the study section, particularly in the currently unshaded sections, could mitigate the influence of increasing air temperature, and would reduce stream temperature maxima below current values even under future climate conditions of warmer air. With the small influence it had, increasing stream flow reduced the 7DADM under low shade conditions. However, increasing stream flow showed counterintuitive results as it contributed to increasing stream temperature maxima when the stream was heavily shaded. The applied study examined the stream temperature response to restoration practices and their potential to mitigate the influence of warmer air conditions (Chapter 4: Estimating Stream Temperature Response to Restoring Channel and Riparian Vegetation and the Potential to Mitigate Warmer Air Conditions). This study focused on a 1.5 km section along the upper part of the Middle Fork John Day River that was modified due to past anthropogenic activities of mining for gold and timber harvest. Currently, the riparian vegetation of the study site is mostly shrubs and stands of short trees. Restoration designs call for the restoration of both the channel structure and replanting the riparian vegetation. Simulation results showed that the 7DADM was higher in the restored channel than the existing channel with both conditions of low and high effective shade conditions. However, a combined restoration practice of channel reconstruction and medium effective shade conditions reduced stream temperature maxima more than restoring riparian vegetation alone. In addition, results showed that restoring riparian vegetation was sufficient to mitigate the influence of warmer air on stream temperature, while restoring the channel alone is not. Heat budget analysis showed that heat accumulation during the daytime increased in the restored channel, which was longer, narrower, and deeper than the existing channel. It is important to emphasize that stream temperature is one of many goals that restoration activities aim to improve. Furthermore, differences in 7DADM among the different scenarios of restoration are negligible. Such small differences could hardly be measure. While this study examined a short section of 1.5 km, longer stream sections may increase the differences in 7DADM. Primary conclusions of this study are: 1) daily maxima of stream temperature will increase in response to increased air temperature regardless of the distribution of air warming during the diel cycle; 2) nighttime air warming caused a greater increase in stream temperature maximum than daytime warming; 3) riparian vegetation was the dominant factor on stream's heat budget, more than air temperature or stream flow; 4) restoring riparian vegetation mitigated the influence of warmer air; 5) restoring channel structure alone was not sufficient to lower temperature maxima; and 6) restoration project was most successful in improving degraded stream temperature when combined with channel reconstruction and improved riparian shade. Close

• 16303. [Article] Crustal architecture and magma dynamics in a large continental magmatic system : a case study of the Purico-Chascon Volcanic Complex, Northern Chile

  The ~1 Myr history of the Purico-Chascon volcanic complex (PCVC) records significant changes in the production and storage of magmas in the crust. At ~1 Ma activity at the PCVC initiated with the eruption ...

  Citation × Citation Citation Abstract Copy Title: Crustal architecture and magma dynamics in a large continental magmatic system : a case study of the Purico-Chascon Volcanic Complex, Northern Chile Author: Burns, Dale H. The ~1 Myr history of the Purico-Chascon volcanic complex (PCVC) records significant changes in the production and storage of magmas in the crust. At ~1 Ma activity at the PCVC initiated with the eruption of a large 80-100 km³ crystal-rich dacite ignimbrite with restricted whole rock ⁸⁷Sr/⁸⁶Sr isotope ratios between 0.7085-0.7090. In-situ analyses of plagioclase from the Purico ignimbrite have ⁸⁷Sr/⁸⁶Sr=0.7087-0.7090. The dacite magma accumulated and evolved at relatively low temperatures around 800-850 °C in the upper crust at 4-8 km depth. Minor andesite and rhyolite pumice late in the sequence have similar restricted whole rock ⁸⁷Sr/⁸⁶Sr=0.7089-0.7091. The radiogenic isotopes of this 0.98 Ma activity are consistent with all these compositions resulting from 50 to 70% crustal assimilation by parental Central Andean "baseline" magmas at depths between 15-30 km. The final eruptions at the PCVC occurred <0.18 Ma producing three small < 5 km³ crystal-rich dacite lava domes with whole rock ⁸⁷Sr/⁸⁶Sr ratios 0.7075 to 0.7081 containing abundant basaltic-andesite enclaves with whole rock ⁸⁷Sr/⁸⁶Sr ratios of 0.7057- 0.7061. Plagioclase and amphibole from samples from the largest of these domes, Cerro Chascon, record two distinct magmatic environments; an upper crustal environment identical to the Purico ignimbrite and a second deeper, ~15-20 km depth, higher temperature (~922-1001 °C) environment consistent with conditions recorded in the basaltic andesite enclaves. Accordingly, plagioclase cores in the host dacite lava and enclaves have enriched in-situ ⁸⁷Sr/⁸⁶Sr isotopic compositions of 0.7083 to 0.7095 while plagioclase rims and microphenocrysts in the enclaves have ⁸⁷Sr/⁸⁶Sr isotope ratios from 0.7057 to 0.7065 and 0.7062 to 0.7064 respectively. Lavas from Cerro Chascon also contain abundant Fo82 olivine with spinel and basaltic melt inclusions that crystallized in a deep crustal environment (>1250 °C) consistent with a lower crustal MASH zone. The high baseline isotopic ratios observed in bulk rock and plagioclase crystals from Cerro Chascon (0.7057-0.7065) are consistent with MASH processes. The evolution of the PCVC is a microcosm of the Andean arc in this region where, from 10 - 1 Ma, dominantly dacitic upper crustal magmatism of the Altiplano-Puna Volcanic Complex ignimbrite flare-up persisted until ~1 Ma, when smaller volume, more heterogeneous and less isotopically enriched basaltic andesite to dacite composite volcanoes signal a return to steady state arc volcanism. I suggest that the PCVC captures the transition of the Andean arc from flare-up to steady state. The temporal trend at the PCVC is consistent with a waning thermal flux. High magmatic fluxes during the flare-up would have resulted in elevated geothermal gradients and efficient crustal processing leading to a dominantly dacitic upper crust (0 to 35 km) that fed the large volume Purico ignimbrite. As magmatic flux and thermal energy wanes, crustal isotherms relax resulting in greater thermal contrast between parental magmas, crust and remnant upper crustal dacite magma. This manifests in more heterogeneity and the survival of less isotopically enriched magmas in the upper crust. These arc scale magma dynamics are recorded even at the intra-crystalline scale. Individual crystals from Cerro Chascon also record vital information on the crystallization and evolution of mantle-derived magmas in continental magmatic arcs. Fo₈₂ olivine, olivine hosted spinel, and basaltic melt inclusions record the crystallization of olivine at >1250 °C in conditions consistent with a lower crustal (~70 km depth) MASH zone. Another significant crystallization event appears to have occurred at ~20 km depth, characterized by the crystallization of high An plagioclase (An₇₂₋₈₄) at ~1100-1050 °C followed by high-Al amphibole (~12-15 wt.% Al₂O₃) at ~1000-950 °C. The appearance of amphibole on the liquidus appears to have resulted from a nearly 2-fold increase in melt water content following ~45% crystallization of high An plagioclase. Following this extensive crystallization the highly crystalline mafic magma ascended into the upper crust and interacted with the remnant crystal mush from the Purico ignimbrite magma reservoir. Low An plagioclase (An₃₉₋₅₅), low Al amphibole (~6-9 wt.% Al₂O₃), sanidine, and biotite retain the chemical composition of the Purico ignimbrite magma, whereas, olivine, high An plagioclase, and high Al amphibole record the mafic recharge magma. The textures and compositions observed in Cerro Chascon are common in both continental and oceanic magmatic arcs worldwide and I propose that multiple crystallization events and upper crustal assimilation are fundamental processes intrinsic to arc magmatism. I have also used in situ ⁸⁷Sr/⁸⁶Sr isotope ratios in plagioclase from andesite, dacite, and rhyolite pumice from the ~1 Ma Purico ignimbrite to determine the cause for compositional zoning in the Purico ignimbrite magma reservoir. Andesite pumice contains two texturally, compositionally, and isotopically distinct types of plagioclase, small (<500 μm) subhedral to euhedral crystals with high MgO (130-490 ppm) and low ⁸⁷Sr/⁸⁶r crystals (0.7076-0.7084) record a hot (>900 °C) andesite magma derived from an ~20 km deep magma reservoir. In contrast, the second type of plagioclase in the andesite appear to broken fragments of larger crystals and have significantly lower MgO (90-240 ppm), higher ⁸⁷Sr/⁸⁶Sr (0.7096-0.7114), and appears to be derived from the lower temperature (crystallized at ~800-900 °C), upper crustal (<10 km) plutonic basement. Dacite pumice also contains two texturally and compositionally distinct types of plagioclase. However, both types have very restricted MgO (b.d.l.-200 ppm) and ⁸⁷Sr/⁸⁶Sr (0.7085-0.7095) ratios and appear to have grown at ~850°C. These crystals are also significantly larger (>1000 μm) than plagioclase from the andesite pumice and have clear euhedral rims. Rhyolite pumice from the Purico ignimbrite also contains distinct types of plagioclase. Both types of plagioclase are similar in size (<500 μm) and appear to be fragments of larger crystals. One type is characterized by low MgO (b.d.l.-240 ppm) and restricted ⁸⁷Sr/⁸⁶Sr isotope ratios (0.7088-0.7095) similar to plagioclase in the dacite pumice, and the other has significantly higher ⁸⁷Sr/⁸⁶Sr ratios (0.7095-0.7103) consistent with the upper crustal ignimbrite basement. The compositional variations observed in plagioclase crystals from the Purico ignimbrites are consistent with the recharge of a previously emplaced upper crustal (4-8 km depth) dacite magma reservoir by a hotter, deeper (20 km deep) andesite. During ascent, the andesite incorporated crystals from the surrounding upper crustal plutonic bodies before pooling against the residence dacite magma and crystallizing. Crystallization of the andesite resulted in the expulsion of a rhyolite interstitial melt that ascended through the dacite reservoir and pooled at the top of the reservoir. The rhyolite melt incorporated crystals from the dacite magma during ascent as well as crystals from the roof rock, which in the case of the Purico ignimbrite represents the plutonic remnants from other large silicic magmatic systems associated with the APVC. Thus, the compositional variations observed in the Purico ignimbrite results from a combination of crustal assimilation, crystallization, and melt extraction all initiated by mafic recharge. Title: Crustal architecture and magma dynamics in a large continental magmatic system : a case study of the Purico-Chascon Volcanic Complex, Northern Chile Author: Burns, Dale H. The ~1 Myr history of the Purico-Chascon volcanic complex (PCVC) records significant changes in the production and storage of magmas in the crust. At ~1 Ma activity at the PCVC initiated with the eruption of a large 80-100 km³ crystal-rich dacite ignimbrite with restricted whole rock ⁸⁷Sr/⁸⁶Sr isotope ratios between 0.7085-0.7090. In-situ analyses of plagioclase from the Purico ignimbrite have ⁸⁷Sr/⁸⁶Sr=0.7087-0.7090. The dacite magma accumulated and evolved at relatively low temperatures around 800-850 °C in the upper crust at 4-8 km depth. Minor andesite and rhyolite pumice late in the sequence have similar restricted whole rock ⁸⁷Sr/⁸⁶Sr=0.7089-0.7091. The radiogenic isotopes of this 0.98 Ma activity are consistent with all these compositions resulting from 50 to 70% crustal assimilation by parental Central Andean "baseline" magmas at depths between 15-30 km. The final eruptions at the PCVC occurred <0.18 Ma producing three small < 5 km³ crystal-rich dacite lava domes with whole rock ⁸⁷Sr/⁸⁶Sr ratios 0.7075 to 0.7081 containing abundant basaltic-andesite enclaves with whole rock ⁸⁷Sr/⁸⁶Sr ratios of 0.7057- 0.7061. Plagioclase and amphibole from samples from the largest of these domes, Cerro Chascon, record two distinct magmatic environments; an upper crustal environment identical to the Purico ignimbrite and a second deeper, ~15-20 km depth, higher temperature (~922-1001 °C) environment consistent with conditions recorded in the basaltic andesite enclaves. Accordingly, plagioclase cores in the host dacite lava and enclaves have enriched in-situ ⁸⁷Sr/⁸⁶Sr isotopic compositions of 0.7083 to 0.7095 while plagioclase rims and microphenocrysts in the enclaves have ⁸⁷Sr/⁸⁶Sr isotope ratios from 0.7057 to 0.7065 and 0.7062 to 0.7064 respectively. Lavas from Cerro Chascon also contain abundant Fo82 olivine with spinel and basaltic melt inclusions that crystallized in a deep crustal environment (>1250 °C) consistent with a lower crustal MASH zone. The high baseline isotopic ratios observed in bulk rock and plagioclase crystals from Cerro Chascon (0.7057-0.7065) are consistent with MASH processes. The evolution of the PCVC is a microcosm of the Andean arc in this region where, from 10 - 1 Ma, dominantly dacitic upper crustal magmatism of the Altiplano-Puna Volcanic Complex ignimbrite flare-up persisted until ~1 Ma, when smaller volume, more heterogeneous and less isotopically enriched basaltic andesite to dacite composite volcanoes signal a return to steady state arc volcanism. I suggest that the PCVC captures the transition of the Andean arc from flare-up to steady state. The temporal trend at the PCVC is consistent with a waning thermal flux. High magmatic fluxes during the flare-up would have resulted in elevated geothermal gradients and efficient crustal processing leading to a dominantly dacitic upper crust (0 to 35 km) that fed the large volume Purico ignimbrite. As magmatic flux and thermal energy wanes, crustal isotherms relax resulting in greater thermal contrast between parental magmas, crust and remnant upper crustal dacite magma. This manifests in more heterogeneity and the survival of less isotopically enriched magmas in the upper crust. These arc scale magma dynamics are recorded even at the intra-crystalline scale. Individual crystals from Cerro Chascon also record vital information on the crystallization and evolution of mantle-derived magmas in continental magmatic arcs. Fo₈₂ olivine, olivine hosted spinel, and basaltic melt inclusions record the crystallization of olivine at >1250 °C in conditions consistent with a lower crustal (~70 km depth) MASH zone. Another significant crystallization event appears to have occurred at ~20 km depth, characterized by the crystallization of high An plagioclase (An₇₂₋₈₄) at ~1100-1050 °C followed by high-Al amphibole (~12-15 wt.% Al₂O₃) at ~1000-950 °C. The appearance of amphibole on the liquidus appears to have resulted from a nearly 2-fold increase in melt water content following ~45% crystallization of high An plagioclase. Following this extensive crystallization the highly crystalline mafic magma ascended into the upper crust and interacted with the remnant crystal mush from the Purico ignimbrite magma reservoir. Low An plagioclase (An₃₉₋₅₅), low Al amphibole (~6-9 wt.% Al₂O₃), sanidine, and biotite retain the chemical composition of the Purico ignimbrite magma, whereas, olivine, high An plagioclase, and high Al amphibole record the mafic recharge magma. The textures and compositions observed in Cerro Chascon are common in both continental and oceanic magmatic arcs worldwide and I propose that multiple crystallization events and upper crustal assimilation are fundamental processes intrinsic to arc magmatism. I have also used in situ ⁸⁷Sr/⁸⁶Sr isotope ratios in plagioclase from andesite, dacite, and rhyolite pumice from the ~1 Ma Purico ignimbrite to determine the cause for compositional zoning in the Purico ignimbrite magma reservoir. Andesite pumice contains two texturally, compositionally, and isotopically distinct types of plagioclase, small (<500 μm) subhedral to euhedral crystals with high MgO (130-490 ppm) and low ⁸⁷Sr/⁸⁶r crystals (0.7076-0.7084) record a hot (>900 °C) andesite magma derived from an ~20 km deep magma reservoir. In contrast, the second type of plagioclase in the andesite appear to broken fragments of larger crystals and have significantly lower MgO (90-240 ppm), higher ⁸⁷Sr/⁸⁶Sr (0.7096-0.7114), and appears to be derived from the lower temperature (crystallized at ~800-900 °C), upper crustal (<10 km) plutonic basement. Dacite pumice also contains two texturally and compositionally distinct types of plagioclase. However, both types have very restricted MgO (b.d.l.-200 ppm) and ⁸⁷Sr/⁸⁶Sr (0.7085-0.7095) ratios and appear to have grown at ~850°C. These crystals are also significantly larger (>1000 μm) than plagioclase from the andesite pumice and have clear euhedral rims. Rhyolite pumice from the Purico ignimbrite also contains distinct types of plagioclase. Both types of plagioclase are similar in size (<500 μm) and appear to be fragments of larger crystals. One type is characterized by low MgO (b.d.l.-240 ppm) and restricted ⁸⁷Sr/⁸⁶Sr isotope ratios (0.7088-0.7095) similar to plagioclase in the dacite pumice, and the other has significantly higher ⁸⁷Sr/⁸⁶Sr ratios (0.7095-0.7103) consistent with the upper crustal ignimbrite basement. The compositional variations observed in plagioclase crystals from the Purico ignimbrites are consistent with the recharge of a previously emplaced upper crustal (4-8 km depth) dacite magma reservoir by a hotter, deeper (20 km deep) andesite. During ascent, the andesite incorporated crystals from the surrounding upper crustal plutonic bodies before pooling against the residence dacite magma and crystallizing. Crystallization of the andesite resulted in the expulsion of a rhyolite interstitial melt that ascended through the dacite reservoir and pooled at the top of the reservoir. The rhyolite melt incorporated crystals from the dacite magma during ascent as well as crystals from the roof rock, which in the case of the Purico ignimbrite represents the plutonic remnants from other large silicic magmatic systems associated with the APVC. Thus, the compositional variations observed in the Purico ignimbrite results from a combination of crustal assimilation, crystallization, and melt extraction all initiated by mafic recharge. Close

• 16304. [Article] Stratigraphy and sedimentology of the middle eocene Cowlitz Formation and adjacent sedimentary and volcanic units in the Longview-Kelso area, southwest Washington

  Geologic mapping of the Longview-Kelso area and the measurement and description of a composite 650-meter thick stratigraphic section of the Cowlitz Formation (Tc) in Coal Creek using bio-, magneto-, litho-, ...

  Citation × Citation Citation Abstract Copy Title: Stratigraphy and sedimentology of the middle eocene Cowlitz Formation and adjacent sedimentary and volcanic units in the Longview-Kelso area, southwest Washington Author: McCutcheon, Mark S. Geologic mapping of the Longview-Kelso area and the measurement and description of a composite 650-meter thick stratigraphic section of the Cowlitz Formation (Tc) in Coal Creek using bio-, magneto-, litho-, and sequence stratigraphy reveals a complex interplay of Cowlitz micaceous, lithic arkosic shelf to tidal/estuarine to delta plain facies associations, and Grays River basalt lava flows and interbedded basalt volcaniclastics from nearby Grays River eruptive centers (e.g., Mt. Solo and Rocky Point). The lower 100 meters of the Coal Creek section (informal unit 1, Chron 18r) consists of micaceous, lithic arkosic sandstone and siltstone and minor coals, was deposited as part of a highstand system tract (HST) at the base of 3rd order cycle number 3. This unit consists of four dominantly tidal shoaling-upward arkosic sandstone parasequences reflecting upper shoreface to delta plain depositional environments. The overlying unit 2 (Chron 18n) is defined by abundant Grays River basalt volcaniclastic interbeds that intertongue with Cowlitz lithic arkoses. This unit represents the latter part of 3rd order cycle 3, and consists of mostly fining- and thinning-upward parasequences of middle shoreface to delta plain successions of an aggradational to transgressive parasequence set. Near the top of unit 2 is a maximum marine flooding surface depositing lower shoreface lithic arkosic sandstone to shelf siltstones over upper shoreface micaceous lithic arkose. Unit 3 comprises 3rd order cycle 4 (Chron 17r), a lowstand system tract, and consists of 6 mostly fining- and thinning-upward parasequences of lower shoreface to delta plain facies associations. A parasequence or erosional boundary at the base of unit 5 (Chron 17r) consists of submarine channel-fill scoured into underlying micaceous siltstones, produced during a lowstand system tract (LST) of 3rd order cycle 5. This deep marine channel-fill sequence is overlain by thinlybedded to laminated overbank distal turbidites and hemipelagic siltstones that define the top of the Coal Creek section. These 5 informal units in Coal Creek lithologically and chronologically correlate to 5 similar informal units defined by Payne (1998) in the type section of Cowlitz Formation in Olequa Creek near Vader -30 km to the north. Middle Eocene Grays River Volcanics of the study area are mapped as two separate units: a lower unit over 150 meters thick in places, consisting of subaerial basaltic flows and invasive flows (Tgvl), intrusions (Tgvis and Tgvid), and volcaniclastics (Tgvsl); and an upper unit consisting of commonly mollusk-bearing, shallow marine basaltic sedimentary interbeds that intertongue with the Cowlitz Formation (Tgvs2), particularly Cowlitz unit 2 of the Coal Creek section. These volcaniclastic deposits are intrabasinal, derived from volcanic highlands to the west and northwest, and local phreatomagmatic tuff cones. The lower Grays River volcaniclastic unit typically overlies Grays River flows in the study area and is divided into 5 informal facies. Geochemically, Grays River flows in the study area fall within normal parameters (3 to 4% TiO2 and high iron tholeiitic basalts). However, basalt flows and bedded scoriaceous breccias near Rocky Point are anomalously low in TiO2 and are considered in this study to be a separate volcanic subunit (Rocky Point Basalts), time equivalent to and interfingering with Grays River lavas, but may represent mixing with shallower western Cascade calc-alkaline magma. Over 60 younger Grays River dikes intrude the Cowlitz Formation in Coal Creek. A dike low in the Coal Creek section is dated at 40 ± 0.36 Ma, and an invasive flow at Mt. Solo is dated at 36.98 ±.78 Ma. Volcanics capping the hills east of the Cowlitz River are chemically distinct as slightly younger western Cascade basaltic andesite flows, and two dikes east of the river are chemically distinct as western Cascade andesite. Overlying Grays River Volcanics and Cowlitz Formation in much of the study area, are clayey and commonly tuffaceous siltstones and silty sandstones, possibly of the late Eocene-early Oligocene Toutle Formation, a new unit to this area. The Toutle Formation is a mixture of wave and stream reworked micaceous and arkosic Cowlitz Formation and fresh silicic pyroclastic ash and pumice from the active western Cascade arc. An angular unconformity separates the Paleogene Grays River Volcanics, Cowlitz Formation, and Toutle Formation from the early to middle Miocene Columbia River Basalt Group. Based on lithology, geochemistry, stratigraphic relationships, and magnetic polarity, 6 individual Columbia River Basalt flows have been mapped in this study. The three lower Grande Ronde flows are of normal polarity and Ortley low MgO chemical composition. The lowermost flow (N2 Ortley #1) is absent in the Columbia Heights area, low MgO, about 10 meters thick and consists of pillow-palagonite sequences in the upper quarry on Mt. Solo. Aphyric N2 Ortley flow #2 is over 35 meters thick with well-developed upper and lower colonnade, and of intermediate MgO. N2 Ortley flow #3 is pillow-palagonite in the Storedahl Quarry and low MgO. A -4-meter thick tuffaceous overbank siltstone and basalt conglomeratic channel interbed separates the three low MgO Ortley flows from the overlying high MgO N2 Grande Ronde Sentinel Bluffs flow. A single exposure of well-developed large colonnade with sparse 1 cm labradorite laths, and reddish oxidized soil, defines the N Sand Hollow flow of the Frenchman Springs Member of the Wanapum Formation. The overlying Pomona Member is mapped based on previous work by other authors. Pliocene gravels and arkosic sand of the Troutdale Formation form upland terrace deposits up to 100 meters thick in southern parts of the study area, and represent the uplifted paleo-thalweg and overbank flood deposits of the downcutting, antecedent ancestral Columbia River. Well-rounded clasts are a mixture of extrabasinal granitic and metamorphic quartzite, and intrabasinal porphyritic basaltic andesite, dacite, and basalt from the western Cascades and Columbia River Basalts. Troutdale terrace gravels grade northward into contemporaneous volcanic pebble and cobble gravel terrace deposits produced along the ancestral Cowlitz River that are dominantly composed of porphyritic andesite gravel and volcanic sand from the western Cascades. Lower terraces along the Cowlitz River were deposited by the late Pleistocene Missoula Floods. All of these unconsolidated to semiconsolidated gravels and sands are prone to landslides, and the Aldercrest-Banyon landslide, the second worst landslide disaster in American history, occurred in the Troutdale Formation gravels. After eruption of the Grays River Volcanics and deposition of the Cowlitz Formation, the forearc underwent a period of transtension in the late-middle Eocene related to magmatic upwelling and reorganization of the subducting Farallon Plate. This event produced a northwest-trending set of oblique slip normal faults, along which Grays River dikes intruded. Starting in the early Miocene the region underwent a transpressional event, reactivating many of the northwest-trending faults, and producing the Columbia Heights Anticline, Hazel Dell Syncline, the Coal Creek Fault, and the Kelso Fault Zone. The paleotopography resulting from this event was stream eroded to a nearly flat plain before emplacement of the Columbia River Basalts, which are nearly horizontal today. Continued offset along the northwest-trending fault set has also offset the Columbia River Basalts. Continued oblique slip post-Miocene broad arching of the Coast Range and downcutting by the Columbia and Cowlitz Rivers has resulted in Pliocene and Pleistocene terraces, and produced an east-west fault set that offsets all earlier structural features. Title: Stratigraphy and sedimentology of the middle eocene Cowlitz Formation and adjacent sedimentary and volcanic units in the Longview-Kelso area, southwest Washington Author: McCutcheon, Mark S. Geologic mapping of the Longview-Kelso area and the measurement and description of a composite 650-meter thick stratigraphic section of the Cowlitz Formation (Tc) in Coal Creek using bio-, magneto-, litho-, and sequence stratigraphy reveals a complex interplay of Cowlitz micaceous, lithic arkosic shelf to tidal/estuarine to delta plain facies associations, and Grays River basalt lava flows and interbedded basalt volcaniclastics from nearby Grays River eruptive centers (e.g., Mt. Solo and Rocky Point). The lower 100 meters of the Coal Creek section (informal unit 1, Chron 18r) consists of micaceous, lithic arkosic sandstone and siltstone and minor coals, was deposited as part of a highstand system tract (HST) at the base of 3rd order cycle number 3. This unit consists of four dominantly tidal shoaling-upward arkosic sandstone parasequences reflecting upper shoreface to delta plain depositional environments. The overlying unit 2 (Chron 18n) is defined by abundant Grays River basalt volcaniclastic interbeds that intertongue with Cowlitz lithic arkoses. This unit represents the latter part of 3rd order cycle 3, and consists of mostly fining- and thinning-upward parasequences of middle shoreface to delta plain successions of an aggradational to transgressive parasequence set. Near the top of unit 2 is a maximum marine flooding surface depositing lower shoreface lithic arkosic sandstone to shelf siltstones over upper shoreface micaceous lithic arkose. Unit 3 comprises 3rd order cycle 4 (Chron 17r), a lowstand system tract, and consists of 6 mostly fining- and thinning-upward parasequences of lower shoreface to delta plain facies associations. A parasequence or erosional boundary at the base of unit 5 (Chron 17r) consists of submarine channel-fill scoured into underlying micaceous siltstones, produced during a lowstand system tract (LST) of 3rd order cycle 5. This deep marine channel-fill sequence is overlain by thinlybedded to laminated overbank distal turbidites and hemipelagic siltstones that define the top of the Coal Creek section. These 5 informal units in Coal Creek lithologically and chronologically correlate to 5 similar informal units defined by Payne (1998) in the type section of Cowlitz Formation in Olequa Creek near Vader -30 km to the north. Middle Eocene Grays River Volcanics of the study area are mapped as two separate units: a lower unit over 150 meters thick in places, consisting of subaerial basaltic flows and invasive flows (Tgvl), intrusions (Tgvis and Tgvid), and volcaniclastics (Tgvsl); and an upper unit consisting of commonly mollusk-bearing, shallow marine basaltic sedimentary interbeds that intertongue with the Cowlitz Formation (Tgvs2), particularly Cowlitz unit 2 of the Coal Creek section. These volcaniclastic deposits are intrabasinal, derived from volcanic highlands to the west and northwest, and local phreatomagmatic tuff cones. The lower Grays River volcaniclastic unit typically overlies Grays River flows in the study area and is divided into 5 informal facies. Geochemically, Grays River flows in the study area fall within normal parameters (3 to 4% TiO2 and high iron tholeiitic basalts). However, basalt flows and bedded scoriaceous breccias near Rocky Point are anomalously low in TiO2 and are considered in this study to be a separate volcanic subunit (Rocky Point Basalts), time equivalent to and interfingering with Grays River lavas, but may represent mixing with shallower western Cascade calc-alkaline magma. Over 60 younger Grays River dikes intrude the Cowlitz Formation in Coal Creek. A dike low in the Coal Creek section is dated at 40 ± 0.36 Ma, and an invasive flow at Mt. Solo is dated at 36.98 ±.78 Ma. Volcanics capping the hills east of the Cowlitz River are chemically distinct as slightly younger western Cascade basaltic andesite flows, and two dikes east of the river are chemically distinct as western Cascade andesite. Overlying Grays River Volcanics and Cowlitz Formation in much of the study area, are clayey and commonly tuffaceous siltstones and silty sandstones, possibly of the late Eocene-early Oligocene Toutle Formation, a new unit to this area. The Toutle Formation is a mixture of wave and stream reworked micaceous and arkosic Cowlitz Formation and fresh silicic pyroclastic ash and pumice from the active western Cascade arc. An angular unconformity separates the Paleogene Grays River Volcanics, Cowlitz Formation, and Toutle Formation from the early to middle Miocene Columbia River Basalt Group. Based on lithology, geochemistry, stratigraphic relationships, and magnetic polarity, 6 individual Columbia River Basalt flows have been mapped in this study. The three lower Grande Ronde flows are of normal polarity and Ortley low MgO chemical composition. The lowermost flow (N2 Ortley #1) is absent in the Columbia Heights area, low MgO, about 10 meters thick and consists of pillow-palagonite sequences in the upper quarry on Mt. Solo. Aphyric N2 Ortley flow #2 is over 35 meters thick with well-developed upper and lower colonnade, and of intermediate MgO. N2 Ortley flow #3 is pillow-palagonite in the Storedahl Quarry and low MgO. A -4-meter thick tuffaceous overbank siltstone and basalt conglomeratic channel interbed separates the three low MgO Ortley flows from the overlying high MgO N2 Grande Ronde Sentinel Bluffs flow. A single exposure of well-developed large colonnade with sparse 1 cm labradorite laths, and reddish oxidized soil, defines the N Sand Hollow flow of the Frenchman Springs Member of the Wanapum Formation. The overlying Pomona Member is mapped based on previous work by other authors. Pliocene gravels and arkosic sand of the Troutdale Formation form upland terrace deposits up to 100 meters thick in southern parts of the study area, and represent the uplifted paleo-thalweg and overbank flood deposits of the downcutting, antecedent ancestral Columbia River. Well-rounded clasts are a mixture of extrabasinal granitic and metamorphic quartzite, and intrabasinal porphyritic basaltic andesite, dacite, and basalt from the western Cascades and Columbia River Basalts. Troutdale terrace gravels grade northward into contemporaneous volcanic pebble and cobble gravel terrace deposits produced along the ancestral Cowlitz River that are dominantly composed of porphyritic andesite gravel and volcanic sand from the western Cascades. Lower terraces along the Cowlitz River were deposited by the late Pleistocene Missoula Floods. All of these unconsolidated to semiconsolidated gravels and sands are prone to landslides, and the Aldercrest-Banyon landslide, the second worst landslide disaster in American history, occurred in the Troutdale Formation gravels. After eruption of the Grays River Volcanics and deposition of the Cowlitz Formation, the forearc underwent a period of transtension in the late-middle Eocene related to magmatic upwelling and reorganization of the subducting Farallon Plate. This event produced a northwest-trending set of oblique slip normal faults, along which Grays River dikes intruded. Starting in the early Miocene the region underwent a transpressional event, reactivating many of the northwest-trending faults, and producing the Columbia Heights Anticline, Hazel Dell Syncline, the Coal Creek Fault, and the Kelso Fault Zone. The paleotopography resulting from this event was stream eroded to a nearly flat plain before emplacement of the Columbia River Basalts, which are nearly horizontal today. Continued offset along the northwest-trending fault set has also offset the Columbia River Basalts. Continued oblique slip post-Miocene broad arching of the Coast Range and downcutting by the Columbia and Cowlitz Rivers has resulted in Pliocene and Pleistocene terraces, and produced an east-west fault set that offsets all earlier structural features. Close

• 16305. [Image] Crater Lake March 1991 peer review of research program and draft report on studies of hydrothermal processes in Crater Lake Oregon: a report of field studies conducted in 1989 for the National Park Service

  	Caption title; Includes bibliographical references
  	Citation × Citation Citation Abstract Copy Title: Crater Lake March 1991 peer review of research program and draft report on studies of hydrothermal processes in Crater Lake Oregon: a report of field studies conducted in 1989 for the National Park Service Author: Goldman, Charles R. Year: 1991, 2009 Caption title; Includes bibliographical references Title: Crater Lake March 1991 peer review of research program and draft report on studies of hydrothermal processes in Crater Lake Oregon: a report of field studies conducted in 1989 for the National Park Service Author: Goldman, Charles R. Year: 1991, 2009 Caption title; Includes bibliographical references Close

• 16306. [Image] Preliminary report on the ground-water resources of the Klamath River Basin, Oregon

  	The Klamath River basin, including the adjacent Lost River basin, includes about ?,5>OO square miles of plateaus, mountain-slopes and valley plains in south-central Oregon* The valley plains range in altitude ...
  	Citation × Citation Citation Abstract Copy Title: Preliminary report on the ground-water resources of the Klamath River Basin, Oregon Author: Newcomb, Reuben Clair Year: 1958, 2005 The Klamath River basin, including the adjacent Lost River basin, includes about ?,5>OO square miles of plateaus, mountain-slopes and valley plains in south-central Oregon* The valley plains range in altitude from about U,100 feet in the south to more than li,500 feet at the northern end; the mountain and plateau lands rise to an average altitude of 6,000 feet at the drainage divide, some peaks rising above 9*000 feet. The western quarter of the ba3in is on the eastern slope of the Cascade Range and the remainder consists of plateaus, mountains, and valleys of the basin-and-range type* The rocks of the Klamath River basin range in age from Recent to Mesozoic* At the southwest side of the basin in Oregon, pre~Tertiary metamorphic, igneous, and sedimentary rocks, which form extensive areas farther west, are overlain by sedimentary rocks of Eocene age and volcanic rocks of Eocene and Oligocene age* These early Tertiary rocks dip east toward the central part of the Klamath River basin. The complex "volcanic rocks of high Cascades" include three units: The lowest unit consists of a sequence of basaltic lava flows about 800 feet thick5 the medial unit is composed of volcanic-sedimentary and sedimentary rocks?the Tonna formation-200 to 2,000 feet thick; the uppermost unit is a sequence of basaltic lava flows commonly about 200 feet thick. These rocks dip east from the Cascade Unpublished records subject to revision 2 Range and are the main bedrock formations beneath most of the basin. Extensive pumice deposits, which emanated ^?^ ancestral Mount Mazaraa, cover large areas in the northwestern part of the basin* The basin has an overall synclinal structure open to the south at the California boundary where it continues as the Klamath Lake basin in California* The older rocks dip into the basin in monoclinal fashion from the adjoining drainage basins* The rocks are broken along rudely rectangular nets of closely spaced normal faults* the most prominent set of which trends northwest* The network of fault displacements includes two main grabens, the Klamath and the Langell, which were downthrown approximately ?00 and 1,000 fast, respectively* The average annual precipitation varies with the altitude, the higher parts of the Cascade Range getting more than 60 inches, and the semierid valley plains receive as little as 13 inches in some places* Most precipitation occurs in the winter. \ The principal tributaries, Williamson and Sprague Rivers, rise near the higher parts of the eastern rim of the basin, flow through narrow valley plains to the western part, and discharge into Upper Klamath Lake* Wood River and associated creeks also empty into Upper Klamath Lake after draining southward along the eastern foot of the Cascade Range* The Klamath River receives the outflow from Upper Klamath Lake, via Lifak River and Lake Ewauna, and flows southwestward through Keno Gap and hence through a youthful canyon, to its lower valley in California* The ground water occurs largely in an unconfined, or water-table, condition, though areas of local confinement are present* The regional Unpublished records subject to revis&oa is graded to water table / a base level about equal to that of the major drainage* where water is confined, on the valley plains. The slope of the water tafele, ~ of/the piezomstric surface is downstream at about the same grade as that "of the surface drainage in each of the larger valleys, attd groufid*water divides occur between the upper parts of adjacent major valleys* The principal water-bearipg units are.the'lower lava rocks and upper lava rocks of the "volcanic rocks of high Cascades,* the pumice of Quaternaryage, and the allusriTuju In places layers of coarse flagmental material in the Tonna formation (Newcorub, 1958) also transmit water* The water-bearing units, especially the breccia layers of the lava rocks and the pumice, yield large amounts of water to wells and provide natural discharge outlets for the ground water. The spring outflows to the Williamson and Wood Rivers-Crooked Creek drainage, measured in September and October 1955, were at a rate equivalent to about 700,000 acre-feet per year. The spring outflows into the Sprague River were at a rate equal to 2l;5>000 apre-feet per year* Large springs occur along the edges of Upper Klamath Lake but their discharges could not be measured, and the known spring discharge from the lower lava rocks in the river canyon below Keno was not measured. The spring discharge into Lost River in the reach ?rom Bonanza to Harpold Bridge was at a rate equivalent to 75,000 acre-feet per year. Much of the water discharged from springs is used for irrigation during the growing season, but ground water has not been extensively Unpublished records subject to revision developed by means of wells except in the'Yonna Valley and other local areas. The total withdrawal of ground water from wells in 1951? was only about 30,000 acre-feet, of which 27,000 was used for irrigation* The ground water is of excellent quality in general, but sodium sulfate water occurs in the belts of warm rock along some faults and alkali bicarbonate water is present in the main evapotranspiration basins. Unpublished records subject to revision Title: Preliminary report on the ground-water resources of the Klamath River Basin, Oregon Author: Newcomb, Reuben Clair Year: 1958, 2005 The Klamath River basin, including the adjacent Lost River basin, includes about ?,5>OO square miles of plateaus, mountain-slopes and valley plains in south-central Oregon* The valley plains range in altitude from about U,100 feet in the south to more than li,500 feet at the northern end; the mountain and plateau lands rise to an average altitude of 6,000 feet at the drainage divide, some peaks rising above 9*000 feet. The western quarter of the ba3in is on the eastern slope of the Cascade Range and the remainder consists of plateaus, mountains, and valleys of the basin-and-range type* The rocks of the Klamath River basin range in age from Recent to Mesozoic* At the southwest side of the basin in Oregon, pre~Tertiary metamorphic, igneous, and sedimentary rocks, which form extensive areas farther west, are overlain by sedimentary rocks of Eocene age and volcanic rocks of Eocene and Oligocene age* These early Tertiary rocks dip east toward the central part of the Klamath River basin. The complex "volcanic rocks of high Cascades" include three units: The lowest unit consists of a sequence of basaltic lava flows about 800 feet thick5 the medial unit is composed of volcanic-sedimentary and sedimentary rocks?the Tonna formation-200 to 2,000 feet thick; the uppermost unit is a sequence of basaltic lava flows commonly about 200 feet thick. These rocks dip east from the Cascade Unpublished records subject to revision 2 Range and are the main bedrock formations beneath most of the basin. Extensive pumice deposits, which emanated ^?^ ancestral Mount Mazaraa, cover large areas in the northwestern part of the basin* The basin has an overall synclinal structure open to the south at the California boundary where it continues as the Klamath Lake basin in California* The older rocks dip into the basin in monoclinal fashion from the adjoining drainage basins* The rocks are broken along rudely rectangular nets of closely spaced normal faults* the most prominent set of which trends northwest* The network of fault displacements includes two main grabens, the Klamath and the Langell, which were downthrown approximately ?00 and 1,000 fast, respectively* The average annual precipitation varies with the altitude, the higher parts of the Cascade Range getting more than 60 inches, and the semierid valley plains receive as little as 13 inches in some places* Most precipitation occurs in the winter. \ The principal tributaries, Williamson and Sprague Rivers, rise near the higher parts of the eastern rim of the basin, flow through narrow valley plains to the western part, and discharge into Upper Klamath Lake* Wood River and associated creeks also empty into Upper Klamath Lake after draining southward along the eastern foot of the Cascade Range* The Klamath River receives the outflow from Upper Klamath Lake, via Lifak River and Lake Ewauna, and flows southwestward through Keno Gap and hence through a youthful canyon, to its lower valley in California* The ground water occurs largely in an unconfined, or water-table, condition, though areas of local confinement are present* The regional Unpublished records subject to revis&oa is graded to water table / a base level about equal to that of the major drainage* where water is confined, on the valley plains. The slope of the water tafele, ~ of/the piezomstric surface is downstream at about the same grade as that "of the surface drainage in each of the larger valleys, attd groufid*water divides occur between the upper parts of adjacent major valleys* The principal water-bearipg units are.the'lower lava rocks and upper lava rocks of the "volcanic rocks of high Cascades,* the pumice of Quaternaryage, and the allusriTuju In places layers of coarse flagmental material in the Tonna formation (Newcorub, 1958) also transmit water* The water-bearing units, especially the breccia layers of the lava rocks and the pumice, yield large amounts of water to wells and provide natural discharge outlets for the ground water. The spring outflows to the Williamson and Wood Rivers-Crooked Creek drainage, measured in September and October 1955, were at a rate equivalent to about 700,000 acre-feet per year. The spring outflows into the Sprague River were at a rate equal to 2l;5>000 apre-feet per year* Large springs occur along the edges of Upper Klamath Lake but their discharges could not be measured, and the known spring discharge from the lower lava rocks in the river canyon below Keno was not measured. The spring discharge into Lost River in the reach ?rom Bonanza to Harpold Bridge was at a rate equivalent to 75,000 acre-feet per year. Much of the water discharged from springs is used for irrigation during the growing season, but ground water has not been extensively Unpublished records subject to revision developed by means of wells except in the'Yonna Valley and other local areas. The total withdrawal of ground water from wells in 1951? was only about 30,000 acre-feet, of which 27,000 was used for irrigation* The ground water is of excellent quality in general, but sodium sulfate water occurs in the belts of warm rock along some faults and alkali bicarbonate water is present in the main evapotranspiration basins. Unpublished records subject to revision Close

• 16307. [Image] Water-quality data from 2002 to 2003 and analysis of data gaps for development of total maximum daily loads in the Lower Klamath River basin, California

  	By Lorraine E. Flint, Alan L. Flint, Debra S. Curry, Stewart A. Rounds, and Micelis C. Doyle Abstract The U.S. Geological Survey (USGS) collected water? quality data during 2002 and 2003 In ...
  	Citation × Citation Citation Abstract Copy Title: Water-quality data from 2002 to 2003 and analysis of data gaps for development of total maximum daily loads in the Lower Klamath River basin, California Author: Flint, Lorraine E.; Flint, Alan L.; Curry, Debra S.; Rounds, Stewart A.; Doyle, Micelis C. Year: 2004, 2006, 2005 By Lorraine E. Flint, Alan L. Flint, Debra S. Curry, Stewart A. Rounds, and Micelis C. Doyle Abstract The U.S. Geological Survey (USGS) collected water? quality data during 2002 and 2003 In the Lower Klamath River Basin, in northern California, to support studies of river conditions as they pertain to the viability of Chinook and Coho salmon and endangered suckers. To address the data needs of the North Coast Regional Water Quality Control Board for the development of Total Maximum Daily Loads (TMDLs), water temperature, dissolved oxygen, specific conductance, and pH were continuously monitored at sites on the Klamath, Trinity, Shasta, and Lost Rivers. Water-quality samples were collected and analyzed for selected nutrients, organic carbon, chlorophyll-a, pheophytin-a, and trace elements. Sediment oxygen demand was measured on the Shasta River. Results of analysis of the data collected were used to identify locations in the Lower Klamath River Basin and periods of time during 200 Title: Water-quality data from 2002 to 2003 and analysis of data gaps for development of total maximum daily loads in the Lower Klamath River basin, California Author: Flint, Lorraine E.; Flint, Alan L.; Curry, Debra S.; Rounds, Stewart A.; Doyle, Micelis C. Year: 2004, 2006, 2005 By Lorraine E. Flint, Alan L. Flint, Debra S. Curry, Stewart A. Rounds, and Micelis C. Doyle Abstract The U.S. Geological Survey (USGS) collected water? quality data during 2002 and 2003 In the Lower Klamath River Basin, in northern California, to support studies of river conditions as they pertain to the viability of Chinook and Coho salmon and endangered suckers. To address the data needs of the North Coast Regional Water Quality Control Board for the development of Total Maximum Daily Loads (TMDLs), water temperature, dissolved oxygen, specific conductance, and pH were continuously monitored at sites on the Klamath, Trinity, Shasta, and Lost Rivers. Water-quality samples were collected and analyzed for selected nutrients, organic carbon, chlorophyll-a, pheophytin-a, and trace elements. Sediment oxygen demand was measured on the Shasta River. Results of analysis of the data collected were used to identify locations in the Lower Klamath River Basin and periods of time during 200 Close

• 16308. [Image] Annual report, Klamath River fisheries assessment program : juvenile salmonid trapping on the mainstem Trinity River at Willow Creek and on the Klamath River at Big Bar, 1990

  	ABSTRACT This report details the third year of Klamath River basin juvenile salmonid fishery investigations and represents the second year of sampling with rotary screw traps. Two traps, positioned side ...
  	Citation × Citation Citation Abstract Copy Title: Annual report, Klamath River fisheries assessment program : juvenile salmonid trapping on the mainstem Trinity River at Willow Creek and on the Klamath River at Big Bar, 1990 Author: Craig, James L. Year: 1992, 2005 ABSTRACT This report details the third year of Klamath River basin juvenile salmonid fishery investigations and represents the second year of sampling with rotary screw traps. Two traps, positioned side to side, were used at both the Klamath and Trinity River sites. The traps on the Klamath River were located at Big Bar (rkm 81) and began operation in March. The traps operated until July 10 and 18 sampling 38 and 31 nights respectively. Combined catch included 333 chinook (Oncorhynchus tshawytscha) , 178 steelhead (O^ mykiss) , and 30 coho (O^ kisutch) . No appreciable difference in mean catch or mean fork length of catch between the two traps was found. Peak weekly chinook catch effort, as an indicator of peak emigration, occurred the week of June 18 to 24. A total of five (1.5%) Ad-clip chinook were captured. A contribution of 134 (40%) hatchery chinook and 199 (60%) natural stock chinook was estimated for the total chinook captured. Mean migration rate for IGH Ad-clip chinook was 5. Title: Annual report, Klamath River fisheries assessment program : juvenile salmonid trapping on the mainstem Trinity River at Willow Creek and on the Klamath River at Big Bar, 1990 Author: Craig, James L. Year: 1992, 2005 ABSTRACT This report details the third year of Klamath River basin juvenile salmonid fishery investigations and represents the second year of sampling with rotary screw traps. Two traps, positioned side to side, were used at both the Klamath and Trinity River sites. The traps on the Klamath River were located at Big Bar (rkm 81) and began operation in March. The traps operated until July 10 and 18 sampling 38 and 31 nights respectively. Combined catch included 333 chinook (Oncorhynchus tshawytscha) , 178 steelhead (O^ mykiss) , and 30 coho (O^ kisutch) . No appreciable difference in mean catch or mean fork length of catch between the two traps was found. Peak weekly chinook catch effort, as an indicator of peak emigration, occurred the week of June 18 to 24. A total of five (1.5%) Ad-clip chinook were captured. A contribution of 134 (40%) hatchery chinook and 199 (60%) natural stock chinook was estimated for the total chinook captured. Mean migration rate for IGH Ad-clip chinook was 5. Close

• 16309. [Image] Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 2 geologic and hydrologic characterization ]

  	SUMMARY The geology and hydrology of the Basin and Range Province of the western conterminous United States are characterized in a series of data sets depicted in maps compiled for evaluation of prospective ...
  	Citation × Citation Citation Abstract Copy Title: Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 2 geologic and hydrologic characterization ] Author: Bedinger, M. S.; Sargent, Kenneth A.; Reed, J. E. Year: 2008, 2005 SUMMARY The geology and hydrology of the Basin and Range Province of the western conterminous United States are characterized in a series of data sets depicted in maps compiled for evaluation of prospective areas for further study of geohydrologic environments for isolation of high-level radioactive waste. The data sets include: (1) Average precipitation and evaporation; (2) surface distribution of selected rock types; (3) tectonic conditions; and (4) surface- and ground-water hydrology and Pleistocene lakes and marshes. Rocks mapped for consideration as potential host media for the isolation of high-level radioactive waste are widespread and include argillaceous rocks, granitic rocks, tuffaceous rocks, mafic extrusive rocks, evaporites, and laharic breccias. The unsaturated zone, where probably as thick as 150 meters (500 feet), was mapped for consideration as an environment for isolation of high-level waste. Unsaturated rocks of various lithologic types are widespread in the Province. Tectonic stability in the Quaternary Period is considered the key to assessing the probability of future tectonism with regard to high-level radioactive waste disposal. Tectonic conditions are characterized on the basis of the seismic record, heat-flow measurements, the occurrence of Quaternary faults, vertical crustal movement, and volcanic features. Tectonic activity, as indicated by seismicity, is greatest in areas bordering the western margin of the Province in Nevada and southern California, the eastern margin of the Province bordering the Wasatch Mountains in Utah and in parts of the Rio Grande valley. Late Cenozoic volcanic activity is widespread, being greatest bordering the Sierra Nevada in California and Oregon, and bordering the Wasatch Mountains in southern Utah and Idaho. The arid to semiarid climate of the Province results in few perennial streams and lakes. A large part of the surface drainage is interior and the many closed basins commonly are occupied by playas or dry lake beds. The Province is divided into ground-water flow units defined on the basis of ground-water divides, ground-water flow lines, and surface streams that receive ground-water discharge. Ground water contains less than 500 milligrams per liter of dissolved solids throughout most of the Province. Ground water is more mineralized in areas underlain by evaporitic rocks, overlain by playas, and near saline lakes. Ground water is of the calcium, magnesium, or sodium bicarbonate type in the areas where dissolved-solids concentrations are less than 500 milligrams per liter, and of the calcium, magnesium, or sodium sulfate or chloride type where dissolved-solids concentrations are greater than 500 milligrams per liter. Geologic and hydrologic evidence is found for about 100 lakes and marshes that existed during the Pleistocene Epoch. The possibility of a recurrence of pluvial conditions, such as existed in the Pleistocene, is of concern in repository siting because of possible changes in hydrologic conditions. The Pleistocene lakes and marshes provide clues to the hydrology during pluvial climates. Title: Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 2 geologic and hydrologic characterization ] Author: Bedinger, M. S.; Sargent, Kenneth A.; Reed, J. E. Year: 2008, 2005 SUMMARY The geology and hydrology of the Basin and Range Province of the western conterminous United States are characterized in a series of data sets depicted in maps compiled for evaluation of prospective areas for further study of geohydrologic environments for isolation of high-level radioactive waste. The data sets include: (1) Average precipitation and evaporation; (2) surface distribution of selected rock types; (3) tectonic conditions; and (4) surface- and ground-water hydrology and Pleistocene lakes and marshes. Rocks mapped for consideration as potential host media for the isolation of high-level radioactive waste are widespread and include argillaceous rocks, granitic rocks, tuffaceous rocks, mafic extrusive rocks, evaporites, and laharic breccias. The unsaturated zone, where probably as thick as 150 meters (500 feet), was mapped for consideration as an environment for isolation of high-level waste. Unsaturated rocks of various lithologic types are widespread in the Province. Tectonic stability in the Quaternary Period is considered the key to assessing the probability of future tectonism with regard to high-level radioactive waste disposal. Tectonic conditions are characterized on the basis of the seismic record, heat-flow measurements, the occurrence of Quaternary faults, vertical crustal movement, and volcanic features. Tectonic activity, as indicated by seismicity, is greatest in areas bordering the western margin of the Province in Nevada and southern California, the eastern margin of the Province bordering the Wasatch Mountains in Utah and in parts of the Rio Grande valley. Late Cenozoic volcanic activity is widespread, being greatest bordering the Sierra Nevada in California and Oregon, and bordering the Wasatch Mountains in southern Utah and Idaho. The arid to semiarid climate of the Province results in few perennial streams and lakes. A large part of the surface drainage is interior and the many closed basins commonly are occupied by playas or dry lake beds. The Province is divided into ground-water flow units defined on the basis of ground-water divides, ground-water flow lines, and surface streams that receive ground-water discharge. Ground water contains less than 500 milligrams per liter of dissolved solids throughout most of the Province. Ground water is more mineralized in areas underlain by evaporitic rocks, overlain by playas, and near saline lakes. Ground water is of the calcium, magnesium, or sodium bicarbonate type in the areas where dissolved-solids concentrations are less than 500 milligrams per liter, and of the calcium, magnesium, or sodium sulfate or chloride type where dissolved-solids concentrations are greater than 500 milligrams per liter. Geologic and hydrologic evidence is found for about 100 lakes and marshes that existed during the Pleistocene Epoch. The possibility of a recurrence of pluvial conditions, such as existed in the Pleistocene, is of concern in repository siting because of possible changes in hydrologic conditions. The Pleistocene lakes and marshes provide clues to the hydrology during pluvial climates. Close

• 16310. [Image] Molecular evolution and ecology of Klamath Basin suckers. Part B - Evidence for a lethal homozyhous genotpe at the Ankyrin(g) locus in Klamath Basin suckers (Catostomidae)

  	One chapter of a seven chapter annual report from 1999 examining ecological issues regarding the shortnose and Lost River sucker populations in Upper Klamath Lake and Williamson River.
  	Citation × Citation Citation Abstract Copy Title: Molecular evolution and ecology of Klamath Basin suckers. Part B - Evidence for a lethal homozyhous genotpe at the Ankyrin(g) locus in Klamath Basin suckers (Catostomidae) Author: Oregon Cooperative Wildlife Research Unit Year: 2000, 2005 One chapter of a seven chapter annual report from 1999 examining ecological issues regarding the shortnose and Lost River sucker populations in Upper Klamath Lake and Williamson River. Title: Molecular evolution and ecology of Klamath Basin suckers. Part B - Evidence for a lethal homozyhous genotpe at the Ankyrin(g) locus in Klamath Basin suckers (Catostomidae) Author: Oregon Cooperative Wildlife Research Unit Year: 2000, 2005 One chapter of a seven chapter annual report from 1999 examining ecological issues regarding the shortnose and Lost River sucker populations in Upper Klamath Lake and Williamson River. Close

• 16311. [Image] The trout and salmon of the Pacific coast

  	This article is an overview of the variety of trout and salmon that are found in Oregon and Washington states.
  	Citation × Citation Citation Abstract Copy Title: The trout and salmon of the Pacific coast Author: Jordan, David Starr Year: 1906, 2005, 2004 This article is an overview of the variety of trout and salmon that are found in Oregon and Washington states. Title: The trout and salmon of the Pacific coast Author: Jordan, David Starr Year: 1906, 2005, 2004 This article is an overview of the variety of trout and salmon that are found in Oregon and Washington states. Close

• 16312. [Image] Fishes and stream habitat in tributaries of the Klamath River in Crater Lake National Park, with special reference to the Sun Creek Bull Trout (Salvelinus confluentus) population

  	"December 1993."; "NPS D-155."; Other agencies: Oregon Department of Fish and Wildlife; National Biological Survey, Cooperative Park Studies Unit, College of Forestry, Oregon State University; Includes ...
  	Citation × Citation Citation Abstract Copy Title: Fishes and stream habitat in tributaries of the Klamath River in Crater Lake National Park, with special reference to the Sun Creek Bull Trout (Salvelinus confluentus) population Author: Dambacher, Jeffrey M; Buktenica, Mark W; Larson, Gary L Year: 1993, 2007, 2005 "December 1993."; "NPS D-155."; Other agencies: Oregon Department of Fish and Wildlife; National Biological Survey, Cooperative Park Studies Unit, College of Forestry, Oregon State University; Includes bibliographical references (p. 44) Title: Fishes and stream habitat in tributaries of the Klamath River in Crater Lake National Park, with special reference to the Sun Creek Bull Trout (Salvelinus confluentus) population Author: Dambacher, Jeffrey M; Buktenica, Mark W; Larson, Gary L Year: 1993, 2007, 2005 "December 1993."; "NPS D-155."; Other agencies: Oregon Department of Fish and Wildlife; National Biological Survey, Cooperative Park Studies Unit, College of Forestry, Oregon State University; Includes bibliographical references (p. 44) Close

• 16313. [Image] Wildlife of the Klamath Basin National Wildlife Refuges, California-Oregon

  	Distributed to depository libraries in microfiche; Shipping list no.: 96-0055-P; "September 1995"--P. [18]; "RF116690"--P. [18]
  	Citation × Citation Citation Abstract Copy Title: Wildlife of the Klamath Basin National Wildlife Refuges, California-Oregon Author: U.S. Fish and Wildlife Service Year: 1995, 2007, 2006 Distributed to depository libraries in microfiche; Shipping list no.: 96-0055-P; "September 1995"--P. [18]; "RF116690"--P. [18] Title: Wildlife of the Klamath Basin National Wildlife Refuges, California-Oregon Author: U.S. Fish and Wildlife Service Year: 1995, 2007, 2006 Distributed to depository libraries in microfiche; Shipping list no.: 96-0055-P; "September 1995"--P. [18]; "RF116690"--P. [18] Close

• 16314. [Image] Chronic toxicity of low dissolved oxygen concentrations, elevated pH, and elevated ammonia concentrations to lost river suckers (deltistes luxatus), and swimming performance of lost river suckers at various temperatures.

  	The study examines two species of sucker,the shortnose sucker(chasmistes brevirostrix), and the Lost River sucker,(deltisties luxatus) that inhabit Upper Klamath Lake and the effects of chronic toxicity ...
  	Citation × Citation Citation Abstract Copy Title: Chronic toxicity of low dissolved oxygen concentrations, elevated pH, and elevated ammonia concentrations to lost river suckers (deltistes luxatus), and swimming performance of lost river suckers at various temperatures. Author: Meyer, Joseph S. Year: 2000, 2007, 2006 The study examines two species of sucker,the shortnose sucker(chasmistes brevirostrix), and the Lost River sucker,(deltisties luxatus) that inhabit Upper Klamath Lake and the effects of chronic toxicity and temperature changes. The study examines two species of sucker,the shortnose sucker(chasmistes brevirostrix), and the Lost River sucker,(deltisties luxatus) that inhabit Upper Klamath Lake and the effects of chronic toxicity and temperature changes. Title: Chronic toxicity of low dissolved oxygen concentrations, elevated pH, and elevated ammonia concentrations to lost river suckers (deltistes luxatus), and swimming performance of lost river suckers at various temperatures. Author: Meyer, Joseph S. Year: 2000, 2007, 2006 The study examines two species of sucker,the shortnose sucker(chasmistes brevirostrix), and the Lost River sucker,(deltisties luxatus) that inhabit Upper Klamath Lake and the effects of chronic toxicity and temperature changes. The study examines two species of sucker,the shortnose sucker(chasmistes brevirostrix), and the Lost River sucker,(deltisties luxatus) that inhabit Upper Klamath Lake and the effects of chronic toxicity and temperature changes. Close

• 16315. [Image] Federal Register - Endangered and Threatened Wildlife and Plants; Determination of Endangered Status of the Shortnose Sucker and the Lost River Sucker

  	The Service determines endangered status for the shortnose sucker [Chasmistes brevirostris) and Lost River sucker [Deltistes luxatus), fishes restricted to the Klamath Basin of south-central Oregon and ...
  	Citation × Citation Citation Abstract Copy Title: Federal Register - Endangered and Threatened Wildlife and Plants; Determination of Endangered Status of the Shortnose Sucker and the Lost River Sucker Author: Williams, Jack E. Year: 1988, 2008, 2005 The Service determines endangered status for the shortnose sucker [Chasmistes brevirostris) and Lost River sucker [Deltistes luxatus), fishes restricted to the Klamath Basin of south-central Oregon and north-central California. Dams, draining of marshes, diversion of rivers and dredging of lakes have reduced the range and numbers of both species by more than 95 percent. Remaining populations are composed of older individuals with little or no successful recruitment for many years. Both species are jeopardized by continued loss of habitat, hybridization with more common closely related species, competition and predation by exotic species, and insularization of remaining habitats. This rule implements the protection provided by the Endangered Species Act of 1973, as amended, for the shortnose sucker and Lost River sucker Title: Federal Register - Endangered and Threatened Wildlife and Plants; Determination of Endangered Status of the Shortnose Sucker and the Lost River Sucker Author: Williams, Jack E. Year: 1988, 2008, 2005 The Service determines endangered status for the shortnose sucker [Chasmistes brevirostris) and Lost River sucker [Deltistes luxatus), fishes restricted to the Klamath Basin of south-central Oregon and north-central California. Dams, draining of marshes, diversion of rivers and dredging of lakes have reduced the range and numbers of both species by more than 95 percent. Remaining populations are composed of older individuals with little or no successful recruitment for many years. Both species are jeopardized by continued loss of habitat, hybridization with more common closely related species, competition and predation by exotic species, and insularization of remaining habitats. This rule implements the protection provided by the Endangered Species Act of 1973, as amended, for the shortnose sucker and Lost River sucker Close

• 16316. [Image] Martha

  	Maria Schwalb, too, had many an opportunity during the long summer, to show her housewife accomplishments. Nor was she unassisted by her humbler sister in these duties. The arrangements for entertaining ...
  	Citation × Citation Citation Abstract Copy Title: Martha Maria Schwalb, too, had many an opportunity during the long summer, to show her housewife accomplishments. Nor was she unassisted by her humbler sister in these duties. The arrangements for entertaining the crowds that came were in the hands of the central committee. This committee assigned travellers to the different hotels and homes. Lodgings cost from $1.00 to $2.50 per day according to location. The meals cost as much more. Here let one (Mrs. Elizabeth Hayhurst of Portland) who witnessed the portrayal of this great play in 1922 tell us some of her observations and experiences. "We left Munich Saturday afternoon on one of the many special trains for Oberammergau which is about a two hour journey by fast train. We went through a picturesque country, whose fir-clad hills reminded us very strongly of Oregon, while the numerous blue lakes and chalet-like houses partook of the characteristics of Switzerland. Soon we were in sight of the lovely Bavarian Alps, and entering the valley of the Ammer, beheld Oberammergau - a small village nestled at the foot of Kofel, a high mountain peak with precipitous sides whose crest is surmounted with a cross. Upon our arrival, we were put in the care of a porter, who was dressed in the quaint garb of the Bavarian peasant - short leather breeches, embroidered velvet jacket, and a peaked leather hat adorned with a feather of a wild fowl. We followed him to the home of our host - Hans Mayr, who had the role of "Pilate" in the play. Frau Mayr greeted us cordially, as she domiciled forty of us Americans seemingly without any effort whatsoever, and made us feel quite like we were her personal guests instead of playing ones. A walk about the village later brought forth many "Ohs and Ahs". Most of the houses are painted a soft green, gray or white, and on the outside walls of many are painted religious scenes, and on one house there was a canopy of ivy growing about a painted shrine to the Virgin. Everywhere there were shrines and on the banks of the clean, clear Ammer river was a splendid monument of the Crucifixion. After our simple but wholesome evening meal, many of us purchased copies of the play, and knowing no German, which is the original text, I obtained an English version, to familiarize myself with the lines I had journeyed so far to see and hear interpreted. The characters are selected by a committee that is elected by the whole community, and the villagers wait with breathless anticipation the announcement of the bestowal of the assignment, as often a near-tragedy is witnessed when one is deemed too old to continue in a famous role. Anton Lang has been the Christus for three consecutive decades but he will not be able to continue in the role, as the crucifixion scene where he is suspended on the cross for twenty minutes is a great physical strain. Frau Lang has never witnessed the crucifixion scene as given by her husband. On the day of the performance, Anton Lang remains at the auditorium all day - simple food being brought to him during the noon intermission when he rests. By profession, he is a potter. He is profound student of the life of Christ, and has made a pilgrimage to the Holy Land in order to portray the role. The bestowal of the role of the Christus is considered the highest honor within the power of the community as there is the character requisite as well as the acting one. That interest in the Play is lifelong can best be revealed by the interest of Johann Zwinck who was first a boy in the play, twice enacted the part of the disciple, Joh, and for three decades interpreted the role of Judas - said to be among the greatest of the Judases and in 1922 was the venerable Simon of Bethany, as well as understudy to the Judas. It is told of him that while he wished nothing to happen to Guida Mayr - the Judans of 1922, but Oh! how much he should like to just once again play the part of Judas, and when he was told that it would be difficult for him to make himself heard with so many of his teeth gone, he replied, "well, if I were sure of the chance, I would try in some way to gather together enough money to buy teeth". George Lang, the director of the play, is a young man of about thirty years. He was wounded in the late war and one hand is atrophied. He is their teacher in the wood carving school. Wood carving is the principal industry of the village and to that fact may be ascribed the artistic success of the play. The Villagers day by day experience the joy of creating beautiful objects. The robes have all been designed and made in the village from wonderful materials gotten mostly from the Orient. No make-up whatsoever is used, not even a wig is worn, another secret of the lovely hair one sees there everywhere. No married woman is given a speaking role, but an exception was made to the understudy of the Virgin Mary of 1922, who was the Virgin Mary of 1910, but who in the meantime has been wooed, wed, and widowed. Nine hundred five people have a part in the production of the play; there are 124 speaking roles; 50 musicians in the orchestra and 45 singers in the well-trained chorus. Seven hundred persons from mere tots of four to men and women of venerable years appear in the mob scene; 75 men are needed to collect the tickets and serve as doorkeepers and ushers, and remember at the same time thousands are being entertained in the homes of the villagers, as the few small hotels cannot begin to provide for the large number who come from all parts of the world to see the Marvelous Play of all time. The prices were established early in the year of 1922, and although the value of the mark declined many times in value before the season had hardly begun, there was no deviation from the established price of either the seats or the accomodations. Thus it was that eleven of the villagers journeyed to American to try to retrieve some of the deficit. Each summer a religious play is given which enables the selecting committee to know who is best adapted to the various roles, and each family hopes it may be represented in the famous characters and shapes its daily life to that end. We were awakened early Sunday morning by such peaceful sounds as the crowing of the cocks, lowing of the calves, tinkling of the bells of the cows as they were being driven through the village streets to the pasture, and the pealing of the chimes from the village's one church. Upon arising, we were greeted with frosted roofs and fences, which was a most welcome sight, as it foretold a clear day. We breakfasted at six-thirty, after which we were given our tickets to the open-air auditorium, as experience has shown that it simplifies matters to retain the tickets as long as possible to avoid all the useless mislayings and losings. The seats are distributed according to the household, the better homes secure the better seats for their guests. Our hostess very thoughtfully suggested our securing robes and cushions, which were provided for a small fee and made our stay in the open-air auditorium much more comfortable. As we went to the Play through the village streets, it seemed as though the whole world had come to Oberammergau. There were monks and nuns of the various orders, Hindoos from India, Syrians from the Near East, a Japanese and Chinese from the Far East, and very, very black people from Africa. We were requested to be in our seats at 7:45, and there we were, 4200 sitting, hundreds standing and scores kneeling, when at precisely eight o'clock the Chorus dressed in rich colorful robes advanced from the colonnades on either side of the stage and sang the opening number which is a prayer of thanks for their deliverance from the awful scourge in ages past and an appeal from the blessing of the presence of the Saviour always. Then the prologist in full, rich voice gave the following beautiful greeting which sounds the keynote of the whole play. "Welcome, welcome, to all, whom here the tender love Of the Saviour unites, mourning, to follow Him On His journey of suffering To the last resting place. Who from far and from near, all here have come today They all feel themselves now joined in brotherly love As disciples of one Lord Who has suffered death for all. Who gave Himself for us, with compassion and love Even to bitter death. To Him let us lift up Our gaze and our hearts too, With love unfeigned and gratitude. Up to Him let us lift all our thoughts and our souls, Pray with us - yea - with us pray, as the hour comes, When the dept of our sacred vow We pray to the supreme GOD". There are twenty-four tableaux and the function of the tableaux is to connect the incidents of the old testament that relate to the incidents of the last seven days of Christ. The dialogue begins with Christ's entry into Jerusalem, and our very souls were quickened as we beheld the face of Him who has beem so familiar to us through the very best of painting and sculpture. As the sad story unfolded, there were lovely pictures of indelible impress left upon our minds. The bleating of the sheep as they were freed from the pens and the flying of the doves over the audience, all added to the realism of the Temple scene. Then the beauty and the humility of Mary Magdalene as she wiped the feet of the Christus with her lovely long hair; the pathos and the tenderness of the leave-taking of the Christus of His mother in Bethany, and the Last Supper which is an animated counterpart of the Da Vinci painting. The play has progressed until the betrayal of the Christus by Judas in the Garden of Gethsamane when the Noon intermission is announced which is the first intermission of the morning. We were all enthralled as we wended our way quietly to our various place of abode for luncheon, which in many instances, is served by those appearing in the performance. At 1:15 we were again in our seats in eager anticipation of the continuance of the wonderful story of the Ages, as the shortening of days of September made it necessary to resume the Play at 1:30 in order to finish before nightfall. The lines of the Play have Judas reveal where the Christus is spending the night rather than an actual betrayal, and when Judas realized all to late what his telling has brought to the Christus, he is so filled with compassion that he receives our pity instead of our scorn. Scene after scene is portrayed until we are confronted with the realistic "Way of the Cross", and the Chorus, now dressed in black, sing a dirge-like refrain all through the Crucifixion Scene, which was too real and too sad for most of us. As the body was removed from the cross we thought at once of another famous painting "Rubens' Descent From the Cross" and during the rites of the last unction, another work of art came to our mind, Michael Angelo's marble masterpiece "Pieta" as Mary, the Mother, folded in her arms the beautiful body of the Christus. The Christ appeared for a moment to Mary Magdalene after the resurrection, and in a final tableau, we had a glimpse of the Ascension. The last chorus was sung--a glad, halleluiah one-- and the somber robes of mourning have been replaced by the first, bright, colorful ones, and the final curtain is drawn about five-thirty upon the marvelous Passion Play. It has filled our very souls with reverence and a prayer that the Great Sacrifice of Reconcilliation upon Golgotha may contribute to a world peace and a better understanding among the nations and within the nations until the whole world is imbued with the same unity and co-operation that makes possible the perfect rendering of this marvellous Play by the villagers of Oberammergau. Title: Martha Maria Schwalb, too, had many an opportunity during the long summer, to show her housewife accomplishments. Nor was she unassisted by her humbler sister in these duties. The arrangements for entertaining the crowds that came were in the hands of the central committee. This committee assigned travellers to the different hotels and homes. Lodgings cost from $1.00 to $2.50 per day according to location. The meals cost as much more. Here let one (Mrs. Elizabeth Hayhurst of Portland) who witnessed the portrayal of this great play in 1922 tell us some of her observations and experiences. "We left Munich Saturday afternoon on one of the many special trains for Oberammergau which is about a two hour journey by fast train. We went through a picturesque country, whose fir-clad hills reminded us very strongly of Oregon, while the numerous blue lakes and chalet-like houses partook of the characteristics of Switzerland. Soon we were in sight of the lovely Bavarian Alps, and entering the valley of the Ammer, beheld Oberammergau - a small village nestled at the foot of Kofel, a high mountain peak with precipitous sides whose crest is surmounted with a cross. Upon our arrival, we were put in the care of a porter, who was dressed in the quaint garb of the Bavarian peasant - short leather breeches, embroidered velvet jacket, and a peaked leather hat adorned with a feather of a wild fowl. We followed him to the home of our host - Hans Mayr, who had the role of "Pilate" in the play. Frau Mayr greeted us cordially, as she domiciled forty of us Americans seemingly without any effort whatsoever, and made us feel quite like we were her personal guests instead of playing ones. A walk about the village later brought forth many "Ohs and Ahs". Most of the houses are painted a soft green, gray or white, and on the outside walls of many are painted religious scenes, and on one house there was a canopy of ivy growing about a painted shrine to the Virgin. Everywhere there were shrines and on the banks of the clean, clear Ammer river was a splendid monument of the Crucifixion. After our simple but wholesome evening meal, many of us purchased copies of the play, and knowing no German, which is the original text, I obtained an English version, to familiarize myself with the lines I had journeyed so far to see and hear interpreted. The characters are selected by a committee that is elected by the whole community, and the villagers wait with breathless anticipation the announcement of the bestowal of the assignment, as often a near-tragedy is witnessed when one is deemed too old to continue in a famous role. Anton Lang has been the Christus for three consecutive decades but he will not be able to continue in the role, as the crucifixion scene where he is suspended on the cross for twenty minutes is a great physical strain. Frau Lang has never witnessed the crucifixion scene as given by her husband. On the day of the performance, Anton Lang remains at the auditorium all day - simple food being brought to him during the noon intermission when he rests. By profession, he is a potter. He is profound student of the life of Christ, and has made a pilgrimage to the Holy Land in order to portray the role. The bestowal of the role of the Christus is considered the highest honor within the power of the community as there is the character requisite as well as the acting one. That interest in the Play is lifelong can best be revealed by the interest of Johann Zwinck who was first a boy in the play, twice enacted the part of the disciple, Joh, and for three decades interpreted the role of Judas - said to be among the greatest of the Judases and in 1922 was the venerable Simon of Bethany, as well as understudy to the Judas. It is told of him that while he wished nothing to happen to Guida Mayr - the Judans of 1922, but Oh! how much he should like to just once again play the part of Judas, and when he was told that it would be difficult for him to make himself heard with so many of his teeth gone, he replied, "well, if I were sure of the chance, I would try in some way to gather together enough money to buy teeth". George Lang, the director of the play, is a young man of about thirty years. He was wounded in the late war and one hand is atrophied. He is their teacher in the wood carving school. Wood carving is the principal industry of the village and to that fact may be ascribed the artistic success of the play. The Villagers day by day experience the joy of creating beautiful objects. The robes have all been designed and made in the village from wonderful materials gotten mostly from the Orient. No make-up whatsoever is used, not even a wig is worn, another secret of the lovely hair one sees there everywhere. No married woman is given a speaking role, but an exception was made to the understudy of the Virgin Mary of 1922, who was the Virgin Mary of 1910, but who in the meantime has been wooed, wed, and widowed. Nine hundred five people have a part in the production of the play; there are 124 speaking roles; 50 musicians in the orchestra and 45 singers in the well-trained chorus. Seven hundred persons from mere tots of four to men and women of venerable years appear in the mob scene; 75 men are needed to collect the tickets and serve as doorkeepers and ushers, and remember at the same time thousands are being entertained in the homes of the villagers, as the few small hotels cannot begin to provide for the large number who come from all parts of the world to see the Marvelous Play of all time. The prices were established early in the year of 1922, and although the value of the mark declined many times in value before the season had hardly begun, there was no deviation from the established price of either the seats or the accomodations. Thus it was that eleven of the villagers journeyed to American to try to retrieve some of the deficit. Each summer a religious play is given which enables the selecting committee to know who is best adapted to the various roles, and each family hopes it may be represented in the famous characters and shapes its daily life to that end. We were awakened early Sunday morning by such peaceful sounds as the crowing of the cocks, lowing of the calves, tinkling of the bells of the cows as they were being driven through the village streets to the pasture, and the pealing of the chimes from the village's one church. Upon arising, we were greeted with frosted roofs and fences, which was a most welcome sight, as it foretold a clear day. We breakfasted at six-thirty, after which we were given our tickets to the open-air auditorium, as experience has shown that it simplifies matters to retain the tickets as long as possible to avoid all the useless mislayings and losings. The seats are distributed according to the household, the better homes secure the better seats for their guests. Our hostess very thoughtfully suggested our securing robes and cushions, which were provided for a small fee and made our stay in the open-air auditorium much more comfortable. As we went to the Play through the village streets, it seemed as though the whole world had come to Oberammergau. There were monks and nuns of the various orders, Hindoos from India, Syrians from the Near East, a Japanese and Chinese from the Far East, and very, very black people from Africa. We were requested to be in our seats at 7:45, and there we were, 4200 sitting, hundreds standing and scores kneeling, when at precisely eight o'clock the Chorus dressed in rich colorful robes advanced from the colonnades on either side of the stage and sang the opening number which is a prayer of thanks for their deliverance from the awful scourge in ages past and an appeal from the blessing of the presence of the Saviour always. Then the prologist in full, rich voice gave the following beautiful greeting which sounds the keynote of the whole play. "Welcome, welcome, to all, whom here the tender love Of the Saviour unites, mourning, to follow Him On His journey of suffering To the last resting place. Who from far and from near, all here have come today They all feel themselves now joined in brotherly love As disciples of one Lord Who has suffered death for all. Who gave Himself for us, with compassion and love Even to bitter death. To Him let us lift up Our gaze and our hearts too, With love unfeigned and gratitude. Up to Him let us lift all our thoughts and our souls, Pray with us - yea - with us pray, as the hour comes, When the dept of our sacred vow We pray to the supreme GOD". There are twenty-four tableaux and the function of the tableaux is to connect the incidents of the old testament that relate to the incidents of the last seven days of Christ. The dialogue begins with Christ's entry into Jerusalem, and our very souls were quickened as we beheld the face of Him who has beem so familiar to us through the very best of painting and sculpture. As the sad story unfolded, there were lovely pictures of indelible impress left upon our minds. The bleating of the sheep as they were freed from the pens and the flying of the doves over the audience, all added to the realism of the Temple scene. Then the beauty and the humility of Mary Magdalene as she wiped the feet of the Christus with her lovely long hair; the pathos and the tenderness of the leave-taking of the Christus of His mother in Bethany, and the Last Supper which is an animated counterpart of the Da Vinci painting. The play has progressed until the betrayal of the Christus by Judas in the Garden of Gethsamane when the Noon intermission is announced which is the first intermission of the morning. We were all enthralled as we wended our way quietly to our various place of abode for luncheon, which in many instances, is served by those appearing in the performance. At 1:15 we were again in our seats in eager anticipation of the continuance of the wonderful story of the Ages, as the shortening of days of September made it necessary to resume the Play at 1:30 in order to finish before nightfall. The lines of the Play have Judas reveal where the Christus is spending the night rather than an actual betrayal, and when Judas realized all to late what his telling has brought to the Christus, he is so filled with compassion that he receives our pity instead of our scorn. Scene after scene is portrayed until we are confronted with the realistic "Way of the Cross", and the Chorus, now dressed in black, sing a dirge-like refrain all through the Crucifixion Scene, which was too real and too sad for most of us. As the body was removed from the cross we thought at once of another famous painting "Rubens' Descent From the Cross" and during the rites of the last unction, another work of art came to our mind, Michael Angelo's marble masterpiece "Pieta" as Mary, the Mother, folded in her arms the beautiful body of the Christus. The Christ appeared for a moment to Mary Magdalene after the resurrection, and in a final tableau, we had a glimpse of the Ascension. The last chorus was sung--a glad, halleluiah one-- and the somber robes of mourning have been replaced by the first, bright, colorful ones, and the final curtain is drawn about five-thirty upon the marvelous Passion Play. It has filled our very souls with reverence and a prayer that the Great Sacrifice of Reconcilliation upon Golgotha may contribute to a world peace and a better understanding among the nations and within the nations until the whole world is imbued with the same unity and co-operation that makes possible the perfect rendering of this marvellous Play by the villagers of Oberammergau. Close

• 16317. [Image] Surface water-supply of the United States. pt. 11. Pacific slope basins in California

  	Includes Klamath River Basin; Chiefly tables; Includes indexes; Prepared in cooperation with the states and other agencies
  	Citation × Citation Citation Abstract Copy Title: Surface water-supply of the United States. pt. 11. Pacific slope basins in California Author: U.S. Dept. of the Interior, Geological Survey Year: 1910, 2008, 2005 Includes Klamath River Basin; Chiefly tables; Includes indexes; Prepared in cooperation with the states and other agencies Title: Surface water-supply of the United States. pt. 11. Pacific slope basins in California Author: U.S. Dept. of the Interior, Geological Survey Year: 1910, 2008, 2005 Includes Klamath River Basin; Chiefly tables; Includes indexes; Prepared in cooperation with the states and other agencies Close

• 16318. [Image] Klamath irrigation project sucker salvage and Langell Valley fish survey report : 1999

  	"Annual report" - T.p. verso
  	Citation × Citation Citation Abstract Copy Title: Klamath irrigation project sucker salvage and Langell Valley fish survey report : 1999 Author: Peck, Brian J. Year: 2000, 2005 "Annual report" - T.p. verso Title: Klamath irrigation project sucker salvage and Langell Valley fish survey report : 1999 Author: Peck, Brian J. Year: 2000, 2005 "Annual report" - T.p. verso Close

• 16319. [Image] Analysis of Tule Lake water quality and sucker telemetry, 1992-1995

  	"3/30/2000"
  	Citation × Citation Citation Abstract Copy Title: Analysis of Tule Lake water quality and sucker telemetry, 1992-1995 Author: Buettner, Mark Year: 2000, 2005 "3/30/2000" Title: Analysis of Tule Lake water quality and sucker telemetry, 1992-1995 Author: Buettner, Mark Year: 2000, 2005 "3/30/2000" Close

• 16320. [Image] The Water Report - The role of science in the ESA

  	Only portions of issues of The Water Report are available in the Klamath Waters Digital Library. See the full report at http://www.thewaterreport.com/
  	Citation × Citation Citation Abstract Copy Title: The Water Report - The role of science in the ESA Author: Envirotech Publications Year: 2004, 2008, 2006 Only portions of issues of The Water Report are available in the Klamath Waters Digital Library. See the full report at http://www.thewaterreport.com/ Title: The Water Report - The role of science in the ESA Author: Envirotech Publications Year: 2004, 2008, 2006 Only portions of issues of The Water Report are available in the Klamath Waters Digital Library. See the full report at http://www.thewaterreport.com/ Close

• 16321. [Image] Relation between selected water-quality variables and lake level in Upper Klamath and Agency Lakes, Oregon

  	Relation Between Selected Water-Quality Constituents and Lake Stage in Upper Klamath and Agency Lakes, Oregon By Tamara M. Wood, Gregory J. Fuhrer, and Jennifer L. Morace SUMMARY Upper Klamath Lake is ...
  	Citation × Citation Citation Abstract Copy Title: Relation between selected water-quality variables and lake level in Upper Klamath and Agency Lakes, Oregon Author: Wood, Tamara M. Year: 1996, 2005, 2004 Relation Between Selected Water-Quality Constituents and Lake Stage in Upper Klamath and Agency Lakes, Oregon By Tamara M. Wood, Gregory J. Fuhrer, and Jennifer L. Morace SUMMARY Upper Klamath Lake is a large (140 square-mile), shallow (mean depth about 8 ft) lake in south-central Oregon that the historical record indicates has been eutrophic since its discovery by non-Native Americans. In recent decades, however, the lake has had annual occurrences of near-monoculture blooms of the blue-green alga Aphanizomenon flos-aquae. In 1988 two sucker species endemic to the lake, the Lost River sucker (Deltistes luxatus) and the shortnose sucker (Chasmistes brevirostris), were listed as endangered by the U.S. Fish and Wildlife Service, and it has been proposed that the poor water quality conditions associated with extremely long and productive blooms are contributing to the decline of those species. It has also been proposed that the low lake levels made possible by the construction of a dam at the outlet from the lake in 1921 have contributed to worsening water quality through a variety of possible mechanisms (Jacob Kann, Klamath Tribes, written com-mun., 1995). One such mechanism would be an increase in internal phosphorus loading from resuspended sediments (Jacoby and others, 1982), resulting from an increase in bottom shear stresses at lower lake levels (Laenen and LeTourneau, 1996), leading in turn to more intense algal blooms. Another possible mechanism is an earlier triggering of algal blooms. When early spring lake levels are low, greater light intensity at the sediment surface might speed recruitment of algal cells from the sediments. Sediment recruitment has been shown to be an important contributor to water column biomass increases in A. flos aquae (Barbiero and Kann, 1994) and Gloeotrichia echinulata (Barbiero, 1993). An earlier bloom could result in poor water quality conditions occurring earlier in the year, when young-of-the-year fish may be more susceptible to those conditions. Lake level can also influence water quality directly. An increased frequency of sediment resuspension at lower lake levels could increase chemical and biological oxygen demand, resulting in decreased dissolved oxygen concentrations. Sediment oxygen demand also may be enhanced at lower lake levels because it is concentrated over a smaller volume of water. Some compensation for increased oxygen demand at lower lake levels might be provided by increased reaeration, if the water column mixes from top to bottom more frequently. Based on the analysis of data that they have been collecting for several years, the Klamath Tribes recently recommended that the Bureau of Reclamation (Reclamation) modify the operating plan for the dam to make the minimum lake levels for the June-August period more closely resemble pre-dam conditions (Jacob Kann, written commun., 1995). The U.S. Geological Survey (USGS) was asked to analyze the available data for the lake and to assess whether the evidence exists to conclude that year-to-year differences in certain lake water-quality variables are related to year-to-year differences in lake level. The results of the analysis will be used as scientific input in the process of developing an operating plan for the Link River Dam. Datasets Two water-quality datasets were analyzed. The first was a series of hourly records of pH, dissolved oxygen, and water temperature, each of approximately a week's duration. The records were collected at 3 sites over 3 years, 1992 through 1994, with enough consistency to define the seasonal patterns. This dataset provided information about the diel extremes in dissolved oxygen and pH and the seasonal pattern in the diel cycle, but measurements were limited to a depth of 1 m(3.28 ft). The second dataset was a set of depth profiles of pH and dissolved oxygen and concurrent depth-integrated samples for nutrients and chlo-rophyll-a. The profiles were collected at approximately biweekly intervals at nine sites (seven in Upper Klamath and two in Agency Lake) over the 5 years 1990 through 1994. These depth profiles provided information on the depth-dependence of dissolved oxygen and pH, and allowed more extensive year-to-year comparisons than did the hourly records. Because measurements were made at each site only once during the sampling day, however, they did not capture the daily extremes in water quality. Lake level is measured daily by the USGS at three sites around the lake: Rocky Point, Rattlesnake Point, and near the city of Klamath Falls. These daily measurements are then used to compute a spatially weighted average of the lake level that is reported in the USGS annual Water-Data Report for Oregon. The average lake levels were used in this report. Two climatic datasets were used in this report; both were collected at the Klamath Falls airport. Air temperature was recorded as a daily maximum and daily minimum value. Cloud cover was quantized on a daily basis into one of seven levels. Because the focus of this study was primarily to examine possible relations between water quality and lake level, the lake level data provide an important context for the discussions that follow. Title: Relation between selected water-quality variables and lake level in Upper Klamath and Agency Lakes, Oregon Author: Wood, Tamara M. Year: 1996, 2005, 2004 Relation Between Selected Water-Quality Constituents and Lake Stage in Upper Klamath and Agency Lakes, Oregon By Tamara M. Wood, Gregory J. Fuhrer, and Jennifer L. Morace SUMMARY Upper Klamath Lake is a large (140 square-mile), shallow (mean depth about 8 ft) lake in south-central Oregon that the historical record indicates has been eutrophic since its discovery by non-Native Americans. In recent decades, however, the lake has had annual occurrences of near-monoculture blooms of the blue-green alga Aphanizomenon flos-aquae. In 1988 two sucker species endemic to the lake, the Lost River sucker (Deltistes luxatus) and the shortnose sucker (Chasmistes brevirostris), were listed as endangered by the U.S. Fish and Wildlife Service, and it has been proposed that the poor water quality conditions associated with extremely long and productive blooms are contributing to the decline of those species. It has also been proposed that the low lake levels made possible by the construction of a dam at the outlet from the lake in 1921 have contributed to worsening water quality through a variety of possible mechanisms (Jacob Kann, Klamath Tribes, written com-mun., 1995). One such mechanism would be an increase in internal phosphorus loading from resuspended sediments (Jacoby and others, 1982), resulting from an increase in bottom shear stresses at lower lake levels (Laenen and LeTourneau, 1996), leading in turn to more intense algal blooms. Another possible mechanism is an earlier triggering of algal blooms. When early spring lake levels are low, greater light intensity at the sediment surface might speed recruitment of algal cells from the sediments. Sediment recruitment has been shown to be an important contributor to water column biomass increases in A. flos aquae (Barbiero and Kann, 1994) and Gloeotrichia echinulata (Barbiero, 1993). An earlier bloom could result in poor water quality conditions occurring earlier in the year, when young-of-the-year fish may be more susceptible to those conditions. Lake level can also influence water quality directly. An increased frequency of sediment resuspension at lower lake levels could increase chemical and biological oxygen demand, resulting in decreased dissolved oxygen concentrations. Sediment oxygen demand also may be enhanced at lower lake levels because it is concentrated over a smaller volume of water. Some compensation for increased oxygen demand at lower lake levels might be provided by increased reaeration, if the water column mixes from top to bottom more frequently. Based on the analysis of data that they have been collecting for several years, the Klamath Tribes recently recommended that the Bureau of Reclamation (Reclamation) modify the operating plan for the dam to make the minimum lake levels for the June-August period more closely resemble pre-dam conditions (Jacob Kann, written commun., 1995). The U.S. Geological Survey (USGS) was asked to analyze the available data for the lake and to assess whether the evidence exists to conclude that year-to-year differences in certain lake water-quality variables are related to year-to-year differences in lake level. The results of the analysis will be used as scientific input in the process of developing an operating plan for the Link River Dam. Datasets Two water-quality datasets were analyzed. The first was a series of hourly records of pH, dissolved oxygen, and water temperature, each of approximately a week's duration. The records were collected at 3 sites over 3 years, 1992 through 1994, with enough consistency to define the seasonal patterns. This dataset provided information about the diel extremes in dissolved oxygen and pH and the seasonal pattern in the diel cycle, but measurements were limited to a depth of 1 m(3.28 ft). The second dataset was a set of depth profiles of pH and dissolved oxygen and concurrent depth-integrated samples for nutrients and chlo-rophyll-a. The profiles were collected at approximately biweekly intervals at nine sites (seven in Upper Klamath and two in Agency Lake) over the 5 years 1990 through 1994. These depth profiles provided information on the depth-dependence of dissolved oxygen and pH, and allowed more extensive year-to-year comparisons than did the hourly records. Because measurements were made at each site only once during the sampling day, however, they did not capture the daily extremes in water quality. Lake level is measured daily by the USGS at three sites around the lake: Rocky Point, Rattlesnake Point, and near the city of Klamath Falls. These daily measurements are then used to compute a spatially weighted average of the lake level that is reported in the USGS annual Water-Data Report for Oregon. The average lake levels were used in this report. Two climatic datasets were used in this report; both were collected at the Klamath Falls airport. Air temperature was recorded as a daily maximum and daily minimum value. Cloud cover was quantized on a daily basis into one of seven levels. Because the focus of this study was primarily to examine possible relations between water quality and lake level, the lake level data provide an important context for the discussions that follow. Close

• 16322. [Image] Water resources data. Oregon. Water Year 2003

  	Cover title; Chiefly tables
  	Citation × Citation Citation Abstract Copy Title: Water resources data. Oregon. Water Year 2003 Author: Geological Survey (U.S.). Water Resources Division Year: 2003, 2005 Cover title; Chiefly tables Title: Water resources data. Oregon. Water Year 2003 Author: Geological Survey (U.S.). Water Resources Division Year: 2003, 2005 Cover title; Chiefly tables Close