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• 41. [Article] Hydrologic Response to Extreme Warm and Cold Summers in the McMurdo Dry Valleys, East Antarctica

  The meteorological characteristics and hydrological response of an extreme warm, and cold summer in the McMurdo Dry Valleys are compared. The driver behind the warmer summer conditions was the occurrence ...

  Citation × Citation Citation Abstract Copy Title: Hydrologic Response to Extreme Warm and Cold Summers in the McMurdo Dry Valleys, East Antarctica Author: Doran, Peter T., McKay, Christopher P., Fountain, Andrew G., Nylen, Thomas H., McKnight, Diane M., Jaros, Chris, Barrett, John E. Year: 2008 The meteorological characteristics and hydrological response of an extreme warm, and cold summer in the McMurdo Dry Valleys are compared. The driver behind the warmer summer conditions was the occurrence of down-valley winds, which were not present during the colder summer. Occurrence of the summer down-valley winds coincided with lower than typical mean sea level pressure in the Ross Sea region. There was no significant difference in the amount of solar radiation received during the two summers. Compared to the cold summer, glaciological and hydrological response to the warm summer in Taylor Valley included significant glacier mass loss, and 3- to nearly 6000-fold increase in annual streamflow. Lake levels decreased slightly during the cold summer, and increased between 0.54 and 1.01 m during the warm summer, effectively erasing the prior 14 years of lake level lowering in a period of three months. Lake level rise during the warm summer was shown to be strongly associated with and increase in degree days above freezing at higher elevations. We suggest that strong summer down-valley winds may have been responsible for the generation of large glacial lakes during the Last Glacial Maximum when ice core records recorded annual temperatures significantly colder than present. Title: Hydrologic Response to Extreme Warm and Cold Summers in the McMurdo Dry Valleys, East Antarctica Author: Doran, Peter T., McKay, Christopher P., Fountain, Andrew G., Nylen, Thomas H., McKnight, Diane M., Jaros, Chris, Barrett, John E. Year: 2008 The meteorological characteristics and hydrological response of an extreme warm, and cold summer in the McMurdo Dry Valleys are compared. The driver behind the warmer summer conditions was the occurrence of down-valley winds, which were not present during the colder summer. Occurrence of the summer down-valley winds coincided with lower than typical mean sea level pressure in the Ross Sea region. There was no significant difference in the amount of solar radiation received during the two summers. Compared to the cold summer, glaciological and hydrological response to the warm summer in Taylor Valley included significant glacier mass loss, and 3- to nearly 6000-fold increase in annual streamflow. Lake levels decreased slightly during the cold summer, and increased between 0.54 and 1.01 m during the warm summer, effectively erasing the prior 14 years of lake level lowering in a period of three months. Lake level rise during the warm summer was shown to be strongly associated with and increase in degree days above freezing at higher elevations. We suggest that strong summer down-valley winds may have been responsible for the generation of large glacial lakes during the Last Glacial Maximum when ice core records recorded annual temperatures significantly colder than present. Close

• 42. [Article] Cenozoic biogenic silica sedimentation in the Antarctic Ocean, based on two deep sea drilling project sites

  The Antarctic Ocean during the Cenozoic experienced four periods of increased surface productivity: the Middle Eocene; the beginning of the Miocene; the Middle Miocene; and near the Miocene-Pliocene boundary. ...

  Citation × Citation Citation Abstract Copy Title: Cenozoic biogenic silica sedimentation in the Antarctic Ocean, based on two deep sea drilling project sites Author: Brewster, Nancy Ann The Antarctic Ocean during the Cenozoic experienced four periods of increased surface productivity: the Middle Eocene; the beginning of the Miocene; the Middle Miocene; and near the Miocene-Pliocene boundary. The fourth increase in productivity began five million years ago and has since progressively increased to the present level of intense surface productivity. The major control of Antarctic surface productivity is climate. Opal production in the Neogene increased during glacial times, due to the intensification of upwelling south of the Polar Front, caused from accelerated atmospheric circulation and an increased volume production of Antarctic Bottom Water. Cenozoic variations in surface productivity are also related to the tectonic changes in the Antarctic Ocean basin, which altered the patterns of surface and thermohaline circulation. Antarctic Surface Waters became more conducive to biological productivity with the progressive latitudinal and thermal isolation of Antarctica, The efficiency of surface productivity has progressed to such an extent that much of the global silica supply has been transferred to the Antarctic at the expense of other productive oceanic regions such as the Central Equatorial Pacific. In the Neogene, the preservation or dissolution of calcium carbonate is influenced by the rate of upwelling south of the Polar Front. During glacial times, the upwelling of COB_rich Circumpolar Deep Water accelerates and effectively raises the calcite compensation depth. Title: Cenozoic biogenic silica sedimentation in the Antarctic Ocean, based on two deep sea drilling project sites Author: Brewster, Nancy Ann The Antarctic Ocean during the Cenozoic experienced four periods of increased surface productivity: the Middle Eocene; the beginning of the Miocene; the Middle Miocene; and near the Miocene-Pliocene boundary. The fourth increase in productivity began five million years ago and has since progressively increased to the present level of intense surface productivity. The major control of Antarctic surface productivity is climate. Opal production in the Neogene increased during glacial times, due to the intensification of upwelling south of the Polar Front, caused from accelerated atmospheric circulation and an increased volume production of Antarctic Bottom Water. Cenozoic variations in surface productivity are also related to the tectonic changes in the Antarctic Ocean basin, which altered the patterns of surface and thermohaline circulation. Antarctic Surface Waters became more conducive to biological productivity with the progressive latitudinal and thermal isolation of Antarctica, The efficiency of surface productivity has progressed to such an extent that much of the global silica supply has been transferred to the Antarctic at the expense of other productive oceanic regions such as the Central Equatorial Pacific. In the Neogene, the preservation or dissolution of calcium carbonate is influenced by the rate of upwelling south of the Polar Front. During glacial times, the upwelling of COB_rich Circumpolar Deep Water accelerates and effectively raises the calcite compensation depth. Close

• 43. [Article] Origin of the Tucannon phase in Lower Snake River prehistory

  Approximately 5,500 years ago a discreet period of wetter and cooler environmental conditions prevailed across the southern Columbia Plateau. This period was marked by the first prominent episodes of erosion ...

  Citation × Citation Citation Abstract Copy Title: Origin of the Tucannon phase in Lower Snake River prehistory Author: Lucas, Steven W. Approximately 5,500 years ago a discreet period of wetter and cooler environmental conditions prevailed across the southern Columbia Plateau. This period was marked by the first prominent episodes of erosion to occur along the lower Snake River following the height of the Altithermal and eruption of Mt. Mazama during the mid post-glacial. In addition to the reactivation of small stream courses choked with debris and sediment, large stream channels began downcutting and scouring older terrace faces incorporated with large accumulations of Mazama ash. The resulting degradation of aquatic habitats forced concurrent changes within human economies adapted to the local riverine-environments. These adjustments reported for the Tucannon phase time period along the lower Snake River are notable and demonstrate the degree to which Cascade phase culture was unsuccessful in coping with environmental instability at the end of the Altithermal time period. This successionary event has demonstratively become the most significant post-glacial, qualitative change to occur in the lifeways of lower Snake River people prior to Euro-American influence. Title: Origin of the Tucannon phase in Lower Snake River prehistory Author: Lucas, Steven W. Approximately 5,500 years ago a discreet period of wetter and cooler environmental conditions prevailed across the southern Columbia Plateau. This period was marked by the first prominent episodes of erosion to occur along the lower Snake River following the height of the Altithermal and eruption of Mt. Mazama during the mid post-glacial. In addition to the reactivation of small stream courses choked with debris and sediment, large stream channels began downcutting and scouring older terrace faces incorporated with large accumulations of Mazama ash. The resulting degradation of aquatic habitats forced concurrent changes within human economies adapted to the local riverine-environments. These adjustments reported for the Tucannon phase time period along the lower Snake River are notable and demonstrate the degree to which Cascade phase culture was unsuccessful in coping with environmental instability at the end of the Altithermal time period. This successionary event has demonstratively become the most significant post-glacial, qualitative change to occur in the lifeways of lower Snake River people prior to Euro-American influence. Close

• 44. [Article] The changing glaciers of Mt. Hood, Oregon and Mt. Rainier, Washington : implications for periglacial debris flows

  Mountain glaciers are receding worldwide with numerous consequences including changing hydrology and geomorphology. This study focuses on changes in glacier area on Mt. Hood, Oregon and Mt. Rainier, Washington ...

  Citation × Citation Citation Abstract Copy Title: The changing glaciers of Mt. Hood, Oregon and Mt. Rainier, Washington : implications for periglacial debris flows Author: Ellinger, Jonathan R. Mountain glaciers are receding worldwide with numerous consequences including changing hydrology and geomorphology. This study focuses on changes in glacier area on Mt. Hood, Oregon and Mt. Rainier, Washington where damaging debris flows have occurred in glaciated basins. Landsat imagery is used to map debris-free ice on a decadal time scale from 1987 to 2005. Debris-free glacier ice is clearly delineated using a ratio of Landsat spectral bands in the near-infrared part of the spectrum (bands 4 & 5). Landsat scenes were chosen during the months of September and October to minimize snow cover left over from the accumulation season and maximize exposure of debris-free glacial ice. SNOTEL data were also used to find the lowest snow year for each decade to minimize the potential of misclassifying remnant snow as glacial ice. Changes in debris-free ice are mapped to produce the most up-to-date rates of glacier retreat. Average glacial slopes, derived from airborne LiDAR data are used to compute slope corrected debris-free ice areas for all glaciers. A threshold value for the Landsat NDGI scenes was selected based on threshold testing on the Eliot and Reid glaciers on Mt. Hood. Contradicting earlier studies that say the glaciers on Mt. Hood are receding faster than the glaciers on Mt. Rainier, results show that from 1987 to 2005 Mt. Rainier and Mt. Hood lost similar amounts of debris-free ice extent at 14.0% and 13.9%, respectively. For both Mt. Hood and Mt. Rainier the change in slope corrected debris-free ice area was greater than that of the projected area change due to the steep slopes of both mountains. For Mt. Rainier an increase in recession rate was shown from 1992-2005 compared to 1987-1992 while on Mt. Hood the opposite is seen. On Mt. Rainier it was found that highly fragmented glaciers at lower elevations such as the Inter, Pyramid, and the Van Trump Glaciers lost the highest percent of their original 1987 ice extent and were also shown to be associated with new debris flows in 2006. On Mt. Hood none of the 2006 debris flows initiated within zones of recent glacial recession, however, all debris flows from 2006 originated from streams with a direct connection to glaciers. The Newton Clark Glacier, having lost the most coverage of debris-free ice from 1987 to 2005, is also associated with the highest number of debris-flows in its drainage since 1980. Precipitation data for both mountains show no trend but there was a statistically significant increase in summer air temperature at Mt. Hood over the period 1984-2009. This study suggests that glaciers may play a role in the location of initiation sites, of debris flows, but there is not enough evidence to argue that glacier recession is responsible for producing debris flows. Title: The changing glaciers of Mt. Hood, Oregon and Mt. Rainier, Washington : implications for periglacial debris flows Author: Ellinger, Jonathan R. Mountain glaciers are receding worldwide with numerous consequences including changing hydrology and geomorphology. This study focuses on changes in glacier area on Mt. Hood, Oregon and Mt. Rainier, Washington where damaging debris flows have occurred in glaciated basins. Landsat imagery is used to map debris-free ice on a decadal time scale from 1987 to 2005. Debris-free glacier ice is clearly delineated using a ratio of Landsat spectral bands in the near-infrared part of the spectrum (bands 4 & 5). Landsat scenes were chosen during the months of September and October to minimize snow cover left over from the accumulation season and maximize exposure of debris-free glacial ice. SNOTEL data were also used to find the lowest snow year for each decade to minimize the potential of misclassifying remnant snow as glacial ice. Changes in debris-free ice are mapped to produce the most up-to-date rates of glacier retreat. Average glacial slopes, derived from airborne LiDAR data are used to compute slope corrected debris-free ice areas for all glaciers. A threshold value for the Landsat NDGI scenes was selected based on threshold testing on the Eliot and Reid glaciers on Mt. Hood. Contradicting earlier studies that say the glaciers on Mt. Hood are receding faster than the glaciers on Mt. Rainier, results show that from 1987 to 2005 Mt. Rainier and Mt. Hood lost similar amounts of debris-free ice extent at 14.0% and 13.9%, respectively. For both Mt. Hood and Mt. Rainier the change in slope corrected debris-free ice area was greater than that of the projected area change due to the steep slopes of both mountains. For Mt. Rainier an increase in recession rate was shown from 1992-2005 compared to 1987-1992 while on Mt. Hood the opposite is seen. On Mt. Rainier it was found that highly fragmented glaciers at lower elevations such as the Inter, Pyramid, and the Van Trump Glaciers lost the highest percent of their original 1987 ice extent and were also shown to be associated with new debris flows in 2006. On Mt. Hood none of the 2006 debris flows initiated within zones of recent glacial recession, however, all debris flows from 2006 originated from streams with a direct connection to glaciers. The Newton Clark Glacier, having lost the most coverage of debris-free ice from 1987 to 2005, is also associated with the highest number of debris-flows in its drainage since 1980. Precipitation data for both mountains show no trend but there was a statistically significant increase in summer air temperature at Mt. Hood over the period 1984-2009. This study suggests that glaciers may play a role in the location of initiation sites, of debris flows, but there is not enough evidence to argue that glacier recession is responsible for producing debris flows. Close

• 45. [Article] Late Quaternary paleoceanography in the Eastern Equatorial Pacific Ocean from Planktonic Foraminifiers : a high-resolution record from Site 846

  High-resolution records of δ¹⁸0 and relative abundances of planktonic foraminifers were generated for ODP Leg 138 Site 846 for the past 800 k.y., with an average sampling interval of 3.6 k.y. The time ...

  Citation × Citation Citation Abstract Copy Title: Late Quaternary paleoceanography in the Eastern Equatorial Pacific Ocean from Planktonic Foraminifiers : a high-resolution record from Site 846 Author: Shackleton, N.J., Le, J., Mix, Alan C. High-resolution records of δ¹⁸0 and relative abundances of planktonic foraminifers were generated for ODP Leg 138 Site 846 for the past 800 k.y., with an average sampling interval of 3.6 k.y. The time scale was constructed by correlating the benthic δ¹⁸0 record to the SPECMAP and ODP Site 677 δ¹⁸0 time scales using the mapping function technique of Martinson et al. (1981). Our observations show that variations in the foraminiferal assemblages, although influenced by dissolution, are interpretable in terms of changing characteristics of upper ocean waters. Carbonate dissolution as indicated by fragmentation of planktonic foraminifers shows concentrated variance that is coherent with δ¹⁸0 at the 100 and 41 k.y. orbital periods. At these periods, maximum dissolution occurs during interglacial extremes. This finding differs from previous studies that have indicated that in this region percent carbonate minimum lags global ice volume minimum. N. dutertrei and dextral N. pachyderma dominate the assemblages, but do not show consistent relationships relative to glacial-interglacial cycles. However, less abundant species G. ruber, G. menardii, G. glutinata and G. sacculifer show positive and G. bulloides negative correlation with the δ¹⁸0 record. Q-mode factor analysis of the Site 846 assemblages and comparison with modern assemblages suggest the following. Prior to and during interglacials, the area was considerably warmer and more subtropical than at present; during glacials, the area was colder than at present with greater upwelling and advection off the eastern boundary, and possibly a stronger Peru Current; the equatorial “cool tongue” was also possibly stronger. Title: Late Quaternary paleoceanography in the Eastern Equatorial Pacific Ocean from Planktonic Foraminifiers : a high-resolution record from Site 846 Author: Shackleton, N.J., Le, J., Mix, Alan C. High-resolution records of δ¹⁸0 and relative abundances of planktonic foraminifers were generated for ODP Leg 138 Site 846 for the past 800 k.y., with an average sampling interval of 3.6 k.y. The time scale was constructed by correlating the benthic δ¹⁸0 record to the SPECMAP and ODP Site 677 δ¹⁸0 time scales using the mapping function technique of Martinson et al. (1981). Our observations show that variations in the foraminiferal assemblages, although influenced by dissolution, are interpretable in terms of changing characteristics of upper ocean waters. Carbonate dissolution as indicated by fragmentation of planktonic foraminifers shows concentrated variance that is coherent with δ¹⁸0 at the 100 and 41 k.y. orbital periods. At these periods, maximum dissolution occurs during interglacial extremes. This finding differs from previous studies that have indicated that in this region percent carbonate minimum lags global ice volume minimum. N. dutertrei and dextral N. pachyderma dominate the assemblages, but do not show consistent relationships relative to glacial-interglacial cycles. However, less abundant species G. ruber, G. menardii, G. glutinata and G. sacculifer show positive and G. bulloides negative correlation with the δ¹⁸0 record. Q-mode factor analysis of the Site 846 assemblages and comparison with modern assemblages suggest the following. Prior to and during interglacials, the area was considerably warmer and more subtropical than at present; during glacials, the area was colder than at present with greater upwelling and advection off the eastern boundary, and possibly a stronger Peru Current; the equatorial “cool tongue” was also possibly stronger. Close

• 46. [Article] Increased dissolved terrestrial input to the coastal ocean during the last deglaciation

  Copyrighted by American Geophysical Union.

  Citation × Citation Citation Abstract Copy Title: Increased dissolved terrestrial input to the coastal ocean during the last deglaciation Author: Haley, B. A., Klinkhammer, Gary P., Mix, Alan C. Copyrighted by American Geophysical Union. Title: Increased dissolved terrestrial input to the coastal ocean during the last deglaciation Author: Haley, B. A., Klinkhammer, Gary P., Mix, Alan C. Copyrighted by American Geophysical Union. Close

• 47. [Article] Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska

  Sediment storage in and release from the Granite Creek catchment over Holocene timescales is modulated by the fluctuations of Tana Glacier, which periodically blocks the outlet of Granite Creek. Little ...

  Citation × Citation Citation Abstract Copy Title: Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska Author: Blair, Mehgan O'Hearn Sediment storage in and release from the Granite Creek catchment over Holocene timescales is modulated by the fluctuations of Tana Glacier, which periodically blocks the outlet of Granite Creek. Little Ice Age expansion from 1500-1900 AD is suggested by lichenometric ages of alpine glacial moraines within Granite Creek valley. Trimlines above the Tana Glacier terminus indicate that, during this period, ice was at least 120 m thicker in the Tana Valley. According to the elevation of shorelines within the valley, the resultant ice-dammed lake occupied 50 km2 in the lower -10 km of Granite Creek valley, contained 5.9 km3 of water, and was at least 90 m deep at its maximum. Removal of the ice dam occurred during twentieth century thinning of Tana Glacier and caused a 100-m drop in the base level of Granite Creek, driving evacuation of lacustrine valley fill. The reestablishment of the fluvial system was characterized by lateral migration of Granite Creek and formation of a series of paired terraces, indicating a on-catastrophic and possibly seasonal drainage of the lake. Roughly 1.3 x 10" ms of stored sediment has been removed from the basin since drainage of the lake. Radiocarbon ages within the valley fill reveal an unconformity between overlying sediment deposited during the Little Ice Age and underlying, older sediment dating to --900 yrs B.P. Two episodes of impoundment and lacustrine deposition in the basin occurred during the mid-late Holocene and may have been separated by a period of incomplete evacuation of the valley fill. These observations reveal that sediment production within, and sediment delivery gut of this catchment are out of phase, which is characteristic of paraglacial landscape response following deglaciation. In southern Alaska, paraglacial landscape adjustment may explain the discrepancy between erosion rates estimated from short-term sediment yields and those from long-term exhumation rates. It is clear that the interpretation of sediment yields requires consideration of all sources of eroded sediment, including stored material, on a variety of timescales. Title: Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska Author: Blair, Mehgan O'Hearn Sediment storage in and release from the Granite Creek catchment over Holocene timescales is modulated by the fluctuations of Tana Glacier, which periodically blocks the outlet of Granite Creek. Little Ice Age expansion from 1500-1900 AD is suggested by lichenometric ages of alpine glacial moraines within Granite Creek valley. Trimlines above the Tana Glacier terminus indicate that, during this period, ice was at least 120 m thicker in the Tana Valley. According to the elevation of shorelines within the valley, the resultant ice-dammed lake occupied 50 km2 in the lower -10 km of Granite Creek valley, contained 5.9 km3 of water, and was at least 90 m deep at its maximum. Removal of the ice dam occurred during twentieth century thinning of Tana Glacier and caused a 100-m drop in the base level of Granite Creek, driving evacuation of lacustrine valley fill. The reestablishment of the fluvial system was characterized by lateral migration of Granite Creek and formation of a series of paired terraces, indicating a on-catastrophic and possibly seasonal drainage of the lake. Roughly 1.3 x 10" ms of stored sediment has been removed from the basin since drainage of the lake. Radiocarbon ages within the valley fill reveal an unconformity between overlying sediment deposited during the Little Ice Age and underlying, older sediment dating to --900 yrs B.P. Two episodes of impoundment and lacustrine deposition in the basin occurred during the mid-late Holocene and may have been separated by a period of incomplete evacuation of the valley fill. These observations reveal that sediment production within, and sediment delivery gut of this catchment are out of phase, which is characteristic of paraglacial landscape response following deglaciation. In southern Alaska, paraglacial landscape adjustment may explain the discrepancy between erosion rates estimated from short-term sediment yields and those from long-term exhumation rates. It is clear that the interpretation of sediment yields requires consideration of all sources of eroded sediment, including stored material, on a variety of timescales. Close

• 48. [Article] The Holocene History of Nares Strait: Transition from Glacial Bay to Arctic-Atlantic Throughflow

  This is the publisher's version of record. The original submission is copyrighted by Oceanography Society and can be found here: http://www.tos.org/

  Citation × Citation Citation Abstract Copy Title: The Holocene History of Nares Strait: Transition from Glacial Bay to Arctic-Atlantic Throughflow Author: Francus, Pierre, Sheldon, Christina, Andrews, John, Stoner, Joseph, Cronin, Thomas M., Jennings, Anne E. This is the publisher's version of record. The original submission is copyrighted by Oceanography Society and can be found here: http://www.tos.org/ Title: The Holocene History of Nares Strait: Transition from Glacial Bay to Arctic-Atlantic Throughflow Author: Francus, Pierre, Sheldon, Christina, Andrews, John, Stoner, Joseph, Cronin, Thomas M., Jennings, Anne E. This is the publisher's version of record. The original submission is copyrighted by Oceanography Society and can be found here: http://www.tos.org/ Close

• 49. [Article] Thorium-230 normalized particle flux and sediment focusing in the Panama Basin region during the last 30,000 years

  Copyright 2007 by the American Geophysical Union

  Citation × Citation Citation Abstract Copy Title: Thorium-230 normalized particle flux and sediment focusing in the Panama Basin region during the last 30,000 years Author: Francois, R., Kienast, M., Calvert, S. E., Kienast, S. S., Mix, Alan C. Copyright 2007 by the American Geophysical Union Title: Thorium-230 normalized particle flux and sediment focusing in the Panama Basin region during the last 30,000 years Author: Francois, R., Kienast, M., Calvert, S. E., Kienast, S. S., Mix, Alan C. Copyright 2007 by the American Geophysical Union Close

• 50. [Article] Eastern Pacific Warm Pool paleosalinity and climate variability: 0–30 kyr

  Multiproxy geologic records of δ18O and Mg/Ca in fossil foraminifera from sediments under the Eastern Pacific Warm Pool (EPWP) region west of Central America document variations in upper ocean temperature, ...

  Citation × Citation Citation Abstract Copy Title: Eastern Pacific Warm Pool paleosalinity and climate variability: 0–30 kyr Author: Haley, Brian A., Benway, Heather M., Mix, Alan C., Klinkhammer, Gary P. Multiproxy geologic records of δ18O and Mg/Ca in fossil foraminifera from sediments under the Eastern Pacific Warm Pool (EPWP) region west of Central America document variations in upper ocean temperature, pycnocline strength, and salinity (i.e., net precipitation) over the past 30 kyr. Although evident in the paleotemperature record, there is no glacial-interglacial difference in paleosalinity, suggesting that tropical hydrologic changes do not respond passively to high-latitude ice sheets and oceans. Millennial variations in paleosalinity with amplitudes as high as ~4 practical salinity units occur with a dominant period of ~3–5 ky during the glacial/deglacial interval and ~1.0–1.5 ky during the Holocene. The amplitude of the EPWP paleosalinity changes greatly exceeds that of published Caribbean and western tropical Pacific paleosalinity records. EPWP paleosalinity changes correspond to millennial-scale climate changes in the surface and deep Atlantic and the high northern latitudes, with generally higher (lower) paleosalinity during cold (warm) events. In addition to Intertropical Convergence Zone (ITCZ) dynamics, which play an important role in tropical hydrologic variability, changes in Atlantic-Pacific moisture transport, which is closely linked to ITCZ dynamics, may also contribute to hydrologic variations in the EPWP. Calculations of interbasin salinity average and interbasin salinity contrast between the EPWP and the Caribbean help differentiate long-term changes in mean ITCZ position and Atlantic-Pacific moisture transport, respectively. Title: Eastern Pacific Warm Pool paleosalinity and climate variability: 0–30 kyr Author: Haley, Brian A., Benway, Heather M., Mix, Alan C., Klinkhammer, Gary P. Multiproxy geologic records of δ18O and Mg/Ca in fossil foraminifera from sediments under the Eastern Pacific Warm Pool (EPWP) region west of Central America document variations in upper ocean temperature, pycnocline strength, and salinity (i.e., net precipitation) over the past 30 kyr. Although evident in the paleotemperature record, there is no glacial-interglacial difference in paleosalinity, suggesting that tropical hydrologic changes do not respond passively to high-latitude ice sheets and oceans. Millennial variations in paleosalinity with amplitudes as high as ~4 practical salinity units occur with a dominant period of ~3–5 ky during the glacial/deglacial interval and ~1.0–1.5 ky during the Holocene. The amplitude of the EPWP paleosalinity changes greatly exceeds that of published Caribbean and western tropical Pacific paleosalinity records. EPWP paleosalinity changes correspond to millennial-scale climate changes in the surface and deep Atlantic and the high northern latitudes, with generally higher (lower) paleosalinity during cold (warm) events. In addition to Intertropical Convergence Zone (ITCZ) dynamics, which play an important role in tropical hydrologic variability, changes in Atlantic-Pacific moisture transport, which is closely linked to ITCZ dynamics, may also contribute to hydrologic variations in the EPWP. Calculations of interbasin salinity average and interbasin salinity contrast between the EPWP and the Caribbean help differentiate long-term changes in mean ITCZ position and Atlantic-Pacific moisture transport, respectively. Close