- Email: [email protected]
The late Pleistocene pluvial history of surprise valley, California
Abstracts / Quaternary International 387 (2015) 131e150
Institute, University of California, Santa Barbara, CA 93106, USA; d LDEO, Columbia University, New York, NY 10964, USA. E-mail address: [email protected].
Southern California has a Mediterranean type climate characterized by warm dry summers associated with the seasonal position of the North Pacific high pressure system and cool, wet winters primarily associated with cyclonic storms originating in low pressure systems in the high latitude North Pacific. Winter storm activity is reduced during negative phases of the Pacific Decadal Oscillation (PDO). Extreme precipitation events in the region, however, occur when strong zonal flow brings warm, moist tropical air across the Pacific (atmospheric rivers), often in associa~ o. Here we present an annually resolved reconstruction of tion with El Nin riverine input into Santa Barbara Basin (SBB) during the Medieval Climate Anomaly (MCA) transition into the Little Ice Age (LIA) based on scanning XRF elemental composition of bulk sediments (AD 800 to 1500). The first Principle Component (PC1) of the elemental data contains high loadings of Ti, K, Al, Si, Rb, and Fe, and explains 40% of the variance in kasten core SPR0901-03KC. We associate PC1 with siliciclastic sediment delivered to SBB by river runoff. Therefore, low PC1 values are interpreted as reduced river runoff as precipitation decreased during droughts. Droughts indicated by the elemental composition of SBB sediments were centered at AD 870, 970, 1140, 1300, and 1450. The dry conditions of the MCA were terminated by flood events at ~AD 1270, 1380, and 1530. Additionally the transition from the MCA to the LIA was associated with a dramatic increase in the abundance of the subpolar planktonic foraminiferal species Neogloboquadrina pachyderma (sinistral). Although variable, this interval is characterized by a foraminiferal species preferring water <10 C lasting from ~AD 1250 to 1330 with peak abundances of 42% at ~AD 1260. A brief increase in subtropical planktonic foraminferal species occurred between ~AD 1350 and 1420 before the foraminiferal assemblage shifted toward cooler subpolar species again at ~AD 1450. Negative PDO has been suggested for AD 1285e1300 (MacDonald and Case, 2005) while strong El ~ o events have been proposed for the late 13th century (Mann and Jones, Nin 2003). These changes in interannual variability follow three major volcanic eruptions occurring between AD 1258 and 1270 that are recorded in ice core aerosols and have been linked in cooling in Europe (Stothers, 2000). MacDonald, G.M., Case, R.A., 2005. Variations in the Pacific Decadal Oscillation over the past millennium: Geophysical Research Letters 32 (8). Mann, M.E., Jones, P.D., 2003. Global surface temperatures over the past two millennia: Geophysical Research Letters 30 (15). Stothers, R.B., 2000. Climatic and demographic consequences of the massive volcanic eruption of 1258. Climatic Change, 45, 361e374.
MULTI-DECADAL VARIATION IN SOUTHERN CALIFORNIA DROUGHT DURING THE MEDIEVAL CLIMATE ANOMALY AND LITTLE ICE AGE (~AD 800e~AD 1600): EVIDENCE FROM COEVAL TERRESTRIAL AND MARINE PROXIES Linda E. Heusser a, Ingrid E. Hendy b, John A. Barron c, Dorothy Pak d. LDEO, Columbia University, Palisades, NY 10962, USA; b Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109, USA; c US Geological Survey, MS910, Menlo Park, CA 94025, USA; d Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.
a
E-mail address: [email protected], [email protected], [email protected], [email protected].
High-resolution studies of precipitation proxies (pollen from coastal, droughtresistant chaparral and upslope mesic oak-pine woodlands, and bulk sediment Ti%) from sediments deposited in Santa Barbara Basin (SPR0901-02KC; 3416.845N, 120 02.332W, water depth 588 m) reflect decadal-scale fluctuations in persistent severe drought spanning from ~AD 800 to 1270. Pollen from chamise and manzanita chaparrals (sclerophyllous woody shrubs dominated by Adenostoma and Arctostaphylos) begins to decline at ~AD 1265, while oak-pine woodlands begin to increase at ~AD 1211 reaching a maximum between ~AD 1500e~1600. Termination of the last major drought in our record coincides with that of major drought events elsewhere in the
137
West (Stine, 1994; Cook et al., 2004), and marks the beginning of gradual, fluctuating increases in precipitation and in coastal southern California mesic, oak-dominated communities. Offshore, diatom, oxygen isotopes, and planktonic foraminifera data imply cold spring and warm winter sea surface temperatures during the Medieval Climate Anomaly (MCA) that reverse in the Little Ice Age (LIA). These major climate-driven changes in southern California and Santa Barbara Basin are consistent with changes in northern hemisphere circulation, i.e., weakened Arctic lows, strengthened North Pacific ~ a-like conditions during the MCA and strengthhighs and extended La Nin ened Aleutian lows, weakened and westward North Pacific highs and ~ o-like atmospheric conditions during the LIA. extended El Nin Cook, E.R., Woodhouse, C.A., Eakin, C.M., Meko, D.M., Stahle, D.W., 2004. Long-term aridity changes in the western United States. Science, 306 (5698), 1015e1018. Stine, S., 1994. Extreme and persistent drought in California and Patagonia during mediaeval time. Nature 369, 546e549.
THE LATE PLEISTOCENE PLUVIAL HISTORY OF SURPRISE VALLEY, CALIFORNIA Daniel E. Ibarra a, Anne E. Egger b, Kate Maher a. a Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305, USA; b Department of Geological Sciences, Central Washington University, Ellensburg, WA 98926, USA. E-mail address: [email protected].
Motivated by the potential for dramatic future hydrologic changes, studies that investigate the transitions between Earth's different climate states have the potential to enhance our understanding of the modern climate system and potential future variability. The interval surrounding the Last Glacial Maximum (LGM) represents a period when Earth's boundary conditions, greenhouse gas concentrations and orbital parameters were substantially different than today, and thus reconstruction of climate at the LGM provides a key test for climate models. Our study examines the performance of the Paleoclimate Model Intercomparison Project 3 (PMIP3) simulations to a lake shoreline record in an effort to better reconstruct changes in the hydrologic cycle over the western United States during the LGM. To enhance the spatial coverage of lake level records in the western United States, we investigated the timing and magnitude of the most recent pluvial lake cycle at Surprise Valley, California, a valley inferred from modern topography to be isolated during the late Pleistocene. To investigate the paleohydrology of Lake Surprise we combine 230Th-U and radiocarbon ages with d18O, d13C, and Sr/Ca measurements of shoreline tufa deposits. This new lake record, spanning the last glacial cycle,places lake level 180 and 100 m above present day playa, at 13,900 ± 1200 and 22,500 ± 4600 cal yr BP, respectively. Modeling of isostasy suggests that contributions from crustal flexure during the late Pleistocene were minor, reaching 11 m at most. Combined isotopic and hydrologic modeling of Lake Surprise indicates that annual precipitation may have increased by as much as 164% and 24%, relative to modern, during the lake highstand and the LGM, respectively. We compare our results to PMIP3 climate model simulations of the LGM (21,000 yr BP). Most PMIP3 models predict varying amounts of increased precipitation during the LGM for Surprise Valley, with an ensemble average predicting a precipitation increase of 14% relative to modern.
DEGLACIAL HYDROCLIMATES ACROSS THE COASTAL SOUTHWEST UNITED STATES INTO THE INTERIOR SOUTHWEST UNITED STATES, INCLUDING NORTHWEST MEXICO: TIMING, PHASING, AND FORCINGS Matthew E. Kirby a, Sarah J. Feakins b, Nicole Bonuso a, Joanna M. Fantozzi a, Christine A. Hiner a. a Department of Geological Sciences, California State University, Fullerton, CA 92834, USA; b Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089, USA. E-mail address: [email protected], [email protected].
Understanding the patterns and causes of the last deglaciation offers insights into how climate changes under abrupt global climate forcings. This
Institute, University of California, Santa Barbara, CA 93106, USA; d LDEO, Columbia University, New York, NY 10964, USA. E-mail address: [email protected].
Southern California has a Mediterranean type climate characterized by warm dry summers associated with the seasonal position of the North Pacific high pressure system and cool, wet winters primarily associated with cyclonic storms originating in low pressure systems in the high latitude North Pacific. Winter storm activity is reduced during negative phases of the Pacific Decadal Oscillation (PDO). Extreme precipitation events in the region, however, occur when strong zonal flow brings warm, moist tropical air across the Pacific (atmospheric rivers), often in associa~ o. Here we present an annually resolved reconstruction of tion with El Nin riverine input into Santa Barbara Basin (SBB) during the Medieval Climate Anomaly (MCA) transition into the Little Ice Age (LIA) based on scanning XRF elemental composition of bulk sediments (AD 800 to 1500). The first Principle Component (PC1) of the elemental data contains high loadings of Ti, K, Al, Si, Rb, and Fe, and explains 40% of the variance in kasten core SPR0901-03KC. We associate PC1 with siliciclastic sediment delivered to SBB by river runoff. Therefore, low PC1 values are interpreted as reduced river runoff as precipitation decreased during droughts. Droughts indicated by the elemental composition of SBB sediments were centered at AD 870, 970, 1140, 1300, and 1450. The dry conditions of the MCA were terminated by flood events at ~AD 1270, 1380, and 1530. Additionally the transition from the MCA to the LIA was associated with a dramatic increase in the abundance of the subpolar planktonic foraminiferal species Neogloboquadrina pachyderma (sinistral). Although variable, this interval is characterized by a foraminiferal species preferring water <10 C lasting from ~AD 1250 to 1330 with peak abundances of 42% at ~AD 1260. A brief increase in subtropical planktonic foraminferal species occurred between ~AD 1350 and 1420 before the foraminiferal assemblage shifted toward cooler subpolar species again at ~AD 1450. Negative PDO has been suggested for AD 1285e1300 (MacDonald and Case, 2005) while strong El ~ o events have been proposed for the late 13th century (Mann and Jones, Nin 2003). These changes in interannual variability follow three major volcanic eruptions occurring between AD 1258 and 1270 that are recorded in ice core aerosols and have been linked in cooling in Europe (Stothers, 2000). MacDonald, G.M., Case, R.A., 2005. Variations in the Pacific Decadal Oscillation over the past millennium: Geophysical Research Letters 32 (8). Mann, M.E., Jones, P.D., 2003. Global surface temperatures over the past two millennia: Geophysical Research Letters 30 (15). Stothers, R.B., 2000. Climatic and demographic consequences of the massive volcanic eruption of 1258. Climatic Change, 45, 361e374.
MULTI-DECADAL VARIATION IN SOUTHERN CALIFORNIA DROUGHT DURING THE MEDIEVAL CLIMATE ANOMALY AND LITTLE ICE AGE (~AD 800e~AD 1600): EVIDENCE FROM COEVAL TERRESTRIAL AND MARINE PROXIES Linda E. Heusser a, Ingrid E. Hendy b, John A. Barron c, Dorothy Pak d. LDEO, Columbia University, Palisades, NY 10962, USA; b Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109, USA; c US Geological Survey, MS910, Menlo Park, CA 94025, USA; d Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.
a
E-mail address: [email protected], [email protected], [email protected], [email protected].
High-resolution studies of precipitation proxies (pollen from coastal, droughtresistant chaparral and upslope mesic oak-pine woodlands, and bulk sediment Ti%) from sediments deposited in Santa Barbara Basin (SPR0901-02KC; 3416.845N, 120 02.332W, water depth 588 m) reflect decadal-scale fluctuations in persistent severe drought spanning from ~AD 800 to 1270. Pollen from chamise and manzanita chaparrals (sclerophyllous woody shrubs dominated by Adenostoma and Arctostaphylos) begins to decline at ~AD 1265, while oak-pine woodlands begin to increase at ~AD 1211 reaching a maximum between ~AD 1500e~1600. Termination of the last major drought in our record coincides with that of major drought events elsewhere in the
137
West (Stine, 1994; Cook et al., 2004), and marks the beginning of gradual, fluctuating increases in precipitation and in coastal southern California mesic, oak-dominated communities. Offshore, diatom, oxygen isotopes, and planktonic foraminifera data imply cold spring and warm winter sea surface temperatures during the Medieval Climate Anomaly (MCA) that reverse in the Little Ice Age (LIA). These major climate-driven changes in southern California and Santa Barbara Basin are consistent with changes in northern hemisphere circulation, i.e., weakened Arctic lows, strengthened North Pacific ~ a-like conditions during the MCA and strengthhighs and extended La Nin ened Aleutian lows, weakened and westward North Pacific highs and ~ o-like atmospheric conditions during the LIA. extended El Nin Cook, E.R., Woodhouse, C.A., Eakin, C.M., Meko, D.M., Stahle, D.W., 2004. Long-term aridity changes in the western United States. Science, 306 (5698), 1015e1018. Stine, S., 1994. Extreme and persistent drought in California and Patagonia during mediaeval time. Nature 369, 546e549.
THE LATE PLEISTOCENE PLUVIAL HISTORY OF SURPRISE VALLEY, CALIFORNIA Daniel E. Ibarra a, Anne E. Egger b, Kate Maher a. a Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305, USA; b Department of Geological Sciences, Central Washington University, Ellensburg, WA 98926, USA. E-mail address: [email protected].
Motivated by the potential for dramatic future hydrologic changes, studies that investigate the transitions between Earth's different climate states have the potential to enhance our understanding of the modern climate system and potential future variability. The interval surrounding the Last Glacial Maximum (LGM) represents a period when Earth's boundary conditions, greenhouse gas concentrations and orbital parameters were substantially different than today, and thus reconstruction of climate at the LGM provides a key test for climate models. Our study examines the performance of the Paleoclimate Model Intercomparison Project 3 (PMIP3) simulations to a lake shoreline record in an effort to better reconstruct changes in the hydrologic cycle over the western United States during the LGM. To enhance the spatial coverage of lake level records in the western United States, we investigated the timing and magnitude of the most recent pluvial lake cycle at Surprise Valley, California, a valley inferred from modern topography to be isolated during the late Pleistocene. To investigate the paleohydrology of Lake Surprise we combine 230Th-U and radiocarbon ages with d18O, d13C, and Sr/Ca measurements of shoreline tufa deposits. This new lake record, spanning the last glacial cycle,places lake level 180 and 100 m above present day playa, at 13,900 ± 1200 and 22,500 ± 4600 cal yr BP, respectively. Modeling of isostasy suggests that contributions from crustal flexure during the late Pleistocene were minor, reaching 11 m at most. Combined isotopic and hydrologic modeling of Lake Surprise indicates that annual precipitation may have increased by as much as 164% and 24%, relative to modern, during the lake highstand and the LGM, respectively. We compare our results to PMIP3 climate model simulations of the LGM (21,000 yr BP). Most PMIP3 models predict varying amounts of increased precipitation during the LGM for Surprise Valley, with an ensemble average predicting a precipitation increase of 14% relative to modern.
DEGLACIAL HYDROCLIMATES ACROSS THE COASTAL SOUTHWEST UNITED STATES INTO THE INTERIOR SOUTHWEST UNITED STATES, INCLUDING NORTHWEST MEXICO: TIMING, PHASING, AND FORCINGS Matthew E. Kirby a, Sarah J. Feakins b, Nicole Bonuso a, Joanna M. Fantozzi a, Christine A. Hiner a. a Department of Geological Sciences, California State University, Fullerton, CA 92834, USA; b Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089, USA. E-mail address: [email protected], [email protected].
Understanding the patterns and causes of the last deglaciation offers insights into how climate changes under abrupt global climate forcings. This