- Email: [email protected]
The late Holocene drought: A persistent dry period between 2800 and 1800 cal yr BP across the central Great Basin
Abstracts / Quaternary International 387 (2015) 131e150
reconstructions hint that variability during the observed period captures moderate-to-long duration (six-, ten-, and twenty-year average) droughts, but it is likely that short (one- and three-year average) and very long (fiftyyear average) dry periods were more severe during the eleventh-throughthirteenth centuries. Evidence for the late-sixteenth century “mega drought” is found in the Klamath basin, though with less strength than in the neighboring Sacramento River basin. Cool-season storm tracks are likely a direct driver of hydroclimatic variability, leading to events with see-saw like relationships between the Klamath and neighboring regions, such as during the fourteenth century, yet the vast region of drought in the twelfth century is suggestive of a long-term northward shift in cool-season storm tracks.
ASSESSING MODERN CLIMATIC CONTROLS ON SOUTHERN SIERRA NEVADA PRECIPITATION AND SPELEOTHEM d18O Staryl McCabe-Glynn a, Kathleen R. Johnson a, Court Strong b, Max Berkelhammer c. a Department of Earth System Science, University of California-Irvine, Irvine, CA 92697, USA; b Department of Atmospheric Sciences, University of Utah, UT 84112, USA; c Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA. E-mail address: [email protected], [email protected], utah.edu, [email protected].
court.strong@
Precipitation in the southwestern United States is highly seasonal and exhibits inter-annual to inter-decadal variability. A 1154-year d18O time series obtained from a southwestern Sierra Nevada stalagmite from Crystal Cave, CRC-3, (36.59 N; 118.72 W; 1386 m) reveals substantial decadal to multi-decadal variability closely linked to the Pacific Decadal Oscillation (PDO), and more specifically, to sea surface temperatures (SSTs) in the Kuroshio Extension region, which impact the atmospheric trajectory and isotopic composition of moisture reaching the study site. The instrumental portion of the CRC-3 d18O time series suggests that more negative precipitation d18O values are delivered from higher latitudes during positive phases of the PDO and/or when SSTs in the Kuroshio Extension region are ~ a events. anomalously cool, such as during La Nin In order to improve our understanding of the controls on speleothem d18O in this region, we have conducted a detailed modern study of the climate, hydrology, and stable isotopic composition of meteoric waters (precipitation and drip water) at the cave. Here we present Crystal Cave drip logger results from AD 2010 to 2011, the isotopic composition of National Atmospheric Deposition Program precipitation samples collected from 2001 to 2011 from Sequoia National Park-Giant Forest (Ca75), AD 2005e2011 from other locations near our site including Yosemite National Park (Ca99), and the isotopic composition of cave drip water and glass plate calcite. The Crystal Cave drip logger results demonstrate a low drip rate variability between July 2010 and July 2011, averaging ~20 drips/hour, but we observe a significant increase during three storms, with the greatest increase occurring during an ‘Atmospheric River’ event, a type of storm known to transport large quantities of water vapor and produce extreme precipitation in coastal regions. We compare the d18O values in the precipitation from these three storms to satellite imagery, NCAR/NCEP data, and NOAA Hysplit Model backward trajectories.
LINKING HOLOCENE HYDROLOGIC EVENTS WITH EPISODIC PERIODS OF FLUVIAL DEPOSITION AND SOIL FORMATION, SANTA CATALINA ISLAND, CALIFORNIA Eric V. McDonald, Thomas F. Bullard, Jose Luis Antinao. Division of Earth and Ecosystem Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA.
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streams across Santa Catalina Island. Soil-stratigraphy associated with surficial deposits, ranging in thickness from 2 to 8 m, provides an excellent record of Holocene periods of hillslope instability and associated aggradation along stream channels. The robust fluvial record contains multiple buried soils which help identify episodes of alluvial deposition. Radiocarbon dates indicate two periods of channel aggradation, consisting of pebble-gravel deposits overlying bedrock channels, occurred from 6825 to 6715 cal yr BP and possibly from 5540 to 4950 cal yr BP. This was followed by multiple discrete episodes of widespread deposition with the last three episodes occurring between about 3305 to 2545 cal yr BP, between 1075 to 920 cal yr BP, and between 780 to 230 cal yr BP. Available radiocarbon dates and soil stratigraphy observed in the major watersheds on Santa Catalina Island consistently show episodic deposition that is linked to hillslope-derived sediments. Initial analysis of soil stratigraphy and records of Holocene climate change in the San Bernardino Mountains and the Santa Barbara Basin suggest that periods of fluvial aggradation are related to periods of intense storm activity, possibly associated with periods of increased wildfire activity. In comparison, more than one hundred years of intense grazing that caused widespread vegetation removal (noted in historic documents and photographs) had limited geomorphic response (intact, well-developed hillslope soils and a sparse historic depositional record) despite record precipitation events during the period of grazing. This suggests that Holocene climate perturbations affected the magnitude of geomorphic responses more profoundly than is observed historically.
THE LATE HOLOCENE DROUGHT: A PERSISTENT DRY PERIOD BETWEEN 2800 AND 1800 CAL YR BP ACROSS THE CENTRAL GREAT BASIN Scott Mensing a, Saxon Sharpe b, Irene Tunno c, Don Sada b, Jeremy Smith a, Jim Thomas b. a Department of Geography, University of Nevada, Reno, NV 89557, USA; b Division of Hydrologic Sciences, Desert Research Institute, Reno, NV 89512, USA; c DAFNE, Tuscia University, Viterbo, 01100, Italy. E-mail address: [email protected].
Two periods of severe and persistent Holocene drought are widely recognized and well-documented in the Great Basin of the western United States; the Middle Holocene dry period about 7500 to 5000 cal yr BP and the Medieval Climate Anomaly between 1200 and 750 cal yr BP. Much less attention has been paid to a potentially equally severe and persistent late Holocene dry period between ~2800 and 1800 cal yr BP. This potential drought period has been described previously in the literature, but its magnitude and extent remain uncertain. The purpose of this paper is to present new pollen and mollusk evidence from Spring Valley in eastern Nevada that supports the presence of a late Holocene multi-centennial drought in the Great Basin and to compare these results with regional studies to constrain the temporal and geographic extent of this event. A suite of evidence from sites extending from the eastern Sierra Nevada to the Great Salt Lake all provide evidence for an extended dry and cool period between ~2800 and 1800 cal yr BP, including lake levels, faunal remains in cave deposits, pollen, chironomids, treeline studies, glacial studies, and geomorphology. The northern Great Basin (north of ~40o N) experienced increased precipitation through most of this period, while the southwest experience fewer flooding events. A cool dry southwest and wet northwest is consistent ~ a dominated circulation pattern. with a negative SOI and persistent La Nin This period, which is beyond the reach of most tree-ring chronologies, may represent a third important persistent Holocene drought and may deserve closer attention to understand the long-term dynamics of Holocene climate change in the western United States.
E-mail address: [email protected].
THE PLEISTOCENE CLIMATE RECORD IN ALLUVIAL FANS OF THE MOJAVE DESERT
Development of records of Holocene climate variation and an increasing recognition of extreme storm events in southern California (e.g. atmospheric rivers) allows evaluation of the linkages between hydrologic events and geomorphic response in semi-arid settings. Alluvial stratigraphy and soils were characterized along ephemeral axial and tributary
David M. Miller a, Andrew Cyr a, Christopher Menges b, Kevin M. Schmidt a, Shannon A. Mahan c, Katherine Maher d, Tanzhuo Liu e. a US Geological Survey, 345 Middlefield Road, Menlo Park, CA 94536, USA; b US Geological Survey, 520 N. Park Ave., Tucson, AZ 85719, USA; c US Geological Survey, Box 25046, DFC, Denver, CO 80225, USA; d Department of Geological and
reconstructions hint that variability during the observed period captures moderate-to-long duration (six-, ten-, and twenty-year average) droughts, but it is likely that short (one- and three-year average) and very long (fiftyyear average) dry periods were more severe during the eleventh-throughthirteenth centuries. Evidence for the late-sixteenth century “mega drought” is found in the Klamath basin, though with less strength than in the neighboring Sacramento River basin. Cool-season storm tracks are likely a direct driver of hydroclimatic variability, leading to events with see-saw like relationships between the Klamath and neighboring regions, such as during the fourteenth century, yet the vast region of drought in the twelfth century is suggestive of a long-term northward shift in cool-season storm tracks.
ASSESSING MODERN CLIMATIC CONTROLS ON SOUTHERN SIERRA NEVADA PRECIPITATION AND SPELEOTHEM d18O Staryl McCabe-Glynn a, Kathleen R. Johnson a, Court Strong b, Max Berkelhammer c. a Department of Earth System Science, University of California-Irvine, Irvine, CA 92697, USA; b Department of Atmospheric Sciences, University of Utah, UT 84112, USA; c Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA. E-mail address: [email protected], [email protected], utah.edu, [email protected].
court.strong@
Precipitation in the southwestern United States is highly seasonal and exhibits inter-annual to inter-decadal variability. A 1154-year d18O time series obtained from a southwestern Sierra Nevada stalagmite from Crystal Cave, CRC-3, (36.59 N; 118.72 W; 1386 m) reveals substantial decadal to multi-decadal variability closely linked to the Pacific Decadal Oscillation (PDO), and more specifically, to sea surface temperatures (SSTs) in the Kuroshio Extension region, which impact the atmospheric trajectory and isotopic composition of moisture reaching the study site. The instrumental portion of the CRC-3 d18O time series suggests that more negative precipitation d18O values are delivered from higher latitudes during positive phases of the PDO and/or when SSTs in the Kuroshio Extension region are ~ a events. anomalously cool, such as during La Nin In order to improve our understanding of the controls on speleothem d18O in this region, we have conducted a detailed modern study of the climate, hydrology, and stable isotopic composition of meteoric waters (precipitation and drip water) at the cave. Here we present Crystal Cave drip logger results from AD 2010 to 2011, the isotopic composition of National Atmospheric Deposition Program precipitation samples collected from 2001 to 2011 from Sequoia National Park-Giant Forest (Ca75), AD 2005e2011 from other locations near our site including Yosemite National Park (Ca99), and the isotopic composition of cave drip water and glass plate calcite. The Crystal Cave drip logger results demonstrate a low drip rate variability between July 2010 and July 2011, averaging ~20 drips/hour, but we observe a significant increase during three storms, with the greatest increase occurring during an ‘Atmospheric River’ event, a type of storm known to transport large quantities of water vapor and produce extreme precipitation in coastal regions. We compare the d18O values in the precipitation from these three storms to satellite imagery, NCAR/NCEP data, and NOAA Hysplit Model backward trajectories.
LINKING HOLOCENE HYDROLOGIC EVENTS WITH EPISODIC PERIODS OF FLUVIAL DEPOSITION AND SOIL FORMATION, SANTA CATALINA ISLAND, CALIFORNIA Eric V. McDonald, Thomas F. Bullard, Jose Luis Antinao. Division of Earth and Ecosystem Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA.
139
streams across Santa Catalina Island. Soil-stratigraphy associated with surficial deposits, ranging in thickness from 2 to 8 m, provides an excellent record of Holocene periods of hillslope instability and associated aggradation along stream channels. The robust fluvial record contains multiple buried soils which help identify episodes of alluvial deposition. Radiocarbon dates indicate two periods of channel aggradation, consisting of pebble-gravel deposits overlying bedrock channels, occurred from 6825 to 6715 cal yr BP and possibly from 5540 to 4950 cal yr BP. This was followed by multiple discrete episodes of widespread deposition with the last three episodes occurring between about 3305 to 2545 cal yr BP, between 1075 to 920 cal yr BP, and between 780 to 230 cal yr BP. Available radiocarbon dates and soil stratigraphy observed in the major watersheds on Santa Catalina Island consistently show episodic deposition that is linked to hillslope-derived sediments. Initial analysis of soil stratigraphy and records of Holocene climate change in the San Bernardino Mountains and the Santa Barbara Basin suggest that periods of fluvial aggradation are related to periods of intense storm activity, possibly associated with periods of increased wildfire activity. In comparison, more than one hundred years of intense grazing that caused widespread vegetation removal (noted in historic documents and photographs) had limited geomorphic response (intact, well-developed hillslope soils and a sparse historic depositional record) despite record precipitation events during the period of grazing. This suggests that Holocene climate perturbations affected the magnitude of geomorphic responses more profoundly than is observed historically.
THE LATE HOLOCENE DROUGHT: A PERSISTENT DRY PERIOD BETWEEN 2800 AND 1800 CAL YR BP ACROSS THE CENTRAL GREAT BASIN Scott Mensing a, Saxon Sharpe b, Irene Tunno c, Don Sada b, Jeremy Smith a, Jim Thomas b. a Department of Geography, University of Nevada, Reno, NV 89557, USA; b Division of Hydrologic Sciences, Desert Research Institute, Reno, NV 89512, USA; c DAFNE, Tuscia University, Viterbo, 01100, Italy. E-mail address: [email protected].
Two periods of severe and persistent Holocene drought are widely recognized and well-documented in the Great Basin of the western United States; the Middle Holocene dry period about 7500 to 5000 cal yr BP and the Medieval Climate Anomaly between 1200 and 750 cal yr BP. Much less attention has been paid to a potentially equally severe and persistent late Holocene dry period between ~2800 and 1800 cal yr BP. This potential drought period has been described previously in the literature, but its magnitude and extent remain uncertain. The purpose of this paper is to present new pollen and mollusk evidence from Spring Valley in eastern Nevada that supports the presence of a late Holocene multi-centennial drought in the Great Basin and to compare these results with regional studies to constrain the temporal and geographic extent of this event. A suite of evidence from sites extending from the eastern Sierra Nevada to the Great Salt Lake all provide evidence for an extended dry and cool period between ~2800 and 1800 cal yr BP, including lake levels, faunal remains in cave deposits, pollen, chironomids, treeline studies, glacial studies, and geomorphology. The northern Great Basin (north of ~40o N) experienced increased precipitation through most of this period, while the southwest experience fewer flooding events. A cool dry southwest and wet northwest is consistent ~ a dominated circulation pattern. with a negative SOI and persistent La Nin This period, which is beyond the reach of most tree-ring chronologies, may represent a third important persistent Holocene drought and may deserve closer attention to understand the long-term dynamics of Holocene climate change in the western United States.
E-mail address: [email protected].
THE PLEISTOCENE CLIMATE RECORD IN ALLUVIAL FANS OF THE MOJAVE DESERT
Development of records of Holocene climate variation and an increasing recognition of extreme storm events in southern California (e.g. atmospheric rivers) allows evaluation of the linkages between hydrologic events and geomorphic response in semi-arid settings. Alluvial stratigraphy and soils were characterized along ephemeral axial and tributary
David M. Miller a, Andrew Cyr a, Christopher Menges b, Kevin M. Schmidt a, Shannon A. Mahan c, Katherine Maher d, Tanzhuo Liu e. a US Geological Survey, 345 Middlefield Road, Menlo Park, CA 94536, USA; b US Geological Survey, 520 N. Park Ave., Tucson, AZ 85719, USA; c US Geological Survey, Box 25046, DFC, Denver, CO 80225, USA; d Department of Geological and