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dc.contributor.authorThompson, Diane M.
dc.contributor.authorConroy, Jessica L.
dc.contributor.authorCollins, Aaron
dc.contributor.authorHlohowskyj, Stephan R.
dc.contributor.authorOverpeck, Jonathan T.
dc.contributor.authorRiedinger-Whitmore, Melanie
dc.contributor.authorCole, Julia E.
dc.contributor.authorBush, Mark B.
dc.contributor.authorWhitney, H.
dc.contributor.authorCorley, Timothy L.
dc.contributor.authorKannan, Miriam Steinitz
dc.date.accessioned2017-10-09T22:21:33Z
dc.date.available2017-10-09T22:21:33Z
dc.date.issued2017-08
dc.identifier.citationTropical Pacific climate variability over the last 6000 years as recorded in Bainbridge Crater Lake, Galápagos 2017, 32 (8):903 Paleoceanographyen
dc.identifier.issn08838305
dc.identifier.doi10.1002/2017PA003089
dc.identifier.urihttp://hdl.handle.net/10150/625825
dc.description.abstractFinely laminated sediments within Bainbridge Crater Lake, Galapagos, provide a record of El Nino-Southern Oscillation (ENSO) events over the Holocene. Despite the importance of this sediment record, hypotheses for how climate variability is preserved in the lake sediments have not been tested. Here we present results of long-term monitoring of the local climate and limnology and a revised interpretation of the sediment record. Brown-green, organic-rich, siliciclastic laminae reflect warm, wet conditions typical of El Nino events, whereas carbonate and gypsum precipitate during cool, dry La Nina events and persistent dry periods, respectively. Applying this new interpretation, we find that ENSO events of both phases were generally less frequent during the mid-Holocene (similar to 6100-4000 calendar years B.P.) relative to the last similar to 1500 calendar years. Abundant carbonate laminations between 3500 and 3000 calendar years B.P. imply that conditions in the Galapagos region were cool and dry during this period when the tropical Pacific E-W sea surface temperature (SST) gradient likely strengthened. The frequency of El Nino and La Nina events then intensified dramatically around 1750-2000 calendar years B.P., consistent with a weaker SST gradient and an increased frequency of ENSO events in other regional records. This strong interannual variability persisted until similar to 700 calendar years B.P., when ENSO-related variability at the lake decreased as the SST gradient strengthened. Persistent, dry conditions then dominated between 300 and 50 calendar years B.P. (A.D. 1650-1900, +/- similar to 100 years), whereas wetter conditions and frequent El Nino events dominated in the most recent century. Plain Language Summary Sediments accumulating at the bottom of Bainbridge Crater Lake have provided a record of Galapagos climate and the frequency of El Nino events over the past similar to 6000 years. Motivated by the importance of this lake for our understanding of climate in the tropical Pacific Ocean, we have been monitoring the link between climate, lake conditions, and the physical and chemical properties of the lake sediments since 2009. Based on this long-term monitoring, we find that the Bainbridge sediment record preserves both El Nino and La Nina events. This makes Bainbridge a particularly valuable archive of past climate, as most sediment-based records typically preserve only one or the other key phase of tropical Pacific climate.
dc.description.sponsorshipNational Science Foundation (NSF) RAPID, Program [AGS-1256970, AGS-1561121]; NOAA Climate Program Office; University of Arizona Department of Geosciences; Philanthropic Education Organization; National Science Foundation (NSF) P2C2, Program [AGS-1256970, AGS-1561121]; National Science Foundation (NSF) Geospace Sciences Paleoclimate Program [AGS-1256970, AGS-1561121]en
dc.language.isoenen
dc.publisherAMER GEOPHYSICAL UNIONen
dc.relation.urlhttp://doi.wiley.com/10.1002/2017PA003089en
dc.rights©2017. American Geophysical Union. All Rights Reserved.en
dc.subjectEl Niño–Southern Oscillation (ENSO)en
dc.subjecttropical Pacific Oceanen
dc.subjectclimate variabilityen
dc.subjectmid-Holoceneen
dc.subjectGalápagos archipelagoen
dc.subjectmonitoringen
dc.titleTropical Pacific climate variability over the last 6000 years as recorded in Bainbridge Crater Lake, Galápagosen
dc.typeArticleen
dc.contributor.departmentUniv Arizona, Dept Hydrol & Atmospher Scien
dc.contributor.departmentUniv Arizona, Inst Environmen
dc.identifier.journalPaleoceanographyen
dc.description.note6 month embargo; published online: 26 August 2017en
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
dc.contributor.institutionEarth and Environment Department; Boston University; Boston Massachusetts USA
dc.contributor.institutionDepartment of Geology; University of Illinois at Urbana-Champaign; Urbana Illinois USA
dc.contributor.institutionDepartment of Biology; Florida Institute of Technology; Melbourne Florida USA
dc.contributor.institutionDepartment of Geosciences; University of Arizona; Tucson Arizona USA
dc.contributor.institutionDepartment of Geosciences; University of Arizona; Tucson Arizona USA
dc.contributor.institutionDepartment of Biological Sciences; University of South Florida St. Petersburg; St. Petersburg Florida USA
dc.contributor.institutionDepartment of Geosciences; University of Arizona; Tucson Arizona USA
dc.contributor.institutionDepartment of Biology; Florida Institute of Technology; Melbourne Florida USA
dc.contributor.institutionDepartment of Biology; Florida Institute of Technology; Melbourne Florida USA
dc.contributor.institutionDepartment of Hydrology and Atmospheric Sciences; University of Arizona; Tucson Arizona USA
dc.contributor.institutionDepartment of Biological Sciences; Northern Kentucky University; Highland Heights Kentucky USA
refterms.dateFOA2018-02-26T00:00:00Z
html.description.abstractFinely laminated sediments within Bainbridge Crater Lake, Galapagos, provide a record of El Nino-Southern Oscillation (ENSO) events over the Holocene. Despite the importance of this sediment record, hypotheses for how climate variability is preserved in the lake sediments have not been tested. Here we present results of long-term monitoring of the local climate and limnology and a revised interpretation of the sediment record. Brown-green, organic-rich, siliciclastic laminae reflect warm, wet conditions typical of El Nino events, whereas carbonate and gypsum precipitate during cool, dry La Nina events and persistent dry periods, respectively. Applying this new interpretation, we find that ENSO events of both phases were generally less frequent during the mid-Holocene (similar to 6100-4000 calendar years B.P.) relative to the last similar to 1500 calendar years. Abundant carbonate laminations between 3500 and 3000 calendar years B.P. imply that conditions in the Galapagos region were cool and dry during this period when the tropical Pacific E-W sea surface temperature (SST) gradient likely strengthened. The frequency of El Nino and La Nina events then intensified dramatically around 1750-2000 calendar years B.P., consistent with a weaker SST gradient and an increased frequency of ENSO events in other regional records. This strong interannual variability persisted until similar to 700 calendar years B.P., when ENSO-related variability at the lake decreased as the SST gradient strengthened. Persistent, dry conditions then dominated between 300 and 50 calendar years B.P. (A.D. 1650-1900, +/- similar to 100 years), whereas wetter conditions and frequent El Nino events dominated in the most recent century. Plain Language Summary Sediments accumulating at the bottom of Bainbridge Crater Lake have provided a record of Galapagos climate and the frequency of El Nino events over the past similar to 6000 years. Motivated by the importance of this lake for our understanding of climate in the tropical Pacific Ocean, we have been monitoring the link between climate, lake conditions, and the physical and chemical properties of the lake sediments since 2009. Based on this long-term monitoring, we find that the Bainbridge sediment record preserves both El Nino and La Nina events. This makes Bainbridge a particularly valuable archive of past climate, as most sediment-based records typically preserve only one or the other key phase of tropical Pacific climate.


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