Independent tephrochronological evidence for rapid and synchronous oceanic and atmospheric temperature rises over the Greenland stadial-interstadial transitions between ca. 32 and 40 ka b2k
Type | Article | ||||||||||||
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Date | 2020-05 | ||||||||||||
Language | English | ||||||||||||
Author(s) | Berben Sarah M.P.1, Dokken Trond M.2, Abbott Peter M.3, 4, Cook Eliza5, Sadatzki Henrik1, 2, 6, Simon Margit H2, Jansen Eystein1, 2 | ||||||||||||
Affiliation(s) | 1 : Department of Earth Science and Bjerknes Centre for Climate Research, University of Bergen, 5007, Bergen, Norway 2 : NORCE Norwegian Research Centre and Bjerknes Centre for Climate Research, 5007, Bergen, Norway 3 : School of Earth and Ocean Sciences, Cardiff University, Cardiff, CF10 3AT, United Kingdom 4 : Institute of Geological Sciences and Oeschger Center for Climate Research, University of Bern, 3012, Bern, Switzerland 5 : Physics of Ice, Climate and Earth, Niels Bohr Institute, University of Copenhagen, 2200, Copenhagen, Denmark 6 : Research School of Earth Sciences, Australian National University, Canberra, ACT, 2601, Australia |
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Source | Quaternary Science Reviews (0277-3791) (Elsevier BV), 2020-05 , Vol. 236 , P. 106277(25p.) | ||||||||||||
DOI | 10.1016/j.quascirev.2020.106277 | ||||||||||||
WOS© Times Cited | 6 | ||||||||||||
Keyword(s) | Quaternary, Paleoclimatology, Paleoceanography, North Atlantic, Sedimentology, Marine cores, Ice cores, Cryptotephrochronology, DO-Events, Synchronization | ||||||||||||
Abstract | Understanding the dynamics that drove past abrupt climate changes, such as the Dansgaard-Oeschger (DO) events, depends on combined proxy evidence from disparate archives. To identify leads, lags and synchronicity between different climate system components, independent and robust chronologies are required. Cryptotephrochronology is a key geochronological tool as cryptotephra horizons can act as isochrons linking disparate and/or distant records. Here, we investigated marine sediment core MD99-2284 from the Norwegian Sea to look for previously identified Greenland ice core cryptotephra horizons and define time-parallel markers between the archives. We explored potential secondary transport and depositional mechanisms that could hamper the isochronous integrity of such horizons. We identified six cryptotephra layers of which four correlate to previously known Greenland ice core horizons. None of those were identified in other marine cores and thus, this study contributes greatly to the North Atlantic tephra framework tripling the original amount of existing isochrons between ca. 25 and 60 ka b2k. The latter allow a synchronization between MD99-2284 and the Greenland ice cores between ca. 32–40 ka b2k, which is, in the North Atlantic, the shortest time-interval during the Last Glacial Period to be constrained by four independent tephra isochrons. These findings provide essential tephra-based evidence for synchronous and rapid oceanic and atmospheric temperature rises during the Greenland Stadial-Interstadial transitions. Furthermore, it enables us to estimate the average peak-duration of interstadial temperature overshoots at approximately 136 years. As such, this well-targeted high-resolution investigation successfully demonstrates the use of cryptotephra for geochronological purposes in the marine realm. |
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