Journal cover Journal topic
Climate of the Past An interactive open-access journal of the European Geosciences Union
Clim. Past, 13, 1097-1110, 2017
https://doi.org/10.5194/cp-13-1097-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
05 Sep 2017
Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins
Thomas M. Cronin1, Matt O'Regan2, Christof Pearce2, Laura Gemery1, Michael Toomey1, Igor Semiletov3,4, and Martin Jakobsson2 1US Geological Survey MS 926A, Reston, Virginia 20192, USA
2Department of Geological Sciences and Bolin Centre for Climate Research, Stockholm University, 10691 Stockholm, Sweden
3Pacific Oceanological Institute, Russian Academy Sciences, Vladivostok, Russia
4Tomsk Polytechnic University, Tomsk, Russia
Abstract. Deglacial (12.8–10.7 ka) sea level history on the East Siberian continental shelf and upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC1) and multicore SWERUS-L2-4-MC1 (4-MC1), and a gravity core from an East Siberian Sea transect, SWERUS-L2-20-GC1 (20-GC1). Cores 4-PC1 and 20-GC were taken at 120 and 115 m of modern water depth, respectively, only a few meters above the global last glacial maximum (LGM;  ∼  24 kiloannum or ka) minimum sea level of  ∼  125–130 meters below sea level (m b.s.l.). Using calibrated radiocarbon ages mainly on molluscs for chronology and the ecology of benthic foraminifera and ostracode species to estimate paleodepths, the data reveal a dominance of river-proximal species during the early part of the Younger Dryas event (YD, Greenland Stadial GS-1) followed by a rise in river-intermediate species in the late Younger Dryas or the early Holocene (Preboreal) period. A rapid relative sea level rise beginning at roughly 11.4 to 10.8 ka ( ∼  400 cm of core depth) is indicated by a sharp faunal change and unconformity or condensed zone of sedimentation. Regional sea level at this time was about 108 m b.s.l. at the 4-PC1 site and 102 m b.s.l. at 20-GC1. Regional sea level near the end of the YD was up to 42–47 m lower than predicted by geophysical models corrected for glacio-isostatic adjustment. This discrepancy could be explained by delayed isostatic adjustment caused by a greater volume and/or geographical extent of glacial-age land ice and/or ice shelves in the western Arctic Ocean and adjacent Siberian land areas.

Citation: Cronin, T. M., O'Regan, M., Pearce, C., Gemery, L., Toomey, M., Semiletov, I., and Jakobsson, M.: Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins, Clim. Past, 13, 1097-1110, https://doi.org/10.5194/cp-13-1097-2017, 2017.
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Short summary
Global sea level rise during the last deglacial flooded the Siberian continental shelf in the Arctic Ocean. Sediment cores, radiocarbon dating, and microfossils show that the regional sea level in the Arctic rose rapidly from about 12 500 to 10 700 years ago. Regional sea level history on the Siberian shelf differs from the global deglacial sea level rise perhaps due to regional vertical adjustment resulting from the growth and decay of ice sheets.
Global sea level rise during the last deglacial flooded the Siberian continental shelf in the...
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