Evolution of temperature and mobilization of terrigenous organic matter in the subarctic Northwest Pacific and adjacent Beringia since the Last Glacial Maximum

• Main Author: Meyer, Vera
• Format: Thesis
• Language: unknown
• Published: 2016
• Subjects: Bering Sea; Greenland; Greenland ice cores; North Atlantic; Subarctic; Alaska; Beringia; Siberia
• Online Access: https://epic.awi.de/id/eprint/42181/; https://epic.awi.de/id/eprint/42181/1/Dissertation_Vera_Meyer.pdf; http://elib.suub.uni-bremen.de/peid=D00105274; https://hdl.handle.net/10013/epic.49082; https://hdl.handle.net/10013/epic.49082.d001

In times of global warming a profound understanding of the climate system is necessary to develop mitigation strategies. Studying episodes of climate change during the Earth’s history (e.g. Glacial-Interglacial cycles) allows insights into the climate system and its feedback processes. In the subarctic Northwest Pacific (NW Pacific) and adjacent Northeast Siberia (NE Siberia) mean climate changes between the Last Glacial Maximum and the Holocene are poorly understood since climate records (e.g. temperature records) spanning the full LGM-Holocene transition are sparse. This thesis shall contribute to a better understanding of climate and environmental change since the LGM and the controlling mechanisms in the region by investigating the development of temperature, glaciation and export of terrigenous organic matter into the North Pacific (N Pacific). Biomarkers in sediment cores from the Western Bering Sea and the NW Pacific/continental margin off Siberia are applied as palaeoclimate archives. In the first part of the thesis LGM-to-Holocene sea surface temperature (SST) records for the marginal Northwest Pacific and the Western Bering Sea are established using the TEXL86 (Tetraether IndeX)-SST proxy. It focusses on the LGM and the early deglaciation since existing deglacial SST records from the region do not reach beyond 15 ka BP. TEXL86-based SSTs in both settings closely follow millennial-scale climate fluctuations known from Greenland ice-cores until 15 ka BP, confirming other SST-records from the region which point to rapid atmospheric teleconnections with abrupt climate changes in the North Atlantic (N Atlantic). During Heinrich Stadial 1 (HS1), Western Bering Sea SSTs decline, similar to the N Atlantic realm, suggesting the Bering Sea was connected to the N Atlantic climate change. Progressively rising SSTs in the NW Pacific differ from the Western Bering Sea and the N Atlantic climate. Similarities between the climate in the Gulf of Alaska and the NW Pacific suggest that the Alaskan Stream accumulated in ...