147-17 Three Meltwater Pulses and a Tsunami: The Postglacial History of the Western Barents Sea

Session: Climate, Ocean and Environmental Changes Through Earth History: From Marine and Terrestrial Proxies to Model Assessments (Posters)

Poster Booth No.: 184

Presenting Author:

Natalia Szymańska

Authors:

Szymańska, Natalia¹, Devendra, Dhanuska², Łącka, Magdalena³, Szymczak-Żyła, Małgorzata⁴, Krajewska, Małgorzata⁵, Telesiński, Maciej Mateusz⁶, De Silva, Prasadi⁷, Zajączkowski, Marek⁸

(1) Department of Paleoceanography, Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland, (2) Department of Paleoceanography, Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland, (3) Department of Paleoceanography, Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland, (4) Department of Paleoceanography, Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland, (5) Department of Paleoceanography, Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland, (6) Department of Paleoceanography, Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland, (7) Department of Paleoceanography, Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland; National and Kapodistrian University of Athens, Athens, Greece, (8) Department of Paleoceanography, Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland,

Abstract:

Over the past 15,000 years, the oceanography of the Barents Sea has been in large part shaped by deglaciation processes in the Northern Hemisphere. The retreat of the Svalbard-Barents and Fennoscandian ice sheets delivered substantial meltwater to the region, supplemented by episodic outburst floods from paleo-lakes such as the Baltic Ice Lake, Ancylus Lake, and Nedre Glomsjø (Norway). The freshwater influx likely disrupted regional ocean circulation, resulting in lower sea surface temperatures and increased sea ice formation in the Barents Sea.

This study reconstructs meltwater pulses using a sediment core from the Kveithola Trough in the western Barents Sea. We applied a multiproxy approach, analyzing biomarkers, stable isotopes, foraminiferal assemblages, and several sedimentological parameters. Three distinct meltwater pulses were identified between 13,000 and 9,000 years BP. Despite temporal and compositional differences, all pulses were characterized by elevated levels of terrestrial biomarkers, alkenones, and sea ice proxy IP25.

We also identified an 18 cm-thick reworked sediment layer, featuring coarser grains at its base and older foraminiferal tests dated between 12,000 and 27,000 years BP. This unit, deposited between 8,100 and 8,600 years BP, also shows elevated concentrations of terrestrial plant sedaDNA and steroids. Its timing coincides with the Storegga tsunami—the largest known paleo-tsunami on record. A two-stage coupled landslide and tsunami modelling confirms that the wave could have reached our study site.

Our results underscore the role of meltwater pulses in shaping regional oceanographic conditions and highlight the potential of ongoing deglacial processes to affect Atlantic Water propagation, primary productivity, and broader environmental dynamics. Additionally, we document the northernmost evidence of the Storegga tsunami, emphasizing its magnitude and far-reaching impact.

 

The research was financially supported by the National Science Centre in Poland, projects 2023/51/B/ST10/01579 and 2024/53/B/ST10/02821.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9691

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