Radiocarbon-datedMytilus edulisandModiolus modiolusfrom northern Svalbard: Climatic implications

Abstract

Eighteen new age determination s on Mytilus edulis shells from northern Svalbard and two new age determination s on Modiolus modiolus shells are presented. Mytilus edulis appeared on the northern coast of Spitsbergen c. 9400 yr BP. Its maximum extension there seems to have been c. 7250 yr BP, which is also indicativ e of a climatic optimum. The rst nding of Modiolu s modiolus shells from northern Spitsbergen is reported, and revealed the age of c. 8300 yr BP, which is also indicativ e of marine climatic optimum conditions . Mytilus lived at the head of Woodfjorden until at least 5300 yr BP, but it is not possible to date its nal disappearance from the northern coast. Mytilus has been absent from large parts of the coasts of Svalbard during the entire Holocene, indicatin g limited in uence of warm Atlantic water there. Recent reports of living Mytilus edulis on Bjørnøya indicate a probable new occurrence there, and the question about a further immigration to Spitsbergen should be kept in mind. Such a faunistic change may provide data about a more general climatic warming in this part of the Arctic.

Atlantic Water advection vs. glacier dynamics in northern Spitsbergen since early deglaciation

“…This may be linked to the presence of AW as a subsurface or even surface water mass, hence amplifying productivity in the photic zone. The appearance of the thermophilous mussel Mytilus edulis at the outer part of Woodfjorden (Reinsdyrflya) supports the assumption of a surface injection of AW at least from ∼ 10.6 ka on (9815 ± 80 14 C a; Salvigsen, 2002). Several studies around Spitsbergen report about a benthic faunal pattern comparable to the record above during the HTM (Groot et al, 2014;Rasmussen et al, 2012;Skirbekk et al, 2010;Ślubowska-Woldengen et al, 2007).…”

Former dynamic behaviour of a cold-based valley glacier on Svalbard revealed by basal ice and structural glaciology investigations

“…The LIA represents the culmination of Neoglacial glacier expansion, which also typically records the most extensive position reached by glaciers during the Holocene (Humlum and others, 2005). Prior to this, conditions during the early and mid-Holocene are suggested to have been warmer than the present-day climate (Salvigsen and others, 1992;Salvigsen, 2002), and most current valley glaciers are likely to have been considerably smaller (Svendsen and Mangerud, 1997;Forwick and Vorren, 2007;Mangerud and Landvik, 2007) or even non-existent (Ingólfsson, 2011) at this time. In the latter case, valley glacier build-up during the early part of the LIA would have been characterized by snow accumulation on permafrost initially leading to the development of cold-based ice; these conditions have persisted beneath some Svalbard glaciers throughout the LIA, as evidenced by the preservation of in situ plants in a subglacial position at Longyearbreen (Humlum and others, 2005).…”

Holocene multi-proxy environmental reconstruction from lake Hakluytvatnet, Amsterdamøya Island, Svalbard (79.5°N)

“…we acknowledge that the moraine ridge might be older than the glacier event detected in the 493 sediment core, but our interpretation that Unit A is a subglacially deposited diamict implies 494 that the glacier at least covered the part of the lake where the core was retrieved and the ridge (Birks, 1991) and marine records (Salvigsen, 2002). We can only speculate as to why the lake 544 dried out, but conclude that there was a large shift in depositional environment at the time of 545 Unit D being deposited, which is also reflected in the diatom assemblages with a shift to a 546 more diverse lake environment and improved light quality in Unit E. Increased productivity is 547 also reflected in the large increase in Si/Ti (Fig.…”