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

• Published in: Climate of the Past
• Main Authors: Bartels, Martin, Titschack, Juergen, Fahl, Kirsten, Stein, Ruediger, Seidenkrantz, Marit-Solveig, Hillaire-Marcel, Claude, Hebbeln, Dierk
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2017
• Subjects: SEA-ICE SHEET; MODERN BENTHIC FORAMINIFERA; RESERVOIR AGE CORRECTIONS; QUATERNARY ARCTIC-OCEAN; EASTERN FRAM STRAIT; YOUNGER-DRYAS; BARENTS SEA; FRESH-WATER; NORDIC SEAS; MIDLATITUDE WEATHER; Arctic; Arctic Ocean; Barents Sea; Foraminifera*; Fram Strait; glacier; Ice Sheet; Nordic Seas; Sea ice; Svalbard; Svalbard-Barents Sea Ice sheet; Woodfjord*; Woodfjorden; Spitsbergen
• Online Access: https://pure.au.dk/portal/da/publications/atlantic-water-advection-vs-glacier-dynamics-in-northern-spitsbergen-since-early-deglaciation(58d9bd90-877c-41b0-8283-e769c1bc88bf).html; https://doi.org/10.5194/cp-13-1717-2017; https://pure.au.dk/ws/files/120110095/cp_13_1717_2017.pdf

Atlantic Water (AW) advection plays an important role in climatic, oceanographic and environmental conditions in the eastern Arctic. Situated along the only deep connection between the Atlantic and the Arctic oceans, the Svalbard Archipelago is an ideal location to reconstruct the past AW advection history and document its linkage with local glacier dynamics, as illustrated in the present study of a 275ĝ€cm long sedimentary record from Woodfjorden (northern Spitsbergen; water depth: 171ĝ€m) spanning the last ĝ1/4 ĝ€15ĝ€500 years. Sedimentological, micropalaeontological and geochemical analyses were used to reconstruct changes in marine environmental conditions, sea ice cover and glacier activity. Data illustrate a partial break-up of the Svalbard-Barents Sea Ice Sheet from Heinrich Stadial 1 onwards (until ĝ1/4 ĝ€14.6ĝ€ka). During the Bølling-Allerød ( ĝ1/4 ĝ€14.6-12.7ĝ€ka), AW penetrated as a bottom water mass into the fjord system and contributed significantly to the destabilization of local glaciers. During the Younger Dryas ( ĝ1/4 ĝ€12.7-11.7ĝ€ka), it intruded into intermediate waters while evidence for a glacier advance is lacking. A short-term deepening of the halocline occurred at the very end of this interval. During the early Holocene ( ĝ1/4 ĝ€11.7-7.8ĝ€ka), mild conditions led to glacier retreat, a reduced sea ice cover and increasing sea surface temperatures, with a brief interruption during the Preboreal Oscillation ( ĝ1/4 ĝ€11.1-10.8ĝ€ka). Due to a ĝ1/4 ĝ€6000-year gap, the mid-Holocene is not recorded in this sediment core. During the late Holocene ( ĝ1/4 ĝ€1.8-0.4ĝ€ka), a slightly reduced AW inflow and lower sea surface temperatures compared to the early Holocene are reconstructed. Glaciers, which previously retreated to the shallower inner parts of the Woodfjorden system, likely advanced during the late Holocene. In particular, topographic control in concert with the reduced summer insolation partly decoupled glacier dynamics from AW advection during this recent interval.