Holocene benthic foraminiferal record from a high‐arctic fjord, nordaustlandet, svalbard

Abstract

Kubischta, F., Knudsen, K.L., Ojala, A.E.K. and Salonen, V.‐P., 2011. Holocene benthic foraminiferal record from a high‐arctic fjord, Nordaustlandet, Svalbard. Geografiska Annaler: Series A, Physical Geography, 93, 227–242. DOI: 10.1111/j.1468‐0459.2011.00434.x

Abstract

This study presents the results of benthic foraminiferal analyses of a marine core record from about 100 m water depth in the fjord environment of Isvika bay, Nordaustlandet, Svalbard. During the Last Glacial Maximum, the bay was glaciated by the north‐western sector of the Svalbard‐Barents Sea Ice Sheet. The foraminiferal assemblages reflect glaciomarine conditions during deglaciation and early Holocene (about 11-250–9640 cal. yr bp) followed by glacier‐distal environment in an open fjord with relatively high influence of Atlantic waters from the open ocean (9640–7430-cal. yr bp). A subsequent foraminiferal indication of a glacial advance was followed by deposition of a diamicton unit within a short time period at 5800–5700 cal. yr bp. The mid‐ and late Holocene were characterized by assemblages indicating restricted open‐ocean connection and gradually more severe conditions, which are considered to be caused partly by a gradual cooling and freshening of the Atlantic water inflow to the shelf area and partly by a continuous isostatic uplift of the area. The foraminiferal record shows that the environmental changes in Murchisonfjorden are not just an effect of changes in solar insolation but are also influenced by local processes, as well as changes in the Atlantic water inflow to the northern Svalbard shelf and to the fjord via Hinlopenstretet.

Key words:

• arctic
• benthic foraminifera
• fjord
• Holocene
• Nordaustlandet
• Svalbard

Acknowledgements

Our thanks go to captain Tadeusz Pastusiak and the crew of MS Horyzont II for making the coring possible, and to Katarzyna Sliwinska and Dorthe Reng Erbs‐Hansen for the help with the foraminiferal determination at Aarhus University. Thanks also go to Aku Heinonen for his support with calculations and maths (the AFARC) and to Seija Kultti and Marek Zajączkowski for valuable discussions. The manuscript benefited from the constructive comments of two anonymous reviewers. The language of the manuscript was improved by Anna Heumann Kaya. This work was financed by the Academy of Finland (project no. 1116709) and is part of the IPY‐Kinnvika project no. 58.

Additional information

Notes on contributors

Frauke Kubischta

Frauke Kubischta, Department of Geosciences and Geography, Division of Geology, University of Helsinki, Gustaf Hällströmin katu 2a, PO BOX 64, 00014 University of Helsinki, Finland

Email: [email protected]

Karen Luise Knudsen

Karen Luise Knudsen, Department of Earth Sciences, Aarhus University, Høegh‐Guldbergs Gade 2, DK‐8000 Aarhus C, Denmark.

Antti E.k. Ojala

Antti E.K. Ojala, Geological Survey of Finland, Betonimiehenkuja 4, PO BOX 96, 02151 Espoo, Finland.

Veli‐pekka Salonen

Veli‐Pekka Salonen, Department of Geosciences and Geography, Division of Geology, University of Helsinki, Gustaf Hällströmin katu 2a, PO BOX 64, 00014 University of Helsinki, Finland.