When the Arctic was warm – the Paleogene of Svalbard as a look into the future
From UNIS, Svalbard, Norway
The Paleogene greenhouse world leading up to the Paleocene-Eocene thermal maximum with average global temperatures 5-8ºC higher than present is considered an analogue for a future warm earth. The combination of the high latitude location of Svalbard in the Paleogene and a warm world is an analogue that does not exist today, making deep-time palaeoclimate work in this area essential for understanding and constraining implications for Earth system models for the Arctic.
Palaeocene coal seams from the Firkanten Fm, Svalbard, Arctic Norway provide a globally important record of environmental change and atmospheric conditions in a terrestrial setting in the high Arctic during greenhouse conditions. The Firkanten Formation comprises continental to shallow marine sandstones, shale and coal deposited in an early foreland basin with alternating sea level at c 78 degrees north. Peat (coal) represents a relatively undisturbed environment from which geochemical signatures of climate change can be extracted. High resolution inorganic geochemical data from coal seams are known to record circulation patterns, dust deposition rates, (atmospheric nutrient supply), wildfires, provenance and its response to changing climate (Marshall et al., 2016). Marshall (2013) interpret the 1,4 m thick Longyear seam as representing continuous deposition for 90 000 – 100 000 years. The up to 5 m thick Svea seam may represent up to 400.000-500.000 years. Such time frames make palaeoclimate records from coal seams comparable to e.g. ice cores and deep marine records, with the added benefit that palaeoclimate data from palaeowetlands, record changes in a terrestrial environment comparable to where people live. Recent sampling of the coal from the still open Mine 7 in Longyearbyen is being analysed currently to confirm this hypothesis, and samples from the recently closed Lunckefjell Mine and soon to be closed Svea Nord mine is taken for future analysis and will provide data for high-resolution palaeoclimate studies in the years to come.
Sedimentary deposits from the Central Tertiary Basin are being put into this climatic context in terms of investigating drainage basin characteristics and sediment transport systems in a warm Arctic. New studies using drone images to provide 3D architecture from even inaccessible mountain sides will improve the possibilities for quantification of precipitation and discharge parameters from the basin.