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Abstract:
Glacial-derived suspended matter is an important source of nutrients to Svalbard fjords, including bioessential nutrients such as iron, ammonia, trace metals. The flux of terrestrial material enhanced by intensive deglaciation in Svalbard results in substantial changes in continental shelf conditions. According to the latest forecasts, the mass of glaciers in the Svalbard is expected to decrease by 20-50% by the end of the century under the RCP 2.6 scenario and by 40-85% under the RCP 8.5 scenario, and the area – by 10-50% and 30-80% accordingly. Further changes in glaciation are expected to result not only in volumetric changes in matter supply to fjords but substantial shift in the mechanics of this process as sustained glacier recession will eventually change the glacial regime from predominately tidewater to land-based.Present study reveals interconnection between glacier melt regime and characteristics of the suspended sediment content in tidal waters. Two contrast glacier basins have been chosen as objects of the study – tidewater Hansbreen draining into Hansbukta and land-based Gåsbreen draining into Gåshamna. The study couples energy-balance modelling of glacier ablation with field measurement of suspended sediment content, sediment flux, and fresh water fraction in the bays during 2015-2022. Possible mechanisms of accelerated glacier melt driving changes in the flux of terrestrial material to Svalbard fjords are discussed. The research contributes to the investigation of consequences of deglaciation on the marine biological production in High Arctic areas.This study is funded by the Norwegian Financial Mechanism 2014-2021, grant agreement no. UMO-2019/34/H/ST10/00504.
