Glacier decay boosts formation of new Arctic coastal environments – lessons learned from Svalbard

The consequences of accelerating climatic warming on Arctic landscape evolution are far-reaching. In Svalbard, glaciers are rapidly retreating after the Little Ice Age, which leads to exposing new coastal landscapes from marine-terminating glaciers. Precise quantification of these changes was limited until the complete dataset of Svalbard glacier outlines from 1930’s was made available. Here, we analyse the new Svalbard glacier change inventory data and demonstrate that glacier retreat was responsible for a major shift from marine-terminating towards land-terminating glaciers in the last century. This retreat also led to the formation of 922.9 km of new coastline since 1930’s (representing increase of 16.37% in coastline length) creating pristine landscapes governed by paraglacial processes and sediment-rich nearshore fjord environments. Recent palaeogeographical reconstructions suggest that such a mode of coastal evolution was dominant over the extended periods of the Holocene. Transitions from marine-terminating to land-based glaciers had significant implications for fjord circulation, biological production, state of marine ecosystems, biogeochemical cycles between land and seas, and CO₂ budget in coastal waters. Still ongoing climate warming with associated further glacier retreat may lead to more coasts to be exposed in the future. Moreover, glacier retreat will likely cause collapse of Hornbreen-Hambergbreen glacier bridge leading to separation of Sørkappland and rest of Spitsbergen with severe consequences for regional ocean circulation and climate dynamics.

New bays, new straits, new peninsulas and new islands, that have appeared in the last decades of unprecedented warming and associated decay of marine-terminating glaciers in the Arctic are predominantely uncharted and unexplored territories which foreshadow ice-free Arctic and other cold regions of the warmer future. The importance of transdisciplinary research exploring those deglaciated oases has never been more important than at present.

Acknowledgement: The research leading to these results has received funding from the Norwegian Financial Mechanism  2014-2021: SVELTA - Svalbard Delta Systems Under Warming Climate (UMO-2020/37/K/ST10/02852) based at the University of Wroclaw.