Útdráttur:

Glaciers worldwide have retreated rapidly over the past century, and this rate is projected to accelerate with future climate change. As glaciers retreat, meltwater can accumulate in proglacial lakes, which often form in overdeepened basins carved by glacial erosion that can store large volumes of water. Glacier retreat and thinning also destabilize surrounding valley walls, making them prone to mass movement events such as landslides or rock avalanches. If a mass movement event enters the lake, it can generate a displacement wave that triggers a glacial lake outburst flood (GLOF), significantly modifying landscapes and impacting communities and infrastructure downstream. This process occurs in glacial regions across the globe, yet it remains understudied in Iceland.

This talk investigates this emerging hazard in south Iceland, focusing on Fjallsjökull, an outlet glacier of Vatnajökull ice cap. It presents: 1) updated maps of proglacial lake bathymetry and subglacial topography derived from multibeam sonar and radio-echo sounding surveys, respectively; 2) past lake volume and glacier changes and projected future evolution; and 3) potential scenarios of mass movement-triggered outburst floods. These results lay the foundation for future work on flood modeling and hazard planning to mitigate impacts on communities, infrastructure, and tourism at Fjallsjökull. We also discuss ongoing work at other proglacial lakes in south Iceland, namely Sólheimajökull, as well as broader application to other Arctic and alpine regions worldwide.

Öll velkomin!