MEER Seminar: Glacial Lake Outburst Floods in Patagonia: A decreasing hazard?

Glacial Lake Outburst Floods in Patagonia: A decreasing hazard?

With the support of the MASTS Engagement with European Research (MEER) grant, Professor Bertrand and Dr Hage visited St Andrews in September to co-develop a COST action to bring together a international network of researchers to better understand carbon cycling in fjord environments.

Talk Summary: 

Glacial Lake Outburst Floods (GLOFs) constitute a major hazard in glacierized environments. Despite a recent increase in the size and number of glacial lakes worldwide, there is only limited evidence that climate change is affecting GLOF frequency and magnitude. In Patagonia, GLOFs are particularly pronounced in the Baker River watershed (47°S), where 23 GLOFs occurred between 2008 and 2020 due to the drainage of Cachet 2 Lake into the Colonia River, a tributary of the Baker River. To assess the possible long-term relationship between GLOF frequency, glacier behavior, and climate variability, flood layers preserved in fjord and floodplain sediments were analyzed. Results show that the sediments deposited in the fjord immediately downstream of the Baker River constitute the best high-resolution archive of GLOF frequency. However, very high accumulation rates at the fjord head (~3 cm/yr) preclude generating GLOF records that go beyond pre-instrumental timescales. The sediments of the Valle Grande floodplain, on the other hand, hold a 3 kyr record of high-magnitude flood frequency. They show that high magnitude GLOFs were more frequent during Neoglacial advances, particularly at 2.6–2.2 and 0.7–0.1 cal kyr BP. This relation most likely reflects the ability of larger ice dams to hold larger glacial lakes, resulting in higher magnitude outburst floods when the dam breaks. Although rapid glacier retreat is likely responsible for high GLOF frequency in the 21st century, our results suggest that high-magnitude GLOFs are more likely to occur when glaciers are larger and thicker.

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MASTS Engagement in European Research (MEER) funding is to help MASTS members apply for European research funding (e.g. Horizon Europe, Interreg etc). MEER funds may be used for a wide range of engagement with the Europe research framework process, not just the preparation of funding proposals. Examples include establishing network connections; showcasing skills and capabilities; and participating in specific networking activities both for policy influencing and project