Linking GLOFs at ice-dammed lakes in Greenland to ice configuration: The case of Lake Tininnilik

Glacier lake outburst floods (GLOFs) from ice-dammed lakes in Greenland are significant hydrological events that have a far-reaching impact on downstream ecosystems, infrastructure and glacier dynamics. A notable example is Lake Tininnilik in western Greenland, which is dammed by the marine-terminating Saqqarleq Sermia. The lake has a history of rapid drainage events involving water volumes of ~1.5 km³ and sudden drops in water level of ~65 m. Glacier thinning has increased the lake's drainage frequency from ten to five years, as evidenced by the 2010 and following GLOFs. The most recent event was observed in late July 2025.

However, GLOFs at Lake Tininnilik vary considerably in timing from year to year, depending on the configuration of the ice, while the trigger factors appear to change between ice-dam flotation and increased glacier velocity. This raises questions regarding the interplay between glacier dynamics and lake drainage processes.

Here, we present a comprehensive analysis of the relationship between the recent and historical drainage behaviour of Lake Tininnilik (occurrence, frequency and volume) and the configuration of the ice (particularly velocity and thickness) by combining time series of remotely sensed lake and ice parameters.

As part of the LIDL (Linking Ice-Dammed Lake Drainage to Ice Dynamics in Greenland) project, our aim is to apply the developed analysis framework to a wide range of ice-dammed lakes in Greenland exhibiting GLOF behaviour. Our goal is to gain a broader understanding of the role of ice flow dynamics, particularly ice thickness and velocity, in modulating and potentially initiating drainage events. This will contribute to improved GLOF prediction in a changing climate.