GLIMMER investigates how glacial lakes influence glacier retreat in High Mountain Asia, with a focus on calving processes and lake evolution in the Lunana region of Bhutan. As glaciers thin and retreat, many develop proglacial lakes at their fronts, which can accelerate ice loss through calving and increase the risk of glacial lake outburst floods (GLOFs).
The project focuses on a set of glacier–lake systems that span different stages of development, from supraglacial ponds to fully developed proglacial lakes. This provides a natural framework to study how lake evolution and glacier dynamics are coupled across a range of conditions.
Objectives
We aim to develop a process-based understanding of glacier–lake interactions. The main objectives are to:
- identify the physical mechanisms controlling calving in lake-terminating glaciers
- understand how evolving lake geometry influences glacier stress and flow
- quantify the role of hydrostatic forcing and frontal ablation in driving retreat
- assess how glacier–lake feedbacks contribute to long-term glacier change and hazard potential
Approach
We use the Ice-Sheet and Sea-level System Model (ISSM) to simulate the coupled evolution of ice flow, lake level, and calving. The modelling framework is designed to isolate key processes by systematically varying lake conditions and basal properties, allowing us to disentangle the relative contributions of buoyancy, stress changes at and beneath the terminus, and calving dynamics.
High-resolution surface topography and lake bathymetry are used to construct realistic model geometries, enabling simulations that capture both subaerial and submerged controls on glacier behaviour. This provides the background for a physics-based framework for understanding glacier–lake systems.