Collaborative Research: RUI: Frontal Ablation Processes on Lake-terminating Glaciers and their Role in Glacier Change

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Glaciers around the world are changing rapidly in response to warming temperatures. Glaciers that end in water often thin and retreat faster than those ending on land because they lose ice through melt below the waterline and through the breaking off of icebergs. While many past researchers have studied the workings of glaciers ending in the ocean, very few have focused on glaciers that end in lakes and how these two types of glaciers might function differently. In our project, we will study a set of three glaciers that end in lakes; collecting information about the glaciers themselves, the lakes they end in, and the sediment moving between the glacier and lake. The investigators will work with students from two different programs in Alaska to identify how much extra ice is being lost due to these lakes and how much that ice loss matters for how the glaciers will change over the coming decades.Globally, lakes at the end of glaciers have grown rapidly over the past decades. However, it remains unclear whether lakes are growing as a passive response to glacier retreat that is largely driven by changing atmospheric conditions (warming air temperature and/or declining winter snowfall), or whether the lakes themselves are driving this retreat by enabling extra ice loss. Our team brings together a glaciologist, an oceanographer, and an Arctic earth system modeler to quantify the amount of ice lost through iceberg production and underwater melt on three large glaciers draining the Juneau Icefield that end in lakes. The investigators will collect both short- and long-term observations of conditions in the lake (depth, temperature, suspended sediment concentration) using a sonar system and probes cast from a boat, as well as buoy-mounted instruments. The investigators will also measure glacier ice thickness and speed using ground-based radar, GPS systems, and satellite observations. These datasets will be fed into computer models to estimate how much additional ice is being lost due to the lake, how this will change in the future, and how much the lake’s presence will alter the glacier’s overall ice loss over the 21st century. This information will help us understand how fast glaciers across the world will change over the coming decades, which will enable better management of downstream ecosystems and water resources, as well as promoting climate change resilience. In addition to the science objectives, the project will strengthen the STEM workforce by partnering with undergraduate programs to develop computational workshops and broaden representation within the earth science community.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.