RAISE: Confronting glacier outburst flood hazards to improve glacial flood forecasts across northwest North America

The Áak’w T’áak Glacier (Mendenhall Glacier) poses an annual flood hazard to Juneau, Alaska, due to glacier outburst floods. This research will develop and apply computer models to assess outburst flood hazards across northwest North America by studying in detail the Áak’w T’áak Glacier. Resulting floods can inundate nearby towns and infrastructure in a matter of hours causing major landscape and socioenomic impacts.

These hazards originate when glacier movements form dammed ice-free basins, which are common in glacier-covered landscapes. Water that flows into an ice-dammed basin is initially unable to drain, causing the water to pool into large reservoirs. After a basin fills, the water bores a hole underneath the glacier.

Once a basin begins to drain, runaway processes cause the basin to drain rapidly over the next few days. This rapid drainage is referred to as a glacier outburst flood. The results from this study will be used to create a large-scale flood hazard model that will be used to improve glacial flood forecasts across northwest North America.

The study will create a detailed assessment of current and future outburst flood hazards using the Áak’w T’áak Glacier. Researchers will use field and remote sensing data to inform physically based models of glacier evolution and outburst floods. Previous research quantified past and future changes in glacier volume and investigated the physics of ice-dammed glacier outburst floods.

But physically based models are needed to identify and quantify how ice-dammed outburst flood hazards will change in the future. Glacier flow models will quantify changes in the storage capacity of flood-producing ice marginal basins during glacier retreat. Results will then be used to model outburst floods and evaluate how flood magnitudes will change over time.

The focused effort on the Áak’w T’áak Glacier will then be used to tune and test the sensitivity of a large-scale model for identifying the location of future outburst flood hazards across northwest North America. The glaciers deemed most prone to destructive outburst floods will be assessed using the resulting model framework. Close collaboration with federal and state agency partners and stakeholders will ensure resulting tools will be useful for forecasting floods, assessing emerging outburst flood hazards, and communicating information about outburst flood hazards to communities.

This project is jointly funded by the Division of Research, Innovation, Synergies, and Education in the Directorate for Geosciences, and the Office of Advanced Cyberinfrastructure through the National Discovery Cloud for Climate initiative.

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.