Rising Threat of Outburst Floods

We found that more than 80 per cent of the lake growth has occurred in the mapped basins, illustrating how this approach can help locate glacial lakes that are likely to form and expand in the future.

With this information, we found that existing glacial lakes in the region may , growing by as much as 1,640 square miles (4,250 square kilometers). A glacial lake at the terminus of , the largest glacier by area in southeast Alaska, could expand to cover an additional 570 square miles (1,475 square kilometers) alone. That would create what would be the second-largest lake in Alaska.

As glaciers continue to retreat, new basins will be exposed, many of which could fill with water. In total, more than 5,500 square miles (about 14,200 square kilometers) of overdeepened basins exist in Alaska, pointing to a landscape that is going to look very different in the coming decades to centuries.

When a glacier terminates in a lake, the warmth of the water can speed up the ice’s melting, making the glacier flow faster, thin and retreat, thereby expanding the size of the lake. We found that glaciers that terminate in lakes are shrinking .

Future as glaciers retreat

Future climate projections combined with sophisticated glacier models indicate that glaciers will cumulatively retreat by 26 per cent to 41 per cent by 2100, spelling the .

This is concerning for numerous reasons. Glacier mass loss is currently the . Melting glaciers also change the  that feed major rivers, particularly Asian rivers such as the Indus and Ganges. And they create hazards, such as the outburst floods that originate from glacial lakes.

The landscapes that we know and love are transforming before our eyes, and with these changes come growing concerns about hazards.