(upbeat music) - I'm Jay Martin Jr. in the Crosscut KCTS9 newsroom.

Mount Rainier's largest glacier is shrinking, raising questions about flooding and water supply as the climate warms.

Emmons, the largest glacier in the continental US, is an important freshwater source for the Puget Sound, feeding into the White River.

Although Emmons grew in size each winter for decades, its surface is now melting irregularly.

Scientists are studying the giant glacier's size, shape, and debris fields, trying to understand how much water Emmons will give off and where it will flow.

Flooding is one risk for melting glaciers like Emmons.

Warmer years are increasing the likelihood for bigger floods, and when a glacier loses water that can't be quickly replenished by snow or rain, water shortages are then the focus.

The waterways normally fed by the glacier's melt no longer receive the same dependable and sizable summer melt-off.

I'm Jay Martin Jr. Find nonprofit Northwest news every day on crosscut.com.

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