Thirsty River

If you live in the northwestern United States or anywhere in the world where rivers are fed by glaciers and summers are dry, you can thank the mountain ice for your summer water. Glaciers act like sponges for winter precipitation. They gather moisture during the winter months in the form of snow and release it when the sun's high-angled solar radiation melts it during the summer dry months. Farmers and those who love being refreshed by a drink of glacial-fed river water—which includes our salmonid friends—might become a bit parched if it weren't for glaciers. Scientists consider glaciers to be hydrologic buffers—when rain and snow is scanty, glaciers fill in the gap.

Over the past 100 years a number of glaciers have disappeared from the mountain cirques of North Cascades National Park. Scientists want to know the status of the remaining glaciers. Are they gaining mass or losing it over the years? The results from these glacial studies are relayed to local communities and others who depend on the water which flows from North Cascades glaciers.

  Glacial Monitoring Summary
  Cordilleran Ice Sheet
  Pleistocene Alpine Ice
  Annual Precipitation

Study these interactive graphs and complete Glacial Balance to receive a clue.

  Sponge it Up!
  Critical Thinking: Imagine the Pleistocene

  Mount Shuksan
  Glacier Peak
  U-Shaped Valley
  Moraine
  Glacier Research
  Glacier Coring
  Data Collection

Glossary: ablation, buffer, cirques, firn line, hydrology, precipitation, salmonid, watershed
Links: Additional NPS Glacial Monitoring, Glacier Change in the Upper Skagit River Basin