Climate and the Gorge

Mt. Hood’s Glaciers Melting Away, Say PSU Glaciologists

By Susan Hess, 3-08-06

How many glaciers are on Mt. Hood? Eleven, spread around the mountain’s summit. That’s how we think of our volcano – snow covered. But if you think Mt. Hood is looking a bit scantily clad lately, you’re right.

Last Friday night, three scientists presented their study of the mountain’s glaciers to a Hood River audience. Dr. Andrew Fountain, professor of geology and geography at Portland State University; Robert Schlicting, of Portland’s Cleveland High School; and Keith Jackson, graduate student at PSU were brought here by the Crag Rats.

The PSU team looked at whether Mt. Hood’s glaciers in particular were growing or shrinking and at what rate. They found that the mountain’s glaciers on average have lost 34 percent of their volume. Since 1982, one of those glaciers, Eliot Glacier, has shrunk 30 meters in depth and lost fifty percent of its volume. White River Glacier has lost 61 percent in volume.

This PSU glacier team has been studying not only Mt. Hood but all the glaciers of the western United States. In the west, excluding Alaska, there are about 1712 glaciers. The state of Washington holds first place with the most – 1225, which provide 470 billion gallons of water each summer in runoff.

Glaciers are climatic indicators, telling us whether our climate is cooling or heating depending on if they are growing or shrinking. Glacial ice age can be hundreds to hundreds of thousands of years old. As such, they contain a record of climatic information and help us understand the earth’s processes and changes. Tiny air bubbles in glacial ice keep air from thousands of years ago. Glaciers cover 10 percent of our earth and store about 75 percent of the world's freshwater.

Mt. Hood’s shrinking glaciers are typical of a worldwide trend. Scientists from many countries are seeing massive retreats of glaciers worldwide over the past 60 to 100 years. Glaciers lose volume in thickness and in length. Some have retreated a mile. In the 120 year period from 1880 to 2000, those retreats have caused a sea level rise of 20 centimeters.

The PSU team also studied the effect of rock debris covering parts of many glaciers and found that it can slow the melting rate. But is seems not enough to slow this dramatic change in earth’s glaciers.

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