At Mount St. Helens, a USGS geologists looks up the Loowit Channel to the rock-covered mass of Crater Glacier. Crater Glacier owes its existence to the large amphitheater (crater) that formed as a consequence of the May 18, 1980, eruption of Mount St. Helens. Throughout each winter, snow avalanches off the 2,000 foot high (610 m) crater walls onto the crater floor. The steep crater walls shade the glacier from sunlight during most of the year and rock debris mantles its top providing insulation to reduce melting. At an elevation of about 2,000 m (6,561 ft), the glacier would not exist on a typical nearby Cascade mountain but is here at Mount St. Helens because of this unique environment. Image by A. Barsotti; Crater Glacier map by Adam Mosbrucker.
No comments:
Post a Comment