Posteruption glacier development within the crater of Mount St. Helens, Washington, USA

摘要: The cataclysmic eruption of Mount St. Helens on May 18, 1980, resulted in a large, north-facing amphitheater, with steep headwall rising 700 m above the crater floor. In this deeply shaded niche glacier, here named Amphitheater has formed. Tongues ice-containing crevasses extend from main ice mass around both east and west sides lava dome that occupies center Aerial photographs taken September 1996 reveal small glacier southwest portion amphitheater containing several bergschrund-like feature at its head. extent time is probably about 0.1 km2. By 2001, debris-laden had grown to 1 km2 area, maximum thickness 200 m, contained an estimated 120,000,000 m3 rock debris. Approximately one-third volume thought be debris derived mainly avalanches surrounding walls. newly formed not only largest but aerial exceeds all other remaining glaciers combined.