Mount Redoubt volcano erupted from 1966 to 1968, causing a lot of glacier ice to be removed from Drift Glacier in Alaska. This led to flooding and separation of the glacier. The lower part of the glacier was covered in sand and ash, which slowed down the melting of ice. By 1976, the upper part of the glacier had recovered due to snowfall and avalanches. When the upper and lower parts reconnected, the glacier thickened and sped up. The lower part thickened by 70 meters and sped up significantly, while the upper part thinned. The glacier seems to be going back to how it was before the eruptions.