View south of Redoubt volcano, Alaska on 7 April 1990. Hot pyroclastic flows during eruptions between December 1989 and June 1990 melted most of upper Drift glacier. Resulting floods threatened an oil storage-and-loading facility at the valley mouth. Debris of the pyroclastic flows thickly mantled the piedmont lobe of the Drift glacier (in foreground).
View northwest of Redoubt volcano, Alaska, on 4 March 1990. Steam commonly vents from the dome in the crater in between eruptions.
View west of Redoubt volcano on 10 April 1990. Drift glacier occupies the valley extending from the vent (at steam plume) to the valley bottom (visible in lower right).
View southwest down Crescent glacier on south flank of Mt. Redoubt volcano in August 1990. A hot pyroclastic surge during the eruption of 15 December 1989 caused thick snowpack near on the upper volcano flank to avalanche and partly melt. The glacier in the right middleground is blanketed (dark material at surface) by an an unusual ice diamict emplaced during the eruption.