1964 Great Alaska Earthquake
1964 March 28 03:36 UTC
1964 March 27 05:36 p.m. local time
Largest Earthquake in Alaska
One span of the "Million Dollar" truss-bridge of the former Copper River and Northwestern Railroad was dropped into the Copper River by the earthquake, and the other truss spans were shifted on their piers.
The earthquake shifted the steel trusses of the Copper River and Northwestern Railroad bridge near Round Island from 1 to 2 feet. This view shows one of the displaced trusses, which pounded against an adjacent steel girder span. The girder span was moved to the right, its concrete pedestal was rotated, and the girder span almost fell into the river. Note the shortening indicated by buckling of the guardrail.
A series of earthquake triggered landslides in glacial deposits disrupted almost a mile of The Alaska Railroad main line at Potter Hill, near Anchorage.
Close-up of damaged homes at Turnagain Heights landslide, Anchorage.
A subsidence trough (or graben) formed at the head of the "L" Street landslide in Anchorage during the earthquake. The slide block, which is virtually unbroken ground to the left of the graben, moved to the left. The subsidence trough sank 7 to 10 feet in response to 11 feet of horizontal movement of the slide block. The volume of the trough is theoretically equal to the volume of the void created at the head of the slide by movement of the slide block. A number of houses seen in this photograph were undercut or tilted by subsidence of the graben. Note also the collapsed Four Seasons apartment building and the undamaged three story reinforced concrete frame building beside it, which are on the stable block beyond the graben.
A detail illustrating the violence of the surge waves that struck Whittier: man holds mounted tire where wave has driven a piece of wood through the tire.
Trees up to 24 inches in diameter and between 88 and 101 feet above sea level were broken and splintered by the surge wave generated by an underwater landslide in Port Valdez, Prince William Sound.
The rails in this approach to a railroad bridge near the head of Turnagain Arm were torn from their ties and buckled laterally by channelward movement of the river banks during the earthquake. The bridge was also compressed and developed a hump from vertical buckling.
The rails were buckled by lateral movement of the embankment fill toward an underlying culvert, which had collapsed.
Photos from the Earth Science Photographs from the U.S. Geological Survey Library, by Joseph K. McGregor and Carl Abston, U.S. Geological Survey Digital Data Series DDS-21, 1995.