1964 Great Alaska Earthquake
1964 March 28 03:36 UTC
1964 March 27 05:36 p.m. local time
Largest Earthquake in Alaska
House displaced by compressional ridge formed at toe of L Street landslide Anchorage district. Cook Inlet region, Alaska. 1964.
Control tower at Anchorage International Airport, collapsed by earthquake shaking. Anchorage district, Cook Inlet region, Alaska.
Close-up view of the damage created at the piers of the "Million Dollar" truss bridge by movement of the truss spans during the earthquake. Note the bent base plates, the sheared 2-inch diameter bolts and the overturned rocker bars.
The Turnagain Heights landslide in Anchorage, occurred along a steep bluff fronting Knik Arm of Cook Inlet. Its length, which is parallel to the bluff, was about 1.5 miles; its width was about .25 to .50 miles. This landslide reduced to rubble many of the finer homes of the city. Failure here, and in the "L" Street, Fourth Avenue, and Government Hill landslides in Anchorage occurred on horizontal or near horizontal slip surfaces in the Bootlegger Cove Clay, a marine silt of Pleistocene age. Alaska.
This reinforced concrete deck of highway bridge across Twenty Mile River near Turnagain Arm of Cook Inlet fell into the river during the earthquake; the adjacent steel railroad bridge survived with only minor damage. Both bridges were founded on thick deposits of soft alluvium and tidal flat mud, and were subjected to severe seismic vibration. During the earthquake some of the concrete deck sections hit the underlying wood pilling with sufficient force to drive the bare ends of the wood piles through the concrete deck.
The marquee of the Denali Theater, which was in the graben of the Fourth Avenue landslide in Anchorage, subsided until it came to rest on the sidewalk in front of the theater, which was on ground that was not involved in the landslide.
This truck at Lowell Point, 2 miles from Seward, was bent around a tree by the surge waves generated by the underwater landslides along the Seward waterfront. The truck was about 32 feet above water level at the time of the earthquake.
Collapse of Fourth Avenue near C Street, Anchorage, due to earthquake caused landslide. Before the earthquake, the sidewalk at left, which is in the graben, was at street level on the right. The graben subsides 11 feet in response to 14 feet of horizontal movement. Anchorage district, Cook Inlet region, Alaska. 1964.
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.