Earthquake

Fourth Avenue in Anchorage, Alaska, looking east from near D Street.

March 27, 1964: The most powerful earthquake [to date] hit the US and North America. Called either the 1964 Alaska earthquake or the Good Friday earthquake, the 9.2 magnitude quake struck at 5:36 PM. It was a megathrust earthquake meaning one tectonic plate was thrust under another plate. These are the most dramatic, highest magnitude, types of quakes. The quake itself lasted for four minutes. The epicenter was 78 miles east of Anchorage, which suffered massive destruction. However, only nine people were killed by the quake and its damage.

The epicenter was also 12.4 miles north of  Prince William Sound and 40 miles west of Valdez. The focus of depth was approximately 15.5 miles. The ocean floor shifted and created tsunamis measuring up to 220 feet high. There were another 106 deaths attributed to the tsunamis in Alaska. More tsunami destruction hit Oregon and California resulting in another 16 casualties. There were also rockslides triggered in Alaska, causing property damage but no deaths. There was a measurable vertical displacement up to 38 feet and the quake affected an area of 100,000 square miles.

Property damage was estimated at $310 million [about $2.12 billion in today’s dollars]. Most of this damage occurred in Anchorage. The downtown area was heavily damaged. Much of the region was built on sandy bluff sitting atop “Bootlegger Cove clay”. The resulting landslides caused buildings to crumble. The Government Hill school was torn into two pieces by the landslide and the area near the rail station was also heavily damage by sliding buildings.

The coastal areas of Prince William Sound, Kenai Peninsula, and Kodak Island were heavily damaged. The ports of Seward, Whittier, and Kodiak were all damaged by the earthquake itself and then inundated by the ensuing tsunami. Fires were also damaging post disaster. Near Cordova, the Million Dollar Bridge collapsed – it was being renovated and work had begun in 1958 and stopped after the quake. The western shore of Canada also was hit by the tsunamis causing more property damage but no deaths. There were over 10,000 aftershocks recorded after the main quake. In the first day alone, eleven aftershocks with a magnitude greater than 6.0 struck and nine more of these major events occurred in the next three weeks.

“All farewells should be sudden, when forever.” – George Byron

“Animals when in company walk in a proper and sensible manner, in single file, instead of sprawling all across the road and being of no use or support to each other in case of sudden trouble or danger.” – Kenneth Grahame

“God answers sharp and sudden on some prayers, And thrusts the thing we have prayed for in our face, A gauntlet with a gift in it.” – Elizabeth Barrett Browning

“Hence the same instant which killed the animals froze the country where they lived. This event was sudden, instantaneous, without any gradual development.” – George Cuvier

Also on this day:
Long Distance Communication – In 1899, the first international radio communication occurred.
Tenerife – In 1977, the worst aviation disaster occurred.