Posted on 03/27/2014 10:20:55 AM PDT by hoagy62
Today is the 50th Anniversary of the Great Alaskan Earthquake. It struck at 5:36pm ADT on March 27, 1964. The moment magnitude was 9.2 on the Richter scale.
There were 11 aftershocks on the day of the earthquake over 6.0, and 9 more over the next three weeks.
The Earth "rang" like a bell for several weeks afterward. Vertical ground movements of 5 to 10 cm were detected in Texas and Florida.
I can’t even fathom how rough that had to have been - especially over a four minute duration.
Alaska is so much more built up now than in ‘64. The damage and loss of life would seem to be much larger if it happened today.
In addition to the magnitude of the shakes, I was always amazed by the duration.
The earthquake lasted approximately 4.5 minutes.
http://earthquake.usgs.gov/earthquakes/events/alaska1964/
I’ve been in small earthquakes. They were all like a second or 3 at the max.
Wow! Very interesting!
Fracking?
Climate change?
Sarah Palin’s Birthday?
I was in the 6.8 Nisqually quake in 2001. It lasted about 30 seconds. That was quite long enough for me.
They say that if the Cascadia Subduction Zone does the “full 9.0 rip”, it could shake for as long....if not longer...than the Alaska quake.
The Koch Bros induced polar bears to rise up against climate change and the resulting stampede caused this earthquake, in the past.
IIRC, my readings on some aspects of this quake was there were vertical displacements of nearly 60 feet. That would seriously ruin your day.
I remember seeing a video taken from the deck of a ship in a harbor. IIRC it was Polish cargo ship..
Anyway a fissure opened next to the ship and the bay started emptying into it. Incredible.
I was down in Georgetown for the Nisqually EQ in an area that was all a bunch of fill built up on old tidal flats. At first I thought a train was derailing on the track that ran next to my shop. There was a big freight yard next door and you could see the waves moving across the ground. It was pretty weird.
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The port of Valdez was wiped out. They had to move the city about 4 miles after the quake.
http://www.youtube.com/watch?v=TdrMKt55VBQ
I had some of my relatives in South Louisiana who reported seeing some of these events.
https://gsa.confex.com/gsa/2011SC/finalprogram/abstract_186940.htm
EFFECTS OF THE 1964 ALASKAN EARTHQUAKE ON SOUTH LOUISIANA AND SOUTH TEXAS
GAGLIANO, Sherwood M., Coastal Environments, Inc, 1260 Main St, Baton Rouge, LA 70802, sgagliano@coastalenv.com
On March 27, 1964, unusual water seiches and felt effects occurred across the Northern Gulf region from the Chandeleur Islands, Louisiana to Freeport, Texas. These effects, chronicled on the front pages of the region’s newspapers, have been attributed to long-period surface shock waves from the magnitude 8.3 Prince William Sound, Alaska earthquake more than 3000 miles away. Re-evaluation of this event, which has attracted little attention from earth scientists, within the context of a revised regional structural model contributes significantly to understanding neotectonics in the Northern Gulf. The model relates distinctive geomorphic signatures of faults to known subsurface faults and fractures. Movements induced by the 1964 event identify live faults within the structural framework.
A series of 5 or 6 waves with peak-to-point amplitudes of one to two meters over a period of 20 to 30 minutes were reported at numerous locations including the Industrial Canal New Orleans, Krotz Springs, Golden Meadow, in Louisiana and Beaumont-Port Arthur, and Houston in Texas. Ocean going vessels were lifted and debris was churned from stream bottoms. Felt reports suggest that shock waves also triggered secondary earthquakes along local faults. A Rice University seismologist reported that Houston was lifted 10 cm as the gigantic surface wave passed through.
I remember hearing this on my transistor radio as I was walking home from Good Friday mass. It was big news for the rest of the week and the footage of the bay disappearing that I saw later was amazing.
I’m sure the buildings are as “earthquake proof” as technology will allow. Alaska is much like Japan, in that it has active volcanos and is subject to earthquakes.
That’s why the Japanese built their homes of wood and paper.
And a man and his son rode out the wave and lived...
A friend of mine was a mortician who volunteered to go up and help with the dead. Pretty grim task.
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