The 1964 Alaska earthquake facts
1964 Alaska Earthquake Facts: I've become really interested in Alaska earthquakes this year, as we've had four good size earthquakes I can recall. (The USGS website says we've actually had thousands, but most are too small to feel.) When I did some calculations last week and learned that the 1964 Alaska earthquake was more than one million times more powerful than the 4.9 magnitude earthquake we had recently, well, let's just say I became very interested in it.
1964 Alaska earthquake magnitude facts
As I did some research on the 1964 Alaska earthquake, these are some of the earthquake facts I dug up:
- The earthquake began at 5:36 p.m. local time, on March 27, 1964.
- The epicenter of the earthquake was 78 miles east of Anchorage, Alaska.
- The magnitude of the earthquake was 9.2. This is the most powerful earthquake ever recorded in North American history. (The strongest we've had so far this year was a 5.4 on September 24, 2010.)
- A 9.2 magnitude earthquake is over one million times more powerful than the 4.9 magnitude earthquake we had on September 20, 2010. (The scale used is not linear.)
- The 1964 Alaska earthquake last more than five minutes. The earthquakes this summer have lasted only a few seconds.
- The 1964 Alaska earthquake was a "subduction zone earthquake" (or "megathrust earthquake"), caused by an oceanic plate sinking under a continental plate.
- Over 10,000 aftershocks were recorded following the main earthquake. In the first day eleven aftershocks were recorded with magnitudes greater than 6.0. All of those were more powerful than any earthquake we've had in 2010.
- Sixteen people died from resulting tsunamis in Oregon and California.
- The 1964 Alaska earthquake is also referred to as The Good Friday Earthquake because of the date.
- The 1964 earthquake generated huge waves in the ocean referred to as a "tsunami", or in this case, multiple tsunamis. (See below.)
1964 Alaska earthquake damage
Here are some reports of the resulting damage from the 1964 Alaska earthquake:
- The 1964 Alaska earthquake is reported to have caused approximately 128-131 deaths.
- Sixteen people died from resulting tsunamis in Oregon and California.
- According to Wikipedia, as far away as 200 miles in Kodiak, the 1964 Alaska earthquake caused some areas to be permanently raised by thirty feet, while areas near Portage dropped about eight feet.
- Vertical displacements of land of up to 38 feet were recorded, affecting an area of 100,000 square miles in Alaska.
- The major areas lifted up "trended northeast from southern Kodiak Island to Price William Sound".
- Near Cordova, the Million Dollar Bridge crossing the Copper River collapsed.
- The town of Valdez was moved to higher ground after the earthquake.
- A 27-foot tsunami destroyed the village of Chenega, killing 23 of the 68 people who then lived there.
- Damage from the earthquake is reported at $311M. Assuming a simple cost of living increase of 4% per year, this equates to roughly $1.8B in 2010 dollars.
Tsunamis resulting from the 1964 Alaska earthquake
Here are the facts I've been able to find about tsunamis resulting from the 1964 Alaska earthquake:
- Tsunamis hit in many areas, including Alaska, Canada, Oregon, California (and presumably Washington), and Hawaii.
- The maximum tsunami wave height recorded was 67 meters (over 200 feet high) at Valdez Inlet.
- A 27-foot tsunami destroyed the village of Chenega, killing 23 of the 68 people who then lived there.
- Anchorage was not hit by tsunamis.
- Sixteen people died from resulting tsunamis in Oregon and California.
1964 Alaska earthquake resources
The following sources of information were used to gather these facts:
Also, to compare the relative power of two earthquakes as I did above, you use the "Moment magnitude scale".
I hope these 1964 Alaska earthquake facts have been interesting, and helpful.