Magnitude 7.5 Earthquake Off Alaskan Coast 36
This morning at 08:58 UTC a magnitude 7.5 earthquake struck off the coast of southeastern Alaska. The depth was just shy of 10km. The quake occurred roughly 106km from the city of Craig and about 341km from the capital city of Juneau. A tsunami warning was issued shortly after the quake, but later canceled when it became apparent that sea level changes would be minor, with no widespread destructive wave. The observed tsunami was no more than six inches high. The earthquake was felt on land, shaking houses and tossing objects to the floor, but as yet there are no reports of injuries. The U.S. Geological Survey said, 'At the location of this earthquake, the Pacific plate is moving approximately northwestward with respect to the North America plate at a velocity of 51 mm/yr. This earthquake is likely associated with relative motion across the Queen Charlotte fault system offshore of British Columbia, Canada, which forms the major expression of the Pacific:North America plate boundary in this region. The surrounding area of the plate boundary has hosted 8 earthquakes of magnitude 6 or greater over the past 40 years."
Didn't feel anything in Juneau (Score:2, Informative)
Slept right though it I guess!
Tsunamis aren't tall in the middle of the ocean (Score:3, Informative)
The observed tsunami was no more than six inches high.
I hope this wasn't the height measured 10km form shore.
Re:Someone observed a 6 inch high Tsunami? (Score:5, Informative)
Shouldn't be too hard to measure. The wavelength is long, and tide gauges are built so short wavelength stuff (sea waves) doesn't change them. They are basically long tube with the bottom down fairly deep. The wavelength of tsunami are in the km.
The thing I found odd was all the other measurements in this article are in metric, then a sudden switch to imperial units. That's odd.
Re:Didn't feel anything in Juneau (Score:4, Informative)
We felt it in Sitka. Long rumbling and shaking. No damage done except to the egos of the emergency planners.
It was a very interesting test of the emergency broadcast system. The sirens went off. The reverse 911 worked. Lots of people heeded the warnings and got in their cars to go to higher ground.
Two small problems. There is basically a single main road that parallels the shore. It's two lanes wide. Hard to evacuate 3000 people on a little bitty two lane road. Then there was the little problem of ice. The idea is to go to higher ground - when the roads entering the higher grounds are iced up such that you need chains you have an oopsy situation. Fortunately, we were prepared to handle the six inch high wave.
I think the debrief today should be kinda amusing. Lesson learned: ALWAYS TEST YOUR BACKUPS!