Wednesday, September 30, 2009

Tsunami hits American Samoa

I've gotten some reports of a five-foot tsunami hitting Pago Pago, American Samoa.

The warning for the Northern Marianas has been cancelled by the Pacific Tsunami Warning Center. Makes you feel better, doesn't it?

Actually, that's so far south and so far away it's no big thing-- to us.

Locally, though, the U.S. Geologic Survey (link expired) reported a magnitude 8.0 quake at about 3:48 am our time, and if you look at the widget on the bottom left of this page you can see there are a lot of aftershocks greater than 5.0.

I'm off to look for news stories, but the USGS has a nifty page (link expired) where people can report: it sounds like the quake itself was felt as "moderate" in AS.

More: According to Pacific Tsunami Kills at Least Five in Samoa Region After Quake. There are a lot of stories now if you Google it.


bigsoxfan said...

Tough deal for the nearby islands, but not such a big deal for anyone else so far. I'm interested how the bottom topography works on tsunami arrival damage for areas outside the immediante area.
This one, like the big quake in the Indian Ocean, were influenced by the local situation. For Somoa, they seemed to be in the barrel of the shotgun, no escaping that. The Indian ocean quake results were concentrated by the massive displacement in an unfortunate direction to towards the tip of the barrel (lots of amount of water, funneled towards shallow populated regions) Blessedly, although the EMO will never admit, Saipan is free of danger from any event other that one very shallow and close or truly massive, like the east coast of japan dropping off into the ocean.
Anyway, I don't suppose they have any option other than to issue an alert until the first wave buoys gather the data and figure out how much ocean was displaced by the event. Good luck to the Samoans tonight, hope they were able to read the signs and flee.

bigsoxfan said...

Not so academic now. Seems the overwash was severe and quick, the region suffered greatly. Looking at Google Earth with the ocean floor clicked on, you can see the channeling, but not predict a danger area.

KAP said...

Like you, I think it *seems* unlikely we'd be affected except in special circumstances, but I'm not responsible for the safety of thousands of people. EMO, like the guy checking your shoes at the airport, is subject to jokes and a little resentment but would have hell to pay if something went wrong.

My son tells me he stood around next to a bus for about an hour at Hopwood -- they were probably monitoring the wave heights as the tsunami approached. That seems reasonable. They probably already knew it was a killer.

I'm sure they don't want the 'crying wolf' effect, but it's always better to err on the side of caution.

bigsoxfan said...

Kap, given the information available, everyone aboard Saipan is wise to err on the side of caution. However, a geologist could lay out a reasonable case for Saipan being about as free from tsnamui as ever a place could be. Of course, a consultant would have to be paid and Ben and Tim are a bit short on consultants who could actually have definete knowledge on a subject. Shallow Earthquakes within 150 NM being the exception.

bigsoxfan said...

Hi Ken, I linked you to this guy last week, but this post answered a lot of my questions. Ran it across my buddy Fraser the geologist and he is up.

KAP said...

Neat stuff (For someone else who may not know how to paste the link)

There was a nugget I may have known but forgotten: there's a graphic saying wind waves cause water to travel in a circle but water in tsunamis flows straight.