Saturday, February 27, 2010

Chile Earthquake

I guess this is the obligatory topic this morning. Al sent me this link earlier this morning; I was a little baffled. The I started going through my reader... Oh my. I don't feel like there is any point in discussing the quake itself. Take a look at any online news source. 8.8 puts this quake firmly in the top ten recorded quakes of all time; the geoblogosphere has set it at the sixth most powerful. My own tendency in most things is to wait until the dust settles, so to speak, and let the facts become clear. For example, most of the wire services rush to get fatality estimates in print as fast as they possibly can. Those sorts of reports are worse than useless. The numbers will certainly be higher. Coming out and saying "at least 62 dead" sort of implies a low impact, and imparts a false sense of relief. A sense that will almost inevitably will be shattered when the final count will most likely be in hundreds to thousands range.

On the positive side, Chile is much better prepared for an earthquake than many if not most countries. The largest recorded, a 9.5, struck that country in 1960.

Despite all the tsunami warning reports I've seen, I haven't been seeing time estimates. Then interestingly I finally found one in OregonLive.
No coastal flooding is expected to be produced by the wave, according to the National Weather Service. However, some areas of the coast could experience dangerous currents and surges in harbors and bays. Coastal residents are advised to stay out of the water, off the beach, and away from harbors and marinas since wave heights and currents are difficult to predict.

Forecasters say a wave surge estimated between one foot and four feet high may occur.

The threat is expected to begin around 1 p.m. this afternoon along the central Oregon coast. Rises in sea levels could continue for several hours. The greatest rise may not occur until an hour or 90 minutes after the initial onset, the weather service says. Boaters in water deeper than 600 feet shouldn't be affected.
So even though the model above seems to imply little impact for the Oregon Coast, this might not be the best day to visit the beach.

Followup, 12:30 PM: NOAA has also posted estimated arrival times for the initial tsunami along the US west coast, with the warning,
The following list gives estimated times of arrival for locations along the North American Pacific coast from a tsunami generated at the given source location. The list is ordered by arrival time starting with the earliest. Since tsunami speed is directly related to water depth, tsunami ETAs can be computed independent of tsunami amplitude. THE LISTING OF A TSUNAMI ARRIVAL TIME BELOW DOES NOT INDICATE A WAVE IS IMMINENT. The listed arrival time is the initial wave arrival. Tsunamis can be dangerous for many hours after arrival, and the initial wave is not necessarily the largest.
I have to admit that I can't say exactly what that means, but I'll boil it down to a simple expression that's probably more or less accurate: Stay the hell away from the coast until tomorrow. Below are the two locations closest to my little burg; the whole list is at the link. Interesting to note that the arrival time is estimated to be earlier for Cascade Head than for Newport, 31 miles farther south.
Cascade Head, Oregon   1426  PST FEB 27    2226 UTC FEB 27
Newport, Oregon 1429 PST FEB 27 2229 UTC FEB 27
Followup: I'm amazed at how quickly The Big Picture responds to events of this scale. 24 pictures "so far."

Followup: Why do I like the science reporting in The Christian Science Monitor? While some of their analogies don't sit very well with me (e.g. a subduction quake is like a growth spurt...), they take time to talk to scientists- you know, the people who study this stuff- before they rush to print. The resulting stories are regularly better informed than those from other sources. Yes, they do publish a religion-spirituality-oriented column each day called "A Christian Science Perspective," but they restrict that perspective to that column, and keep it well away from their reporting on politics, news, science, and so on. If you want a good US news source, I'd rate The CSM right up there with the NYT, and perhaps better.

2 comments:

ReBecca Hunt-Foster said...

Thanks for sharing that!

Bob said...

A friend lives on the Nicoya Peninsula here in Costa Rica, and she reported a 1' surge about two hours ago. But we're pretty much protected by having the Colombian coast between here and Chile.