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GPS Could Speed Tsunami Warning
wwood_98 writes to tell us that Wired is running a story about how GPS could serve more than its traditional role. From the article: "International organizations like the Pacific Tsunami Warning Center, or PTWC, in Hawaii currently depend on coastal seismic stations to record deep-sea earthquakes that could cause giant waves. But according to Jeff Freymueller, a geophysicist at the University of Alaska Fairbanks, data from GPS receivers could provide quicker, more accurate estimates of the magnitude of a tsunami-causing quake, buying time for evacuation. Freymueller presented his findings at this week's American Geophysical Union conference in San Francisco."
From "Wiki: "The accuracy of the GPS signal itself is about 5 meters (16 ft) as of 2005 and has steadily improved over the last 15 years. Using differential GPS and other error-correcting techniques, the accuracy can be improved to about 1 cm (.4 in) over short distances.". Given a fixed GPS sensor, the relative accuracy in ground measurements would be more than adequate for seismic warnings.
I don't think the core idea is to be able say "In 23 minutes and 12 seconds a tsunami of height 13.6 meters will hit blah blah blah...". I believe they are building a warning system - "Within the hour conditions will be extremely favorable for tsunami conditions to occur, and residents should take precautions...".
Excellent, if you live in a coastal city, you'll get to know that you have 20 minutes left to live...
You misspelled the last word. You have 20 minutes left to drive. Inland. As quickly as your car can. You should be okay about 20-30 miles from the coastline.
You can try and drive out in your car.
You'll be going nowhere, because everyone else will be trying to go, too.
My motorcycle will make much better time.
You'll be fine!
"In 23 minutes and 12 seconds a tsunami of height 13.6 meters will hit blah blah blah...".
Actually it is the core idea.
Tsunamis not caused by weather. They are generally sparked off by earthquakes, which we cannot predict reliably. However, once one is sparked off and we know the nature of the event(what kind of earthquake, magnitude, location) we can predict the tsunami once we crunch the numbers. However, this takes time.
Tsunamis are basically shock waves. They travel at 500-1000 kilometers an hour while in the deep ocean. That means that you are going to have much less than an hour in most situations. If you're talking over an hour of travel time you're talking about a minor tsunami for anything less than a huge asteroid hit. Near shore it slows down to 'dozens of kilometers' as it builds into a huge wave.
Seconds count in this situation. We're talking sirens annoncing the need to take immediate shelter, or travel inland/out to ocean. The most dangerous area is the coast region. If you're far enough out to sea, the wave can be handled, if you even notice it. Coastal mega-hotels need to be built strong enough to take the wave, though I'd see evacuating all of the ocean side and lower level rooms.
20 minutes can save a huge number of lives, though. A moderatly healthy person should be able to walk at least a mile and a half in that time. It's also the sort of situation where you're likely better off walking than trying to take your car. So many other people will be trying to drive, panicing, that accidents and traffic will slow you to a stop.
I don't read AC A human right
I guess I'll bite.
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Tsunami warning systems give many affected areas hours, yes hours, of warning. Plenty of time to save most people in most areas.
Large earthquake in Chile in 1960, wiped out most of Hilo, Hawaii 14.8 hours later. (http://www.geophys.washington.edu/tsunami/genera
Only a fool would not see the value in having an effective warning system for that.
In fact, tsunami warning systems are one of the most effective natural disaster mitigation systems we use. If you're going to complain, try earthquake warning systems that are trying to give you 30 seconds of warning (of course that's enough to shutdown trains and other transit).
Or maybe you're from Kansas and just don't get it.
In last year's tsunami, often people that sought shelter on the third floor survived. Those that stayed in one-floor shelters were washed away.
The densest population areas (coastal India) that happen to be the most vulnerable are the ones least able to use this information. In general, there aren't any buildings to seek shelter in, and the land is so flat surrounding the coast that there isn't anywhere to run.
-Rob
Biblical fiscal responsibility