Satellite System Will Speed Up Tsunami Warnings 8
ananyo writes "NASA and a group of universities known as the READI network have begun testing an earthquake-warning system based on satellite data from the Global Positioning System. The method could have allowed Japanese officials to issue accurate warnings of the deadly March 2011 earthquake and tsunami ten times faster than they did, say scientists. The system is currently being tested using the U.S. Pacific Northwest Geodetic Array: hundreds of GPS receivers placed along the North American coast between Northern California and British Columbia in Canada. While conventional seismometers provide similar information, they run into trouble with earthquakes of magnitude 7 or higher. This is partly because in big quakes, the ground may shake for longer, but not significantly harder. GPS has no such problem, because it directly measures the movement of the ground."
Nice (Score:2)
Re: (Score:2)
Actually, BOTH the size and the location of the earthquake (which was centered off-shore) was known fairly quickly.
What wasn't know was whether or not a tsunami would result.
So issuing an accurate warning ten times faster (they had to have meant 1/10th the time) would have meant little, since the actual ground uplift movement was 80 miles out to sea [guardian.co.uk], where no GPS meters would have been available. The actual quake itself was already known to be very large the instant it happened and the location was pin-poi
Funding (Score:2)
Yes. The Pacific Tsunami Warning System is already fast. I can get earthquake info almost as fast from the USGS as I can from a million people on facebook live-reporting the earthquake.
So this project, while cool, sounds more like a way to get funding than anything else.
Re: (Score:2)
Right - Yes GPS doesn't work underwater but that doesn't matter. The detectors are mostly close to shore - they detect the seismic waves. As tsunamis are caused by earthquakes out to sea (as one commenter notes) the tsunami follows some time later - depending on how far from shore the earthquake happened.
According to the source story, GPS measurements of the ground movement (close to shore) is MORE accurate than the seismometer readings. Seismometers detect the amount of shaking but struggle with the durati
Nonsense (Score:1)
"The method could have allowed Japanese officials to issue accurate warnings of the deadly March 2011 earthquake and tsunami ten times faster than they did, say scientists."
The tsunami was known almost instantaneously and warnings issued where they could be. The METHOD of warning was affected since many loudspeakers didn't work because of the widespread power outage.
We see tsunami warnings almost instantly on Japanese TV immediately after a quake, or the information that there is no tsunami warning. For lar
well duh (Score:1)
of course they are going to know when there is going to be a tsunami when the satellites start shooting lasers off the coast of small islands.
"We can provide protection from tsunamis by tellin' yous guys when they gonna hit. it would be a shame if something were to happen to this nice unprotected island. Isn't that right Tony?"
"Yeah boss, it'd be a real shame."
Using GPS latency (Score:2)
Japanese universities have been working on a system that measures the latency of GPS signals to detect earthquakes before they happen. Apparently in the time before a quake there are changes in the atmosphere which affect the transmission of signals from the satellites to receivers on the ground, resulting in the time delay changing. By detecting the changes they can give up to half an hour of warning.
There was some coverage on Japanese TV and I think the BBC picked up on it too, but I can't find the link r