Researchers in Japan and France have begun a joint study of data from the recent tsunami catastrophe in the Indian Ocean to study the prospect of using the global positioning system to track earthquakes and warn of tsunamis, it was learned Wednesday.
"If the focus of an earthquake is near a GPS observation point, we will be able to grasp the condition of the sea surface from directly above and calculate details of the size and speed of a tsunami right after it forms," said Makoto Murakami, a research coordinator at Japan's Geographical Survey Institute.
If successful, geologists will be able to record tsunamis immediately after an earthquake is detected, track the movements of any consequent tsunamis and issue precise warnings before the waves hit shore.
When quakes and tsunamis jolt land and sea surfaces, the atmosphere above is in turn pushed up and down. These vibrations shake up electrons in the ionosphere and result in a delay in electric waves transmitted to observation stations from GPS satellites some 20,000 km above ground, Murakami said.
By analyzing data from the 1,200 GPS stations operated by the institute in Japan, scientists will be able to track the conditions of tsunamis within several hundred kilometers of the coast, he said.
Because there are few points at sea where tsunami observation equipment has been set up, scientists currently can only estimate the movement and scale of tsunamis using data from seismometers and tide gauges along coasts.