GPS System Can Warn of Tsunami Faster Than Current Model

A German team has developed a faster and more accurate method for providing early warning of an oncoming tsunami, at least for countries that have sizable satellite networks.

Using data from global positioning systems (GPS) to measure ground deformation caused by a large underwater earthquake, scientists can now provide an accurate warning of the resulting tsunami just minutes after the onset of an earthquake.

The system will reportedly offer accurate data much quicker than the current methods of tsunami prediction, which can take as long as 10 minutes to compute and relay data gathered by seismic recorders.

Using the devastating tsunami that hit Japan after the 9.0-magnitude March 2011 earthquake as a a case study, the scientists say that if GPS systems had been used to predict the tsunami, it would taken more more than three minutes to have the most accurate information about the size and strength of the wave.

The scientists used raw data from the Japanese GPS Earth Observation Network (GEONET) recorded a day before to a day after the 2011 earthquake. To shorten the time needed to provide a tsunami alert, they only used data from 50 GPS stations on the northeast coast of Japan, out of about 1,200 GEONET stations available in the country.

"Japan has a very dense network of GPS stations, but these were not being used for tsunami early warning as of 2011. Certainly this is going to change soon," Andreas Hoechner, from the German Research Centre for Geosciences, said in a statement.

By using GPS data, scientists can use computer simulations to reconstruction the earthquake source and calculate the uplift on the sea floor, which can in turn be used as an initial tsunami model to predict wave height and arrival time.

Hoechner said that speedy data will be of great use in preventing casualties from tsunami, but he stressed the importance of having well-thought out evacuation plans

"One point is to have the technology to realize what the earthquake is and where tsunami will be. But it is at least as important is to disseminate the warning," he told the BBC.

"You have to have the infrastructure to transmit this information to the population, and the population has to be ready to know what to do."

The research is published in Natural Hazards and Earth System Sciences.