GPS could offer better fault line mapping

Washington, May 26: Global positioning systems (GPS) could help identify the places most at risk of devastating earthquakes.

Using technology to identify high-hazard 'locked zones' that can spawn giant quakes, researchers attending a meeting in Acapulco, Mexico, held by the American Geophysical Society and several Latin American geophysical associations, claimed that GPS has been used to reveal the location of a locked zone to the west of Seattle.

Locked zones occur where adjacent tectonic plates appear 'locked' together as a result of the friction between them. When the plates eventually overcome the friction and break free, the release can cause devastating earthquakes as the Earth's surface lifts or falls.

Because the worst damage occurs when an earthquake's epicentre is right under a metropolitan area, the team, according to nature.com, is now working to confirm the locked zone's location. Potential catastrophes are why researchers are hoping that GPS can help them map locked zones more effectively.

GPS networks send altitude and location readings to satellites that can thus chart movements on the earth's surface with an accuracy of a few millimetres. This allows them to monitor 'slow-slip events' to define locked zones.

As more GPS are installed and produce measurements, the researchers hope to be able to regularly locate zones of higher risk.