University
scientists using Global Positioning System software,
developed by NASA, have shown GPS can determine, within
minutes, whether an earthquake is big enough to generate
an ocean-wide tsunami. This NASAfunded technology can
be used to provide faster tsunami warnings.
A team led by Geoffrey Blewitt of the Nevada Bureau
of Mines and Geology and Seismological Laboratory, University
of Nevada, Reno, demonstrated that a large quake’s
true size can be determined within 15 minutes using
GPS data. This is much faster than current methods.
The new method, called GPS displacement, works by measuring
the time radio signals from GPS satellites arrive at
ground stations located within a few thousand kilometers
of a quake. From these data, scientists can calculate
how far the stations moved because of the quake. They
can derive an earthquake model and the quake’s
true size, called its ‘moment magnitude.’
This magnitude is directly related to a quake’s
potential for generating tsunamis. www.nasa.gov/home |