They also use GPS units for tectonic shift. Put a unit on each plate and measure the difference between them. When it gets to be a large enough number, something, somewhere will slip and you will have a quake.
Dave > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Hal Murray > Sent: Saturday, May 19, 2012 18:09 > To: [email protected] > Subject: [time-nuts] USGS: GPS for seismic work > > It wasn't hard to find the right people at the Open House. > > GPS is interesting for big quakes. > > Most seismometers measure acceleration. It's a double > integration to get > displacement which is what they are used to working with. > Big quakes last > longer which leads normal seismometers to get into troubles > with drift. GPS > doesn't have any drift problems. The cross over is somewhere > in the mag 7-8 > range. > > Japan has a large earthquake warning system. On the big > tsunami of last > year, they weren't looking for long enough. They estimated 7.9. In > hindsight, they probably could have gotten better data sooner > by using GPS. > > This news story says that they can see the disturbance in the > ionosphere. > > http://www.cbc.ca/news/technology/story/2012/04/23/f-tsunami-r > esearch.html > > > -- > These are my opinions. I hate spam. > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
