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<DIV><FONT size=4>GPS data could speed up tsunami warnings</FONT></DIV>
<DIV class=source>Source: Nature </DIV>
<DIV class=date>13 December 2011</DIV>
<DIV class=date><A
href="http://www.scidev.net/en/agriculture-and-environment/tsunami/news/gps-data-could-speed-up-tsunami-warnings.html">http://www.scidev.net/en/agriculture-and-environment/tsunami/news/gps-data-could-speed-up-tsunami-warnings.html</A></DIV>
<DIV class="article_content cf">
<P><SPAN>Faster <A
href="http://www.scidev.net/en/agriculture-and-environment/tsunami/"><FONT
color=#336699>tsunami</FONT></A> warnings could be issued by using Global
Positioning System (GPS) data alongside existing earthquake detection
technology, scientists have found. </SPAN></P>
<P><SPAN>GPS data — provided by a <A
href="http://www.scidev.net/en/new-technologies/space-technology/"><FONT
color=#336699>satellite</FONT></A> navigation system — could help cut the time
lag from 20 minutes to around three minutes, according to results presented at
the <A href="http://sites.agu.org/fallmeeting/" target=_blank><FONT
color=#336699>American Geophysical Union meeting</FONT></A> in the United
States, last week (8 December). </SPAN></P>
<P><SPAN>Seismic instruments — on which current warning systems are based — can
take a long time accurately to assess an earthquake's strength, because readings
from several locations need to be analysed. However, GPS stations can measure
large vertical drops in ground elevation — the factor responsible for tsunamis —
in real time. </SPAN></P>
<P><SPAN>This information, when added to preliminary seismic data from the same
location, can determine the size — and likely effects — of the earthquake in a
matter of minutes. </SPAN></P>
<P><SPAN>All the technology is already in place in California and Japan, it is
just a case of coordinating it, said Yehuda Bock, a researcher at the University
of California, United States, who led the team. </SPAN></P>
<P><SPAN>"There's a separation between [scientific] communities that we need to
fix," he said. </SPAN></P>
<P><SPAN>Adding seismic instruments to GPS centres would be costly — perhaps
around US$22,000 per station — but Bock has developed a method at a fraction of
the cost. Attaching an accelerometer — a device that measures the vibration or
change in motion of a structure — instead can be achieved for a few thousand
dollars and has already been shown to work in the laboratory. </SPAN></P>
<P><SPAN>"It should work really well, where it works," said Andrew Newman of the
Georgia Institute of Technology in United States. But, with only a few places
with the necessary GPS and seismic technology and with small islands lacking the
space for installing the instruments, he stressed that the system might not be
suitable for everywhere. </SPAN></P>
<P><SPAN>Only a small number of the roughly 1,200 GPS stations that exist in
both Japan and the United States are close enough to seismic sensors to be used
in the way that Bock proposes. </SPAN></P>
<P><SPAN>His team has received funding to develop and test a prototype device,
which could be in place within six months. </SPAN></P>
<DIV><A
href="http://blogs.nature.com/news/2011/12/simple_tools_speed_up_quake_wa.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+news%2Frss%2Fthe_great_beyond+%28Nature+News+Blog+-+Blog+Posts%29"
target=_blank><FONT color=#336699>Link to full article in
<EM>Nature</EM></FONT></A></DIV></DIV></FONT><BR>
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