<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=iso-8859-1" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 8.00.6001.18928">
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff><FONT size=2 face=Arial>
<DIV><FONT size=4>Radar could detect tsunamis more accurately</FONT></DIV>
<DIV class=author>Kafil Yamin</DIV>
<DIV class=source>19 September 2011</DIV>
<DIV class=date><A
href="http://www.scidev.net/en/agriculture-and-environment/tsunami/news/radar-could-detect-tsunamis-more-accurately.html">http://www.scidev.net/en/agriculture-and-environment/tsunami/news/radar-could-detect-tsunamis-more-accurately.html</A></DIV>
<DIV class="article_content cf">
<P><SPAN>[JAKARTA] A tsunami has been observed with radar for the first time,
promising a cheap and more accurate early warning method, according to a
study.</SPAN></P>
<P><SPAN>Researchers have found that the devastating </SPAN><A
href="http://www.scidev.net/en/agriculture-and-environment/tsunami/"><FONT
color=#336699>tsunami</FONT></A><SPAN> that hit Japan on 11 March could had been
spotted up to 45 minutes before it reached tide gauges, using high-frequency
radars installed along the shorelines in California and Japan.</SPAN></P>
<P><SPAN>The warning time depended on how shallow the water was — the shallower
the water, further away the method can detect a tsunami.</SPAN></P>
<P><SPAN>So the method would work best in regions with wide and shallow
continental shelves such as </SPAN><A
href="http://www.scidev.net/en/south-east-asia/"><FONT color=#336699>South-East
Asia</FONT></A><SPAN> and the west coast of India, where it could give the most
warning time, according to John Largier, an oceanographer at the</SPAN>
<SPAN>Bodega Marine Laboratory, University of California, Davis, and a co-author
of the study published in <EM>Remote Sensing</EM> last month (3
August).</SPAN></P>
<P><SPAN>"The benefit of using the shore-based radar systems to provide warning
of tsunamis is that one obtains data at many locations, improving the detection
in terms of both timing and intensity of the tsunami at the coast, which can
vary significantly," Largier told <EM>SciDev.Net</EM>.</SPAN></P>
<P><SPAN>Such a system would also measure waves that sometimes follow within a
day of the initial tsunami, which the current systems do not detect well, he
said.</SPAN></P>
<P><SPAN>Radar is already commonly used in ports around the world for monitoring
surface current flow, and used for oil spill response, search and rescue,
fisheries, and ecosystem management, so transforming it for tsunami detection
would be cost-effective, but would need dedicated funds, said
Largier.</SPAN></P>
<P>"<SPAN>No funds exist for the modest development effort to convert the
existing hardware into a tsunami system," he said, but added that compared with
some other initiatives, such as </SPAN><A
href="http://www.scidev.net/en/news/global-tsunami-monitoring-could-follow-from-discovery.html"><SPAN><FONT
color=#336699>tracking tsunamis from space</FONT></SPAN></A><SPAN>, "development
of an operational radar-based system is 'low hanging fruit' that can be plucked
with relatively little additional funding".</SPAN></P>
<P><SPAN>"This system should be combined with existing offshore buoys and
predictive computer models. One does not remove the value of the other. But, in
regions where offshore buoys are absent, this radar approach may be more cost
effective — specifically given the multiple benefits."</SPAN></P>
<P><SPAN>But the need to process radar data into reliable information for the
public could slow down the development of the new system, warned Indonesian
scientists.</SPAN></P>
<P><SPAN>"Radar gives data much quicker than the tide gauge, [but] at the end of
the day, it is the ensuing data processing that matters," said Baba Barus, a
senior geology lecturer at the Bogor Agricultural University,
Indonesia.</SPAN></P>
<P><SPAN>Didit Okta Pribadi, a radar expert at the Indonesian Institute of
Sciences, said there was no doubt that radar would outperform the current
tsunami early warning system because "radar can see through the depth of the
ocean".</SPAN></P>
<P><SPAN>But the shortage of radar operators and experts in South-East Asian
countries means it may take some time before such a method could be deployed
there.</SPAN></P>
<P><SPAN>"In Indonesia, those who know the nitty-gritty of radar can still be
counted on fingers," Didit said. "I think other South-East Asian nations have
the same situation."</SPAN></P>
<P><SPAN><A href="http://www.mdpi.com/2072-4292/3/8/1663/pdf"
target=_blank><FONT color=#336699>Link to full paper in <EM>Remote
Sensing</EM></FONT></A></SPAN></P></DIV>
<DIV class="article_box article_citations">
<H3 style="COLOR: #000000">References</H3>
<P><EM>Remote Sensing</EM> doi:10.3390/rs3081663
(2011)</P></DIV></FONT><BR>
<BR>
__________ Información de ESET NOD32 Antivirus, versión de la base de firmas de virus 6495 (20110926) __________<BR>
<BR>
ESET NOD32 Antivirus ha comprobado este mensaje.<BR>
<BR>
<A HREF="http://www.eset.com">http://www.eset.com</A><BR>
</BODY></HTML>