Mysterylights Group Message 0203

Subject: Fwd = Electromagnetic signals "can predict earthquakes"
From: Frits Westra <fwestra@...>
Date: 15 Jun 2002 11:58


Forwarded by:     fwestra@... (Frits Westra)
URL:              http://www.newscientist.com/news/news.jsp?id=ns99992395
Original Date:    Fri, 14 Jun 2002 14:47:07 -0500

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   Electromagnetic signals "can predict earthquakes"

   19:00 12 June 02

   Exclusive from New Scientist 

   Strange  electromagnetic  signals  were  detected  two months before a
   major  earthquake hit Japan. The signals support controversial work by
   Greek  researchers,  who  say  they  could  one day be used to predict
   earthquakes.

   For  several years seismologists have intensely debated whether or not
   you can forecast earthquakes by the electromagnetic signals emitted by
   rocks under stress.

   Proponents of the idea - known as the VAN method after the initials of
   the  Greek  researchers  who developed it, Panayiotis Varotsos, Kessar
   Alexopoulos and Konstantine Nomicos, all of the University of Athens -
   maintain  that  electrical  and  magnetic  activity  in the ground can
   predict the location, time and magnitude of some earthquakes.

   Other  researchers  have  had  difficulty  repeating  the Greek team's
   results.  But  now  Seiya  Uyeda's team from the Earthquake Prediction
   Research  Center  at  Tokai  University  in  Japan  reports  measuring
   anomalous  changes  in  the  Earth's electrical and magnetic fields in
   Japan's  Izu  islands,  from  the  end  of March 2000. And a couple of
   months later, a series of earthquakes started on 26 June.

   The researchers used telephone wires as antennas, to measure extremely
   low frequency electromagnetic waves every 10 seconds.

   Rock faults

   They  say  their  geoelectrical  field readings showed "clear, unusual
   changes".  The strength of the signals increased over time, reaching a
   peak  just  before  the first large earthquake of magnitude 6.4 on the
   Richter  scale  on  1 July 2000. After the seismic activity died down,
   the fields returned to normal.

   The group also saw changes in the Earth's magnetic field strength over
   the  same period. After allowing for other possible causes of magnetic
   noise,  such  as  rainfall  or man-made sources, the researchers saw a
   tiny  but  unexplained distortion. The variations were about a million
   times smaller than the Earth's natural magnetic field.

   The signals were picked up at only two antennas, which the researchers
   admit  is  puzzling.  They  think  that  the  stress  signals  may  be
   propagated  along  highly  conductive  channels, such as faults in the
   rock  that  contain  pools  of  water,  making them detectable only in
   certain areas.

   "Grasping at straws"

   Seismologists  are  divided  over  the  significance  of  the results.
   Varotsos  says  that  Uyeda's experimental results are impressive, and
   confirm the signals he has seen in Greece over the past 20 years.

   Max  Wyss  of  the  University of Alaska Fairbanks, on the other hand,
   dismisses the Japanese measurements. The group's assertions that these
   signals predict earthquakes are "grasping at straws", Wyss says. "They
   simply want to believe that, no matter what the facts are."

   Phil  Reppert  of Clemson University in South Carolina says that while
   Uyeda's  work  doesn't  prove  it  will  ever  be  possible to predict
   earthquakes,  it  does  show the need for more research. "I agree with
   the authors that the chances of their signals being man-made noise are
   slim."

   More  at:  Proceedings  of the National Academy of Sciences (vol 99, p
   7352)

   David Appell

   ©  Copyright Reed Business Information Ltd.

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