The strongest earthquakes prediction

Geophysicist Kosuke Heki of Hokkaido University in Sapporo, Japan, begins one of his recent articles [1] with the following words:

"Thousands of lives were saved by the “Large Tsunami Warning” announcements of the Japan Meteorological Agency that followed the Tohoku-Oki earthquake of 11 March 2011. A similar alert followed the Central Chile (Maule) earthquake on 27 February 2010. Understanding better how such earthquakes develop might provide even more effective early-warning systems to help mitigate their devastating power."

Crustal deformation causes several geophysical phenomena. Vertical deformation of boundaries between layers with different density (as between the sea floor and the base of the Earth’s crust, called by geophysicists Moho) and changes in rock density around the tectonic fault produce subtle changes in gravity. The 26 December 2004 earthquake in Sumatra-Andaman region was the first earthquake whose gravity change was detected by satellite gravimetry. The 27 February 2010 earthquake in Central Chile was the second and the 11 March 2011 earthquake in Japan is the recent one. The combination of dense detector networks in these regions and the suite of new techniques provide today a picture of earthquakes and their dynamics never before available.

Heki`s investigations begun with his analysis of the variations of total electron content (TEC) in inonsphere over Japan during 2008. Five large earthquakes with magnitude M>6.8 occurred around the Japanese Islands between April and September 2008. Knowing that the decisive role in the ionosphere state is performed by space weather effects, his team has compared the estimated TEC values with such parameters as time series of the vertical component of the interplanetary magnetic field, UV solar radiation, and a corresponding index of the geomagnetic activity [2]. Though he was forced to conclude that it is rather difficult to find evident correlation between the observed TEC anomalies and the five large earthquakes, he was still optimistic writing:

"Our results do not disprove the possibility of precursory phenomena but show the difficulties in identifying earthquake precursors in the ionosphere TEC on the background of TEC changes produced by space weather effects, even during solar minimum."

In order to collect more experience, Heki has even investigated the tracks of ballisic missiles crossing the upper layers of the Earth`s atmosphere [3], using the dense array of global positioning system (GPS) receivers over Japan to study ionospheric disturbances.
The newest study by Heki and his group suggests that changes in the ionospheric electromagnetism could be used as a precursor for the strongest earthquakes (at least to those with magnitude larger than 8).

Kate Ramsayer, science writer of the American Geophysical Union (AGU), describes the discovery on the AGU-blog [4]:

"The study suggests that the total electron content, or TEC, in the ionosphere starts increasing as much as eight percent above background levels prior to massive earthquakes, with the biggest effect above the rupturing fault. The electron buildup before the Japan earthquake started 40 minutes before disaster struck.
Days after the devastating magnitude 9.0 Tohoku-Oki earthquake struck Japan, Heki downloaded data from satellites that are part of the GPS Earth Observation Network. He was interested in oscillations of the TEC when acoustic waves echo from the epicenter into the ionosphere.
“I thought I’d see a very strong signal after this earthquake,” Heki says. “And in the course of working on that, I found something strange happened.” The TEC was higher before the expected oscillations occurred than it was after the oscillations, so he took another look at the raw data from the GPS satellites.
But changes in total electron content aren’t rare, Heki says. Solar flares and other ionospheric disturbances can cause fluctuations. So he looked at TEC prior to other major earthquakes, including the 2010 Chile earthquake.
“I saw almost the same signature as the Tohoku earthquake,” Heki says. And although there were fewer GPS stations operational during the 2004 Sumatra quake, those showed a similar TEC anomaly. Smaller quakes, around magnitude 8.0 and below, don’t appear to have the same TEC increases.
It’s currently not feasible to use total electron content as a warning system for giant quakes, Heki says. There is a dense network of GPS satellites, especially over earthquake-prone areas like Japan, California and Indonesia, but the organization running the GPS network over Japan uploads the data once every few hours. And it takes time to analyze the data and weed out other disturbances to the total electron content like solar flares.
The next step for researchers could be to both determine what causes a change in TEC prior to earthquakes, as well as establish additional measuring stations on the ground to monitor the electric field."

Naturics (being based on the Unified Physics) is able to do this next step just now and explain "what causes a change in TEC prior to earthquakes" (compare in our Hot News the point: "The next step towards our understanding of the origin of life").
______________
[1] "A Tale of Two Earthquakes" by Kosuke Heki in 17 JUNE 2011 VOL 332 SCIENCE
(http://www.ep.sci.hokudai.ac.jp/~heki/pdf/Science-2011-Heki-1390-1.pdf)
[2] "Vertical TEC over seismically active region during low solar activity"
by Elvira Astafyeva, Kosuke Heki in Journal of Atmospheric and Solar-Terrestrial Physics73 (2011) 1643–1652
(http://www.ep.sci.hokudai.ac.jp/~heki/pdf/Elvira_Heki_JATP2011.pdf)
[3] "Ionospheric holes made by ballistic missiles from North Korea detected with a Japanese dense GPS array" by Masaru Ozeki and Kosuke Heki in Journal of Geophysical Research, Vol. 115, A09314, 2010
(http://www.ep.sci.hokudai.ac.jp/~heki/pdf/OzekiHeki_JGR2010.pdf)
[4] "Atmospheric electrons may act differently before megaquakes" posted 14 September 2011 by Kate Ramsayer, American Geophysical Union (AGU) science writer
(http://blogs.agu.org/geospace/2011/09/14/atmospheric-electrons/)

The strongest earthquakes prediction

Leave a Reply

Your email address will not be published. Required fields are marked *