November 2, 2011 19:59
The devastating earthquake that struck Japan in March this year, the impact on the upper atmosphere before as tremors were reported on the ground. This is the conclusion reached by Japanese scientists at the University of Hokkaido. The article was published in the journal Geophysical Research Letters.
Scientists hope that this discovery can be used to prevent subsequent earthquakes. The researchers found that during the movement of the earth's crust formed and tsunami waves that reached ionosphere — one of the highest layers of the atmosphere.
Now surveyor and geophysicist Kosuke Heki (Kosuke Heki) from Hokkaido University reported that the March earthquake caused a disturbance in the ionosphere directly to ourselves jerks. Shortages of electrically charged particles in the ionosphere led to disruptions of radio signals between global positioning system satellites (GPS) and terrestrial receivers, data which scientists can measure.
The researchers analyzed data from about 1,000 GPS receivers in Japan. Was found to increase by about 8% of total electron content in the ionosphere above the area affected by the earthquake, 40 minutes before the earthquake started. This increase was the strongest of the epicenter and decreases with distance from it. Analysis of GPS records of the earthquake in Chile in 2010 (magnitude 8.8) showed a similar picture. Perhaps these changes occurred during the earthquake in Sumatra, Indonesia, in 2004 (magnitude 9.3) and the earthquake in Hokkaido in 1994 (magnitude 8.3). If the findings are confirmed, further investigations could lead to a new type of early warning system for giant earthquakes.
Anomaly is currently being considered for aftershocks greater than 8.5. However, if researchers can find what exactly is causing the ionospheric phenomena becomes possible to detect precursors and small earthquakes.
Kosuke Heki said such anomalies can also cause and solar storms. So before you develop an early warning of earthquakes based on ionospheric phenomena, exclude other possible causes.
Recall what happened in March this year, the earthquake in Japan caused a tsunami height of over 4 meters. Then killed more than 20 thousand people.