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Taiwan scientists find link between earth, ionospheric activity

2010/09/21 18:51:05

Taipei, Sept. 21 (CAN) Two researchers from National CentralUniversity in Jhongli, Taoyuan County have discovered a co-seismiceffect in the ionosphere, which they say could help detect tsunamisearlier.

Liu Jann-yeng and Yen Horng-yuan, from the university'sDepartment of Earth Science, said at a news conference in TaipeiTuesday that their research found earth tremors could prompt asimilar movement in the ionosphere, which can be monitored on theground.

The ionosphere consists of several ionized layers 80 km to 400 km

above the surface of the Earth.

An earth movement of eight meters will be magnified andtransformed into a vibration across 80 km in the ionosphere, Liusaid.

By monitoring the time, location and the vibration of theionosphere, scientists may be able to determine the source of theearth movement, Liu said.

For example, he said, the research team used the data from thevibration in the ionosphere to pinpoint the epicenter of7.3-magnitude earthquake that occurred in Taiwan on Sept. 21, 1999.The quake was centered 30 km northeast of Jiji in Nantou County.

Yen said the research has proved a correlation, called aco-seismic effect, between earthquakes and ionospheric vibrations andthe latter may determine the source of the earth movement.

The movement of the surface of the sea will cause similarionospheric vibrations and by monitoring the latter, the source ofthe former could be identified, he said.

With the use of his theory, Liu said, he was able to work out thetime and location of the 2004 Indian Ocean tsunami based on theionospheric movement at the time.

The findings of the study could give forecasters about half anhour to an hour to issue a warning before a tsunami arrives, he said.

Yen said he was motivated to study the co-seismic effect betweenearthquakes and ionospheric movement after the 1999 earthquake, butwhen he first publicized his theory in 2005, it was greeted withskepticism.

However, the perseverance of the research team bore fruit thisyear, when the prestigious Journal of Geophysical Research publishedthe findings in August, he said.

The journal, published by the American Geophysical Union, isdevoted to reporting research on the physical, chemical, andbiological processes that contribute to the understanding of theEarth, Sun, and solar system.

(By Hsu Chi-wei and Maubo Chang)
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