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| Titel |
The auspice gravity signals of the Wenchuan earthquake based on the superconducting gravimeter data |
| VerfasserIn |
W. B. Shen, C. Hwang, D. J. Wang |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250030261
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| Zusammenfassung |
| Scientists pay great attention on various pre-signals of different physical fields before
earthquakes, especially before large earthquakes. Various studies demonstrate that some times
the gravity anomalies could be observed by absolute gravimeters through several days to
several hours before large earthquakes. In the present study we focus on detecting the auspice
gravity signal (AGS) before a large earthquake based on the superconducting gravimeter
(SG) data. The Wenchuan earthquake (Mw = 8.0) occurred in the afternoon on the
12th of May, 2008, in the western area of China. Using the data recorded in 2008
by two superconducting gravimeters located at Hsinchu, Taiwan, we found the
AGS. We separated the original SG data into the gravity tides and gravity residuals.
Based on Hilbert-Huang transform (HHT) the gravity residuals were decomposed
into various spectra. The spectra analysis demonstrates clearly that there existed
the continuous AGS around 40 hours previous to the Wenchuan earthquake. The
period of the AGS is between 5 s and 10 s. The same results were obtained by using
wavelet analysis. Hence, we may conclude that the SG data might be the significant
information source in “forecasting” the large earthquakes. Further investigations are
in process. This study is supported by National 863 Project of China (Grant No.
2006AA12Z211) and Natural Science Foundation of China (Grant No.: 40637034;
40574004). |
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