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| Possible thermal brightness temperature anomalies associated with the Lushan (China) MS7.0 earthquake on 20 April 2013 |
| Tao Xie1 2, Weiyu Ma2 |
1 Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
2 China Earthquake Networks Center, Beijing 100045, China |
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Abstract Lushan MS7.0 earthquake occurred in Lushan county, Ya’an city, Sichuan province of China, on 20 April 2013, and caused 196 deaths, 23 people of missing and more than 12 thousand of people injured. In order to analyze the possible seismic brightness temperature anomalies which may be associated with Lushan earthquake, daily brightness temperature data for the period from 1 June 2011 to 31 May 2013 and the geographical extent of 25E–35N latitude and 98E–108E longitude are collected from Chinese geostationary meteorological satellite FY-2E. Continuous wavelet transform method which has good resolution both in time and frequency domains is used to analyze power spectrum of brightness temperature data. The results show that the relative wavelet power spectrum (RWPS) anomalies appeared since 24 January 2013 and still lasted on 19 April. Anomalies firstly appeared at the middle part of Longmenshan fault zone and gradually spread toward the southwestern part of Longmenshan fault. Anomalies also appeared along the Xianshuihe fault since about 1 March. Eventually, anomalies gathered at the intersection zone of Longmenshan and Xianshuihe faults. The anomalous areas and RWPS amplitude increased since the appearance of anomalies and reached maximum in late March. Anomalies attenuated with the earthquake approaching. And eventually the earthquake occurred at the southeastern edge of anomalous areas. Lushan earthquake was the only obvious geological event within the anomalous area during the time period, so the anomalous changes of RWPS are possibly associated with the earthquake.
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Received: 11 August 2014
Published: 25 December 2014
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| Fund:12th Five-year Science and Technology Support Project of China (No. 2012BAK19B02-03) and Youth Earthquake Situation Trace of China Earthquake Administration (No. 2014020402). |
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Corresponding Authors:
Tao Xie
E-mail: xtaolake@163.com
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