GPS detection of the coseismic ionospheric disturbances following the 12 May 2008 M7.9 Wenchuan earthquake in China  

作　　者：SONG Qian DING Feng YU Tao WAN WeiXing NING BaiQi LIU LiBo ZHAO BiQiang 

机构地区：[1]National Center for Space Weather,China Meteorological Administration [2]Key Laboratory of Earth and Planetary Physics,Institute of Geology and Geophysics,Chinese Academy of Sciences

出　　处：《Science China Earth Sciences》2015年第1期151-158,共8页中国科学（地球科学英文版）

基　　金：supported by the Chinese Academy of Sciences(Grant No.KZZDEW-01-2);the National Natural Science Foundation of China(Grant Nos.41274162,41131066,41304126);the National Basic Research Program of China(Grant No.2011CB811405)

摘　　要：Here we report two cases of coseismic ionospheric disturbances observed through a GPS network in China after the great Wenchuan earthquake at 06：28 UT on 12 May, 2008. One is detected 7.9 rain after the earthquake and had an intensive ＂N＂ shape oscillated waveform with a pronounced amplitude of about 1 TECU, which propagates approximately southward to the distance about 1000 km with the horizontal phase velocity of 600±84 m/s and the period of 9.5±1.3 min. The other is detected 8.5 min after the earthquake and has an oscillated waveform more like a positive pulse with an amplitude of about 0.5 TECU, which propagates eastward to the distance about 800 km with the horizontal phase velocity of 720＋59 m/s and the period of 7.4±0.8 min. These two coseismic ionospheric disturbances are caused by the acoustic gravity waves excited by partial trans-formation of the acoustic waves originated from the energy release of the earthquake, somewhere near the epicenter. The directional preferences of these two coseismic ionospheric disturbances may be associated with the oblique geomagnetic field lines and the background winds filtering effect.Here we report two cases of coseismic ionospheric disturbances observed through a GPS network in China after the great Wenchuan earthquake at 06:28 UT on 12 May,2008.One is detected 7.9 min after the earthquake and had an intensive"N"shape oscillated waveform with a pronounced amplitude of about 1 TECU,which propagates approximately southward to the distance about 1000 km with the horizontal phase velocity of 600±84 m/s and the period of 9.5±1.3 min.The other is detected8.5 min after the earthquake and has an oscillated waveform more like a positive pulse with an amplitude of about 0.5 TECU,which propagates eastward to the distance about 800 km with the horizontal phase velocity of 720±59 m/s and the period of7.4±0.8 min.These two coseismic ionospheric disturbances are caused by the acoustic gravity waves excited by partial transformation of the acoustic waves originated from the energy release of the earthquake,somewhere near the epicenter.The directional preferences of these two coseismic ionospheric disturbances may be associated with the oblique geomagnetic field lines and the background winds filtering effect.

关 键 词：GPS coseismic ionospheric disturbances acoustic gravity waves total electron content EARTHQUAKE 

分 类 号：P228.4[天文地球—大地测量学与测量工程] P315.728[天文地球—测绘科学与技术]