CAJ | 학술논문

利用地基GPS观测资料反演的垂直电子总含量(VTEC),本文考察了2008年5月12日汶川M_s8.0地震期间的电离层变化.在考察过程中,以前10天的VTEC均值和伴随的2倍标准偏差作为参考来识别电离层异常.最终的考察分析结果表明:(1)VTEC的异常增加出现在5月3日和5月9日,而VTEC的异常减小出现在4月29日和5月6日;(2)所有这4天的电离层VTEC异常持续时间均超过了4 h,且异常自东向西漂移;(3)相对于电离层的非扰动状态,在5次电离层异常的峰值时刻,震中附近VTEC增加或减小超过30%的空间区域沿经、纬向分别超过了4000 km和1500 km.鉴于地震期间的日-地空间环境和电离层VTEC异常特征,我们认为,5月3日下午和5月9日的VTEC正异常可能是本次汶川地震的电离层前兆.
이용지기GPS관측자료반연적수직전자총함량(VTEC),본문고찰료2008년5월12일문천M_s8.0지진기간적전리층변화.재고찰과정중,이전10천적VTEC균치화반수적2배표준편차작위삼고래식별전리층이상.최종적고찰분석결과표명:(1)VTEC적이상증가출현재5월3일화5월9일,이VTEC적이상감소출현재4월29일화5월6일;(2)소유저4천적전리층VTEC이상지속시간균초과료4 h,차이상자동향서표이;(3)상대우전리층적비우동상태,재5차전리층이상적봉치시각,진중부근VTEC증가혹감소초과30%적공간구역연경、위향분별초과료4000 km화1500 km.감우지진기간적일-지공간배경화전리층VTEC이상특정,아문인위,5월3일하오화5월9일적VTEC정이상가능시본차문천지진적전리층전조.
In this paper, we investigated the variations of the ionospheric Vertical Total Electron Content (VTEC) derived from the ground-based GPS observations during the 12 May 2008 M_s8.0 Wenchuan earthquake. A mean of the previous 10-day VTECs and the associated two standard deviations are utilized as a reference for identifying the ionospheric anomalies. The analysis showed that (1) the anomalous enhancements of VTEC appeared on May 3 and 9, while the anomalous decreases appeared on April 29 and May 6; (2)all of the ionospheric anomalies lasted beyond 4 hours and drifted from east to west; (3)relative to a non-perturbed state of the ionosphere, the zones of the VTEC decrease or enhancement by more than 30% around the epicenter had spatial scale of more than 4000 km in longitude and 1500 km in latitude at five peak times of the ionospheric anomalies. In view of the solar-terrestrial environment and the characters of the ionospheric anomalies, we think that the positive anomalies of VTEC in the afternoon of May 3 and on May 9 are probably the ionospheric precursors of Wenchuan earthquake.