新疆地区6级以上地震前小震固体潮调制比异常演化特征

Analysis of the modulation ratio of the solid tide before earthquakes with a magnitude over 6 in Xinjiang since 2016

选取新疆地区2016年以来发生的3次M_(S) 6.0以上浅源地震,对发震前震中区小震调制比变化进行系统对比分析,发现3次地震前均出现不同程度的固体潮调制比异常:①2016年12月8日呼图壁M_(S) 6.2地震仅在震前2年于震中出现调制比高值异常;②2017年8月9日精河M_(S) 6.6地震震中于发生前2年、1年、0.5年均落于调制比高值异常区域,受调制作用较明显;③2020年1月19日伽师M_(S) 6.4地震于发生前2年、1年,在震中位置附近出现调制比异常。

The characteristics of the spatial distribution of the earth tide modulation ratio before three shallow M_(S)≥6.0 earthquakes in Xinjiang(73°—96.5°E,34°—49.5°N)since 2016 are systematically studied.It was found that the three earthquakes were preceded by different degrees of anomalies in the modulation ratio of solid tides:①Only a high modulation ratio anomaly appeared in the epicentral area 2 years before the M_(S) 6.2 earthquake that occurred on Dec.8,2016;②The epicenter of the M_(S) 6.6 earthquake in Jinghe County on August 9,2017,falls in high modulation ratio anomaly regions 2,1 and 0.5 years before the occurrence,showing an obvious modulation effect;③The modulation ratio anomalies appeared near the epicenter of the Jiashi M_(S) 6.4 earthquake that occurred on January 19,2020,2 and 1 years before the occurrence.