扫描2022年芦山MS 6.1地震和马尔康MS 6.0地震震前不同震级档调制比图像，同时给出震前b值分布图像，结果表明：2次6级地震前震中附近不同震级档调制比均出现高值异常。最小扫描震级越高，调制比扫描结果越稳定清晰，调制比高值异常出现时间越晚，同时最小扫描震级越高，异常范围、幅度也越大，异常与震中位置和发震时间关联性越强。调制比异常的幅度和范围与应力水平有关，2次地震震前震中附近均出现低b值区域，且马尔康MS 6.0地震震中附近调制比异常和低b值异常都比芦山MS 6.1地震更突出，推断马尔康MS 6.0地震孕震区应力水平可能高于芦山MS 6.1地震孕震区应力水平。
We scan the modulation ratio images of different magnitude intervals before the Lushan MS 6.1 earthquake and the Markang MS 6.0 earthquake in 2022 and give the distribution image of the b value before the two earthquakes. The results show that high-value anomalies appear in the modulation ratio of different magnitude intervals near the epicenters before the two MS 6 earthquakes. The higher the minimum scanning magnitude is, the more stable and clear the scanning result of the modulation ratio is, and the later the high-value anomaly of the modulation ratio occurs. At the same time, the higher the minimum scanning magnitude is, the larger the anomaly amplitude and range are, and the stronger the correlation between the anomaly and the epicenter and the earthquake occurrence time is. The amplitude and range of the modulation ratio anomaly are related to the stress level. There are low b value areas near the epicenters before the two earthquakes, and the modulation ratio anomaly and low b value anomaly near the epicenter of the Markang MS 6.0 earthquake were more prominent than those of the Lushan MS 6.1 earthquake. It is inferred that the stress level in the seismogenic zone of the Markang MS 6.0 earthquake may be higher than that of the Lushan MS 6.1 earthquake.
2022,43（6）: 1-7 收稿日期：2022-07-15
DOI：10.3969/j.issn.1003-3246.2022.06.001
基金项目：河北省地震科技星火计划项目（项目编号：DZ20200827054）；河北省省级科技计划（项目编号：22375406D）
作者简介：陈婷(1990-),工程师,主要从事地震活动性及中长期预测等研究工作。E-mail:chenting_ouc@163.com
*通讯作者：张新东(1964-),正高级工程师,主要从事地震监测和震防工作。E-mail:1030017350@qq.com
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