Determination of the focal mechanism solutions of the earthquakes with MS≥4.0 occurred in the mainland of China in January 2022
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摘要: 本文利用中国地震台网记录的宽频带波形资料,采用近震全波形反演方法得到2022年1月1—31日发生在中国大陆地区的MS≥4.0共13次地震的震源机制解。结果显示逆断型1次,走滑型9次,未知型3次。Abstract: In this paper, the regional full waveform inversion of the broadband waveforms from China Seismic Network are conducted, and the focal mechanism solutions of the 13 earthquakes with MS≥4.0 in the mainland of China from January 1 to January 31, 2022 are obtained. The results show that these earthquakes include 1 reverse faulting , 9 strike-slip faulting and 3 unknown earthquakes.
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Key words:
- focal mechanism /
- source parameters
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图 2 1月23日青海德令哈MS5.8(MW5.5)地震震源机制解反演
(a)波形相关系数随反演深度分布,彩色条棒表示偏量矩张量反演时双力偶分量所占比例;(b)本文所得震源机制解对应的三分量理论(红色)和实际(黑色)波形对比图,图中右测字符表示台站代码,波形上方数字为方差减少量值,代表波形拟合程度
Figure 2. Focal mechanism inversion of Qinghai Delingha MS5.8 (MW5.5) earthquake on January 23
(a) Correlation between observed and synthetic waveforms versus depth,the colored-bar shows double couple percentage using ISOLA in deviatoric mode;(b) Comparison of the three-component theoretical (red) and observational (black) waveforms corresponding to focal mechanism solutions obtained in this paper. The station codes are plotted on the right of figure, the numbers above the waveforms are variance reduction, which indicate the fitting degree of waveform
表 1 2022年1月中国大陆地区MS≥4.0地震基本参数
Table 1. Events list of the earthquakes with MS≥4.0 in the mainland of China in January 2022
序号 发震时刻(BJT)
(年-月-日 时:分:秒)北纬
/°东经
/°深度
/km震级(MS) 参考地名 1 2022-01-02 15:02:06.9 27.79 100.65 10 5.5 云南丽江市宁蒗县 2 2022-01-03 08:28:06.3 34.30 88.22 10 4.1 西藏那曲市双湖县 3 2022-01-04 12:45:03.5 43.36 82.13 21 4.8 新疆伊犁州巩留县 4 2022-01-08 01:45:27.9 37.77 101.26 10 6.9 青海海北州门源县 5 2022-01-08 01:55:19.8 37.75 101.24 10 4.1 青海海北州门源县 6 2022-01-08 02:09:05.7 37.78 101.24 12 5.1 青海海北州门源县 7 2022-01-08 14:30:05.5 37.77 101.15 10 4.0 青海海北州门源县 8 2022-01-12 18:20:40.9 37.69 101.49 10 5.2 青海海北州门源县 9 2022-01-12 20:16:17.6 37.75 101.42 10 4.8 青海海北州门源县 10 2022-01-12 21:01:53.2 37.69 101.49 8 4.5 青海海北州门源县 11 2022-01-13 00:17:59.6 37.76 101.42 8 4.0 青海海北州门源县 12 2022-01-18 06:59:30.1 29.15 94.28 50 4.8 西藏林芝市米林县 13 2022-01-20 05:52:37.1 32.34 105.13 10 4.0 四川广元市青川县 14 2022-01-23 10:21:17.9 38.44 97.37 8 5.8 青海海西州德令哈市 表 2 2022年1月中国大陆地区MS≥4.0地震的震源机制结果
Table 2. Focal mechanism solutions of the earthquakes with MS≥4.0 in the mainland of China in January 2022
序号 发震时刻(BJT)
(年-月-日 时:分:秒)节面Ⅰ 节面Ⅱ P轴 T轴 矩心
深度
/km矩震级
(MW)VR CN 走向
/°倾角
/°滑动
角/°走向
/°倾角
/°滑动
角/°方位
角/°仰角
/°方位
角/°仰角
/°1 2022-01-02 15:02:06.9 197 54 −30 306 66 −140 167 45 69 8 3 5.2 0.82 4.7 2 2022-01-03 08:28:06.3 143 89 23 52 67 179 275 16 10 17 16 4.6 0.65 2.3 3 2022-01-04 12:45:03.5 267 52 76 110 40 108 7 6 126 77 14 4.6 0.85 2.3 4 2022-01-08 01:45:27.9 288 85 21 196 69 174 60 11 153 18 4 6.4 0.62 3.2 5 2022-01-08 02:09:05.7 265 61 −19 5 73 −149 228 33 133 8 10 5.0 0.42 2.0 6 2022-01-08 14:30:05.5 281 84 25 188 65 173 52 13 147 22 7 4.4 0.70 2.3 7 2022-01-12 18:20:40.9 305 45 6 211 86 135 267 27 157 34 3 5.0 0.80 3.5 8 2022-01-12 20:16:17.6 357 78 −160 263 71 −13 221 23 129 5 9 4.7 0.73 2.5 9 2022-01-12 21:01:53.2 324 65 32 219 61 151 91 2 183 40 3 4.5 0.71 3.4 10 2022-01-13 00:17:59.6 261 75 9 169 81 164 215 4 124 17 8 4.2 0.72 2.4 11 2022-01-18 06:59:30.1 151 51 −12 248 81 −141 117 34 14 19 29 4.6 0.63 2.4 12 2022-01-20 05:52:37.1 107 29 175 202 87 61 317 36 85 40 11 4.0 0.76 2.0 13 2022-01-23 10:21:17.9 169 71 −179 79 89 −19 33 14 126 13 11 5.5 0.71 2.1 -
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