Characteristics of regional tectonic stress field in Wenchuan area and the effect of Wenchuan MS8.0 earthquake on surrounding major fault surfaces
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摘要: 为剖析2008年汶川MS8.0地震对后期地震的影响及发震区域构造应力场特征,首先利用2008年5月12日—2013年4月19日汶川地震及其邻区的1660条震源机制解,同时采用同一地震多个震源机制中心解的方法筛去重复地震事件的震源机制解,最终获得911个震源机制解。其次,通过网格搜索法分段反演出区域构造应力场。结果显示:东北区主要受WNW-ESE向的挤压,西南区受W-E向的挤压,中区受WSW-ENE向的挤压。西南到东北主压应力轴方向有所变化,这可能与龙门山地区受到来自印度板块北北东方向的俯冲推挤、四川盆地的阻挡和巴颜喀拉块体东南向挤压的联合作用有关。然后,基于USGS给出的汶川MS8.0地震的破裂模型,计算出该地震对附近强震的触发关系,结果表明,本次汶川地震对同属龙门山断裂西南端的芦山地震触发作用明显,对位于东昆仑断裂上的玛多地震也有一定的触发作用。最后,计算汶川MS8.0地震对周围断层的同震库仑应力变化,发现本次地震造成龙门山断裂南北两端、秦岭南缘断裂、鲜水河断裂东南端、东昆仑断裂、白玉断裂的库仑破裂应力增加,龙门山断裂南北两端和秦岭南缘断裂增加最为明显,对分析地震危险性有一定的参考意义。Abstract: To analyze the influence of the 2008 Wenchuan MS8.0 earthquake on later earthquakes and the characteristics of the tectonic stress field in the seismogenic region, we first used 1660 source mechanism solutions of the Wenchuan earthquake and its neighboring areas from May 12, 2008 to April 19, 2013, and also used the method of sieving the central solution of multiple source mechanism solutions of the same earthquake to remove the source mechanism solutions of repeated seismic events, and finally 911 solutions were obtained. Then, the regional tectonic stress field is inverse-performed by the grid search method. The results show that the northeast zone is mainly squeezed by the WNW-ESE direction, the southwest zone is squeezed by the W-E direction, and the central zone is squeezed by the WSW-ENE direction. There is a change in the direction of the main compressive stress axis from southwest to northeast, which may be related to the combined effect of subduction thrusting from the north-northeast direction of the Indian plate, blocking from the Sichuan basin and southeastward extrusion of the Bayan Kara block in the Longmenshan area. Then, based on the rupture model of the Wenchuan MS8.0 earthquake given by the USGS, the triggering relationship of this earthquake on nearby strong earthquakes is calculated. The results show that this Wenchuan earthquake has a significant triggering effect on the Lushan earthquake, which also belongs to the southwest end of the Longmenshan fault, and on the Maduo earthquake, which is located on the East Kunlun fault. Finally, the coseismic Coulomb stress changes of the surrounding faults caused by the Wenchuan MS8.0 earthquake were calculated. It is found that this earthquake caused an increase in Coulomb rupture stress on the north and south ends of the Longmenshan fault, the south edge of the Qinling fault, the southeast end of the Xianshui River fault, the East Kunlun fault, and the Baiyu fault, with the most obvious increase on the north and south ends of the Longmenshan fault and the south edge of the Qinling fault, which is a reference for the analysis of seismic hazards.
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图 3 分区的应力场及辐射花样图
(a、c、e) 黑色弧线是中心震源机制的2个节面,绿色覆盖区是不确定范围;紫色弧线是机构和学者给出的震源机制的节面;红色、黄色和蓝色的封闭区分别表示震源机制解的P轴、B轴和T轴,对应颜色的封闭曲线表示其对应的不确定范围;绿点、蓝点和黑点分别为各个机构和学者给出震源机制的P轴、B轴和T轴;此图投影方式为下半球等面积投影;(b、d、f) 黄色为压缩区域,蓝色为膨胀区域
Figure 3. Stress field and radiation pattern of zoning
(a,c,e) The black arc is the two nodal planes of the central focal mechanism,and the green coverage area represents the uncertainty range;The purple arc represents the nodal plane of the focal mechanism given by the mechanism and scholars;The closed areas in red,yellow and blue represent the P-axis,B-axis and T-axis of focal mechanism solution respectively,and the closed curve represents its corresponding uncertainty range;Green dot,blue dot and black dot are the P-axis,B-axis and T-axis of focal mechanism given by various institutions and scholars respectively;The projection method of this figure is equal area projection of the lower hemisphere; (b,d,f) Yellow is the extrusion area and blue is the expansion area
图 4 2008年汶川地震14 km深度处在周围主要断裂上产生的库仑破裂应力变化
黑色和绿色震源机制解分别为走滑和逆冲型;填充在断层上的颜色表示库仑破裂应力变化的大小,红色表示增加,蓝色表示减小,大小如色标所示
Figure 4. Variation of Coulomb fracture stress on the surrounding main faults at the depth of 14 km of Wenchuan earthquake in 2008
The black and green focal mechanism solutions in the figure are strike slip and thrust type respectively; The color filled on the fault indicates the change of Coulomb fracture stress,red indicates increase,blue indicates decrease,and the size is shown in the color code
图 5 汶川地震产生的应力场在深度14 km处的水平面投影
图中白色箭头、黑色箭头分别表示主张应力(最大主应力)和主压应力(最小主应力);底色为面应力分量,红色为膨胀区,蓝色为压缩区
Figure 5. Horizontal projection of stress field generated by Wenchuan earthquake at the depth of 14 km
The white arrow and black arrow in the figure represent the principal tensile stress (maximum principal stress) and principal compressive stress (minimum principal stress) respectively; The background color is the surface stress component, red is the expansion zone and blue is the compression zone
图 6 2008年汶川地震震前(a)及震后(b)构造应力场的水平分量
黑色箭头和白色箭头分别表示水平面最小主应力和最大主应力的方向;底色表示面应力
Figure 6. Horizontal components of tectonic stress field before (a) and after (b) the 2008 Wenchuan earthquake
The black arrow and the white arrow indicate the direction of the minimum principal stress and the maximum principal stress in the horizontal plane respectively;The background color indicates surface stress
类型 P 轴倾伏角 B 轴倾伏角 T 轴倾伏角 正断型(NF) ≥52° ≤35° 正走滑型(NS) 40°≤倾角<52° ≤20° 走滑型(SS) ≤20° ≥45° <40° <40° ≥45° ≤20 逆走滑型(TS) ≤20° 40°≤倾角<52° 逆冲型(TF) ≤35° ≥52° 不确定型(U) 上述类型之外的震源机制解 I 同一地震多个震源机制的中心解结果
I. Central solution results of multiple focal mechanisms of the same earthquake
序号 日期 时间 东经/° 北纬/° 震级 节面I 最小三维空间旋转角
的标准差/°所用参考
资料走向/° 倾向/° 滑动角/° 1 2008-05-12 11:11:00 103.5 31.3 6.1 26.6 87.9 −162.4 10.4 AKC 2 2008-05-12 13:40:52 103.5 31.0 5.2 243.9 64.3 77.5 46.1 AKC 3 2008-05-12 14:28:00 103.4 31.0 8.0 12.3 63.6 82.7 15.9 EJG 4 2008-05-12 15:05:15 103.8 31.2 5.2 126.7 −19.9 221.8 46.3 AK 5 2008-05-12 15:28:26 103.6 31.1 5.1 296.2 64.7 −28.6 46.7 AK 6 2008-05-12 18:23:33 103.3 31.0 4.8 201.2 51.0 103.3 12.2 EFH 7 2008-05-12 19:11:16 103.4 31.3 5.9 207.1 90.0 146.5 32.9 DEFHJ 8 2008-05-12 19:33:09 105.3 32.6 4.3 353.5 53.1 −41.2 42.0 FH 9 2008-05-12 19:41:05 105.0 32.4 4.3 162.4 63.6 −13.1 12.0 FH 10 2008-05-12 19:52:22 105.3 32.6 4.3 107.1 82.4 −19.6 55.5 FH 11 2008-05-12 20:11:28 103.8 31.4 4.0 355.7 87.0 −22.3 12.2 FH 12 2008-05-12 20:15:28 104.4 31.9 4.6 40.7 25.1 150.8 7.7 FH 13 2008-05-12 20:23:14 105.3 32.6 4.2 322.4 59.3 41.2 11.0 FH 14 2008-05-12 20:29:28 103.8 31.4 3.9 199.0 53.3 62.5 16.4 FH 15 2008-05-12 20:54:28 103.5 31.3 3.9 119.5 82.9 9.3 14.3 FH 16 2008-05-12 21:02:02 103.3 31.0 3.9 176.5 72.5 129.4 4.9 FH 17 2008-05-12 21:07:07 103.4 31.2 3.7 199.4 41.7 64.4 7.1 FH 18 2008-05-12 21:32:06 103.8 31.3 4.0 233.6 86.9 −111.7 45.0 FH 19 2008-05-12 21:40:52 103.4 31.1 5.0 223.3 87.1 −93.9 13.1 DEFH 20 2008-05-12 22:09:23 104.5 31.9 4.1 296.2 78.0 101.8 40.5 FH 21 2008-05-12 22:46:03 105.5 32.7 5.0 68.9 81.2 −144.0 8.9 DEFHJ 22 2008-05-12 23:05:16 103.6 31.2 4.8 301.1 38.0 −189.4 52.6 DEFH 23 2008-05-12 23:05:28 103.5 31.3 4.7 248.0 83.2 40.6 48.8 DFH 24 2008-05-12 23:28:45 103.4 31.0 5.1 17.8 25.7 151.3 17.8 DEFHJ 25 2008-05-13 00:28:27 103.6 31.2 4.3 60.1 49.5 101.5 34.6 FH 26 2008-05-13 01:01:22 103.4 30.9 3.8 169.1 20.3 −138.5 12.3 FH 27 2008-05-13 01:03:05 103.4 31.2 5.0 31.5 57.5 101.4 17.9 EF 28 2008-05-13 01:29:03 103.4 31.3 4.8 5.2 87.7 −140.2 28.1 DEFH 29 2008-05-13 01:54:30 103.4 31.3 4.9 31.8 80.8 −162.3 13.0 DEFH 30 2008-05-13 02:46:07 105.0 32.4 4.2 335.4 68.7 165.2 29.9 FH 31 2008-05-13 04:08:44 103.8 31.4 5.5 5.6 56.8 73.6 14.6 DEFGHJ 32 2008-05-13 04:45:36 104.3 31.8 5.0 26.3 35.9 86.2 12.5 DEFHJ 33 2008-05-13 05:08:08 103.2 31.3 4.2 240.8 55.9 −136.5 12.0 DFH 34 2008-05-13 07:07:05 103.3 31.0 6.1 244.5 45.4 140.2 31.8 ACK 35 2008-05-13 07:46:13 103.4 31.3 5.0 118.2 66.0 −1.2 17.1 DEFHJ 36 2008-05-13 07:54:38 103.4 31.3 5.1 200.5 84.0 −154.7 31.3 DEFH 37 2008-05-13 08:22:07 103.8 31.3 4.1 12.1 68.9 48.7 1.7 FH 38 2008-05-13 09:07:28 103.7 31.4 3.7 28.6 43.4 58.7 9.6 FH 39 2008-05-13 10:15:12 103.9 31.6 5.0 224.3 42.6 122.9 45.0 DEFJ 40 2008-05-13 10:33:19 103.6 31.3 3.9 49.9 47.0 89.9 3.2 FH 41 2008-05-13 10:59:15 103.4 31.0 4.2 44.5 55.5 147.0 2.8 FH 42 2008-05-13 11:00:19 103.5 31.2 4.5 −7.4 51.6 62.1 21.6 FH 43 2008-05-13 11:48:30 103.8 31.3 4.1 268.3 44.8 115.4 30.7 DFH 44 2008-05-13 12:45:27 103.3 31.0 3.8 284.9 88.0 −164.5 4.2 FH 45 2008-05-13 12:50:30 103.4 31.3 4.2 292.2 60.7 −6.4 38.9 AFH 46 2008-05-13 13:37:17 103.5 31.0 4.0 195.0 87.4 −157.9 41.8 DFH 47 2008-05-13 15:07:07 103.2 31.0 6.0 221.2 44.5 113.9 9.4 DEFGHJ 48 2008-05-13 16:20:55 103.8 31.4 5.3 39.3 57.3 106.5 34.9 DEFJ 49 2008-05-13 18:16:04 104.3 31.7 4.4 10.6 54.8 56.0 10.8 FDH 50 2008-05-13 18:36:20 103.6 31.3 4.2 59.6 46.9 75.4 2.5 FH 51 2008-05-13 20:51:36 105.0 32.3 4.4 346.8 40.3 39.8 15.6 DFH 52 2008-05-13 21:31:22 105.0 32.3 4.3 102.9 61.9 144.9 5.0 DFH 53 2008-05-14 00:23:33 104.3 31.7 4.4 10.5 55.7 62.4 7.3 DFH 54 2008-05-14 03:30:16 103.3 31.1 4.2 49.3 48.4 −9.9 20.6 DFH 55 2008-05-14 03:51:51 103.3 31.0 4.1 187.5 55.4 72.7 16.0 DFHJ 56 2008-05-14 09:09:19 103.8 31.4 4.2 14.8 53.4 84.1 10.0 DFH 57 2008-05-14 09:56:27 103.5 31.3 4.2 268.1 39.1 32.4 7.9 DFH 58 2008-05-14 10:54:24 310.1 94.0 5.3 34.2 67.1 −164.6 18.6 DFH 59 2008-05-14 13:54:43 104.1 31.9 4.9 358.7 79.5 132.8 14.9 DEFH 60 2008-05-14 17:26:30 103.9 31.4 5.0 25.1 38.9 97.4 10.1 DEFHJ 61 2008-05-14 18:00:19 105.0 32.4 4.4 228.6 47.9 116.9 5.5 DFH 62 2008-05-15 01:17:11 103.8 31.5 4.4 45.5 55.0 99.7 10.7 DFHJ 63 2008-05-15 01:33:11 103.5 31.3 4.6 197.7 89.9 −174.9 24.0 DFHJ 64 2008-05-15 03:59:00 103.5 31.1 4.3 24.5 80.2 −178.8 5.1 DFHJ 65 2008-05-15 05:01:02 104.1 31.7 4.9 346.8 59.8 60.8 10.9 DEFHJ 66 2008-05-15 06:10:04 103.6 31.2 4.8 144.0 76.0 −10.1 18.8 DEFH 67 2008-05-15 13:27:31 104.3 32.0 4.3 110.3 70.7 67.0 10.1 DFH 68 2008-05-15 21:04:04 105.6 32.7 4.3 337.9 77.8 −29.3 4.7 DFH 69 2008-05-16 05:55:36 104.7 32.3 4.6 350.3 52.6 132.5 7.5 DFHJ 70 2008-05-16 06:10:22 103.9 31.4 4.3 212.0 49.1 115.3 34.9 DFH 71 2008-05-16 11:34:13 103.9 31.5 4.8 48.7 69.4 93.3 5.5 DEFH 72 2008-05-16 13:25:43 103.2 31.4 5.8 142.9 77.8 −23.8 6.8 DEFGHJ 73 2008-05-16 18:17:13 103.5 31.3 4.1 264.6 78.2 6.8 37.1 DFH 74 2008-05-17 00:14:37 103.4 31.2 4.9 163.7 81.1 119.7 27.8 DEFH 75 2008-05-17 01:22:20 103.6 31.2 4.2 50.0 85.7 14.0 5.2 DFH 76 2008-05-17 04:15:07 104.9 32.3 4.2 73.2 40.8 74.6 34.9 FHJ 77 2008-05-17 04:16:43 103.5 31.3 4.9 4.2 60.2 −160.6 36.6 EFHJ 78 2008-05-17 04:29:03 103.3 31.4 4.2 31.5 84.5 168.4 7.0 DFH 79 2008-05-17 06:33:06 105.0 32.3 4.3 233.2 66.2 110.1 25.4 DFHJ 80 2008-05-17 07:23:02 103.7 31.3 4.3 208.7 68.7 −117.8 38.7 FHJ 81 2008-05-17 08:28:55 103.8 31.3 3.9 190.7 60.7 −69.7 39.3 DFHK 82 2008-05-17 21:32:06 104.6 32.1 4.5 315.4 40.8 8.4 7.8 DFHJ 83 2008-05-18 01:08:12 104.9 32.3 5.9 233.8 46.4 92.2 8.1 DEFGHJ 84 2008-05-18 04:26:02 103.5 31.2 4.1 243.9 74.0 3.5 29.0 DFH 85 2008-05-18 08:45:55 104.0 31.9 4.1 38.0 88.2 107.6 3.0 DFH 86 2008-05-18 09:04:51 103.6 31.1 4.2 11.7 61.5 177.9 9.0 DFHJ 87 2008-05-19 12:08:38 105.0 32.2 4.6 49.8 50.0 101.5 16.6 FHJ 88 2008-05-19 14:06:24 105.3 32.6 5.3 220.3 84.9 140.9 29.9 DEFHJ 89 2008-05-20 01:52:37 104.9 32.3 4.9 37.9 46.8 71.9 10.9 DEFHJ 90 2008-05-20 12:17:37 103.3 30.8 4.1 136.3 78.5 41.0 9.8 DFH 91 2008-05-20 14:54:07 104.2 31.8 4.1 140.4 84.4 49.8 90.1 FHJ 92 2008-05-21 17:33:04 105.1 32.4 4.4 243.1 86.2 163.5 7.5 FHJ 93 2008-05-21 21:59:03 103.9 31.4 4.4 206.5 30.5 102.6 13.3 DFHJ 94 2008-05-22 15:18:36 103.6 31.2 4.9 220.9 74.6 −113.6 19.7 DEFH 95 2008-05-22 19:22:09 105.4 32.7 4.2 120.1 68.9 30.6 20.8 FHJ 96 2008-05-22 23:00:06 104.4 31.9 4.4 136.6 81.4 53.3 10.8 DFHJ 97 2008-05-23 01:37:34 103.6 31.3 4.6 229.3 31.0 135.0 4.6 DFHJ 98 2008-05-23 08:05:04 103.6 31.2 4.5 98.7 33.3 −37.7 5.5 DFH 99 2008-05-23 09:23:13 103.5 31.2 4.1 35.0 84.5 −174.5 19.3 DFHJ 100 2008-05-24 01:53:26 105.2 32.5 4.1 33.4 86.7 61.7 10.9 FHJ 101 2008-05-25 16:21:44 105.3 32.6 6.3 60.4 82.1 178.2 14.0 DEFGHJ 102 2008-05-26 08:39:38 103.3 30.8 4.5 31.7 76.9 89.8 19.5 DFHJ 103 2008-05-27 16:03:09 105.6 32.8 5.2 338.9 77.9 −1.2 4.4 DEFGHJ 104 2008-05-27 16:37:45 105.6 32.8 5.6 83.9 70.3 −158.6 17.3 DEFGHJ 105 2008-05-27 21:59:33 105.2 32.6 4.7 297.8 84.9 −18.2 11.2 DFHJ 106 2008-05-28 00:46:06 104.6 32.2 4.1 334.5 62.0 129.0 5.8 DFHJ 107 2008-05-28 01:35:04 105.4 32.7 4.8 106.4 79.1 84.4 14.9 DEFHJ 108 2008-05-29 12:48:37 105.4 32.6 4.5 116.0 78.3 81.8 5.2 DFHJ 109 2008-05-29 15:10:13 103.7 31.4 4.3 1.0 43.9 38.3 6.8 DFH 110 2008-05-31 14:22:35 105.0 32.4 4.2 23.6 46.6 83.7 16.4 FHJ 111 2008-05-31 15:34:07 105.4 32.7 4.1 169.2 40.8 62.8 19.3 FHJ 112 2008-06-01 11:23:39 104.0 31.6 4.3 180.0 20.2 99.0 15.3 FHJ 113 2008-06-05 12:41:03 105.0 32.4 5.0 47.6 55.2 91.9 8.2 DEFHJ 114 2008-06-05 14:02:11 105.4 32.7 4.3 169.1 73.3 95.6 29.3 FHJ 115 2008-06-06 19:03:39 103.7 31.3 4.3 11.4 81.8 27.9 9.3 DFHJ 116 2008-06-06 22:38:36 103.3 31.1 4.3 197.8 55.8 85.8 6.8 FHJ 117 2008-06-07 08:48:06 103.4 31.2 4.6 350.2 78.2 −105.3 7.3 DFHJ 118 2008-06-07 15:32:31 105.1 32.5 3.9 94.9 67.8 48.0 21.8 DFH 119 2008-06-07 18:42:02 105.7 32.5 4.6 −1.9 88.4 8.8 8.8 DFHJ 120 2008-06-08 18:51:07 104.2 31.9 5.0 92.9 41.1 4.2 15.7 DEFHJ 121 2008-06-11 00:27:07 105.7 32.8 4.4 145.3 87.5 −8.9 8.1 DFHJ 122 2008-06-11 06:23:08 103.3 30.9 4.9 191.2 28.4 75.3 8.4 DEFHJ 123 2008-06-15 00:11:14 103.7 31.2 4.7 314.0 62.8 154.9 17.1 ACK 124 2008-06-15 08:11:10 103.6 31.2 4.7 51.0 70.8 21.1 19.2 DFHJ 125 2008-06-17 13:14:22 104.1 31.7 4.3 215.0 49.4 94.3 12.2 DFH 126 2008-06-17 21:32:02 104.3 31.9 4.1 6.8 64.3 167.6 16.4 FHJ 127 2008-06-18 06:43:04 103.4 31.3 4.1 278.1 82.9 −27.3 20.0 FHJ 128 2008-06-19 10:55:14 103.5 31.2 4.4 230.4 49.2 −21.3 17.9 DFHJ 129 2008-06-19 20:27:23 103.7 31.1 4.7 235.6 81.9 83.0 21.6 AK 130 2008-06-20 04:27:46 103.5 31.2 4.5 246.1 77.0 87.0 10.9 DF 131 2008-06-23 05:38:31 105.1 32.4 4.0 241.8 50.6 93.3 16.7 DFHJ 132 2008-06-27 08:55:35 103.4 31.1 4.2 3.6 76.8 −177.7 8.5 DFHJ 133 2008-06-28 02:20:42 103.3 31.5 4.5 234.5 85.7 −167.1 9.8 DFHJ 134 2008-06-28 05:42:06 104.9 32.3 4.6 69.1 66.7 −99.8 11.6 DFHJ 135 2008-06-29 07:55:10 104.5 32.1 4.3 329.2 54.0 103.8 8.9 DFHJ 136 2008-07-02 03:57:55 103.9 31.4 4.8 18.5 87.4 67.8 24.4 DFJ 137 2008-07-03 04:08:03 103.7 31.2 4.0 68.7 71.5 −147.8 31.3 AK 138 2008-07-05 06:10:55 104.1 31.7 4.6 148.8 47.4 70.3 36.3 DFJ 139 2008-07-05 15:00:34 104.1 31.7 4.4 140.9 71.8 42.1 38.7 FHJ 140 2008-07-06 02:50:09 104.1 31.6 4.5 48.7 45.5 88.3 10.4 DFJ 141 2008-07-08 20:12:44 103.9 31.4 4.7 183.1 53.7 80.7 12.6 DFHJ 142 2008-07-15 03:56:31 104.0 31.6 4.4 146.1 88.9 −48.9 11.3 DFHJ 143 2008-07-15 17:26:08 104.0 31.6 4.8 175.9 72.3 −54.1 7.6 DEFHJ 144 2008-07-24 15:09:14 105.5 32.8 5.8 130.7 56.5 45.9 45.2 DEFGHJ 145 2008-08-01 16:32:51 104.7 32.1 6.1 217.8 71.5 107.6 11.4 DEFJ 146 2008-08-02 02:12:16 105.2 32.5 4.8 78.0 84.3 −170.4 8.9 DFJ 147 2008-08-02 21:25:50 105.6 32.8 4.6 69.6 88.7 −173.9 5.9 DFJ 148 2008-08-05 17:49:10 105.5 32.8 6.0 161.7 54.0 89.9 14.2 DFGHJ 149 2008-08-07 16:15:32 104.6 32.1 5.0 246.0 46.3 105.1 6.3 DFHJ 150 2008-08-08 21:12:18 103.9 31.5 4.0 320.4 76.0 39.9 14.7 DF 151 2008-08-10 00:31:35 105.2 32.6 4.0 32.2 69.0 177.0 23.9 DF 152 2008-08-13 05:03:20 104.2 31.8 4.5 100.6 51.6 57.3 3.7 DF 153 2008-08-14 17:06:24 103.4 31.0 4.9 81.2 82.3 176.6 8.6 ACK 154 2008-08-15 01:06:39 103.2 31.0 4.3 168.9 86.0 1.0 14.3 DF 155 2008-08-18 10:22:22 103.4 31.3 3.9 214.3 83.1 155.6 11.1 DF 156 2008-09-11 18:30:22 103.7 31.3 4.1 232.1 46.7 72.6 6.2 DF 157 2008-09-12 01:38:58 105.6 33.0 4.9 324.2 39.1 63.9 19.1 DF 158 2008-10-04 20:11:46 104.1 31.8 4.2 12.5 65.1 120.4 2.2 DF 159 2008-10-16 10:08:38 103.5 31.3 3.9 176.3 87.9 165.5 14.5 DF 160 2008-10-16 17:46:16 103.7 31.2 4.3 42.6 85.7 90.2 3.5 DF 161 2008-10-25 01:50:25 103.9 31.4 4.0 54.0 67.7 120.1 10.6 DF 162 2008-11-04 20:43:12 104.5 32.1 4.3 118.4 53.3 61.9 5.0 DF 163 2008-11-14 14:33:32 105.4 32.8 4.0 151.4 48.9 107.3 26.8 DF 164 2008-11-16 06:59:43 104.6 32.2 4.7 260.5 89.5 6.5 3.9 DF 165 2008-12-04 21:57:32 103.4 31.3 4.2 297.0 72.0 −21.9 17.1 DF 166 2008-12-07 11:02:11 104.4 31.7 4.1 121.4 66.0 26.6 5.3 DF 167 2008-12-10 02:52:42 105.4 32.6 4.8 225.0 43.2 84.3 8.6 ADF 168 2008-12-23 08:33:11 103.1 31.3 4.3 132.6 85.5 −49.5 31.2 DF 169 2009-01-12 19:36:33 103.7 31.1 3.8 52.4 89.9 110.3 7.8 BK 170 2009-01-14 18:23:37 103.2 31.3 4.6 237.4 61.7 −125.0 11.6 BK 171 2009-01-15 02:23:36 103.2 31.3 4.5 109.3 45.9 −48.4 7.4 DF 172 2009-02-01 01:36:30 105.3 32.5 4.0 199.2 47.0 128.7 16.3 DF 173 2009-02-16 10:11:37 103.7 31.2 3.6 77.9 81.9 −64.0 41.8 BK 174 2009-03-04 00:21:38 104.9 31.9 4.3 259.3 58.8 82.4 35.0 DF 175 2009-03-19 13:43:25 105.0 32.3 4.1 64.8 49.0 84.8 13.4 DF 176 2009-04-06 00:47:03 104.2 31.8 4.3 266.5 73.5 −65.0 3.9 DF 177 2009-05-14 23:49:28 104.8 32.3 4.1 160.2 84.5 161.6 12.5 DF 178 2009-06-02 06:01:36 103.6 31.2 3.5 59.5 84.6 64.7 10.9 BK 179 2009-06-02 19:31:34 103.2 31.3 3.7 211.3 73.6 −132.5 9.6 BK 180 2009-06-30 02:03:50 104.0 31.5 5.1 71.2 61.5 107.3 4.4 DF 181 2009-06-30 13:40:24 104.0 31.5 4.1 84.7 70.7 114.6 4.0 DF 182 2009-06-30 15:22:19 104.0 31.5 4.7 188.9 44.8 51.7 1.9 DF 183 2009-07-20 09:50:21 103.3 31.0 3.5 187.9 65.8 144.0 9.6 BK 184 2009-07-31 05:50:32 103.5 31.3 3.5 7.4 79.4 −145.7 8.8 BK 185 2009-08-01 05:54:38 104.1 31.8 4.1 40.8 57.8 80.7 10.5 DF 186 2009-08-03 15:06:38 103.7 31.3 3.7 36.6 85.3 −8.5 28.4 BK 187 2009-08-03 22:18:16 103.6 31.2 4.0 150.6 86.9 −23.6 25.7 BK 188 2009-08-26 01:49:32 103.2 30.6 3.5 220.0 83.9 −83.5 7.1 BK 189 2009-09-07 13:11:48 103.6 31.3 3.6 14.8 69.3 65.2 10.2 BK 190 2009-09-19 12:16:39 102.7 30.5 3.7 324.3 89.9 32.0 17.5 BK 191 2009-09-19 16:54:14 105.5 32.9 4.7 23.4 49.0 114.5 16.2 DF 192 2009-10-18 21:43:24 103.3 30.9 3.7 13.5 61.2 93.0 10.8 BK 193 2009-12-05 01:43:40 104.2 32.1 3.9 147.5 88.0 170.5 2.9 DF 194 2010-03-23 15:52:21 103.4 31.3 4.0 241.4 70.1 −69.6 48.5 BK 195 2010-03-23 16:20:54 103.4 31.3 3.5 49.9 53.0 −75.5 12.3 BK 196 2010-04-26 22:15:56 103.4 31.2 3.7 222.8 67.5 77.1 3.8 BK 197 2010-05-25 06:11:53 103.5 31.2 4.9 217.7 59.5 86.3 1.2 BK 198 2010-05-25 14:11:52 103.5 31.2 4.8 225.7 48.0 89.8 11.2 DF 199 2010-05-28 11:04:52 104.1 31.8 4.3 356.5 55.0 103.0 3.3 DF 200 2010-07-06 13:03:41 103.3 30.9 3.4 200.2 47.4 77.2 6.4 BK 201 2010-07-11 05:24:37 104.5 30.6 3.5 143.6 75.1 −166.9 2.7 BK 202 2010-07-17 11:39:37 103.4 30.7 3.3 61.7 57.4 135.4 8.6 BK 203 2010-09-11 05:07:01 103.5 31.1 3.3 46.7 46.8 −52.8 40.2 BK 204 2010-09-11 20:16:15 103.3 31.0 3.5 204.7 88.8 −108.8 12.8 BK 205 2010-10-01 07:42:47 103.4 31.0 3.5 140.2 82.6 43.2 39.8 BK 206 2010-10-19 13:28:08 103.3 31.2 3.4 251.7 51.4 87.9 10.9 BK 207 2010-10-25 02:55:48 103.3 30.9 4.2 152.9 49.1 60.7 28.2 BK 208 2011-02-01 23:15:28 103.4 31.3 3.3 200.9 67.8 141.7 14.0 BK 209 2011-02-10 09:56:47 103.4 31.0 3.4 139.7 64.4 33.4 3.6 BK 210 2011-03-05 18:31:04 103.6 31.3 3.7 206.7 87.8 160.4 6.7 BK 211 2011-03-27 20:18:40 103.3 31.0 3.4 111.2 52.4 54.9 4.7 BK 212 2011-04-16 03:36:24 103.4 31.2 3.3 106.6 74.1 146.0 3.7 BK 213 2011-04-19 09:40:46 103.4 31.1 3.5 58.1 57.7 138.9 33.1 BK 214 2011-04-21 18:43:57 103.2 30.9 3.5 210.9 77.3 −138.6 2.0 BK 215 2011-04-29 13:30:57 103.4 31.0 3.9 17.9 66.6 86.6 6.7 BK 216 2011-05-06 10:48:15 103.6 31.3 4.1 348.0 50.8 82.2 13.3 BK 217 2011-10-26 20:01:55 103.3 31.0 3.9 181.0 51.7 74.8 5.3 BK 218 2011-12-06 14:03:13 103.5 31.2 3.8 351.8 63.1 −131.5 2.6 BK 219 2012-01-18 01:28:28 103.5 31.2 3.5 210.5 78.1 120.6 8.9 BK 220 2012-02-08 02:34:38 103.5 31.0 3.8 49.8 81.8 179.0 34.9 BK 221 2012-04-09 10:33:17 103.2 31.0 3.7 13.6 50.1 119.1 8.1 BK 222 2012-06-30 02:51:04 103.6 31.2 3.6 231.9 68.4 −113.2 4.9 BK 223 2012-07-27 21:28:14 103.4 30.8 4.1 19.6 49.3 77.9 6.2 BK 224 2012-10-19 02:44:16 102.9 30.1 4.1 37.9 80.7 126.2 5.9 BK 225 2012-10-23 02:14:26 103.7 31.0 3.7 −0.4 51.9 111.2 32.3 BK 226 2012-12-11 15:26:00 103.7 31.3 3.5 42.8 55.7 88.3 8.4 BK 227 2013-02-19 14:17:43 105.2 31.2 4.9 319.4 89.4 −172.6 2.7 BK 228 2013-03-04 15:42:19 103.4 31.0 3.9 148.0 82.4 34.7 25.9 BK 229 2013-04-07 23:51:29 103.3 30.8 3.8 41.7 62.9 101.5 1.8 BK 资料:A为郭祥云等[16]的数据,B为李先瑞手稿数据,C为Tian等[18]的数据,D为中国地震台网数据,E为胡幸平等[12]的数据,F为易桂喜等[14]的数据,G为蒋海昆等[17]的数据,H为郑勇等[11]的数据,J为崔效锋等[13]的数据,K为杨宜海等[15]的数据 表 2 应力场反演结果
Table 2. Inversion results of stress field
分区 最大主压应力轴 中间应力轴 最大主张应力轴 P 轴走向/° P 轴倾伏角/° B 轴走向/° B 轴倾伏角/° T 轴走向/° T 轴倾伏角/° 东北区 281.84—282.90 1.50—3.00 11.50—13.00 2.50—3.50 157.79—159.29 85.89—86.89 中区 255.31—264.31 0.99—2.48 165.00—174.00 8.00—11.00 −2.42—6.58 79.78—82.78 西南区 267.50—270.00 −0.50—0.80 177.50—180.00 36.50—38.00 357.50—360.00 52.50—54.00 表 3 本研究所用的断层面性质和库仑破裂应力增加段
Table 3. Fault plane properties and Coulomb fracture stress increasing section used in this study
断层名称 分段数 走向/° 倾角/° 倾向 性质 $\Delta {\sigma }_{\mathrm{f}}$/Pa 龙门山断裂西南端 3 43 65 NW 逆冲 258700 龙门山断裂东北端 5 76 65 NW 右旋走滑 9707 鲜水河断裂东南端 4 325 75 NE/SW 左旋走滑 15960 秦岭南缘断裂 2 80 75 NE 左旋逆走滑 46850 西秦岭北缘 6 98 60 SW 左旋逆走滑 4207 龙日坝断裂东北端 1 45 75 NW 走滑 34330 -
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