通过对漾濞MS 6.4地震云南数字化井水位分钟值数据同震响应特征进行分析,分析观测仪器采样率对井水位映震能力的影响,并对水位同震响应机理进行初步分析。结果表明,对于漾濞MS 6.4地震,13口同震响应观测井主要分布在震中距200 km范围内的红河断裂带北侧和小滇西地区;同震响应形态可分为阶升(上升)型、阶降(或缓降)型、阶变(阶升、阶降)—复原型等3种变化类型,阶升型同震响应幅度相对大于其他2种类型;由漾濞MS 6.4地震烈度长轴和短轴共同划定的椭圆区域来划分此次地震静态应力和动态应力的影响范围,可以从各观测井受力状态初步分析水位同震响应变化形态的力学机理;在静态应力影响范围内,井水位同震响应主要表现为阶升变化;在静态应力影响范围以外,除以阶变(阶升、阶降)—复原变化为主外,还有阶降(缓降)、阶升变化。观测仪器采样率对井水位映震能力的影响较大,水位秒钟值数据的同震响应变化形态更加完整,但目前水位秒钟值数据的收集和使用都还在不便之处,这种情况有待改进。
Based on the analysis of the characteristics of co-seismic response of digital well water level minute data in Yunnan Province caused by Yangbi MS 6.4 earthquake, the influence of the sampling rate of the observation instrument on the seismic recording ability and the mechanism of the co-seismic response of the water level are discussed. The results show that the 13 co-seismic response observation wells of Yangbi MS 6.4 earthquake are mainly distributed on the north side of the Red River fault zone and the area in the west of Yunnan province within 200 km from the epicenter. Co-seismic response can be divided into three types: step up (ascend), step down (descend), and step change (step up, step down)-restores. The co-seismic response amplitude of step-up type is relatively larger than the other two types. The influence range of static stress and dynamic stress of Yangbi earthquake is divided by the ellipse region determined by both the long axis and the short axis of Yangbi earthquake intensity, the mechanical mechanism of water level co-seismic response variation can be analyzed from the stress state of each observation well. In the influence range of static stress, the co-seismic response of well water level mainly shows step-up variation, and outside the influence range, there are step-down (slow-down) and step-up variation besides mainly step-up variation (step-up, step-down). The sampling rate of the observation instrument has a great influence on recording seismic capability of the well water level, and the co-seismic response change pattern of the second value data of the water level is more complete, however, it is not convenient to collect and apply.
2022,43(4): 131-139 收稿日期:2022-03-10
DOI:10.3969/j.issn.1003-3246.2022.04.017
基金项目:云南省地震局自立科研项目“漾濞地震专项”(项目编号:2021YBZX07)
作者简介:段胜朝(1986—),男,本科,工程师,主要从事地震监测、地震预报及地下流体研究等工作。E-mail:619239180@ qq.com
参考文献:
[1] 车用太, 鱼金子. 地震地下流体学[M]. 北京: 气象出版社, 2006.
[2] 付虹, 邬成栋, 刘强, 等. 印尼巨大地震引起的云南水位异常记录及其意义[J]. 地震地质, 2007, 29(4): 873-882.
[3] 廖丽霞, 秦双龙, 陈昌泳. 不同采样率水位同震响应能力及其特征分析[J]. 地震地磁观测与研究, 2013, 34(3/4): 150-155.
[4] 刘耀炜, 杨选辉, 刘永铭, 等. 地下流体对苏门答腊8.7级地震的响应特征[M]//中国地震局监测预报司. 2004年印度尼西亚苏门答腊8.7级大地震及其对中国大陆地区的影响. 北京: 地震出版社, 2005: 131-285.
[5] 汪成民, 车用太, 万迪堃, 等. 地下水微动态研究[M]. 北京: 地震出版社, 1988.
[6] 向阳, 孙小龙, 梁卉. 2016年12月8日呼图壁MS 6.2地震引起的新10、新11井水位同震响应对比分析[J]. 内陆地震, 2017, 31(3): 259-269.
[7] 杨竹转, 邓志辉, 赵云旭, 等. 云南思茅大寨井水位同震阶变的初步研究[J]. 地震学报, 2005, 27(5): 569-574.
[8] 杨竹转, 邓志辉, 高小其, 等. 新疆乌鲁木齐04号井数字化水位同震阶变的研究[J]. 中国地震, 2010, 26(3): 329-339.
[9] 张子广, 万迪堃, 董守玉. 水震波与地震面波的对比研究及其应用[J]. 地震, 1998, 18(4): 399-404.
[10] 中国地震局监测预报司. 2004年印度尼西亚苏门答腊8.7级大地震及其对中国大陆地区的影响[M]. 北京: 地震出版社, 2005.
[11] Brodsky E E, Roeloffs E A, Woodcock D, et al. A mechanism for sustained groundwater pressure changes induced by distant earthquakes[J]. J Geophys Res, 2003, 108(B8): 2390, doi: 10.1029/2002JB002321.
[12] Cooper H H Jr, Bredehoeft J D, Papadopulos I S, et al. The response of well-aquifer systems to seismic waves[J]. J Geophys Res, 1965, 70(16): 3 915-3 926.
[13] Manga M, Wang C Y. Earthquake hydrology[M]//Schubert G. Treatise on Geophysics. Amsterdam: Elsevier, 2007, 4: 293-320.
[14] Roeloffs E A. Persistent water level changes in a well near Parkfield, California, due to local and distant earthquakes[J]. J Geophys Res, 1998, 103(B1): 869-889.
[15] Wakita H. Water wells as possible indicators of tectonic strain[J]. Science, 1975, 189(4 202): 553-555.
[16] Zhang Y, Huang F Q. Mechanism of different coseismic water-level changes in wells with similar epicentral distances of intermediate field[J]. Bulletin of the Seismological Society of America, 2011, 101(4): 1 531-1 541.