Seismogenic fault and aftershock characteristics for the 2014 MS7.3 Yutian earthquake，Xinjiang
-
摘要: 利用2014年10月至2019年9月期间欧空局Sentinel-1卫星采集的合成孔径雷达数据分析了2014年2月12日新疆于田MS7.3地震的震后形变场。结果表明，此次地震造成了南硝尔库勒断裂上明显的震后形变，首次从地震形变场的角度验证了此次地震的发震构造为NE向的左旋走滑断裂，而非部分研究所认为的近NS向断裂。由合成孔径雷达干涉测量得到的多年平均速率图显示主震的西侧仅出现了少量震后余滑且仍为强闭锁区，这意味着2008年和2014年于田两次MS7.3地震之间的区域仍存在发生强震的风险；在2014年主震的东侧，南硝尔库勒断裂和阿什库勒—硝尔库勒断裂呈蠕滑状态，故而余震较少，表明该区域近期发生强震的风险较低。
-
关键词:
- 2014于田MS7.3地震 /
- 发震构造 /
- 震后形变 /
- 余震 /
- 干涉合成孔径雷达
Abstract: Using synthetic aperture radar （SAR for short） data collected by the European Space Agency’s Sentinel-1 satellites during the period from October 2014 to September 2019, the postseismic deformation following the MS7.3 earthquake in Yutian, Xinjiang on 12 February 2014 was analyzed. The result showed that this earthquake induced obvious postseismic deformation along the southern Xorkol fault. It is for the first time that the seismogenic fault is confirmed to be one northeast-striking left-laterally strike-slip fault in the seismic deformation view, instead of another north-south-trending fault as proposed by a few studies. The InSAR （interferometric SAR） mean velocity map shows that there are only small postseismic slips and the fault is still strongly locked in the west of the main shock, which indicates that the risk of strong earthquake is high in the gap between the 2008 and 2014 Yutian MS7.3 earthquakes. However, in the east of the 2014 main shock, both the southern Xorkol fault and Ashikule-Xorkol fault are creeping with few aftershock activities, suggesting a lower level risk of strong earthquake for this region in the near future.-
Keywords:
- MS7.3 Yutian earthquake in 2014 /
- seismogenic fault /
- postseismic deformation /
- aftershock /
- InSAR
-
-
![]()
图 1 2014年于田地震周边地形及活动构造图
底图为地形（http://www2.jpl.nasa.gov/srtm/），实线为活动断裂（Taylor，Yin，2009；李海兵等，2015），红色圆点为历史大震的宏观震中（宋春燕等，2015），绿色圆点为2008年以来发生的地震（引自中国地震台网中心地震编目系统）。红色、蓝色虚线框分别表示本文处理的Sentinel-1卫星升轨（A：T158）和降轨（D：T165）数据的图幅范围，白色箭头表示卫星飞行方向，红、蓝色填充的箭头分别表示升、降轨卫星的视线方向（LOS）。F1：阿什库勒—硝尔库勒断裂；F2：南硝尔库勒断裂；F3：阿尔金断裂带；F4：康西瓦断裂；F5：郭扎错断裂
Figure 1. Map of topography and active faults around the 2014 Yutian earthquake
The shaded map is topography （http://www2.jpl.nasa.gov/srtm/）. The solid lines are active faults （Taylor，Yin，2009；Li et al，2015）. Red dots are hypocenters for strong historical earthquakes （Song et al，2015）. The green dots are earth-quakes occurred since 2008 （from the Earthquake Catalog System，China Earthquake Networks Center）. The red and blue dashed polygons represent the footprints of the ascending （A：T158） and descending （D：T165） Sentinel-1 orbital frames，respectively. White arrows denote the flight directions of satellites. The red and blue shaded arrows represent the LOS directions of the ascending and descending satellites，respectively. F1：Ashikule-Xorkol fault；F2：Southern Xorkol fault；F3：Altun fault zone；F4：Kangxiwa fault；F5：Guozha Co fault
![]()
图 2 Sentinel-1数据的时空基线及SBAS法分析中所使用的干涉对
Figure 2. Temporal and spatial baselines of Sentinel-1 data and interferograms used in SBAS analysis
![]()
图 3 地震分布及升（a）、降（b）轨2014年于田地震震后形变场图
红色粗实线为地表破裂（李海兵等，2015）；蓝色虚线为基于InSAR速率图得到的处于蠕滑状态的断裂位置。黑色圆圈为2012年8月12日MW6.2地震之前发生的地震；蓝色圆圈为2012年8月12日MW6.2至2014年2月12日MW6.9 （MS7.3）地震之间发生的地震；红色圆圈为2014年2月12日MW6.9地震之后发生的地震。黄色圆圈为不同机构或研究给出的2014年于田MW6.9地震的震中位置：① 唐明帅等（2016）；② 冉慧敏等（2014）一文中的单纯形法重定位结果；③ 冉慧敏等（2014）一文中的双差定位结果；④ GCMT （2014）；⑤ NEIC （2014）；⑥ 中国地震台网中心（2014）；⑦ 张广伟等（2014）；⑧ 王俊等（2014）；⑨ 王晓欣等（2014）
Figure 3. Seismicity distribution and the ascending （a）/ descending （b） postseismic deformation field due to 2014 Yutian earthquake
The thick red lines are surface rupture （Li et al，2015）. The blue dashed lines are inferred creeping fault segment derived from InSAR rate map. The black circles are the earthquakes happened before 12 August 2012 MW6.2 earthquake. Blue circles are earthquakes occurred between 12 August 2012 MW6.2 earthquake and 12 February MW6.9 （MS7.3） earthquake，and red circles are earthquakes occurred after the 12 February 2014 MW6.9 earthquake. The yellow-shaded circles are hypocenters of the 2014 MW6.9 event derived by varied research groups or studies：① Tang et al （2016）；② Simplex method relocation result from Ran et al （2014）；③ Double-difference relocation result from Ran et al （2014）；④ GCMT （2014）；⑤ NEIC （2014）；⑥ CENC （2014）；⑦ Zhang et al （2014）；⑧ Wang et al （2014）；⑨ Wang et al （2014）
![]()
图 4 T158 （a）和T165 （b）轨道的InSAR速率图（左）及相应典型剖面（右）
速率正值为抬升（朝向卫星运动）；速率图中的点线为用于构建剖面的“断裂线”；虚线表示剖面位置；圆圈大小表示由弹性位错理论估计的断裂闭锁深度。在速率剖面图中，圆点为原始速率值，虚线为按照弹性位错理论得到的拟合值
Figure 4. InSAR velocity maps （left） and profiles （right） of the tracks T158 （a） and T165 （b）
The positive velocity represents uplifting （moves towards the satellite）. The dotted line in the velocity map is the“fault trace” for creating profiles；the dashed lines show the locations of profiles；the size of circle denotes the fault locking depth estimated by the elastic dislocation theory. In the velocity profile plots，dots are raw velocities，and the dashed lines are modeled velocities using the elastic dislocation theory
-
李海兵,潘家伟,孙知明,刘栋梁,张佳佳,李成龙,刘亢,Chevalier M L,云锟,龚正. 2015. 2014年于田MS7.3地震地表破裂特征及其发震构造[J]. 地质学报,89(1):180–194. Li H B,Pan J W,Sun Z M,Liu D L,Zhang J J,Li C L,Liu K,Chevalier M L,Yun K,Gong Z. 2015. Seismogenic structure and surface rupture characteristics of the 2014 MS7.3 Yutian earthquake[J]. Acta Geologica Sinica,89(1):180–194 (in Chinese).
梁洪宝,武艳强,陈长云,熊威. 2018. 2014年新疆于田MS7.3地震同震位移及位错反演研究[J]. 地球物理学报,61(12):4817–4826. doi: 10.6038/cjg2018M0065 Liang H B,Wu Y Q,Chen C Y,Xiong W. 2018. Coseismic displacement and dislocation inversion of 2014 Yutian MS7.3 earthquake in Xinjiang[J]. Chinese Journal of Geophysics,61(12):4817–4826 (in Chinese).
冉慧敏,魏斌,张志斌,赵庆. 2014. 2014年新疆于田MS7.3地震及余震序列定位研究[J]. 地震研究,37(4):565–571. doi: 10.3969/j.issn.1000-0666.2014.04.012 Ran H M,Wei B,Zhang Z B,Zhao Q. 2014. Research on location of Yutian MS7.3 earthquake and aftershocks sequence in 2014[J]. Journal of Seismological Research,37(4):565–571 (in Chinese).
宋春燕,马瑾,冉慧敏,黄辅琼. 2015. 2014年新疆于田7.3级地震发震构造和震前地震活动过程讨论[J]. 地震地质,37(3):780–791. doi: 10.3969/j.issn.0253-4967.2015.03.009 Song C Y,Ma J,Ran H M,Huang F Q. 2015. Discussion on seismogenic structures and seismic activity process before the Yutian MS7.3 earthquake on February 12,2014,Xinjiang[J]. Seismology and Geology,37(3):780–791 (in Chinese).
唐明帅,王海涛,李艳永,热依木江,孔祥艳,魏芸芸,上官文明,魏斌. 2016. 2014年新疆于田MS7.3地震序列重定位及其发震构造初步研究[J]. 地球物理学报,59(6):2126–2137. doi: 10.6038/cjg20160618 Tang M S,Wang H T,Li Y Y,Reyi M J,Kong X Y,Wei Y Y,Shangguan W M,Wei B. 2016. Relocation of the 2014 Yutian,Xinjiang,MS7.3 earthquake sequence and a preliminary study of its seismogenic structure[J]. Chinese Journal of Geophysics,59(6):2126–2137 (in Chinese).
王俊,宋秀青,陈向军,詹小艳,缪发军,刘双庆,朱元清. 2014. 新疆于田MS7.3地震主震精定位研究[J]. 中国地震,30(2):188–197. doi: 10.3969/j.issn.1001-4683.2014.02.006 Wang J,Song X Q,Chen X J,Zhan X Y,Miao F J,Liu S Q,Zhu Y Q. 2014. Study on precision positioning the Yutian,Xinjiang MS7.3 earthquake[J]. Earthquake Research in China,30(2):188–197 (in Chinese).
王晓欣,刘瑞丰,邹立晔,袁菲,陈宏峰,陈运泰,张立文,梁建宏. 2014. 2014年2月12日新疆于田MS7.3地震参数测定[J]. 地震学报,36(3):522–528. doi: 10.3969/j.issn.0253-3782.2014.03.017 Wang X X,Liu R F,Zou L Y,Yuan F,Chen H F,Chen Y T,Zhang L W,Liang J H. 2014. Determination of the parameters for the 12 February 2014 Yutian MS7.3 earthquake in Xinjiang Uygur Autonomous Region[J]. Acta Seismologica Sinica,36(3):522–528 (in Chinese).
徐彦,李丹宁,冉慧敏. 2015. 2014年2月12日新疆于田MW6.9级地震破裂方向研究[J]. 地球物理学进展,30(6):2574–2580. doi: 10.6038/pg20150615 Xu Y,Li D N,Ran H M. 2015. Study of the rupture direction of the 12 Feb 2014 Yutian,Xinjiang MW6.9 earthquake[J]. Progress in Geophysics,30(6):2574–2580 (in Chinese).
张广伟,雷建设,孙长青. 2014. 2014年2月12日新疆于田MS7.3级地震主震及余震序列重定位研究[J]. 地球物理学报,57(3):1012–1020. doi: 10.6038/cjg20140330 Zhang G W,Lei J S,Sun C Q. 2014. Relocation of the 12 February 2014 Yutian,Xinjiang,mainshock (MS7.3) and its aftershock sequence[J]. Chinese Journal of Geophysics,57(3):1012–1020 (in Chinese).
张勇,许力生,陈运泰,汪荣江. 2014. 2014年2月12日于田MW6.9地震破裂过程初步反演:兼论震源机制对地震破裂过程反演的影响[J]. 地震学报,36(2):159–164. doi: 10.3969/j.issn.0253-3782.2014.02.001 Zhang Y,Xu L S,Chen Y T,Wang R J. 2014. Fast inversion for the rupture process of the 12 February 2014 Yutian MW6.9 earthquake:Discussion on the impacts of focal mechanisms on rupture process inversions[J]. Acta Seismologica Sinica,36(2):159–164 (in Chinese).
中国地震台网中心. 2014. 新疆维吾尔自治区和田地区于田县7.3级地震[EB/OL]. [2020-03-03]. http://news.ceic.ac.cn/CC20140212171950.html. CENC. 2014. Yutian 7.3 earthquake, Hetian, Xinjiang Uyghur Autonomous Region[EB/OL]. [2020-03-03]. http://news.ceic.ac.cn/CC20140212171950.html （in Chinese）.
Chen C W,Zebker H A. 2000. Network approaches to two-dimensional phase unwrapping:Intractability and two new algorithms[J]. J Opt Soc Am A,17(3):401–414. doi: 10.1364/JOSAA.17.000401
GCMT. 2014. Global CMT catalog search （Event name: 201402120919A）[EB/OL]. [2020-03-03]. https://www.globalcmt.org/CMTsearch.html.
NEIC. 2014. USGS event （usc000mnvj） M6.9: 272 km ESE of Hotan, China[EB/OL]. [2020-03-03]. https://earthquake.usgs.gov/earthquakes/eventpage/usc000mnvj.
Savage J C,Burford R O. 1973. Geodetic determination of relative plate motion in central California[J]. J Geophys Res,78(5):832–845. doi: 10.1029/JB078i005p00832
Taylor M,Yin A. 2009. Active structures of the Himalayan-Tibetan orogen and their relationships to earthquake distribution,contemporary strain field,and Cenozoic volcanism[J]. Geosphere,5(3):199–214. doi: 10.1130/GES00217.1
Tong X P,Schmidt D. 2016. Active movement of the Cascade landslide complex in Washington from a coherence-based InSAR time series method[J]. Remote Sens Environ,186:405–415. doi: 10.1016/j.rse.2016.09.008
Wang H,Elliott J R,Craig T J,Wright T J,Liu-Zeng J,Hooper A. 2014. Normal faulting sequence in the Pumqu-Xainza rift constrained by InSAR and teleseismic body-wave seismology[J]. Geochem Geophys Geosyst,15(7):2947–2963. doi: 10.1002/2014GC005369
Wessel P,Smith W H F. 1995. New version of the generic mapping tools released[J]. Eos Trans AGU,76(33):329.
Yu C,Li Z H,Penna N T,Crippa P. 2018. Generic atmospheric correction model for interferometric synthetic aperture radar observations[J]. J Geophys Res:Solid Earth,123(10):9202–9222. doi: 10.1029/2017JB015305
下载:
计量
- 文章访问数: 985
- HTML全文浏览量: 419
- PDF下载量: 89
