SHI HaiXia,
MENG LingYuan,
ZHANG XueMei et al
.2018.Decrease in b value prior to the Wenchuan earthquake (MS8.0).Chinese Journal Of Geophysics,61(5): 1874-1882,doi: 10.6038/cjg2018M0024
Decrease in b value prior to the Wenchuan earthquake (MS8.0)
SHI HaiXia1, MENG LingYuan1, ZHANG XueMei1, CHANG Ying2, YANG ZhenTao2, XIE WeiYun3, HATTORI Katsumi3, HAN Peng2
1. China Earthquake Networks Center, Beijing 100045, China; 2. Southern University of Science and Technology, Shenzhen 518055, China; 3. Chiba University, Chiba, Japan
Abstract:The Gutenberg-Richter Law describes the frequency-magnitude distribution of earthquakes. A number of studies have shown that the slope (b value) of the relationship between frequency and magnitude decreased before large earthquakes. Based on the analysis of the earthquake catalog from January, 2000 to April, 2008, we have investigated seismicity change and b value variation prior to the MS8.0 Wenchuan earthquake. The results show clear drops of both monthly and quarterly frequency of earthquakes during 2005—2006. The b value exhibits a long-term decrease trend since 2002, and reaches to the minimum just before the onset of the main shock. The temporal variation of b value is quite similar to that prior to the MW9.0 Tohoku earthquake in Japan, which may reflect the stress evolution during the preparation process of large earthquakes. These results indicate that the b value is an important indicator of an impending great earthquake, and has high potential in terms of predicting a future large quake.
Akaike H. 1974. A new look at the statistical model identification. IEEE Transactions on Automatic Control, 19(6): 716-723, doi: 10.1109/TAC.1974.1100705. Aki K. 1965. Maximum likelihood estimate of b in the formula log N=a-bM and its confidence limits. Bulletin of the Earthquake Research Institute, Tokyo University, 43: 237-239. Chen X Z, Li Y E. 2012. Distribution characteristics of the month-scale and week-scale numbers for small earthquakes around the epicenter prior to the April 14, 2010 Yushu earthquake with MS7.1. Earthquake Research in China (in Chinese), 28(1):10-21. Chen C H, Wen S, Liu J Y, et al. 2014. Surface displacements in Japan before the 11 March 2011 M9.0 Tohoku-Oki earthquake. Journal of Asian Earth Sciences, 80: 165-171, doi: 10.1016/j.jseaes.2013.11.009. Ghosh A, Newman A V, Thomas A M, et al. 2008. Interface locking along the subduction megathrust from b-value mapping near Nicoya Peninsula, Costa Rica. Geophysical Research Letters, 35(1): L01301, doi: 10.1029/2007GL031617. Gutenberg B, Richter C F. 1944. Frequency of earthquakes in California. Bulletin of the Seismological Society of America, 34: 185-188. Han P, Hattori K, Hirokawa M, et al. 2014. Statistical analysis of ULF seismomagnetic phenomena at Kakioka, Japan, during 2001—2010. Journal of Geophysical Research:Space Physics, 119(6): 4998-5011, doi: 10.1002/2014JA019789. Han P, Hattori K, Xu G J, et al. 2015. Further investigations of geomagnetic diurnal variations associated with the 2011 off the Pacific coast of Tohoku earthquake (MW9.0). Journal of Asian Earth Sciences, 114: 321-326, doi: 10.1016/j.jseaes.2015.02.022. Han P, Hattori K, Huang Q H, et al. 2016. Spatiotemporal characteristics of the geomagnetic diurnal variation anomalies prior to the 2011 Tohoku earthquake (MW9.0) and the possible coupling of multiple pre-earthquake phenomena. Journal of Asian Earth Sciences, 129: 13-21, doi: 10.1016/j.jseaes.2016.07.011. Han P, Hattori K, Zhuang J C, et al. 2017. Evaluation of ULF seismo-magnetic phenomena in Kakioka, Japan by using Molchan's error diagram. Geophysical Journal International, 208(1): 482-490, doi: 10.1093/gji/ggw404. Hattori K, Han P, Yoshino C, et al. 2013. Investigation of ULF seismo-magnetic phenomena in Kanto, Japan During 2000—2010: Case studies and statistical studies. Surveys in Geophysics, 34(3): 293-316. He P C, Shen Z K. 2014. Rupture triggering process of Wenchuan earthquake seismogenic faults. Chinese Journal of Geophysics (in Chinese), 57(10): 3308-3317, doi: 10.6038/cjg20141018. Huang Q H, Sobolev G A, Nagao T. 2001. Characteristics of the seismic quiescence and activation patterns before the M=7.2 Kobe earthquake. Tectonophysics, 337(1-2): 99-116. Huang Q H, Nagao T. 2002. Seismic quiescence before the 2000 M=7.3 Tottori earthquake. Geophysical Research Letters, 29(12): 19-1-19-4, doi: 10.1029/2001GL013835. Huang Q H. 2004. Seismicity pattern changes prior to large earthquakes—An approach of the RTL algorithm. Terrestrial, Atmospheric and Oceanic Sciences, 15(3): 469-491. Huang Q H. 2006. Search for reliable precursors: A case study of the seismic quiescence of the 2000 western Tottori prefecture earthquake. Journal of Geophysical Research: Solid Earth, 111(B4): B04301, doi: 10.1029/2005JB003982. Huang Q H. 2008. Seismicity changes prior to the MS8.0 Wenchuan earthquake in Sichuan, China. Geophysical Research Letters, 35(23): L23308, doi: 10.1029/2008GL036270. Li Q L, Yu L, Hao B L, et al. 1979.Time-space scan of earthquake magnitude-frequency relation (in Chinese). Beijing: Seismological Press. Lei X L. 2003. How do asperities fracture? An experimental study of unbroken asperities. Earth and Planetary Science Letters, 213(3-4): 347-359, doi: 10.1016/S0012-821X(03)00328-5. Liu R F, Wu Z L, Yin C M, et al. 2003. Development of China digital seismological observational systems. Acta Seismologica Sinica, 16(5): 568-573. Lombardi A M. 2003. The maximum likelihood estimator of b-value for mainshocks. Bulletin of the Seismological Society of America, 93(5): 2082-2088. Main I G, Meredith P G, Jones C. 1989. A reinterpretation of the precursory seismic b-value anomaly from fracture mechanics. Geophysical Journal International, 96(1): 131-138. Molchan G M, Dmitrieva O E. 1992. Aftershock identification: Methods and new approaches. Geophysical Journal International, 190(3): 501-516. Ma J, Liu P X, Liu Y Z. 2013. Features of seismogenic process of the Longmenshan fault zone derived from analysis on the temporal-spatial evolution of earthquakes. Seismology & Geology (in Chinese), 35(3): 462-471. Mousavi S M, Ogwari P O, Horton S P, et al. 2017. Spatio-temporal evolution of frequency-magnitude distribution and seismogenic index during initiation of induced seismicity at Guy-Greenbrier, Arkansas. Physics of the Earth and Planetary Interiors, 267: 53-66. Nanjo K Z, Hirata N, Obara K, et al. 2012. Decade-scale decrease in b value prior to the M9-class 2011 Tohoku and 2004 Sumatra quakes. Geophysical Research Letters, 39(20): L20304, doi: 10.1029/2012GL052997. Narteau C, Byrdina S, Shebalin P, et al. 2009. Common dependence on stress for the two fundamental laws of statistical seismology. Nature, 462(7273): 642-645, doi: 10.1038/nature08553. Orihara Y, Kamogawa M, Nagao T. 2014. Preseismic changes of the level and temperature of confined groundwater related to the 2011 Tohoku Earthquake.Scientific Reports, 4:6907, doi: 10.1038/srep06907. Smith W D. 1981. The b-value as an earthquake precursor. Nature, 289(5794): 136-139, doi: 10.1038/289136a0. Sobiesiak M, Meyer U, Schmidt S, et al. 2007. Asperity generating upper crustal sources revealed by b value and isostatic residual anomaly grids in the area of Antofagasta, Chile. Journal of Geophysical Research: Solid Earth, 112(B12): B12308, doi: 10.1029/2006JB004796. Tsunomori F, Tanaka H. 2014. Anomalous change of groundwater radon concentration monitored at Nakaizu well in 2011. Radiation Measurements, 60: 35-41. Utsu T. 1965. A method for determining the value of b in a formula log n=a-bM showing the magnitude-frequency relation for earthquakes. Geophysical Bulletin of Hokkaido University (in Japanese), 13: 99-103. Utsu T. 1992. On seismicity, Report of the Joint Research Institute for Statistical Mathematics. Institute for Statistical Mathematics. Tokyo, 34,139-157. Utsu T. 1999. Representation and analysis of the earthquake size distribution: A historical review and some new approaches. Pure and Applied Geophysics, 155(2-4): 509-535. Wen X Z, Du F, Yi G X, et al. 2013. Earthquake potential of the Zhaotong and Lianfeng fault zones of the eastern Sichuan-Yunnan border region. Chinese Journal of Geophysics (in Chinese), 56(10): 3361-3372, doi: 10.6038/cjg20131012. Wyss M, Habermann R E. 1988. Precursory seismic quiescence. Pure and Applied Geophysics, 126(2-4): 319-332. Yi G X, Wen X Z, Xin H, et al. 2013. Stress state and major-earthquake risk on the southern segment of the Longmen Shan fault zone. Chinese Journal of Geophysics (in Chinese), 56(4): 1112-1120, doi: 10.6038/cjg20130407. Zhang S J, Zhou S Y. 2016. Spatial and temporal variation of b -values in southwest China. Pure Appl.Geophys., 173: 85-96. Zhao Y Z, Wu Z L. Mapping the b-values along the Longmenshan fault zone before and after the 12 May 2008, Wenchuan, China, MS8.0 earthquake. Natural Hazards and Earth System Science, 2008, 8(6): 1375-1385. Zhu J S. 2008. The Wenchuan earthquake occurrence background in deep structure and dynamics of lithosphere. Journal of Chengdu University of Technology (in Chinese), 35(4):348-356. 附中文参考文献 陈学忠, 李艳娥. 2012. 2010年4月14日青海玉树7.1级地震前震中附近地区小震活动的周、月频次分布特征. 中国地震, 28(1): 10-21. 邓起东, 张培震, 冉勇康等. 2002. 中国活动构造基本特征. 中国科学(D辑), 32(12): 1020-1030, 1057. 贺鹏超, 沈正康. 2014. 汶川地震发震断层破裂触发过程. 地球物理学报, 57(10): 3308-3317, doi: 10.6038/cjg20141018. 李全林, 于渌, 郝柏林等. 1979. 地震频度-震级关系的时空扫描. 北京: 地震出版社. 马瑾, 刘培洵, 刘远征. 2013. 地震活动时空演化中看到的龙门山断裂带地震孕育的几个现象. 地震地质, 35(3): 462-471, doi: 10.3969/j.issn.0253-4967.2013.03.001. 田勤俭, 刁桂苓, 郝平等. 2009. 汶川8.0级地震及余震破裂的地质构造特征. 地震, 29(1): 141-148. 闻学泽, 杜方, 易桂喜等. 2013. 川滇交界东段昭通、莲峰断裂带的地震危险背景. 地球物理学报, 56(10): 3361-3372, doi: 10.6038/cjg20131012. 易桂喜, 闻学泽, 辛华等. 2013. 龙门山断裂带南段应力状态与强震危险性研究. 地球物理学报, 56(4): 1112-1120, doi: 10.6038/cjg20130407. 朱介寿. 2008. 汶川地震的岩石圈深部结构与动力学背景. 成都理工大学学报(自然科学版), 35(4): 348-356.