Decoding the variation laws of the deformation field before strong earthquakes has long been recognized as an essential issue in earthquake prediction research. In this paper, the temporal and spatial distribution cha...Decoding the variation laws of the deformation field before strong earthquakes has long been recognized as an essential issue in earthquake prediction research. In this paper, the temporal and spatial distribution characteristics of deformation anomalies in the northeastern margin of the Qinghai-Tibetan Plateau before and after the Menyuan M_(S)6.9 earthquake were studied by using the Fisher statistical test method. By analyzing the characteristics of these anomalies, we found that: 1) The deformation anomalies are mainly distributed in the marginal front area of the Qinghai-Tibetan Plateau, where short-term deformation anomalies are prone to occur due to a high gradient of gravity;2) The deformation anomalies along the northeastern margin of the Qinghai-Tibetan Plateau are characterized by spatial propagation, and the migration rate is about 2.4 km/d. The propagation pattern is counterclockwise, consistent with the migration direction of M_(S)≥ 6.0 earthquakes;3) The time and location of the Menyuan earthquake are related to the group migration of earthquakes with M_(S)≥ 6.0. Finally,based on the results of gravity field variation and the theory of crust stress wave, the law of deformation anomaly distribution was discussed. We suggest that both the deformation propagation along the northeastern margin of the Qinghai-Tibetan Plateau and the earthquake migration are possibly associated with the variation of the stress field caused by subsurface mass flow.展开更多
It is critical to determine whether a site has potential damage in real-time after an earthquake occurs,which is a challenge in earthquake disaster reduction.Here,we propose a real-time Earthquake Potential Damage pre...It is critical to determine whether a site has potential damage in real-time after an earthquake occurs,which is a challenge in earthquake disaster reduction.Here,we propose a real-time Earthquake Potential Damage predictor(EPDor)based on predicting peak ground velocities(PGVs)of sites.The EPDor is composed of three parts:(1)predicting the magnitude of an earthquake and PGVs of triggered stations based on the machine learning prediction models;(2)predicting the PGVs at distant sites based on the empirical ground motion prediction equation;(3)generating the PGV map through predicting the PGV of each grid point based on an interpolation process of weighted average based on the predicted values in(1)and(2).We apply the EPDor to the 2022 M_(S) 6.9 Menyuan earthquake in Qinghai Province,China to predict its potential damage.Within the initial few seconds after the first station is triggered,the EPDor can determine directly whether there is potential damage for some sites to a certain degree.Hence,we infer that the EPDor has potential application for future earthquakes.Meanwhile,it also has potential in Chinese earthquake early warning system.展开更多
The paper discusses quantitatively the influence of the Yutian Ms7.4 earthquake of March 21, 2008 and Wuqia Ms6.9 earthquake of October 5, 2008 on regional seismicity in Xinjiang, and explains primarily the possible r...The paper discusses quantitatively the influence of the Yutian Ms7.4 earthquake of March 21, 2008 and Wuqia Ms6.9 earthquake of October 5, 2008 on regional seismicity in Xinjiang, and explains primarily the possible reason of earthquake activity feature in Xinjiang after the Yutian Ms7.4 earthquake by analyzing the static Coulomb failure stress change produced by the Yutian Ms7.4 earthquake and Wuqia Ms6.9 earth-quake, and the seismicity feature of Ms≥3 earthquakes in the positive Coulomb stress change region of Kashi-Wuqia joint region, the central segment of Tianshan Mountain and Kalpin block. The result shows that the Yutian Ms7.4 earthquake of March 21, 2008, may encourage the Wuqia Ms6.9 earth-quake of October 5, 2008, and the Yutian Ms7.4 earthquake and Wuqia Ms6.9 earthquake may change the seismicity state in the central segment of Tianshan Mountain, Kalpin block and Kashi-Wuqia joint region, and encourage the subsequent Ms≥3 earthquakes.展开更多
Co-seismic ground-surface deformation of the Yushu earthquake on April 14, 2010 is studied on the basis of interferometry principle by using InSAR images from ALOS PALSAR and ENVISAT ASAR pairs. The observed maximum l...Co-seismic ground-surface deformation of the Yushu earthquake on April 14, 2010 is studied on the basis of interferometry principle by using InSAR images from ALOS PALSAR and ENVISAT ASAR pairs. The observed maximum line-of-sight displacement is 54 cm, which is equivalent to a sinistral strike slip of 180 cm on the surface. The location of macro-epicenter is very close to the epicenter determined by in situ investigation, suggesting that InSAR is an ideal tool for quick identification of the macro-epicenter, and thus for timely disaster assessment after a destructive earthquake.展开更多
At 06:34(CST)on Nov.18,2017,an M6.9 earthquake occurred in the Mainling County,Nyingchi Region of Xizang Autonomous Region,China.The epicenter is located at 95.02°E,29.75°N and the focal depth is about 10 km...At 06:34(CST)on Nov.18,2017,an M6.9 earthquake occurred in the Mainling County,Nyingchi Region of Xizang Autonomous Region,China.The epicenter is located at 95.02°E,29.75°N and the focal depth is about 10 km(Figure 1).The epicenter is about 100 km from the Mainling County.The average elevation within 5 km is about 3100 m.This earthquake has caused widespread concern among members of government,research institutions,and public media.展开更多
The 2010 Mw 6.9 Yushu earthquake produced a ~33-km-long co-seismic surface rupture zone along the pre-existing active Yushu Fault on China’s central Tibetan Plateau. Sand boils occurred along the tension cracks of th...The 2010 Mw 6.9 Yushu earthquake produced a ~33-km-long co-seismic surface rupture zone along the pre-existing active Yushu Fault on China’s central Tibetan Plateau. Sand boils occurred along the tension cracks of the co-seismic surface rupture zone, and locally spouted up above the ground to coat the top of limestone blocks that had slid down from an adjacent ~300-m-high mountain slope. Based on our observations, the relations between the arrival times of P- and S-waves at the sand-boil location and the seismic rupture velocity, we conclude that 1) the sand boils occurred at least 18.24 s after the main shock;2) it took at least 4.09 - 9.79 s after the formation of co-seismic surface rupture to generate liquefaction at the sand-boil location;3) the spouting height of sand boils was at least 65 cm. Our findings help to clarify the relationships between the timing of lique-faction and the spouting height of sand boils during a large-magnitude earthquake.展开更多
中国大陆发生强震动力来源主要是在印度—欧亚板块碰撞下,青藏高原的北向运动、东部地区的东向运动作用(Wang and Shen,2020);近20年青藏高原北缘地块运动主流观点是巴颜喀拉块体向东运动带动周边地块的运动,但从近十年的地震活动分析,...中国大陆发生强震动力来源主要是在印度—欧亚板块碰撞下,青藏高原的北向运动、东部地区的东向运动作用(Wang and Shen,2020);近20年青藏高原北缘地块运动主流观点是巴颜喀拉块体向东运动带动周边地块的运动,但从近十年的地震活动分析,柴达木和祁连块体向东运动是增强的,2022年门源M_(S)6.9地震等一系列地震是典型的震例。展开更多
基金sponsored by the National Natural Science Foundation of China (41330314)。
文摘Decoding the variation laws of the deformation field before strong earthquakes has long been recognized as an essential issue in earthquake prediction research. In this paper, the temporal and spatial distribution characteristics of deformation anomalies in the northeastern margin of the Qinghai-Tibetan Plateau before and after the Menyuan M_(S)6.9 earthquake were studied by using the Fisher statistical test method. By analyzing the characteristics of these anomalies, we found that: 1) The deformation anomalies are mainly distributed in the marginal front area of the Qinghai-Tibetan Plateau, where short-term deformation anomalies are prone to occur due to a high gradient of gravity;2) The deformation anomalies along the northeastern margin of the Qinghai-Tibetan Plateau are characterized by spatial propagation, and the migration rate is about 2.4 km/d. The propagation pattern is counterclockwise, consistent with the migration direction of M_(S)≥ 6.0 earthquakes;3) The time and location of the Menyuan earthquake are related to the group migration of earthquakes with M_(S)≥ 6.0. Finally,based on the results of gravity field variation and the theory of crust stress wave, the law of deformation anomaly distribution was discussed. We suggest that both the deformation propagation along the northeastern margin of the Qinghai-Tibetan Plateau and the earthquake migration are possibly associated with the variation of the stress field caused by subsurface mass flow.
基金financially supported by the National Natural Science Foundation of China (U2039209, U1839208, and 51408564)the Natural Science Foundation of Heilongjiang Province (LH2021E119)+1 种基金Spark Program of Earthquake Science (XH23027YB)the National Key Research and Development Program of China (2018YFC1504003).
文摘It is critical to determine whether a site has potential damage in real-time after an earthquake occurs,which is a challenge in earthquake disaster reduction.Here,we propose a real-time Earthquake Potential Damage predictor(EPDor)based on predicting peak ground velocities(PGVs)of sites.The EPDor is composed of three parts:(1)predicting the magnitude of an earthquake and PGVs of triggered stations based on the machine learning prediction models;(2)predicting the PGVs at distant sites based on the empirical ground motion prediction equation;(3)generating the PGV map through predicting the PGV of each grid point based on an interpolation process of weighted average based on the predicted values in(1)and(2).We apply the EPDor to the 2022 M_(S) 6.9 Menyuan earthquake in Qinghai Province,China to predict its potential damage.Within the initial few seconds after the first station is triggered,the EPDor can determine directly whether there is potential damage for some sites to a certain degree.Hence,we infer that the EPDor has potential application for future earthquakes.Meanwhile,it also has potential in Chinese earthquake early warning system.
基金supported by the Joint Seismological Science Foundation of China(No.A07095)Special Public Sector Research(No.20090804)
文摘The paper discusses quantitatively the influence of the Yutian Ms7.4 earthquake of March 21, 2008 and Wuqia Ms6.9 earthquake of October 5, 2008 on regional seismicity in Xinjiang, and explains primarily the possible reason of earthquake activity feature in Xinjiang after the Yutian Ms7.4 earthquake by analyzing the static Coulomb failure stress change produced by the Yutian Ms7.4 earthquake and Wuqia Ms6.9 earth-quake, and the seismicity feature of Ms≥3 earthquakes in the positive Coulomb stress change region of Kashi-Wuqia joint region, the central segment of Tianshan Mountain and Kalpin block. The result shows that the Yutian Ms7.4 earthquake of March 21, 2008, may encourage the Wuqia Ms6.9 earth-quake of October 5, 2008, and the Yutian Ms7.4 earthquake and Wuqia Ms6.9 earthquake may change the seismicity state in the central segment of Tianshan Mountain, Kalpin block and Kashi-Wuqia joint region, and encourage the subsequent Ms≥3 earthquakes.
基金supported by National Natural Science Foundation of China( 41004008) Key Foundation of Institute of Seismology China Earthquake Administration ( IS201026019) +3 种基金State Key Laboratory of Cryo-spheric Sciences,Cold and Arid Regions Environment and Engineering Research Institute,Chinese Academy of Sciences ( SKL CS09 - 03) the Foundation of State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University( 2009B54) the Foundation of Institute of Seismology China Earthquake Administration( IS200826057 ) National Key Technology R&D Program of China( 2008BAC35B04 -5)
文摘Co-seismic ground-surface deformation of the Yushu earthquake on April 14, 2010 is studied on the basis of interferometry principle by using InSAR images from ALOS PALSAR and ENVISAT ASAR pairs. The observed maximum line-of-sight displacement is 54 cm, which is equivalent to a sinistral strike slip of 180 cm on the surface. The location of macro-epicenter is very close to the epicenter determined by in situ investigation, suggesting that InSAR is an ideal tool for quick identification of the macro-epicenter, and thus for timely disaster assessment after a destructive earthquake.
基金The National Natural Science Foundation of China (Grants 41774069 and 41274062) sponsored this study
文摘At 06:34(CST)on Nov.18,2017,an M6.9 earthquake occurred in the Mainling County,Nyingchi Region of Xizang Autonomous Region,China.The epicenter is located at 95.02°E,29.75°N and the focal depth is about 10 km(Figure 1).The epicenter is about 100 km from the Mainling County.The average elevation within 5 km is about 3100 m.This earthquake has caused widespread concern among members of government,research institutions,and public media.
文摘The 2010 Mw 6.9 Yushu earthquake produced a ~33-km-long co-seismic surface rupture zone along the pre-existing active Yushu Fault on China’s central Tibetan Plateau. Sand boils occurred along the tension cracks of the co-seismic surface rupture zone, and locally spouted up above the ground to coat the top of limestone blocks that had slid down from an adjacent ~300-m-high mountain slope. Based on our observations, the relations between the arrival times of P- and S-waves at the sand-boil location and the seismic rupture velocity, we conclude that 1) the sand boils occurred at least 18.24 s after the main shock;2) it took at least 4.09 - 9.79 s after the formation of co-seismic surface rupture to generate liquefaction at the sand-boil location;3) the spouting height of sand boils was at least 65 cm. Our findings help to clarify the relationships between the timing of lique-faction and the spouting height of sand boils during a large-magnitude earthquake.
文摘中国大陆发生强震动力来源主要是在印度—欧亚板块碰撞下,青藏高原的北向运动、东部地区的东向运动作用(Wang and Shen,2020);近20年青藏高原北缘地块运动主流观点是巴颜喀拉块体向东运动带动周边地块的运动,但从近十年的地震活动分析,柴达木和祁连块体向东运动是增强的,2022年门源M_(S)6.9地震等一系列地震是典型的震例。
