In this paper,we computed the fractal dimension of three survey areas within the central and southern sections of the Tan-Lu fault zone using fractal analysis.Subsequently,simulations were conducted to analyze the gra...In this paper,we computed the fractal dimension of three survey areas within the central and southern sections of the Tan-Lu fault zone using fractal analysis.Subsequently,simulations were conducted to analyze the gravity response under a forward model of equivalent density changes.Additionally,we thoroughly investigated the seismic monitoring capabilities of the gravity network in the central and southern regions of the Tan-Lu fault.Expanding on these analyses.Recent gravity field variations were examined in the mid-southern segment of the Tan-Lu fault zone and its surrounding areas from 2013 to2023.The results indicate that the observation capabilities of the northern network in the study area outperform those of the southern gravity network,with the northern network demonstrating a more evenly distributed coverage.The optimal gravity anomaly recovery effect for the entire study area is achieved at a resolution of 0.5°×0.5°.With an equivalent observable signal in the range of 30×10^(-8)m/s^(2) to 40×10^(-8)m/s^(2),the spatial resolution of the gravity network's field source is estimated to be approximately 55 km.From 2013 to 2023,a significant positive change has been observed in the gravity field within the study area.The Tan-Lu fault zone plays a crucial role in governing the crustal movement in this region,with the dextral strike-slip movement trend of the fault persisting.Small earthquakes occur more frequently in the southern section of the fault zone,while strong earthquakes are less common.The alignment of gravity field changes with the fault strike indicates ongoing activity in the fault zone without any signs of locking.In the central segment of the Tan-Lu fault zone in the Shandong region,there appears to be a weaker correlation between gravity field changes and fault trends.This discrepancy may suggest that the area is locked,resulting in the accumulation of stress and strain.It is imperative to monitor the continuous evolution of the gravity field in this region to gain insights into potential seismic risks.展开更多
The North-South Seismic Belt was analyzed using gravity observation data from 2011 to 2015, and the nontidal analysis results show that there was a nonlinear gravity change at both the Chengdu and Guza seismostations ...The North-South Seismic Belt was analyzed using gravity observation data from 2011 to 2015, and the nontidal analysis results show that there was a nonlinear gravity change at both the Chengdu and Guza seismostations one month before the Leshan M5.0 earthquake.展开更多
In order to explore the abnormal variations before and after the Wen＇an MS. 1 earthquake on July 4, 2006, the gravity data observed by the Wenba Gravity Observation Network before and after the earthquake was analyze...In order to explore the abnormal variations before and after the Wen＇an MS. 1 earthquake on July 4, 2006, the gravity data observed by the Wenba Gravity Observation Network before and after the earthquake was analyzed. The relationships between gravity change and vertical displacement and shallow groundwater level were discussed, and elevation correction of the gravity was preliminarily performed. The results show that there were abnormal gravity changes before the MS. ! earthquake, which appeared as gravity rising in the whole observation network, especially in the south part. A high gradient of gravity variation appeared around the epicenter before the MS. 1 earthquake, especially during the short period between October 2005 to April 2006. The boundary of the positive and negative gravity variations gradually deflected and began to recover from October 2007.展开更多
基金supported by the Three-pronged Project on Earthquake Monitoring,Forecasting and Scientific Research of the China Earthquake Administration(No.3JH-202402026)The Open Fund of Wuhan,Gravitation and Solid Earth Tides,National Observation and Research Station(WHYWZ202209)+1 种基金The Joint Open Fund of Mengcheng National Geophysical Observatory(No.MENGO-202210 and MENGO-202211)The Science for Earthquake Resilience,China Earthquake Administration(No.XH22002YA)。
文摘In this paper,we computed the fractal dimension of three survey areas within the central and southern sections of the Tan-Lu fault zone using fractal analysis.Subsequently,simulations were conducted to analyze the gravity response under a forward model of equivalent density changes.Additionally,we thoroughly investigated the seismic monitoring capabilities of the gravity network in the central and southern regions of the Tan-Lu fault.Expanding on these analyses.Recent gravity field variations were examined in the mid-southern segment of the Tan-Lu fault zone and its surrounding areas from 2013 to2023.The results indicate that the observation capabilities of the northern network in the study area outperform those of the southern gravity network,with the northern network demonstrating a more evenly distributed coverage.The optimal gravity anomaly recovery effect for the entire study area is achieved at a resolution of 0.5°×0.5°.With an equivalent observable signal in the range of 30×10^(-8)m/s^(2) to 40×10^(-8)m/s^(2),the spatial resolution of the gravity network's field source is estimated to be approximately 55 km.From 2013 to 2023,a significant positive change has been observed in the gravity field within the study area.The Tan-Lu fault zone plays a crucial role in governing the crustal movement in this region,with the dextral strike-slip movement trend of the fault persisting.Small earthquakes occur more frequently in the southern section of the fault zone,while strong earthquakes are less common.The alignment of gravity field changes with the fault strike indicates ongoing activity in the fault zone without any signs of locking.In the central segment of the Tan-Lu fault zone in the Shandong region,there appears to be a weaker correlation between gravity field changes and fault trends.This discrepancy may suggest that the area is locked,resulting in the accumulation of stress and strain.It is imperative to monitor the continuous evolution of the gravity field in this region to gain insights into potential seismic risks.
基金supported by the Director Foundation of Institute of Seismology,China Earthquake Administration(201326123)the National Natural Science Foundation of China(41204058,41474064)the Ministry of Science and Technology major instrument special sub topic(2012YQ10022506)
文摘The North-South Seismic Belt was analyzed using gravity observation data from 2011 to 2015, and the nontidal analysis results show that there was a nonlinear gravity change at both the Chengdu and Guza seismostations one month before the Leshan M5.0 earthquake.
基金Supported by the Technology Research and Development Program of Institute of Earthquake Science, CEAthe National Key Technology R&D Program(2006BAC01B02-02),China
文摘In order to explore the abnormal variations before and after the Wen＇an MS. 1 earthquake on July 4, 2006, the gravity data observed by the Wenba Gravity Observation Network before and after the earthquake was analyzed. The relationships between gravity change and vertical displacement and shallow groundwater level were discussed, and elevation correction of the gravity was preliminarily performed. The results show that there were abnormal gravity changes before the MS. ! earthquake, which appeared as gravity rising in the whole observation network, especially in the south part. A high gradient of gravity variation appeared around the epicenter before the MS. 1 earthquake, especially during the short period between October 2005 to April 2006. The boundary of the positive and negative gravity variations gradually deflected and began to recover from October 2007.
