The Mw 6.8 Adassil earthquake that occurred in the High Atlas on September 8,2023,was a catastrophic event that provided a rare opportunity to study the mechanics of deep crustal seismicity.This research aimed to deci...The Mw 6.8 Adassil earthquake that occurred in the High Atlas on September 8,2023,was a catastrophic event that provided a rare opportunity to study the mechanics of deep crustal seismicity.This research aimed to decipher the rupture characteristics of the Adassil earthquake by analyzing teleseismic waveform data in conjunction with interferometric synthetic aperture radar(InSAR)observations from both ascending and descending orbits.Our analysis revealed a reverse fault mechanism with a centroid depth of approximately 28 km,exceeding the typical range for crustal earthquakes.This result suggests the presence of cooler temperatures in the lower crust,which facilitates the accumulation of tectonic stress.The earthquake exhibited a steep reverse mechanism,dipping at 70°,accompanied by minor strike-slip motion.Within the geotectonic framework of the High Atlas,known for its volcanic legacy and resulting thermal irregularities,we investigated the potential contributions of these factors to the initiation of the Adassil earthquake.Deep seismicity within the lower crust,away from plate boundaries,calls for extensive research to elucidate its implications for regional seismic hazard assessment.Our findings highlight the critical importance of studying and preparing for significant seismic events in similar geological settings,which would provide valuable insights into regional seismic hazard assessments and geodynamic paradigms.展开更多
Purpose Coded aperture imaging was a widely used imaging method for radiation sources.However,the traditional gamma camera based on two-dimensional projection information for coded aperture imaging ignored the influen...Purpose Coded aperture imaging was a widely used imaging method for radiation sources.However,the traditional gamma camera based on two-dimensional projection information for coded aperture imaging ignored the influence of the interaction depth of particles and detectors on the projection information,which reduced the imaging quality of the camera to some extent.Therefore,a method of correcting the coded gamma camera based on the interaction depth of particles and detectors is proposed to improve the location accuracy of detectors.Methods The camera developed in this work uses a 7×7 YSO crystal array coupled with two 7×7 Si-PM arrays.The crystal is evenly divided into 11 parts in the depth direction,with a voxel size of 3×3×3 mm3.The coded mask is a 13×13 array,which is a mosaic of two cycles of 7×7 modified uniformly redundant array mask.The depth resolution of the detector is obtained via the subsurface laser engraving dual-end readout method.After obtaining the three-dimensional position information of the interaction point the projection information obtained by the detector is layered,and the image is reconstructed.According to the spatial position information of the detector and the coded mask,the corresponding field of view of each layer of the detector is calculated,and the reconstructed image of each layer is amplified and superimposed according to the ratio of the field of view to obtain the reconstructed image combined with the depth information.Results and conclusion According to Monte Carlo simulation and radiation source imaging experiment results,this method can effectively improve the positioning ability of the detector.For the experimental scenario mentioned in the paper,the location accuracy can be improved by up to 1.54°.展开更多
基金the National Natural Science Foundation of China(Grant Nos.42030311,and 42325401)the Science and Tech-nology Innovation Talent Program of Hubei Province(Grant No.2022EJD015).
文摘The Mw 6.8 Adassil earthquake that occurred in the High Atlas on September 8,2023,was a catastrophic event that provided a rare opportunity to study the mechanics of deep crustal seismicity.This research aimed to decipher the rupture characteristics of the Adassil earthquake by analyzing teleseismic waveform data in conjunction with interferometric synthetic aperture radar(InSAR)observations from both ascending and descending orbits.Our analysis revealed a reverse fault mechanism with a centroid depth of approximately 28 km,exceeding the typical range for crustal earthquakes.This result suggests the presence of cooler temperatures in the lower crust,which facilitates the accumulation of tectonic stress.The earthquake exhibited a steep reverse mechanism,dipping at 70°,accompanied by minor strike-slip motion.Within the geotectonic framework of the High Atlas,known for its volcanic legacy and resulting thermal irregularities,we investigated the potential contributions of these factors to the initiation of the Adassil earthquake.Deep seismicity within the lower crust,away from plate boundaries,calls for extensive research to elucidate its implications for regional seismic hazard assessment.Our findings highlight the critical importance of studying and preparing for significant seismic events in similar geological settings,which would provide valuable insights into regional seismic hazard assessments and geodynamic paradigms.
基金supported by the National Natural Science Foundation of China under Grant Nos.12005234 and 12105307.
文摘Purpose Coded aperture imaging was a widely used imaging method for radiation sources.However,the traditional gamma camera based on two-dimensional projection information for coded aperture imaging ignored the influence of the interaction depth of particles and detectors on the projection information,which reduced the imaging quality of the camera to some extent.Therefore,a method of correcting the coded gamma camera based on the interaction depth of particles and detectors is proposed to improve the location accuracy of detectors.Methods The camera developed in this work uses a 7×7 YSO crystal array coupled with two 7×7 Si-PM arrays.The crystal is evenly divided into 11 parts in the depth direction,with a voxel size of 3×3×3 mm3.The coded mask is a 13×13 array,which is a mosaic of two cycles of 7×7 modified uniformly redundant array mask.The depth resolution of the detector is obtained via the subsurface laser engraving dual-end readout method.After obtaining the three-dimensional position information of the interaction point the projection information obtained by the detector is layered,and the image is reconstructed.According to the spatial position information of the detector and the coded mask,the corresponding field of view of each layer of the detector is calculated,and the reconstructed image of each layer is amplified and superimposed according to the ratio of the field of view to obtain the reconstructed image combined with the depth information.Results and conclusion According to Monte Carlo simulation and radiation source imaging experiment results,this method can effectively improve the positioning ability of the detector.For the experimental scenario mentioned in the paper,the location accuracy can be improved by up to 1.54°.
