Research On Crustal Activity In Tengchong Volcanic Area Based On InSAR/GPS Data

Combining the geophysical,geological structure and seismic research of the Tengchong volcanic area: the area has a low-velocity,low-resistance,high-conductivity and high heat flow area;it is located in the northeast of the Indian Ocean-Eurasia plate collision and compression zone;and there are volcanoes in this area.Type earthquake occurred.The above research shows that Tengchong volcano is not calm and is in danger of erupting again.Therefore,this paper uses SAR data processing,open source GPS data screening and mathematical modeling,and based on the above data processing,we have obtained InSAR-GPS deformation data,three-dimensional deformation data,strain data,stress data,and magma capsule geometric parameter data in volcanic areas.The data obtained above is used to explore the crustal activity in the Tengchong volcanic area.The specific research results are as follows:1.By constructing a GPS-InSAR three-dimensional deformation model,the advantages of GPS and InSAR technology are complemented;specifically,the widely used short baseline set method(SBAS)is used for interferometric processing of multitemporal SAR data to obtain millimeter-level data in volcanic areas.InSAR deformation monitoring data.GPS comes from open source data published in the literature.PSO is used to optimize the improved objective function(the improved version is more suitable for the characteristics of the above two types of deformation data)to obtain the high spatial resolution three-dimensional deformation velocity field in the Tengchong volcano area2.Based on the acquisition of high spatial resolution three-dimensional deformation information,the rigid motion model(RM),the rotation of the entire block and uniform strain model(REHSM)and the rotation of the entire block and linear strain model(RELSM)of the crustal movement in the study area were constructed respectively.By comparing the three models constructed,it is found that RELSM is the best model to describe the crustal movement in the study area.Based on RELSM,the strain field in the study area was inverted,and the fine strain field in the small-scale study area was obtained than previous studies based on GPS data alone.At the same time,strain tensor and stress tensor constitutive relationship are used,and strain is used to obtain the stress in the study area.From the perspective of strain,the crustal movement in the Tengchong volcanic area is not the squeeze of the southeastern margin of the Qinghai-Tibet Plateau,nor the extension of Southeast Asia,but the activity of its own magma pocket or magma loss and gas release.status.3.Based on the obtained deformation field,supplemented by the strain field stress field,it is found that there may be 3 magma pockets in the study area(the magma pockets in the northwest and southwest directions show contraction;the magma pockets in the northeast show expansion).Based on the three-dimensional deformation information of the area where the magma sac is located,the mogi model(also using PSO for parameter optimization)inverted the parameters of the magma sac.It was found that the magma sac was located about 1.4km underground in the northwest direction,and the contraction speed was about 0.002659861km3/a in the southwest direction.The magma sac is located about 4km underground,and the contraction speed is about 0.002622485km3/a.There is no threat of volcanic eruption in these two areas,but other geological disasters may occur due to the contraction of the magma sac.Based on the above obtained results,a comprehensive study of crustal activity in the Tengchong volcanic area has been carried out.The research shows that the entire crust of the study area is relatively calm,but the crustal activity in individual areas is relatively active.