Volcanic Activity Deformation Monitoring And Inversion Analysis Based On InSAR Technology

Tectonic activities in the deep crust may lead to earthquakes,volcanoes and other disasters,which will have a significant impact on people’s living environment.Therefore,effective monitoring of volcanic deformation process,establishment of reasonable disaster mechanism model,and inversion of the occurrence and development laws of disasters such as volcanoes are of great significance for the protection of human life and property.In SAR technology is a modern geodetic technology used to study natural disasters.It can establish a one-dimensional surface deformation field through repeated observation of the ground,and can show the evolution process of surface movement over time under long-term monitoring.In addition,In SAR can effectively reduce the error term while maintaining the high spatial resolution of the image,so as to obtain more accurate time-domain deformation signals.Therefore,this paper will use In SAR technology to accurately obtain the volcanic disaster deformation field,simulate the location of volcanic pressure source and the volume change of magma flow,understand the mechanism model of volcanic activity,and better explore the law of volcanic activity through the observation of the large topographic deformation of Sakurajima and Nyiragongo volcanoes.1)In response to the acquisition of shallow source parameters below Sakurajima volcano,this article uses differential interferometry technology and reduced orbit Sentinel-1 data to conduct differential measurements of the volcanic eruption event in Sakurajima,Kagoshima,Japan in August 2020.The surface deformation of the volcanic area caused by this eruption event was restored,and the obtained LOS deformation values were used for point like Mogi source fitting.Based on In SAR data,various parameters of the shallow source below Nanyue were obtained.2)In response to the problem of shallow source volume changes in Sakurajima volcano,this paper applies SBAS-In SAR technology to calculate the average velocity and cumulative shape variables of the volcano during this time period.Using the location parameters of the volcanic magma reservoir obtained from the Sakurajima volcano eruption event in August 2020 as constraints,the nonlinear time series data observed by SBAS-In SAR is divided into three stages of linear deformation time series,and the volume changes of the magma reservoir in each stage are inverted,Based on In SAR data,long-term changes in shallow source volume beneath Sakurajima volcano were obtained.3)According to the fracture diameter length of the magma lake in Nyiragongo crater and the acquisition of the shallow source parameters below,this paper uses the SAR amplitude image to extract the fracture profile of the lava lake and fit it to obtain the fracture diameter of the lava lake;The deformation field of the lifting track obtained using In SAR technology and GNSS data were combined with linear and nonlinear inversion to obtain various parameters of the shallow Dyke source beneath the Nyiragongo volcano.