基于D-InSAR的樱岛火山喷发形变场解算与反演分析

Deformation Field Solution and Inversion Analysis of Sakurajima Volcanic Eruption Based on D-InSAR

采用D-InSAR技术对覆盖2020年日本鹿儿岛市樱岛火山喷发前后时段的2景降轨Sentinel-1A数据进行处理,获取日本鹿儿岛市樱岛火山南岳火山口喷发事件引起的地表形变场,并在此基础上结合点源Mogi模型对樱岛火山喷发时的岩浆源进行反演分析。结果表明,2020-07-28~08-09期间沉降主要集中在火山中心地区,最大沉降区域为火山中心地带,最大沉降量与平均沉降量分别为5.5 cm与2.85 cm;抬升主要发生在火山边缘区域,最大抬升量与平均抬升量分别为5 cm与2.24 cm,抬升可能与艾拉火山口下方的岩浆活动有关。根据点源Mogi模型反演得到岩浆源深度和体积变化量分别为1.016 km和-0.139×10^(6)m^(3),岩浆源位于南岳下方,与南岳火山口的喷发活动有关。

We use the D-InSAR technique to process the 2-view descending track Sentinel-1A data covering the period before and after the eruption of 2020 Sakurajima volcano in Kagoshima city,Japan.We obtain the surface deformation field caused by the volcanic eruption event,and on this basis,we carry out the inversion analysis of the magma source during the eruption of Sakurajima volcano by combining the point source Mogi model.The results show that subsidence during 2020-07-28~08-09 is mainly concentrated in the central area of the volcano,and the maximum subsidence area is the central area of the volcano,with maximum and average subsidence amounts of 5.5 cm and 2.85 cm,respectively.The uplift mainly occurs in the rim area of the volcano,with maximum and average uplift amounts of 5 cm and 2.24 cm,respectively.The uplift may be related to the magmatic activity below the crater of Ayla.The inversion of the point-source Mogi model yields a magma source depth and volume change of 1.016 km and-0.139×10^(6)m^(3),respectively,and the magma source is located below Minami-dake,which is related to the eruptive activity of Minami-dake.