长白山天池火山2015—2022年InSAR变形与活动状态分析  

ANALYSING THE SURFACE DEFORMATION AND PRESENT-DAY MAGMA ACTIVITY OF CHANGBAISHAN-TIANCHI VOLCANO FROM 2015 TO 2022 WITH INSAR TECHNOLOGY

作　　者：熊国华 季灵运[1,2] 刘传金 XIONG Guo-hua;JI Ling-yun;LIU Chuan-jin(The Second Monitoring and Application Center,CEA,Xi an 710054,China;Department of Geological Hazards,National Remote Sensing Center of China,Beijing 100036,China)

机构地区：[1]中国地震局第二监测中心,西安710054 [2]国家遥感中心地质灾害研究部,北京100036

出　　处：《地震地质》2023年第6期1309-1327,共19页Seismology and Geology

基　　金：吉林长白山火山国家野外科学观测研究站研究课题(NORSCBS20-01);国家自然科学基金(42104061);陕西省自然科学基础研究计划(2023-JC-QN-0292)共同资助。

摘　　要：地表形变信息可有效反映火山下岩浆房的活动状态,对于理解火山活动演化过程非常重要。文中利用Sentinel-1A/B的升、降轨影像,采用SBAS InSAR与Stacking InSAR技术,获取了长白山天池火山2015—2022年间的地表形变时间序列及速率,并结合Mogi点源模型反演岩浆房的几何参数,得到的主要结论如下:(1)火山口及周围区域整体下沉,火山口附近视线向形变速率约为-4~-2mm/a,远离火山口的局部形变速率可达-6mm/a。(2)根据Mogi模型反演的火山下浅层岩浆房深约6km,体积变化率为-3.3×10^(5)m^(3)/a,岩浆房位于长白山天池火山口下偏西的位置。(3)1992—2022年期间,火山经历了从平静到扰动、再到平静的岩浆活动过程,在2002—2005年监测到明显的地表隆升变形,岩浆房体积显著膨胀,之后岩浆的活动性逐渐减弱。The surface deformation information can effectively reflect the activity status of the magma chamber under the volcano,which is very important for understanding the evolution process of volcanic activity.By capturing deformation anomalies,the volcanic hazard can be assessed,providing insights into the supply,storage,and triggering mechanisms of volcanic magma systems.According to statistics,there are 14 active volcanoes in China with potential eruption risks.Among them,Tianchi volcano of Changbaishan is considered the largest and most dangerous active volcano within China s borders.It is located on the northern edge of the Sino-Korean Plate,situated to the east of the Dunhua-Mishan fault at the outermost edge of the Northeast rift system and to the west of the back-arc basin of the Japan Sea.Multiple groups of faults in the NE-SW and NW-SE directions are widely developed in the region.Since 2002,seismic activity in the Tianchi volcano area has gradually increased,with the annual average earthquake frequency rising from dozens to over a hundred times,reaching its peak in 2003 with over a thousand occurrences.However,seismic activity has gradually decreased after 2006.Nevertheless,between 2020 and 2022,two episodes of seismic swarms occurred beneath the Tianchi volcano,with epicenters exhibiting a dispersing pattern gradually spreading from beneath the volcanic vent.This indicates that the Tianchi volcano still retains the potential for eruption.This study investigates the Tianchi volcano as the research area.It utilizes Sentinel-1A/B images from three orbits,namely ascending and descending passes,and employs advanced techniques including Small Baseline Subset(SBAS)InSAR and Stacking InSAR to retrieve Line of Sight(LOS)surface deformation results of the Tianchi volcano from 2015 to 2022.Additionally,InSAR observations are used as surface constraints,and the geometric distribution of the magma reservoir in Tianchi volcano is inverted using the Mogi point source model.By analyzing the inferred volume change rate of t

关 键 词：长白山天池火山 INSAR技术 岩浆房 地表形变反演 

分 类 号：P315.2[天文地球—地震学]