地震地质 ›› 2023, Vol. 45 ›› Issue (6): 1309-1327.DOI: 10.3969/j.issn.0253-4967.2023.06.004

• 研究论文 • 上一篇    下一篇

长白山天池火山2015—2022年InSAR变形与活动状态分析

熊国华1,2)(), 季灵运1,2),*(), 刘传金1,2)   

  1. 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
  • 收稿日期:2023-02-27 修回日期:2023-05-05 出版日期:2023-12-20 发布日期:2024-01-16
  • 通讯作者: 季灵运, 男, 1982年生, 博士, 研究员, 主要从事构造大地测量学研究, E-mail: dinsar010@163.com
  • 作者简介:

    熊国华, 女, 1996年生, 2022年于长安大学获测绘科学与技术硕士学位, 助理工程师, 现主要研究方向为InSAR地质灾害监测, E-mail:

  • 基金资助:
    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)

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

XIONG Guo-hua1,2)(), JI Ling-yun1,2),*(), LIU Chuan-jin1,2)   

  1. 1) The Second Monitoring and Application Center, CEA, Xi’an 710054, China
    2) Department of Geological Hazards, National Remote Sensing Center of China, Beijing 100036, China
  • Received:2023-02-27 Revised:2023-05-05 Online:2023-12-20 Published:2024-01-16

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-3.3×105m3/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。

关键词: 长白山天池火山, InSAR技术, 岩浆房, 地表形变反演

Abstract:

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 the magma reservoir and integrating it with previously published results obtained from geodetic measurements, the mechanisms underlying the variations in the magma reservoir and the temporal sequence of volcanic activity in Tianchi volcano are explored. The primary conclusions are as follows:

(1)According to the acquired LOS InSAR average deformation rate data from 2015 to 2022, covering the Tianchi volcano, the deformation results from different orbits show good consistency in their distribution. Near the volcano crater, there is an overall trend of deformation, while in areas farther away from the crater, local deformation exists. Over the past seven years of monitoring, there has been a slow subsidence phenomenon near the volcano crater, with a deformation rate of approximately -4mm/a to -2mm/a. By extracting the profile deformation time series from one descending orbit, it is found that the maximum cumulative deformation is about -40mm. The results of the deformation time series indicate that the surface deformation of the Tianchi volcano was relatively small between 2014 and 2017, indicating relatively stable magmatic activity during this period. However, starting in 2018, there has been a certain degree of accelerated deformation, and surface deformation mainly occurs around the volcano crater.

(2)According to the inversion results of the Mogi model, the shallow magma chamber beneath the Tianchi volcano has an estimated depth of approximately 6km, with a volume change rate of -3.3×105m3/a. The geographical location of the magma chamber is situated slightly below and to the west of the Tianchi volcano crater. The inversion results indicate that during the monitoring period, the magma chamber displayed an overall slow contraction. It is speculated that the deformation activity of the magma chamber may be attributed to magma cooling and crystallization processes.

(3)According to the inversion of geodetic measurement data on magma chamber volume changes, during the period from 1995 to 1998, the magma chamber of the Tianchi volcano underwent progressive expansion deformation at a sluggish rate. The Tianchi volcano experienced significant surface uplift deformation from 2002 to 2005. During this period, the magma chamber exhibited a rapid expansion deformation with a fast volume change rate. Starting from 2006, the surface deformation rate weakened, and the volume change rate slowed down. From 2009 to 2011, the inversion of leveling observation data indicated a contraction of the magma chamber volume. Throughout the observation period of this study, the magma chamber continued to exhibit a contraction phenomenon. From 1995 to 2022, the Tianchi volcano underwent a process of magma activity, transitioning from a state of quiescence to perturbation and back to quiescence.

Key words: Changbaishan Tianchi volcano, InSAR technique, magma chamber, deformation inversion