The Sumatra volcano-triggering experiment: Contributions from Space Geodesy

火山科学中的一个悬而未决的问题是，地震是否以及如何引发火山喷发。众所周知，存在与地震波传播有关的短期相互作用(地震后几分钟到几天)，但尚不清楚是否存在中期或长期相互作用(地震后几周到几个月或几个月到几十年)。该项目使用卫星干涉测量法调查苏门答腊岛2004年和2005年地震前后的火山活动，以回答这个问题。这些地震是有史以来最大的仪器地震之一，并为研究火山喷发的触发提供了一个独特的机会，因为它们与火山弧的显著减压有关。InSAR调查验证了地震引起的减压触发喷发的假设。该项目的理由是，新的火山活动与岩浆从深源上升到地表有关，因此可以通过精确的空间大地测量来探测到。在2005-2010年项目的第一阶段，将分析加拿大Radarsat-1卫星和日本ALOS卫星的图像，以发现地震后发生的任何地表异常变形。在第二阶段，将对JERS-1卫星1993-1998年的图像进行分析，以绘制地震前的地表形变图。将震前和震后数据进行比较，将确定触发的火山变形。该项目是迈阿密大学和印度尼西亚万隆理工学院(ITB)的合作项目。ITB将与印度尼西亚政府和研究机构合作，领导对卫星探测到的活跃中心的地面调查。

An open question in volcano science is whether and how earthquakes trigger volcanic eruptions. It is well known that there is a short-term interaction related to the passage of the seismic waves (minutes to days after the earthquake) but it is not understood whether there is an intermediate-term or a long-term interaction (weeks to month or month to decades after the earthquake). This project uses satellite interferometry to survey the volcanic activity in Sumatra before and after the 2004 and 2005 earthquakes to answer this question. The earthquakes were among the largest-ever instrumental earthquakes and provide a unique opportunity to investigate eruption triggering because they were associated with significant decompression of the volcanic arc. The InSAR survey tests the hypothesis that earthquake-induced decompression triggers eruptions. The rationale of this project is that new volcanic activity is associated with the ascent of magma from deep sources towards the surface and thus detectable by precise space geodetic measurements. In the first phase of the project 2005-2010 imagery of the Canadian Radarsat-1 and the Japanese ALOS satellite will be analyzed to detect any anomalous surface deformation that occurred after the earthquakes. In the second phase 1993-1998 imagery from the JERS-1 satellites will be analyzed to map surface deformation prior to the earthquakes. Comparison of pre-earthquake with post-earthquake data will identify triggered volcano deformation. This project is a partnership between the University of Miami and the Institute of Technology in Bandung (ITB), Indonesia. ITB will lead ground-based investigations of satellite-detected active centres in collaboration with Indonesian government and research institutions.