Imaging magma plumbing system using InSAR analyses with corner reflectors

Suwanose-gia火山是日本最活跃的火山之一，自1957年以来一直处于准持续的动荡状态。它是用宽带地震仪和倾斜仪监测的，但由于难以到达该岛的地面通道，我们无法建造足够大的网络，仅从地面监测网络来了解岩浆管道系统。因此，InSAR分析观测到的地面变形有可能更深入地了解这座火山的岩浆管道系统。我们分析了2007年3月至2011年2月期间拍摄的43张图像(分别为19张上升图像和24张下降图像)。尽管2007-2011年有强烈的喷发活动，但除了2007年8月17日至2008年1月2日期间干涉图上的小变形(几厘米的视线变化)外，所有可能的干涉图都没有检测到形变，这可能是由于2007年12月的爆炸性喷发造成的变形。没有明显变形的爆炸性喷发可以解释为没有从深处注入岩浆的喷发，或者没有变形的岩浆通过管道传播。

Suwanose-jima is one of the most active volcano of Japan with quasi-continuous unrest since 1957. It is monitored with broadband seismometers and tiltmeters but the difficulty in ground access to the island prohibits us to construct large-enough network to understand the magma plumbing system solely from the ground-based monitoring network. Ground deformation observed by the InSAR analysis thus has a potential to gain moreinsights into our understanding of the magma plumbing system of this volcano.We analyzed 43 images (19 ascending and 24 descending images, respectively) taken between March, 2007, and February, 2011. Despite strong explosive eruption activity in2007-2011, no deformation was detected for interferograms from all possible pairs except for small (several centimeters of line-of-sight changes) deformaiton in an interferogram between August 17, 2007, and January 2, 2008, which could represent deformation due to explosive eruptions in December, 2007. Explosive eruptions without significant deformation can be interpreted as eruptions without feeding magma from depth or magma propagation through the conduit without deformation.