Volcanic activity analysis of Mt. sinabung in Indonesia using InSAR and GIS techniques

Abstract

Sinabung volcano in Indonesia is a part of the Pacific Ring of Fire, formed due to the subduction between the Eurasian and the Indo-Australian plate. We study the deformation of Sinabung volcano using ALOS/PALSAR interferometric synthetic aperture radar (InSAR) images acquired from Feb. 2007 to Jan. 2011. Based on multi-temporal InSAR processing, we have mapped the ground surface deformation before, during, and after the 2010 eruption. During the 3 years before the 2010 eruption, the volcano inflated at an average rate ∼1.7 cm/yr with marked higher rate of 6.6 cm/year during the 6 months prior to the 2010 eruption. The inflation is constrained to the top of the volcano. Since the 2010 eruption to Jan. 2011, the volcano has subsided for about 3 cm. The observed inflation and deflation are modeled with a Mogi and Prolate spheroid source. The source of inflation is located about 0.3–1.3 km below sea level directly underneath the crater. On the other hand, deflation source is modeled about 0.6–1.0 km depth with coeruption period. The average volumetric change was about from −2.7×10−5 to 1.9×10−6 km3/yr during the deformation event. Modified Laharz model compare to Landsat-7 ETM+ image through supervised classification method. We interpret the inflation was due to magma accumulation at a shallow reservoir beneath Sinabung. Pyroclastic flow's inundation area is highly matched between two different methods with about 86 % common region inserting for deflation pattern of volume by Mogi model.