The Depth of Pressure Source and Magma Supply Volume for Merapi Eruption during 2009-2011 Using the Combination of Yokoyama and Mogi Model

Merapi Volcano is an active stratovolcano located on the border between Central Java and Yogyakarta Province, Indonesia. A VEI (Volcano Explosively Index) IV eruption of Merapi began on 26th october 2010. This research aims to estimate the depth of pressure source and magma supply volume during 2009 2011. There are eight GPS stations installed around merapi volcano. During the eruption in October 2010, GPS data have shown lengthening of the baselines between Merapi’s crater and monitoring stations, it means that merapi has already entered into inflation process. Merapi Volcano begins to deflate in 2011. Estimation of the depth of pressure source and magma supply volume has been done using Mogi and Yokoyama models. The result shown the depth of pressure source before eruption is around 2.3 km and the magma supply volume about 55 million m3.