PEMODELAN BAWAH PERMUKAAN GUNUNGAPI MERAPI BERDASARKAN ANOMALI GRAVITASI SETELAH LETUSAN BESAR 2010

Subsurface modeling of Merapi Volcano based on gravity data after the 2010 big eruption has been done. The aim is to analyze the changes in the internal structure of Merapi Volcanoe, by comparing the complete Bouguer anomaly in 1998 with 2011 and describes the structure of Merapi Volcano in three-dimensional moddelling (3D). Complete Bouguer anomaly was projected into a regular plane of 2000 m above sea level. The Regional and Local anomalies were separated using upward continuation. In order to determine regional anomaly, total Bouguer anomaly was projected to 4000 m above sea level. The quantitative interpretation of gravity anomalies indicate that there was magma chamber on northeast of Merapi at depth 800 m up to 5900 m and there was indication of a new rock layer formed on the surface with a thickness of 500 m due to magma intrusion in Gendol River�s stream on southeastern of Merapi