Two dimensional modeling (2D) gravity method for interpreting subsurface structure of Mount Merapi

Abstract

Mount Merapi is one of the active volcanoes in Indonesia. The characteristics of this mount are explosive and eruptive. Moreover, its eruption causes lava floods. Its last eruption took many victims, and they were both dead and injured. They lost belongings and anything surroundings as well. Considering the negative impacts, research is needed to determine the subsurface structure of Mount Merapi as a disaster mitigation measure. One method that can be used is the gravity method. The gravity method is a geophysical method with an interpretation based on the different density of masses obtained from the Earth’s gravity acceleration data. In this research, an interpretation of the results of two-dimensional modeling will be performed. Research data is secondary data obtained from satellites. The research uses a literature study method on Mount Merapi by processing gravity data to obtain Bouguer anomalies, separating Bouguer anomalies into local and regional anomalies using MagPick and Surfer software, and two-dimensional modeling to determine density value density of subsurface mass using Grav2dc software. The results obtained consist of lithological interpretation consisting of basalt-andesite rocks, pyroclastic rocks, and magma chamber.