Detecting hot spring manifestations based on gravity data satellite on mountain Lawu

Abstract

Mount Lawu is in the transition zone among Western and Eastern Java. Gunung Lawu consists of two volcanic systems separated by the East-West trending Cemorosewu Fault. The geology of Mount Lawu is dominated by Andesite Lava. Mount Lawu area has a geothermal energy prospect with indications of the appearance of hot springs and fumaroles. 2D modeling of subsurface structure of Mount Lawu's manifestation area has been carried out using gravity method. The aims of study to investigate the appearance of hot springsis related with fault structure. Data used using GGMplus (Gravity model plus) satellite image data in the form of gravity disturbance or anomaly free air with spaces each points is 200 meter respectively. GGMplus gravity anomaly data are performed bouger correction and field correction to produce a complete bouger anomaly (ABL). The ABL results present that the anomaly corresponds to the geological map, otherwise the higher topography correlated with with the smaller value of the gravity anomaly. 2D modelling and interpretation has done based on ABL results. Based on 2D modeling the appearance of hot springs is controlled by the presence of faults, moreover Mount Lawu consists of three layers of rock, namely Tuff with a density of 1.27-2.66 gr / cm3, andesite lava 2.90 gr / cm3, and basalt lava 2.99 gr / cm3.The results of study are expected be used as a reference and policy decision in geothermal development of Mount. Lawu.