KARAKTERISASI DATA TEMPERATUR, CO2 DAN GEOLISTRIK DI LERENG SELATAN GUNUNG MERBABU PADA KETINGGIAN 2586 HINGGA 3170 METER DPL

Abstract

Several geophysical observation has been carried out such as; shallow temperature measurement, carbondioxide (CO2) gas surface emission and geoelectric. The aim of research is to know the distribution of temperature and CO2 and also it’s corelations with resistivity property of subsurface at Merbabu Volcano. The research was been done from August 23 - 28, 2008 in south flank of Merbabu at coordinat 110026’31,8” BT to 110026’45,3” BT and 07027’32,5” LS to 07028’04,9” LS. The shallow ground temperature and carbondioxide (CO2) gas emission data consist of 20 poinst with the deepness 75 cm from the surface. Termocouple sensors and gauges the level of carbon dioxide (CO2) were used to observed shallow ground temperature and carbondioxide (CO2). The geoelectric data was carried out by two configurations, the Wenner and Schlumberger The result shows an decrease of the temperature and carbondioxide (CO2) emissions against increase the topography. This is in accordance with the general form of the distribution of temperature and CO2 gas emissions at the volcano. Based on the resistivity result at measurement locations obtained rock litologi with resistivity values between 1000 - 2200 m at a depth of less than 40 meters. In general, the study area has a low conductivity rocks. This is identified by the high value of the resistivity of rocks. Decreasing of temperature and carbondioxide (CO2) emissions against increasing of the topographic caused by the heat energy reduction that flows to the surface and the conductivity of the rocks is low so the heat is not easily conducted to the south flank of Merbabu.