Pemantauan deformasi permukaan gunung merapi dengan pengukuran sudut dan jarak

ABSTRACT Merapi volcano is one of 129 active volcanoes in Indonesia. Volcanic risk (primary hazard and secondary, hazard) is the most spectacular and widely feared of natural disasters. Volcanic hazard has taken, tolls of life and property. In order to anticipate and mitigate volcanic hazard, volcano observation must be done in term of routine monitoring. Monitoring and forecasting of volcanic eruption are closely related. Ground surface deformation monitoring is one of methods used in volcano monitoring. In Merapi volcano, there is a net work for three dimensional monitoring by using optical instrument (angular data) and electrical instrument (distance data). The period of monitoring observation is carried out once a year The net work consists of two reference stations and seven monitoring stations. The deformation computation is carried out by least square adjustment and statistical tests. The result shows that one year observation period of seven monitoring stations had undergone (its resultant) 6.1 cm to 58.7 cm displacement