Lombok Island and its surrounding is an area that has a high seismicitys level because it is located in the Eastern Sunda Arc. Tectonically, Lombok Island located between the Indo-Australia plate collision zone with Eurasia in the south and the fult of the backarc Bali-Flores in the north. This research’s purposed to determine the distribution of vulnerability index and peak ground acceleration value are used to determine the GSS value, so mapping of potential damage areas could be done. The microtremor data taken on 32 observation points distributed in Lombok Island. Microtremor data is analysed using Horizontal to Vertical Spectral Ratio (HVSR) method to get seismic vulnerability index (Kg) and dominant period. Determination of Peak Ground Acceleration (PGA) value using data from the MASE Stasion measurement results based on earthquake events on August 5, 2018. Seismic vulnerability index and peak ground acceleration value are used to determine the GSS value. Determination of potential damage area using analysis of the dominant period, seismic vulnerability indexs and Ground Shear Strain values. The results of this research showed that seismic vulneribility index value in research area is about 0,029 sekon to 1,360 sekon, seismic vulneribility index value is about 0,56 to 189,92 and GSS value is about 2,52 x 10-5 to 8,46 x 10-3. The results show that the light damage dominated in East Lombok Districts, the moderate damage is on Mataram City and it dominated in West Lombok Districts. The heavy damage present in the most parts of West Lombok Districts.

Indonesia is one of the biggest gold producing countries in the world. the discovery of new gold reserves makes the passion of the gold mining industry increase. The Gunung Gupit area of Magelang Regency in Central Java has discovered new gold potential, but has not been thoroughly explored. The magnetic method is applied to identify and determine the distribution of the presence of gold mineralized zones based on the magnetic properties of rocks. A total of 1001 points on 41 magnetic line were acquired using Proton Precession Magnetometer (PPM) Geometrics model G-856 in an area of 2.5 km2. Field data is obtained as Magnetic Field Anomaly. Reduction to pole (RTP) and low-pass filter process is applied to the magnetic anomaly. The results showed the Gunung Gupit area was divided into 4 zones based on magnetic anomaly responses, i.e strong, medium, weak anomaly and igneous rock zones. The 2.5 D modeling result shows the presence of northwest-southeast normal fault and strike slip fault that is perpendicular to the normal fault. These faults control the hydrothermal alteration in Gunung Gupit and its surroundings. A strong mineralization zone lies between these two faults. The presence of gold and other metal minerals lies in this strong mineralization zone, and moderate alteration. The coverage area is quite wide and distributed along the two faults.

No abstract

No abstract