Gede volcano is an active volcano in West Java, Indonesia. Research about determination the volcanotectonic earthquake source positions has given results using volcano-tectonic earthquakes data from January until November 2015. Volcano-tectonic earthquakes contained deep (VT-A) have frequency (maximum amplitude) range 5 -15 Hz. Furthermore, they contain shallow earthquake, VT-B have range 3-5 Hz and LF have range 1-3 Hz. Geiger's Adaptive Damping (GAD) methods used for determining the hypocenter of these volcano-tectonic (VT) events. Hypocenter distribution divided into 4 clusters. Cluster I located in the crater of Gede volcano dominated by VT-B earthquakes their depth range 2 km below MSL to 2 km above MSL including the VT-B swarm. The seismic sources in cluster I indicated dominant due to the volcanic fluid or gas filled in conduit pipes. Cluster II located at the west of Gede volcano caused by Gede-Pangrango fault-line dominated by VT-A earthquakes with depths range 1.5 km below MSL to 700 m above MSL. Cluster III located in the North of Gede volcano dominated by VT-A events there caused by graben fault area with those depths range 7.5 -1.65 km below MSL. Cluster IV located in South West of Gede volcano contained VT-A earthquakes with depth range at 10 km below MSL and VT-B earthquakes this depth 2 km below MSL. Due to magma intrusion filled into fractures of the fault in the West of Gede volcano this shallow magma filling-fractures and degassing in subsurface assumed dominates the volcano-tectonic events from January to November 2015 due to faults extends from North to South occured in the West of Gede volcano.

Research that uses the Schlumberger configuration resistivity method had been conducted in Cangar. The purpose of this study is to identify cracks/faults and potential hot springs use resistivity well analysis and correlate it with rock lithology in Cangar, East Java. Data acquisition is carried out using 3 tracks with 10 sounding points. The space between points is 50 meters. The rock resistivity values obtained were 9945 Ωm, 7360 Ωm, and 5573 Ωm which were thought to be breccia layers and functioned as hot springs. This estimation is strengthened by the existence of a layer of breccia-andesite because this layer is very good as a water reservoir. In addition, based on the lateral cross-section on lane 1, there was a decrease in boulder-sized breccia-andesite layers; this decrease was the production of faults.

Telah dilakukan penelitian tentang potensi panas bumi di daerah pemandian air panas Cangar Kota Batu Jawa Timur berdasarkan metode gravity dengan menggunakan alat Gravity-meter La Coste & Romberg seri G1053. Pengambilan data dilakukan di 20 titik pengamatan disekitar Pemandian air panas Cangar. Hasil penilitan  nilai kontras densitas sayatan AA’ dibagi menjadi 3 lapisan utama secara umum, ketiga lapisan batuan tersebut masing-masing adalah : Andesit di bagian dasar pada kedalaman 0,5 km – 1 km nilai densitas sebesar 2,617 gr/cm3. Yaitu di lapisan atasnya terdapat breksi-andesitik dengan nilai densitas yang tidak jauh berbeda yaitu 2,680 gr/cm3 dengan kedalaman 0,3 – 0,5 km. Sedangkan dekat permukaan berupa endapan tufa andesitik dengan nilai densitas yaitu 2,685 gr/cm3. Untuk nilai kontras densitas Sayatan BB’ dibagi menjadi tiga lapisan batuan utama diantaranya : Andesit dengan nilai densitas 2,62 gr/cm3 pada basement atau dasar lapisan dari model tersebut (kedalaman 0,5 – 1 km). Kemudian breksi-andesitik dengan nilai densitas 2,678 – 2,695 gr/cm3. Pada bagian dekat permukaan berupa tufa andesitik dengan nilai densitas berkisar 2,66 – 2,677 gr/cm3. Dengan adanya lapisan breksi-andesit ini sangat baik sebagai penampung air karena memiliki porositas yang tinggi.

In the previous research in Badut temple, it resulted in the conclusion that on the research path, there is a Badut temple foundation, at a depth of 0 m -1.5m, which is square wide. The results of this study require further research to detect the presence of a cavity zone because the presence of cavity zones has the potential for subsidence of the temple foundation. This study aims to determine the distribution of cavity zones under the temple foundation. Research in the first location around the temple building was carried out by scanning 8 straight lines, then combined and analyzed. Based on the results of the analysis, it is found that the cavity zones are spread from trajectory 1-8. The largest cavity zone is located in the corner of the intersection of lanes 1 and 2. The second location research was carried out in the pool in front of the temple; the results showed that the pool floor was dominated by the cavity and watery zone. Only a few points showed buried rock, which was shown by reddish-yellow color. Based on the data analysis, it can be concluded that around the temple, there are still many cavity zones, and there are still some buried rocks. As for the pool area, it is dominated by a cavity zone, so it is possible that there is still a lot of empty space under the ground floor of the pool, and it is watery.