Sumatra and West Java have a high potential for geological disasters, including volcanic eruptions and earthquakes. In the last two years BMKG has significantly increased the number of seismic stations in this area, by utilizing seismic waveforms recorded by the BMKG seismograph network of earthquake monitoring stations spread across the Sumatra (110 stations) and West Java (48 stations) for 5 months using the ANT method. The dispersion curve shows the subsurface information that can be imaged from a period of 1 to 50 seconds. We use subspace inversion to test the resolution to get the best parameters for inversion. Based on the results of the resolution test, subspace inversion will use a grid parameter of 100 x 100 km, and smoothing and dumping of 500 each. The resulting group velocity mapping information also corresponds to the geological information and Bouguer anomalies. To generate subsurface information in Vs against depth we use the Neighborhood Algorithm (NA) method. The subsurface information generated shows excellent results on a regional scale. Large faults that are scattered throughout Sumatra and West Java, the dimensions of the faults, as well as the existence of the basin in the western part of Sumatra can be well imaged.
The results of this study indicate that the subsurface areas of Sumatra and West Java have the potential for natural resources as well as deadly geological disasters. This result can be used by the local government in planning investments to build an area.