We have made a set of earthquake source parameters for events which can occur in subduction zones surrounding the Philippines and cause large tsunamis and damages. The earthquake source parameters consist of location of fault (longitude, latitude, depth), fault length, fault width, strike angle, dip angle, rake angle, and slip amount, and the maximum plausible earthquake magnitude for each fault segmentation. To set these parameters, first we collated tsunami databases and reviewed the historical tsunamigenic events with other studies such as re-evaluation of historical records and magnitudes. Then, we reviewed seismicity data and Global Centroid Moment Tensor solutions. We followed the segmentation set by Bautista, and set the maximum plausible magnitude, fault width and slip amount following the scaling laws. We also utilized some geophysical studies such as slab dip models, geometry of subducting slabs, and recent studies on Global Positioning System (GPS) and plate motions.
Combining all the above-mentioned information, we identified six source regions (Manila Trench, Negros Trench, Sulu Trench, Cotabato Trench, East Luzon Trough, and the Philippine Trench) with 17 segments surrounding the Philippines. Then, we set the earthquake source parameters for these 17 segments.
These sets of earthquake source parameters can be used as input data to tsunami simulation, the results of which will be used for further tsunami hazard assessment studies that are now under implementation.