Fault Distribution, Segmentation and Earthquake Generation Potential of the Philippine Fault in Eastern Mindanao, Philippines

Abstract

The 1,250-km-long, NNW-trending, arc-parallel Philippine fault, one of the world’s most active tectonic structures, traverses the Philippine archipelago and has been the source of surface-rupturing earthquakes during the last four centuries. In this paper, we will discuss Philippine fault distribution and segmentation in Mindanao Island by integrating detailed fault mapping together with new geological and paleoseismic data and the analysis of historical surface-rupturing earthquakes. Using geometric segmentation criteria, we have identified nine geometric segments separated by discontinuities such as en echelon steps, bends, changes in strike, gaps, steps and bifurcation in the surface trace. Fault segments ranges from 20 to 100 km in length and are capable of generating earthquakes ofMw6.6 toMw7.4. The results of our study have important implications for earthquake generation potential and seismic hazard assessment of the Philippine fault in Mindanao Island.