著者

Hiroyuki Tsutsumi Jeffrey S. Perez

出版者

Japanese Society for Active Fault Studies

雑誌

活断層研究 (ISSN:09181024)

巻号頁・発行日

vol.2013, no.39, pp.29-37, 2013-09-30 (Released:2016-03-31)

参考文献数

32

---

The Philippine fault is a ~1250-km-long, left-lateral strike-slip fault extending NNW parallel to the Philippine archipelago. This fault has been very active in the past 200 years with several destructive earthquakes accompanied by surface rupture. However, there was no large-scale map of the Philippine fault, which is essential for mitigating seismic hazard from future earthquakes. We mapped the surface trace of the Philippine fault on 1:50000-scale topographic maps based mainly on interpretation of ~1:30000-scale aerial photographs. We then compiled these fault trace data on a Geographic Information System to produce the first digital active fault map of the Philippine fault. These 1:50000-scale active fault maps are available from the website of Philippine Institute of Volcanology and Seismology (PHIVOLCS). These maps reveal that there are notable along-strike variations in fault trace geometry and magnitudes of historical seismicity of the Philippine fault. The Philippine fault in central Luzon and Mindanao Islands are well segmented and produced large (M≥7) earthquakes. In contrast, the fault in Masbate and Leyte Islands are more continuous and produced only moderate earthquakes in the past 400 years. There are geomorphic and geodetic evidence of aseismic creeping on the Philippine fault in northern and central Leyte. These observations suggest that the Philippine fault may be comparable to the San Andreas fault in that both of the faults are composed of locked, transition and creeping segments as previously suggested.

著者

Jeffrey S. Perez Hiroyuki Tsutsumi Mabelline T. Cahulogan Desiderio P. Cabanlit Ma. Isabel T. Abigania Takashi Nakata

出版者

Fuji Technology Press Ltd.

雑誌

Journal of Disaster Research (ISSN:18812473)

巻号頁・発行日

vol.10, no.1, pp.74-82, 2015-02-01 (Released:2019-07-01)

参考文献数

35

被引用文献数

7

---

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 of Mw6.6 to Mw7.4. The results of our study have important implications for earthquake generation potential and seismic hazard assessment of the Philippine fault in Mindanao Island.