Seismotectonic Reactions to the Arc–continent Convergence in Central Philippines
Presenter：Shi-Ming Wen Date：2014/9/25
Abstract
High seismic activity in the Philippines originates from tectonic convergence related to surface and subsurface seismotectonic features. Based on earthquake data, the archipelago can be divided into the seismically-active Philippine Mobile Belt and the aseismic North Palawan Block. The latter represents a rifted continental fragment of the Eurasian margin that juxtaposed with the rest of island arc units in central Philippines. Earthquake hypocenter plots on planar and in vertical profiles show that the seismic events are associated with known seismotectonic features. In addition, data suggest that the collision zone between the North Palawan Block and the Philippine Mobile Belt is characterized by a decreased amount of hypocenters at >100 km depths. Although field evidence favors the presence of a subducted slab or slabs beneath western central Philippines, these are difficult to image using the present seismicity distribution dataset.
References
Lin, J. Y., & Lo, C. L. (2013). Earthquake-induced Crustal Gravitational Potential Energy Change in the Philippine Area. Journal of Asian Earth Sciences, 66 (2013) 215-223.
Yumul, G.P., Dimalanta, C.B., Marquez, E. J. & Queano, K. L. (2009b). Onland signatures of the Palawan microcontinental block and Philippine mobile belt collision and crustal growth process：a review. Journal of Asian Earth Sciences, 34, 610-623.
Yumul, G.P., Jumawan, F.T., and Dimalanta, C.B. (2009b). Geology, geochemistry and chromite mineralization potential of the Amnay Ophiolitic Complex, Mindoro, Philippines. Resource Geology, v. 59, p.263-281.