The Philippine archipelagos represent one of the most complex geologic regions of our planet. Composed of numerous microplates and terranes that became trapped between or split from the Eurasian Plate, to their west, the Philippine Sea Plate, to their east, and the Australian Plate to their south, the Philippine Mobile Belt stretches south from Taiwan to the northern edge of the Australian Plate. It is bounded on the east by the East Luzon and Philippine Trenches and, on the west, by the Manila, Negros and Cotabato Trenches.
The microplates and terranes, many of which are composed of metamorphic Paleozoic and early Mesozoic bedrock, have been subjected to fusion, compression, transverse faulting and subduction volcanism throughout the Cenozoic Era; all of these geological processes continue today. The Philippine Fault runs down the center of the Mobile Belt, triggering uplift and earthquakes while stream erosion and volcanic debris have produced nutrient rich plains between the numerous mountain ridges.
Lying in the Tropical Zone, the Philippines are also lashed by tropical storms and typhoons which mold their coastlines and channels, further altering the geography of the component archipelagos. Indeed, there are few regions of our globe where plate tectonics and violent weather produce such a regular chain of "natural disasters."
