Geography of The Philippines - Terrain

Terrain

The islands are volcanic in origin, being part of the Pacific Ring of Fire, and are mostly mountainous. The highest point in the country is the peak of Mount Apo in Mindanao, which is 2,954 m above sea level. The second highest point can be found on Luzon at Mount Pulog, a peak 2,842 m above sea level.

The Philippine Archipelago is geologically part of the Philippine Mobile Belt located between the Philippine Sea Plate, the South China Sea Basin of the Eurasian Plate, and the Sunda Plate. The Philippine Trench (also called the Mindanao Trench) is a 1,320-kilometer-long submarine trench found directly east of the Philippine Mobile Belt and is the result of a collision of tectonic plates. The Philippine Sea Plate is subducting under the Philippine Mobile Belt at the rate of about 16 cm per year. Its deepest point, the Galathea Depth, has a depth of 10,540 meters (5,763 fathoms or 34,580 feet). The Philippine Fault System consists of a series of seismic faults that produce several earthquakes per year, most of which are not felt.

Many volcanoes in the country are active, the most recent eruption being that of Mount Pinatubo on Luzon in 1991. Mount Mayon is another of the active volcanoes and has the world's most perfectly-shaped cone. Mayon has a violent history of 47 eruptions since 1616 and another violent eruption is currently feared. Taal Volcano, also located on Luzon, is one of the Decade Volcanoes.

The islands typically have narrow coastal plains and numerous swift-running streams. Every island has sand beaches, but few open onto spacious lowlands. There are few large plains or navigable rivers. The longest river is the Cagayan River or Rio Grande de Cagayan in northern Luzon measuring 354 kilometers. In Mindanao, the longest river is the Mindanao River or Rio Grande de Mindanao which drains Maguindanao and other parts in western-central Mindanao. Agusan River drains eastern Mindanao.

Most of the islands used to be covered by tropical rainforests. However, illegal logging has reduced forest cover to less than 10% of the total land area.