The Philippine Trench (also Philippine Deep, Mindanao Trench, and Mindanao Deep) is a

submarine trench Oceanic trenches are prominent long, narrow topographic depressions of the ocean floor. They are typically wide and below the level of the surrounding oceanic floor, but can be thousands of kilometers in length. There are about of oceanic tren ...

to the east of the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

. The trench is located in the Philippine sea of the western North Pacific Ocean and continues NNW-SSE. It has a length of approximately and a width of about from the center of the Philippine island of

Luzon Luzon (; ) is the largest and most populous island in the Philippines. Located in the northern portion of the Philippines archipelago, it is the economic and political center of the nation, being home to the country's capital city, Manila, as ...

trending southeast to the northern Maluku island of

Halmahera Halmahera, formerly known as Jilolo, Gilolo, or Jailolo, is the largest island in the Maluku Islands. It is part of the North Maluku province of Indonesia, and Sofifi, the capital of the province, is located on the west coast of the island. Ha ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. At its deepest point, the trench reaches 10,540 meters (34,580 ft or 5,760 fathoms). PhilippineMobileBelt007

Immediately to the north of the Philippine Trench is the East Luzon Trench. They are separated, with their continuity interrupted and displaced, by Benham Plateau on the

Philippine Sea Plate The Philippine Sea Plate or the Philippine Plate is a tectonic plate comprising oceanic lithosphere that lies beneath the Philippine Sea, to the east of the Philippines. Most segments of the Philippines, including northern Luzon, are part o ...

Information

The Philippine trench is hypothesized to be younger than 8–9 million years old. The central part of the Philippine fault formed during the

Plio-Pleistocene The Plio-Pleistocene is an informally described geological pseudo-period, which begins about 5 million years ago (Mya) and, drawing forward, combines the time ranges of the formally defined Pliocene and Pleistocene epochs—marking from about 5&nb ...

times is considered to be an active depression of the Earth's crust. The trench formed from a collision between the

Palawan Palawan (), officially the Province of Palawan ( cyo, Probinsya i'ang Palawan; tl, Lalawigan ng Palawan), is an archipelagic province of the Philippines that is located in the region of Mimaropa. It is the largest province in the country in t ...

and Zamboanga plates. This caused a change in geological processes creating a subduction zone, that is dropping the ocean floor deeper. The rate of subduction on these plates is estimated to be about 15 cm per year. A convergent zone borders an estimate of 45% of the Philippine Trench today. Although there are vast areas of subduction zones, some authors have considered this region to have low

seismic activity An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

, though the

USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...

has recorded many earthquakes with magnitude ≥ 7.2 in the region as shown by the map to the side. Most recently, in 2012 the Philippine Trench experienced an earthquake of M_w 7.6 (the 2012 Samar earthquake). It hit the trench with a hypocenter depth of 34.9 km. Areas adjacent to the subduction zones have experienced large seismic activity. In 1897, northern Samar experienced a M_s 7.3 earthquake while in 1924 southern Mindanao experienced one with a M_s 8.2.

Depth

The trench reaches one of the greatest depths in the ocean. Its deepest point is known as

Galathea Depth The Emden Deep, also known as the Galathea Deep or Galathea Depth, is the portion of the Philippine Trench exceeding depths in the south-western Pacific Ocean. Originally discovered by the German ship ''Emden'' in 1927, it was first explored ...

and reaches 10,540 meters (34,580 ft or 5,760 fathoms).

Sedimentation

Sedimentation of the Philippine trench contains slightly

metamorphosed Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...

, calc-alkalic, basic, ultrabasic rock and sand grains. The southern area of the trench contains homogeneous blue

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel ...

and is poor in

lime Lime commonly refers to: * Lime (fruit), a green citrus fruit * Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide * Lime (color), a color between yellow and green Lime may also refer to: Botany ...

. Sand grains that were also found contained fresh basaltic andesite. The sediments found in the trenches are hypothesized to have been deposited by

turbidity current A turbidity current is most typically an underwater current of usually rapidly moving, sediment-laden water moving down a slope; although current research (2018) indicates that water-saturated sediment may be the primary actor in the process. T ...

s. A turbidity current is an underwater current that moves rapidly and carries sediment.

Significant quakes

This is a list of significant quakes related to the Philippine Trench, which are 7.0+

Trenches in the Philippine region

Known trenches in LuzViMinda are: * Manila Trench * East Luzon Trench * Negros Trench * Sulu Trench * Cotabato Trench

References

{{coord missing, Pacific Ocean Philippine Sea Oceanic trenches of the South China Sea Philippine tectonics Subduction zones Geology of Indonesia