Central Basin Spreading Center (formerly Central Basin Fault) is a seafloor spreading center of the West Philippine Basin. [1]
The Philippines is an archipelago that comprises 7,641 islands with a total land area of 300,000 square kilometers (115,831 sq mi). It is the world's fifth largest island country. The eleven largest islands contain 95% of the total land area. The largest of these islands is Luzon at about 105,000 square kilometers (40,541 sq mi). The next largest island is Mindanao at about 95,000 square kilometers (36,680 sq mi). The archipelago is around 800 kilometers (500 mi) from the Asian mainland and is located between Taiwan and Borneo.
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 well as Quezon City, the country's most populous city. With a population of 53 million as of 2015, it contains 52.5% of the country's total population and is the fourth most populous island in the world. It is the 15th largest island in the world by land area.
Seafloor spreading or Seafloor spread is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.
Soccsksargen, formerly known as Central Mindanao, is an administrative region of the Philippines, designated as Region XII. Located in south-central Mindanao, its name is an acronym that stands for the region's four provinces and one highly urbanized city. The regional center is in Koronadal, located in the province of South Cotabato, and the center of commerce and industry is General Santos, which is the most populous city in the region.
Tropical cyclones and subtropical cyclones are named by various warning centers to simplify communication between forecasters and the general public regarding forecasts, watches and warnings. The names are intended to reduce confusion in the event of concurrent storms in the same basin. Once storms develop sustained wind speeds of more than 33 knots, names are generally assigned to them from predetermined lists, depending on the basin in which they originate. Some tropical depressions are named in the Western Pacific; while tropical cyclones must contain a significant amount of gale-force winds before they are named in the Southern Hemisphere.
The Celebes Sea of the western Pacific Ocean is bordered on the north by the Sulu Archipelago and Sulu Sea and Mindanao Island of the Philippines, on the east by the Sangihe Islands chain, on the south by Sulawesi's Minahasa Peninsula, and on the west by northern Kalimantan in Indonesia. It extends 420 miles (675 km) north-south by 520 mi (840 km) east-west and has a total surface area of 110,000 square miles (280,000 km2), to a maximum depth of 20,300 feet (6,200 m). South of the Cape Mangkalihat, the sea opens southwest through the Makassar Strait into the Java Sea.
A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about 2,600 meters (8,500 ft) and rises about 2,000 meters (6,600 ft) above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a divergent plate boundary. The rate of seafloor spreading determines the morphology of the crest of the mid-ocean ridge and its width in an ocean basin.
A typhoon is a mature tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere. This region is referred to as the Northwestern Pacific Basin, and is the most active tropical cyclone basin on Earth, accounting for almost one-third of the world's annual tropical cyclones. For organizational purposes, the northern Pacific Ocean is divided into three regions: the eastern, central, and western. The Regional Specialized Meteorological Center (RSMC) for tropical cyclone forecasts is in Japan, with other tropical cyclone warning centers for the northwest Pacific in Hawaii, the Philippines, and Hong Kong. Although the RSMC names each system, the main name list itself is coordinated among 18 countries that have territories threatened by typhoons each year.
The Izanagi Plate was an ancient tectonic plate, which began subducting beneath the Okhotsk Plate 130–100 Ma years ago. The rapid plate motion of the Izanagi Plate caused north-west Japan and the outer zone of south-west Japan to drift northward. High-pressure metamorphic rocks were formed at the eastern margin of the drifting land mass in the Sanbagawa metamorphic belt, while low-pressure metamorphic rocks were formed at its western margin in the Abukuma metamorphic belt. At approximately 95 Ma, the Izanagi Plate was completely subducted and replaced by the western Pacific Plate, which also subducted in the north-western direction. Subduction-related magmatism took place near the Ryoke belt. No marked tectonics occurred in the Abunkuma belt after the change of the subducted plate.
A back-arc basin is a type of geologic basin, found at some convergent plate boundaries. Presently all back-arc basins are submarine features associated with island arcs and subduction zones, with many found in the western Pacific Ocean. Most of them result from tensional forces, caused by a process known as oceanic trench rollback, where a subduction zone moves towards the subducting plate. Back-arc basins were initially an unexpected phenomenon in plate tectonics, as convergent boundaries were expected to universally be zones of compression. However, in 1970, Dan Karig published a model of back-arc basins consistent with plate tectonics.
Traditionally, areas of tropical cyclone formation are divided into seven basins. These include the north Atlantic Ocean, the eastern and western parts of the northern Pacific Ocean, the southwestern Pacific, the southwestern and southeastern Indian Oceans, and the northern Indian Ocean. The western Pacific is the most active and the north Indian the least active. An average of 86 tropical cyclones of tropical storm intensity form annually worldwide, with 47 reaching hurricane/typhoon strength, and 20 becoming intense tropical cyclones, super typhoons, or major hurricanes.
The Izu–Bonin–Mariana (IBM) arc system is a tectonic plate convergent boundary in Micronesia. The IBM arc system extends over 2800 km south from Tokyo, Japan, to beyond Guam, and includes the Izu Islands, the Bonin Islands, and the Mariana Islands; much more of the IBM arc system is submerged below sealevel. The IBM arc system lies along the eastern margin of the Philippine Sea Plate in the Western Pacific Ocean. It is the site of the deepest gash in Earth's solid surface, the Challenger Deep in the Mariana Trench.
The Mariana Trough is an active back-arc basin in the western Pacific Ocean. It is an integral part of the Izu–Bonin–Mariana Arc system.
The Mariana Plate is a micro tectonic plate located west of the Mariana Trench which forms the basement of the Mariana Islands which form part of the Izu–Bonin–Mariana Arc. It is separated from the Philippine Sea Plate to the west by a divergent boundary with numerous transform fault offsets. The boundary between the Mariana and the Pacific Plate to the east is a subduction zone with the Pacific Plate subducting beneath the Mariana. This eastern subduction is divided into the Mariana Trench, which forms the southeastern boundary, and the Izu–Ogasawara Trench the northeastern boundary. The subduction plate motion is responsible for the shape of the Mariana plate and back arc.
In the geology of the Philippines, the Philippine Mobile Belt is a complex portion of the tectonic boundary between the Eurasian Plate and the Philippine Sea Plate, comprising most of the country of the Philippines. It includes two subduction zones, the Manila Trench to the west and the Philippine Trench to the east, as well as the Philippine Fault System. Within the Belt, a number of crustal blocks or microplates which have been shorn off the adjoining major plates are undergoing massive deformation.
The Lau Basin is a back-arc basin at the Australian-Pacific plate boundary. It is formed by the Pacific plate subducting under the Australian plate. The Tonga-Kermadec Ridge, a frontal arc, and the Lau-Colville Ridge, a remnant arc, sit to the eastern and western sides of the basin, respectively.
Throughout 2006, 133 tropical cyclones formed in seven bodies of water known as tropical cyclone basins. Of these, 80 have been named, including two tropical cyclones in the South Atlantic Ocean, and a tropical cyclone in the Mediterranean Sea, by various weather agencies when they attained maximum sustained winds of 65 km/h (40 mph). The strongest storms of the year were Typhoon Yagi in the Western Pacific, and Cyclone Glenda of the Australian region. The deadliest and costliest storms of the year were a series of five typhoons that struck the Philippines; Chanchu, Bilis, Saomai, Xangsane, and Durian, with most of the damage being caused by Durian of November. Five Category 5 tropical cyclones were formed in 2006.
The West Philippine Basin, is the oceanic crust located underneath the western part of the Philippine Sea. It was formed during the early Oligocene epoch. To its southwest is the Philippine Trench, and to its east is the Kyushu–Palau Ridge. The West Philippine Basin is deeper and older than the eastern basins and has crustal heat-flow values approaching that of old oceanic crust. It is roughly bisected by the Central Basin Fault zone which comprises a band of high relief running from the northwest corner to the Kyushu–Palau Ridge near 14°N. Characterized by the presence of several submarine plateaus.
During 2004, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 132 systems formed with 82 of these developing further and were named by the responsible warning centre. The strongest tropical cyclone of the year was Cyclone Gafilo, which was estimated to have a minimum barometric pressure of 895 hPa (26.43 inHg).
The subduction tectonics of the Philippines is the control of geology over the Philippine archipelago. The Philippine region is seismically active and has been progressively constructed by plates converging towards each other in multiple directions. The region is bounded by subduction zones, where surrounding oceanic plates to the east and west slide towards the centre of the Philippine archipelago. Subduction results in deep oceanic trenches, such as the Philippine Trench and Manila Trench, bounding the eastern and western sides of the Philippine archipelago, respectively. The Philippine archipelago is also cut along its length by a left-lateral strike-slip fault known as the Philippine Fault. The region is also known as the Philippine mobile belt due to its complex tectonic setting.