Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries.
The Lesser Antilles are a group of islands in the Caribbean Sea. Most of them are part of a long, partially volcanic island arc between the Greater Antilles to the north-west and the continent of South America. The islands of the Lesser Antilles form the eastern boundary of the Caribbean Sea where it meets the Atlantic Ocean. Together, the Lesser Antilles and the Greater Antilles make up the Antilles. The Lesser and Greater Antilles, together with the Lucayan Archipelago, are collectively known as the West Indies.
The Ring of Fire is a region around much of the rim of the Pacific Ocean where many volcanic eruptions and earthquakes occur. The Ring of Fire is a horseshoe-shaped belt about 40,000 km (25,000 mi) long and up to about 500 km (310 mi) wide.
Mount Pelée or Mont Pelée is an active volcano at the northern end of Martinique, an island and French overseas department in the Lesser Antilles Volcanic Arc of the Caribbean. Its volcanic cone is composed of stratified layers of hardened ash and solidified lava. Its most recent eruption was in 1932.
Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle along the subduction zone. They are the principal way by which continental growth is achieved.
The Soufrière Hills are an active, complex stratovolcano with many lava domes forming its summit on the Caribbean island of Montserrat. After a long period of dormancy, the Soufrière Hills volcano became active in 1995 and has continued to erupt ever since. Its eruptions have rendered more than half of Montserrat uninhabitable, destroying the capital city, Plymouth, and causing widespread evacuations: about two-thirds of the population have left the island. Chances Peak in the Soufrière Hills was the highest summit on Montserrat until the mid-1990s, but it has since been eclipsed by various rising and falling volcanic domes during the recent volcanic activity.
A volcanic arc is a belt of volcanoes formed above a subducting oceanic tectonic plate, with the belt arranged in an arc shape as seen from above. Volcanic arcs typically parallel an oceanic trench, with the arc located further from the subducting plate than the trench. The oceanic plate is saturated with water, mostly in the form of hydrous minerals such as micas, amphiboles, and serpentine minerals. As the oceanic plate is subducted, it is subjected to increasing pressure and temperature with increasing depth. The heat and pressure break down the hydrous minerals in the plate, releasing water into the overlying mantle. Volatiles such as water drastically lower the melting point of the mantle, causing some of the mantle to melt and form magma at depth under the overriding plate. The magma ascends to form an arc of volcanoes parallel to the subduction zone.
The Sunda Arc is a volcanic arc that produced the volcanoes that form the topographic spine of the islands of Sumatra, Nusa Tenggara, and Java, the Sunda Strait and the Lesser Sunda Islands. The Sunda Arc begins at Sumatra and ends at Flores, and is adjacent to the Banda Arc. The Sunda Arc is formed via the subduction of the Indo-Australian Plate beneath the Sunda and Burma plates at a velocity of 63–70 mm/year.
La Soufrière or Soufrière Saint Vincent is an active stratovolcano on the Caribbean island of Saint Vincent in Saint Vincent and the Grenadines. It is the highest peak in Saint Vincent, and has had five recorded explosive eruptions since 1718. The latest eruptive activity began in December 2020, with a series of explosive events beginning in April 2021.
The Caribbean Plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the north coast of South America.
The Central American Volcanic Arc is a chain of volcanoes which extends parallel to the Pacific coastline of the Central American Isthmus, from Mexico to Panama. This volcanic arc, which has a length of 1,100 kilometers is formed by an active subduction zone, with the Cocos Plate subducting underneath the Caribbean Plate. The region has been volcanically and geologically active for at least the past several million years. Numerous volcanoes are spread throughout various Central American countries; many have been active in the geologic past, some more so than others.
Guadeloupe is an archipelago of more than 12 islands, as well as islets and rocks situated where the northeastern Caribbean Sea meets the western Atlantic Ocean. It is located in the Leeward Islands in the northern part of the Lesser Antilles, a partly volcanic island arc. To the north lie Antigua and Barbuda and the British Overseas Territory of Montserrat, with Dominica lying to the south.
The West Indies is a subregion of North America, surrounded by the North Atlantic Ocean and the Caribbean Sea that includes 13 independent island countries and 18 dependencies and other territories in three major archipelagos: the Greater Antilles, the Lesser Antilles, and the Lucayan Archipelago.
The Leeward Antilles are a chain of islands in the Caribbean – specifically, the southerly islands of the Lesser Antilles along the southeastern fringe of the Caribbean Sea, just north of the Venezuelan coast of the South American mainland. The Leeward Antilles, while among the Lesser Antilles, are not to be confused with the Leeward Islands to the northeast.
The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca Plate and Antarctic Plate underneath the South American Plate. The belt is subdivided into four main volcanic zones which are separated by volcanic gaps. The volcanoes of the belt are diverse in terms of activity style, products, and morphology. While some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences within volcanic zones and even between neighboring volcanoes. Despite being a type location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a broad range of volcano-tectonic settings, as it has rift systems and extensional zones, transpressional faults, subduction of mid-ocean ridges and seamount chains as well as a large range of crustal thicknesses and magma ascent paths and different amounts of crustal assimilations.
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 Lesser Antilles subduction zone is a convergent plate boundary on the seafloor along the eastern margin of the Lesser Antilles Volcanic Arc. In this subduction zone, oceanic crust of the South American Plate is being subducted under the Caribbean Plate.
The 2004 Les Saintes earthquake occurred at on November 21, 2004 with a moment magnitude of 6.3 and maximum European macroseismic intensity of VIII. The shock was named for Îles des Saintes "Island of the Saints", a small island to the south of Guadeloupe, which is an overseas department of France. Although it occurred near the Lesser Antilles subduction zone, this was an intraplate, normal fault event. It resulted in one death, 13 injuries, and 40 people being made homeless, but the overall damage was considered moderate. A small, nondestructive tsunami was reported, but run-up and inundation distances were difficult to measure due to a storm that occurred on the day of the event. Unusual effects at a volcanic lake on Dominica were also documented, and an aftershock caused additional damage three months later.
The Grenada Basin is an 11–15 km thick back-arc sedimentary basin located in the southeastern region of the Caribbean Sea. It is bordered by the Lesser Antilles in the north, south, and east, and the Aves Ridge in the west.
The 1839 Martinique earthquake occurred on the morning of January 11 with an estimated magnitude of 7.8 Ms , the largest in the Lesser Antilles since 1690. The maximum intensity of this earthquake was assigned IX on both the Mercalli and MSK intensity scales, which left the cities of Saint-Pierre and Fort Royal almost completely destroyed. Estimation on the number of human losses varies from 390 to even 4,000 making this one of the deadliest earthquakes in the Caribbean.
