The North American plate is a tectonic plate containing most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of 76 million km2 (29 million sq mi), it is the Earth's second largest tectonic plate, behind the Pacific plate.
Windward Passage is a strait in the Caribbean Sea, between the islands of Cuba and Hispaniola. The strait specifically lies between the easternmost region of Cuba and the northwest of Haiti. 80 km (50 mi) wide, the Windward Passage has a threshold depth of 1,700 m (5,600 ft).
The Cascadia subduction zone is a 960 km (600 mi) fault at a convergent plate boundary, about 100–200 km (70–100 mi) off the Pacific coast, that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is capable of producing 9.0+ magnitude earthquakes and tsunamis that could reach 30 m (98 ft). The Oregon Department of Emergency Management estimates shaking would last 5–7 minutes along the coast, with strength and intensity decreasing further from the epicenter. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, and Gorda plates move to the east and slide below the much larger mostly continental North American plate. The zone varies in width and lies offshore beginning near Cape Mendocino, Northern California, passing through Oregon and Washington, and terminating at about Vancouver Island in British Columbia.
The Puerto Rico Trench is located on the boundary between the North Atlantic Ocean and Caribbean Sea, parallel to and north of Puerto Rico, where the oceanic trench reaches the deepest points in the Atlantic Ocean. The trench is associated with a complex transition from the Lesser Antilles frontal subduction zone between the South American Plate and Caribbean Plate to the oblique subduction zone and the strike-slip transform fault zone between the North American Plate and Caribbean Plate, which extends from the Puerto Rico Trench at the Puerto Rico–Virgin Islands microplate through the Cayman Trough at the Gonâve Microplate to the Middle America Trench at the Cocos Plate.
The Caribbean plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the northern coast of South America.
The Aleutian Trench is an oceanic trench along a convergent plate boundary which runs along the southern coastline of Alaska and the Aleutian islands. The trench extends for 3,400 kilometres (2,100 mi) from a triple junction in the west with the Ulakhan Fault and the northern end of the Kuril–Kamchatka Trench, to a junction with the northern end of the Queen Charlotte Fault system in the east. It is classified as a "marginal trench" in the east as it runs along the margin of the continent. The subduction along the trench gives rise to the Aleutian Arc, a volcanic island arc, where it runs through the open sea west of the Alaska Peninsula. As a convergent plate boundary, the trench forms part of the boundary between two tectonic plates. Here, the Pacific plate is being subducted under the North American plate at a dip angle of nearly 45°. The rate of closure is 7.5 centimetres (3 in) per year.
The Mona Passage is a strait that separates the islands of Hispaniola and Puerto Rico. The Mona Passage connects the Atlantic Ocean to the Caribbean Sea and is an important shipping route between the Atlantic and the Panama Canal.
The Geology of Puerto Rico can be divided into three major geologic provinces: The Cordillera Central, the Carbonate, and the Coastal Lowlands. Puerto Rico is composed of Jurassic to Eocene volcanic and plutonic rocks, which are overlain by younger Oligocene to recent carbonates and other sedimentary rocks. Most of the caverns and karst topography on the island occurs in the northern Oligocene to recent carbonates. The oldest rocks are approximately 190 million years old (Jurassic) and are located at Sierra Bermeja in the southwest part of the island. These rocks may represent part of the oceanic crust and are believed to come from the Pacific Ocean realm.
The 1918 San Fermín earthquake, also known as the Puerto Rico earthquake of 1918, struck the island of Puerto Rico at on October 11. The earthquake measured 7.1 on the moment magnitude scale and IX (Violent) on the Mercalli intensity scale. The mainshock epicenter occurred off the northwestern coast of the island, somewhere along the Puerto Rico Trench.
The Enriquillo–Plantain Garden fault zone is a system of active coaxial left lateral-moving strike slip faults which runs along the southern side of the island of Hispaniola, where Haiti and the Dominican Republic are located. The EPGFZ is named for Lake Enriquillo in the Dominican Republic where the fault zone emerges, and extends across the southern portion of Hispaniola through the Caribbean to the region of the Plantain Garden River in Jamaica.
The 1787 Boricua earthquake struck offshore of the island of Puerto Rico on May 2. The magnitude of the earthquake was believed to have been around 8.0–8.25, however there is evidence that it was only about 6.9. The epicenter is thought to have been somewhere north of Puerto Rico, probably on the Puerto Rico Trench. Puerto Rican geomorphologist José Molinelli considers it "the strongest" in the seismic history of the country.
The 1842 Cap-Haïtien earthquake occurred at 17:00 local time on 7 May. It had an estimated magnitude of 8.1 on the scale and triggered a destructive tsunami. It badly affected the northern coast of Haiti and part of what is now the Dominican Republic. Port-de-Paix suffered the greatest damage from both earthquake and tsunami. Approximately 5,000 people were killed by the effects of the earthquake shaking and another 300 by the tsunami.
Starting on December 28, 2019, and progressing into 2020, the southwestern part of the island of Puerto Rico was struck by an earthquake swarm, including 11 that were of magnitude 5 or greater. The largest and most damaging of this sequence was a magnitude 6.4 , which occurred on January 7 at 04:24 AST (08:24 UTC), with a maximum felt intensity of VIII (Severe) on the Modified Mercalli intensity scale. At least one person was killed, and several others were injured.
The 1867 Virgin Islands earthquake and tsunami occurred on November 18, at 14.45 in the Anegada Passage about 20 km southwest of Saint Thomas, Danish West Indies. The Ms 7.5 earthquake came just 20 days after the devastating San Narciso Hurricane in the same region. Tsunamis from this earthquake were some of the highest ever recorded in the Lesser Antilles. Wave heights exceeded 10 m (33 ft) in some islands in the Lesser Antilles. The earthquake and tsunami resulted in no more than 50 fatalities, although hundreds of casualties were reported.
The 1900 Venezuelan earthquake also known as the San Narciso earthquake, occurred on October 28 at between 4:30 and 4:45 am local time. This earthquake had an epicenter off Miranda State or near the Venezuelan capital Caracas, in the Cariaco Basin. It had an estimated moment magnitude of 7.6–7.7 and a surface-wave magnitude of 7.7–8.4. It had a maximum Mercalli intensity assigned VIII–X, causing landslides and liquefaction events. Many buildings were severely damaged or collapsed during the earthquake. It is thought to be the last great earthquake of the 19th century and the largest instrumentally recorded in the republic, having been felt throughout.
An earthquake occurred off the coast of the Alaska Peninsula on July 28, 2021, at 10:15 p.m. local time. The large megathrust earthquake had a moment magnitude of 8.2 according to the United States Geological Survey (USGS). A tsunami warning was issued by the National Oceanic and Atmospheric Administration (NOAA) but later cancelled. The mainshock was followed by a number of aftershocks, including three that were of magnitude 5.9, 6.1 and 6.9 respectively.
The 2010 Aguas Buenas earthquake, also referred to as the 2010 Christmas Eve earthquake, occurred on December 24 at 7:43 p.m. local time in Aguas Buenas, Puerto Rico. It measured 5.1 on the moment magnitude scale and had a maximum Mercalli intensity of VI (Strong). The event was the largest in Puerto Rico since May 16th of the same year, and the largest to impact the San Juan metropolitan area since 1975. The earthquake was felt throughout the island of Puerto Rico, the island municipalities of Vieques and Culebra, the American and British Virgin Islands, and even in the Dominican Republic across the Mona Passage.
The 2010 Moca earthquake, also referred to as the 2010 Puerto Rico earthquake, occurred on May 16 at 1:16 a.m. local time in Moca, Puerto Rico. The earthquake measured 5.8 on the moment magnitude scale and had a maximum Mercalli intensity of VI (Strong). This was the largest earthquake to strike Puerto Rico since the 1943 Puerto Rico earthquake which measured 7.7 on the Richter scale. This was also the first moderate to major earthquake in recorded history to originate on land in Puerto Rico, as earthquakes in the region usually have their epicenter in the ocean; another earthquake with an epicenter on land would occur later in December of the same year.
Mona Canyon, also known as the Mona Rift, is an 87-mile long (140 km) submarine canyon located in the Mona Passage, between the islands of Hispaniola and Puerto Rico, with steep walls measuring between 1.25 and 2.17 miles (2-3.5 km) in height from bottom to top. The Mona Canyon stretches from the Desecheo Island platform, specifically the Desecheo Ridge, in the south to the Puerto Rico Trench, which contains some of the deepest points in the Atlantic Ocean, in the north. The canyon is also particularly associated with earthquakes and subsequent tsunamis, with the 1918 Puerto Rico earthquake having its epicenter in the submarine canyon.
The Puerto Rico–Virgin Islands microplate (PRVI), also known as the Puerto Rico–Virgin Islands block, is a tectonic microplate formed at the boundary zone between the Caribbean plate and the obliquely subducting North American plate.
