Magnitude 5.9 Earthquake to the northeast of the Dominican Republic.

The United States Geological Survey recorded a Magnitude 5.9 Earthquake at a depth of 46 km roughly 109 km to the northeast of the Dominican Republic, slightly before 1.50 am local time (slightly before 5.50 am GMT) on Tuesday 25 February 2025. There are no reports of any damage or injuries associated with this event, and nor was a tsunami warning issued but people have reported feeling it across the eastern Dominican Republic as well as on Puerto Rico.

The approximate location of the 25 February 2025 Puerto Rico Earthquake. USGS.

The Dominican Republic forms the eastern part of the island of La Hispaniola, in the Greater Antilles.  The island has a complex geological structure, with parts of it lying on three different tectonic plates, and two plate margins running east-to-west across the island. The northernmost part of the island lies on the North American Plate. This is divided from the Gonâve Microplate by the Septentrional Fault Zone, which runs through Rio San Juan, along the north coast of the Dominican Republic and Haiti, then across the Windward Passage and along the south coast of Cuba. The Gonâve Microplate is moving east relative to the North American Plate, pushed by the Mid-Cayman Spreading centre to the west of Jamaica. To the south the Gonâve Microplate is separated from the Caribbean Plate by the Enriquilo-Plantain Garden Fault Zone, which runs across Southern Haiti and the Dominican Republic. To the west the fault runs through central Jamaica. The Caribbean Plate is rotating clockwise, effectively moving east relative to the Gonâve Microplate.

Plate movements and fault zones around the Gonâve Microplate. Mike Norton/Wikimedia Commons.

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Magnitude 6.1 earthquake off the south coast of Cuba.

The National Seismological Research Service of Cuba recorded a Magnitude 6.1 Earthquake at a depth of 9 km, about 35 km off the south coast of Cuba at about 1.00 am local time (about 6.00 am GMT) on Monday 23 December 2024. The event was felt across eastern Cuba, Jamaica, and the Cayman Islands, and while there are no reports of any injuries, minor damage to buildings has been reported from across eastern Cuba, and several roads were blocked by landslides triggered by the Earthquake.

The approximate location of the 23 January 2024 Cuba Earthquake. USGS.

Cuba lies on the southern portion of the North American Plate, to the north of the Septentrional Fault Zone, which forms the boundary with the Gonâve Microplate, a small tectonic plate underlying northern Jamaica and most of the island of Hispaniola. The Gonâve Microplate is moving east relative to the North American Plate, pushed by the Mid-Cayman Spreading centre to the west of Jamaica.

To the south the Gonâve Microplate is separated from the Caribbean Plate by the Enriquilo-Plantain Garden Fault Zone, which runs across Southern Haiti and the Dominican Republic. To the west the fault runs through central Jamaica. The Caribbean Plate is rotating clockwise, effectively moving east relative to the Gonâve Microplate.

Plate movements and fault zones around the Gonâve Microplate. Mike Norton/Wikimedia Commons.

None of these movements are smooth, with rock formations at the boundaries of the plates constantly sticking together then breaking apart as the pressure from the plate movement builds up, triggering Earthquakes in the process.

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Magnitude 5.2 Earthquake in Kern County, California.

The United States Geological Survey recorded a Magnitude 5.2 Earthquake at a depth of about 11.7 km roughly 23 km to the southwest of Lamont in Kern County, California, slightly before 9.10 pm local time on Tuesday 6 August 2024 (slightly before 4.10 am on Wednesday 7 August, GMT). There are no reports of any damage or injuries relating to this quake, but people have reported feeling it across much of southern California.

The approximate location of the 6 August 2024 County Earthquake. USGS.

California is extremely prone to Earthquakes due to the presence of the San Andreas Fault, a tectonic plate margin that effectively bisects the state. The west of California, including Santa Barbara and Los Angeles, is located on the Pacific Plate, and is moving to the northwest. The east of California, including Fresno and Bakersfield is on the North American Plate, and is moving to the southeast. The plates do not move smoothly past one-another, but constantly stick together then break apart as the pressure builds up. This has led to a network of smaller faults that criss-cross the state, so that Earthquakes can effectively occur anywhere.

Tectonic boundaries and faults in California and the surrounding area. USGS.

Witness accounts of Earthquakes can help geologists to understand these events and the underlying structures that cause them. If you felt this quake (or if you were in the area but did not, which is also useful information) then you can report it to the United States Geological Survey here.

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Magnitude 6.4 Earthquake off the coast of the Mexico/Guatemala border.

The United States Geological Survey recorded a Magnitude 6.4 Earthquake at a depth of 75.4 km, approximately 17 km off the south coast of the border between Mexico and Guatemala, slightly before 5.40 am local time (slightly before 11.40 am GMT) on Sunday 12 May 2024. This even was felt across much of southern Guatemala, and Chiapas State, Mexico, and triggered a number of small landslides as well as minor damage to some buildings, but there are no reports of any injuries.

The approximate location of the 12 May 2024 Mexico/Guatemala Earthquake. Contour lines show rates of movement during the quake, the red line is the Middle American Trench. USGS.

Mexico is located on the southernmost part of the North American Plate. To the south, along the Middle American Trench, which lies off the southern coast off Mexico, the Cocos Plate is being subducted under the North American Plate, passing under southern Mexico as it sinks into the Earth. Guatemala is located on the southern part of the Caribbean Plate, close to its boundary with the Cocos Plate, which underlies part of the east Pacific. The Cocos Plate is being pushed northwards by expansion of the crust along the East Pacific Rise, and is subducted beneath the Caribbean Plate along the Middle American Trench. This is not a smooth process, and the plates frequently stick together then break apart as the pressure builds up, causing Earthquakes on the process. 

The position of the Cocos, Nazca and Rivera Plates. MCEER/University at Buffalo.

The Cocos Plate is thought to have formed about 23 million years ago, when the Farallon Plate, an ancient tectonic plate underlying the East Pacific, split in two, forming the Cocos Plate to the north and the Nazca Plate to the south. Then, roughly 10 million years ago, the northwesternmost part of the Cocos Plate split of to form the Rivera Plate, south of Beja California.

In a paper published in the Journal of Geophysical Research, in 2012, a team led by Igor Stubailo of the Department of Earth and Space Sciences at the University of California Los Angeles, published a model of the subduction zone beneath Mexico using data from seismic monitoring stations belonging to the Mesoamerican Seismic Experiment, the Network of Autonomously Recording Seismographs, the USArray, Mapping the Rivera Subduction Zone and the Mexican Servicio Sismologico Nacional.

The seismic monitoring stations were able to monitor not just Earthquakes in Mexico, but also Earthquakes in other parts of the world, monitoring the rate at which compression waves from these quakes moved through the rocks beneath Mexico, and how the structure of the rocks altered the movement of these waves.

Based upon the results from these monitoring stations, Stubailo et al. came to the conclusion that the Cocos Plate was split into two beneath Mexico, and that the two plates are subducting at different angles, one steep and one shallow. Since the rate at which a plate melts reflects its depth within the Earth, the steeper angled plate melts much closer to the subduction zone than the shallower angled plate, splitting the Trans-Mexican Volcanic Belt into sections above the different segments of the Cocos Plate, and causing it to apparently curve away from the subduction zone.

Top the model of the Cocos Plate beneath Mexico, split into two sections (A & B) subducting at differing angles. (C) Represents the Rivera Plate, subducting at a steeper angle than either section of the Cocos Plate. The Split between the two has been named the Orozco Fracture Zone (OFZ) which is shown extended across the Cocos Plate; in theory this might in future split the Cocos Plate into two segments (though not on any human timescale). Bottom Left, the position of the segments on a map of Mexico. Darker area is the Trans-Mexican Volcanic Belt, orange circles are volcanoes, brown triangles are seismic monitoring stations, yellow stars are major cities. Bottom Right, an alternative model showing the subducting plate twisted but not split. This did not fit the data. Stubailo et al. (2012).

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Eruptions on Mount Popocatépetl.

Mount Popocatépetl, a 3020 m high stratovolcano (cone-shaped volcano made up of layers of ash and lava) about 70 km from Mexico City in the eastern Trans-Mexican Volcanic Belt, began suffering regular seismic events (small Earthuakes associated with the movement of magma in chambers beneath the volcano) on 14 February 2024, followed by a series of eruptions which produced ash columns up to 6 km high, which drifted to the north, northeast, and south. Ashfalls were reported in the municipalities of Nativitas, Santa Isabel, Tetlatlahuaca, Tlaxcala, Santa Ana Chiautempan, and Zacatelco, and Hermanos Serdán International Airport, was forced to be closed while ash was cleared from its runways. Earthquakes and smaller eruptions persisted for the nest week, with an ashfall again reported in the municipality of Hueyapan on 19 February. A 12 km exclusion zone around the volcano has been declared as a precaution.

An eruption on Mount Popocatépetl seen from Puebla. Daniel Llerandi/BBC.

Popocatépetl has been more or less constantly erupting since the mid 1990s, but most of the time this activity remains at a low level. Major eruptions on Popocatépetl are a cause for concern as the volcano is in a densely populated area, with 30 million people living within the potential hazard zone. The last major eruption, a Plinian (or Vesuvian) event in about 800 AD, triggered a series of pyroclastic flows and lahars that scoured the basins around the volcano.

The volcanoes of the Trans-Mexican Volcanic Belt are fuelled by the subduction of the Cocos Plate beneath the North American Plate along the Middle American Trench to the south of Mexico. As the subducting plate sinks into the Earth it is melted by the heat and pressure, and volatile minerals liquefy and rise through the overlying North American Plate as magma, fuelling Mexico's volcanoes. 

The subduction of the Cocos Plate beneath the North American Plate in Mexico, and how it leads to volcanoes and Earthquakes. King Saud University.

The Cocos Plate is thought to have formed about 23 million years ago, when the Farallon Plate, an ancient tectonic plate underlying the East Pacific, split in two, forming the Cocos Plate to the north and the Nazca Plate to the south. Then, roughly 10 million years ago, the northwesternmost part of the Cocos Plate split of to form the Rivera Plate, south of Beja California.

The position of the Cocos, Nazca and Rivera Plates. MCEER/University at Buffalo.

In a paper published in the Journal of Geophysical Research: Solid Earth, in 2011, a team led by Igor Stubailo of the Department of Earth and Space Sciences at the University of California Los Angeles, published a model of the subduction zone beneath Mexico using data from seismic monitoring stations belonging to the Mesoamerican Seismic Experiment, the Network of Autonomously Recording Seismographs, the USArray, Mapping the Rivera Subduction Zone and the Mexican Servicio Sismologico Nacional.

The seismic monitoring stations were able to monitor not just Earthquakes in Mexico, but also Earthquakes in other parts of the world, monitoring the rate at which compression waves from these quakes moved through the rocks beneath Mexico, and how the structure of the rocks altered the movement of these waves.

Based upon the results from these monitoring stations, Stubailo et al. came to the conclusion that the Cocos Plate was split into two beneath Mexico, and that the two plates are subducting at different angles, one steep and one shallow. Since the rate at which a plate melts reflects its depth within the Earth, the steeper angled plate melts much closer to the subduction zone than the shallower angled plate, splitting the Trans-Mexican Volcanic Belt into sections above the different segments of the Cocos Plate, and causing it to apparently curve away from the subduction zone.

Top the new model of the Cocos Plate beneath Mexico, split into two sections (A & B) subducting at differing angles. (C) Represents the Rivera Plate, subducting at a steeper angle than either section of the Cocos Plate. The Split between the two has been named the Orozco Fracture Zone (OFZ) which is shown extended across the Cocos Plate; in theory this might in future split the Cocos Plate into two segments (though not on any human timescale). Bottom Left, the position of the segments on a map of Mexico. Darker area is the Trans-Mexican Volcanic Belt, orange circles are volcanoes, brown triangles are seismic monitoring stations, yellow stars are major cities. Bottom Right, an alternative model showing the subducting plate twisted but not split. This did not fit the data. Stubailo et al. (2012).

See also...