Tehuantepec Ridge

Last updated
Tehuantepec Ridge
Approximate surface projection on Pacific Ocean of the Tehuantepec Ridge (orange). To its north-west off the coast of Mexico is the O’Gorman fracture zone (also orange). It is subducting under the Middle America Trench (white). Click to expand map to obtain interactive details.'"`UNIQ--ref-00000000-QINU`"'

The Tehuantepec Ridge (Tehuantepec Fracture Zone, Tehuntepec Ridge) [1] is a linear undersea ridge located off the west coast of Mexico in the Pacific Ocean. It is the remnant of an old fracture zone, and not a tectonic spreading center ridge (see mid-ocean ridge). It extends from the eastern end of the Clipperton fracture zone northeastward toward Mexico into Chiapas and El Chichón [2] until it is subducted into the Middle America Trench. It lies within the tectonic Cocos plate, separating the lower and older seafloor of the Guatemala Basin which lies southeast of the ridge from higher and younger seafloor which lies to its north-west.

Current research indicates that the ridge was formed as a fracture zone and transform fault along the East Pacific Rise. As a result of a change in the motion of the Pacific plate about 13 million years ago, there was also a change in the orientation of the East Pacific Rise, which in turn reoriented the fracture zone, creating the current alignment that is today's Clipperton Fracture Zone. The Tehuantepec Ridge preserves the previous orientation. To its north the O’Gorman Fracture Zone has a similar orientation.

Some researchers have hypothesized that the subducted portion of the Tehuantepec Ridge under Mexico is responsible for the existence of El Chichón volcano as well as the other volcanoes of what is called the Chiapanecan Volcanic Arc. Studies of the 1982 eruption of El Chichón indicated its erupted output was unusual compared to other volcanoes in the Trans-Mexican Volcanic Belt which lies well to the northwest. The anomaly is thought to result from the distinctive composition of the rocks which comprise the Tehuantepec Ridge. [3] [4]

12°21′40.8″N97°46′21.5″W / 12.361333°N 97.772639°W / 12.361333; -97.772639 [1]

Related Research Articles

<span class="mw-page-title-main">Subduction</span> A geological process at convergent tectonic plate boundaries where one plate moves under the other

Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second plate, the heavier plate dives beneath the other 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 rates of convergence as high as 11 cm/year.

<span class="mw-page-title-main">Transform fault</span> Plate boundary where the motion is predominantly horizontal

A transform fault or transform boundary, is a fault along a plate boundary where the motion is predominantly horizontal. It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subduction zone. A transform fault is a special case of a strike-slip fault that also forms a plate boundary.

<span class="mw-page-title-main">Coast Mountains</span> Mountain range in Canada and the United States

The Coast Mountains are a major mountain range in the Pacific Coast Ranges of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Columbia south to the Fraser River. The mountain range's name derives from its proximity to the sea coast, and it is often referred to as the Coast Range. The range includes volcanic and non-volcanic mountains and the extensive ice fields of the Pacific and Boundary Ranges, and the northern end of the volcanic system known as the Cascade Volcanoes. The Coast Mountains are part of a larger mountain system called the Pacific Coast Ranges or the Pacific Mountain System, which includes the Cascade Range, the Insular Mountains, the Olympic Mountains, the Oregon Coast Range, the California Coast Ranges, the Saint Elias Mountains and the Chugach Mountains. The Coast Mountains are also part of the American Cordillera—a Spanish term for an extensive chain of mountain ranges—that consists of an almost continuous sequence of mountain ranges that form the western backbone of North America, Central America, South America and Antarctica.

<span class="mw-page-title-main">Ring of Fire</span> Region around the rim of the Pacific Ocean where many volcanic eruptions and earthquakes occur

The Ring of Fire is a tectonic belt of volcanoes and earthquakes.

<span class="mw-page-title-main">North American plate</span> Large tectonic plate including most of North America, Greenland and part of Siberia

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.

<span class="mw-page-title-main">Cocos plate</span> Young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America

The Cocos plate is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. The Cocos plate was created approximately 23 million years ago when the Farallon plate broke into two pieces, which also created the Nazca plate. The Cocos plate also broke into two pieces, creating the small Rivera plate. The Cocos plate is bounded to the northeast by the North American plate and the Caribbean plate. To the west it is bounded by the Pacific plate and to the south by the Nazca plate.

<span class="mw-page-title-main">Trans-Mexican Volcanic Belt</span> Active volcanic belt that covers central-southern Mexico

The Trans-Mexican Volcanic Belt, also known as the Transvolcanic Belt and locally as the Sierra Nevada, is an active volcanic belt that covers central-southern Mexico. Several of its highest peaks have snow all year long, and during clear weather, they are visible to a large percentage of those who live on the many high plateaus from which these volcanoes rise.

<span class="mw-page-title-main">East Pacific Rise</span> Mid-oceanic ridge at a divergent tectonic plate boundary on the floor of the Pacific Ocean

The East Pacific Rise (EPR) is a mid-ocean rise, at a divergent tectonic plate boundary, located along the floor of the Pacific Ocean. It separates the Pacific plate to the west from the North American plate, the Rivera plate, the Cocos plate, the Nazca plate, and the Antarctic plate. It runs south from the Gulf of California in the Salton Sea basin in Southern California to a point near 55°S130°W, where it joins the Pacific-Antarctic Ridge (PAR) trending west-south-west towards Antarctica, near New Zealand. Much of the rise lies about 3,200 km (2,000 mi) off the South American coast and reaches a height about 1,800–2,700 m (5,900–8,900 ft) above the surrounding seafloor.

<span class="mw-page-title-main">Caribbean plate</span> A mostly oceanic tectonic plate including part of Central America and the Caribbean Sea

The Caribbean plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the northern coast of South America.

<span class="mw-page-title-main">El Chichón</span> Volcano in Chiapas, Mexico

El Chichón, also known as Chichonal, is an active volcano in Francisco León, north-western Chiapas, Mexico. El Chichón is part of a geologic zone known as the Chiapanecan Volcanic Arc. El Chichón is a stratovolcano with a complex of domes with a tuff ring, made of ejected volcanic material, located between the Trans-Mexican Volcanic Belt and the Central America Volcanic Arc. El Chichón erupted in 1982; prior to this, activity had not occurred since c.1360, with a possible eruption c.1850.

<span class="mw-page-title-main">Back-arc basin</span> Submarine features associated with island arcs and subduction zones

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.

<span class="mw-page-title-main">Explorer Ridge</span> Mid-ocean ridge west of British Columbia, Canada

The Explorer Ridge is a mid-ocean ridge, a divergent tectonic plate boundary located about 241 km (150 mi) west of Vancouver Island, British Columbia, Canada. It lies at the northern extremity of the Pacific spreading axis. To its east is the Explorer plate, which together with the Juan de Fuca plate and the Gorda plate to its south, is what remains of the once-vast Farallon plate which has been largely subducted under the North American plate. The Explorer Ridge consists of one major segment, the Southern Explorer Ridge, and several smaller segments. It runs northward from the Sovanco fracture zone to the Queen Charlotte triple junction, a point where it meets the Queen Charlotte Fault and the northern Cascadia subduction zone.

<span class="mw-page-title-main">Andean Volcanic Belt</span> Volcanic belt in South America

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.

<span class="mw-page-title-main">Izu–Bonin–Mariana Arc</span> Convergent boundary in Micronesia

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.

<span class="mw-page-title-main">Outline of oceanography</span> Hierarchical outline list of articles related to oceanography

The following outline is provided as an overview of and introduction to Oceanography.

This is a list of articles related to plate tectonics and tectonic plates.

<span class="mw-page-title-main">Lau Basin</span> Oceanic basin in the South Pacific Ocean between Fiji and Tonga

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. The basin has a raised transition area to the south where it joins the Havre Trough.

<span class="mw-page-title-main">Geology of the Pacific Ocean</span>

The Pacific Ocean evolved in the Mesozoic from the Panthalassic Ocean, which had formed when Rodinia rifted apart around 750 Ma. The first ocean floor which is part of the current Pacific plate began 160 Ma to the west of the central Pacific and subsequently developed into the largest oceanic plate on Earth.

The Vanuatu subduction zone is currently one of the most active subduction zones on Earth, producing great earthquakes, with potential for tsunami hazard to all coastlines of the Pacific Ocean. There are active volcanoes associated with arc volcanism.

References

  1. 1 2 "Marine Gazetteer:Tehuantepec Fracture Zone" . Retrieved 11 January 2024.
  2. Manea, Marina; Manea, Vlad C. (2008-08-20). "On the origin of El Chichón volcano and subduction of Tehuantepec Ridge: A geodynamical perspective". Journal of Volcanology and Geothermal Research. 175 (4): 459–471. Bibcode:2008JVGR..175..459M. doi:10.1016/j.jvolgeores.2008.02.028.
  3. Vlad C. Manea and Marina Manea, 2005, The Origin Of Modern Chiapanecan Volcanic Arc In Southern Mexico Inferred From Thermal Models, http://www.geo.mtu.edu/~raman/papers2/Manea_Chiapas_2005.pdf 2.2mb
  4. Rose, William Ingersoll (2006-01-01). Volcanic Hazards in Central America. Geological Society of America. ISBN   978-0-8137-2412-6.

Further reading