Tanganasoga is the main

volcano A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most oft ...

El Hierro El Hierro (), nicknamed ''Isla del Meridiano'' (the "Meridian Island"), is the farthest south and west of the Canary Islands (an autonomous community of Spain), in the Atlantic Ocean off the coast of Africa, with a population of 11,659 (2023). ...

's El Golfo area in the

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

, consisting of a

cinder cone A cinder cone or scoria cone is a steep, volcanic cone, conical landform of loose pyroclastic rock, pyroclastic fragments, such as volcanic ash, clinkers, or scoria that has been built around a volcanic vent. The pyroclastic fragments are forme ...

. The volcano is part of a much larger

shield volcano A shield volcano is a type of volcano named for its low profile, resembling a shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava ...

system.

The volcano

El Hierro is a 278.5 km² island, formed approx 1.2 million year ago after three successive eruptions, the island emerged from the ocean as a triangle of

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

ic dykes topped with a

volcanic A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often fo ...

cone more than 2,000 metres high. With continued activity resulting in the island expanding to have the largest number of

es in the Canaries (over 500 cones, another 300 covered by more recent deposits), together with approximately 70 caves and volcanic galleries, including the

Cueva de Don Justo The Cueva de Don Justo (or Cave of Don Justo) is one of approximately 70 caves and volcanic galleries on the island of El Hierro in the Canaries. The Cueva de Don Justo is over in length, the cave is located in the El Lajial pahoehoe lava field ...

whose collection of channels is over 6 km in length.

Landslides Landslides, also known as landslips, rockslips or rockslides, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslide ...

have reduced the size and height of the island. Tanganasoga is now the main volcano on the island.

Landslides

There is evidence of at least three major gravitational landslides that have affected El Hierro in the last few hundred thousand years. The most recent of these was the 'El Golfo' landslide that occurred about 15 thousand years ago, involving collapse of the northern flank of the island. The landslide formed the El Golfo valley and created a debris avalanche with a volume of 150–180 km³.

Turbidite A turbidite is the geologic Deposition (geology), deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean. Sequencing ...

deposits related to this landslide have been recognized in drill cores from the Agadir Basin to the north of the Canary Islands. Detailed analysis of these deposits suggests that the slope failure did not occur as a single event but a series of smaller failures over a period of hours or days. Local tsunami are likely to have been triggered by these landslides but no evidence has been found to confirm this. Tanganasoga formed near the top of the El Golfo landslide headwall, on the upper part of the north-facing scarp slope.

Recent volcanic activity

Perhaps as a mark of the island's relative isolation, only one eruption has ever been recorded on the island, from the Volcan de Lomo Negro vent of Tanganasoga in 1793. The eruption lasted a month. It is considered that the 2011-2012 El Hierro eruption at La Restinga in the southernmost part of the island is a vent of Tanganasoga. Swift deformation of Tanganasoga was recorded during the October 2011-March 2012 eruptive phase of this volcanic activity, and in June 2012 a new phase was heralded by earthquakes and rapid deformation upwards and outwards of Tanganasoga, indicating the deep-seated movement of magma below.

References

External links

Tanganasoga at the Global Volcanism Project
* {{cite conference , last1=Longpre , first1=M. , last2=Troll , first2=V. , last3=Hansteen , first3=T. H. , last4=Anderson , first4=E. , title=Ankaramitic Lavas and Clinopyroxene Megacrysts From the Tanganasoga Volcano, El Hierro Island (Canary Archipelago) , conference=American Geophysical Union , date=December 2009 , pages=V51A–1662 , bibcode=2009AGUFM.V51A1662L Volcanoes of the Canary Islands

The volcano

Landslides

Recent volcanic activity

See also

References

External links