East Mata is an hydrothermally active

submarine volcano Submarine volcanoes are underwater vents or fissures in the Earth's surface from which magma can erupt. Many submarine volcanoes are located near areas of tectonic plate formation, known as mid-ocean ridges. The volcanoes at mid-ocean ridges ...

located in the northeastern Lau Basin, right beside the far known

West Mata West Mata, located in the far northern portion of Tonga, is an active submarine volcano. Known for the deepest recorded volcanic eruption to date, West Mata does not have a very long recorded history since it was recently discovered in 2008 along ...

volcano, which effusively erupted in 2009. It is located roughly north of

Hihifo Hihifo is the main village on the island of Niuatoputapu in the Kingdom of Tonga. Hihifo (which means 'west' in the Tongan language) is situated on the west side of Niuatoputapu and is the main centre for public and government facilities that se ...

, Tonga. It can be found on the northern portion of the

Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...

Kermadec Kermadec or de Kermadec may refer to: Geography * Kermadec Islands, a subtropical island arc in the South Pacific Ocean northeast of New Zealand * Kermadec Plate, a long narrow tectonic plate located west of the Kermadec Trench * Kermadec Trench, ...

volcanic arc which extends from

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

all the way to

Samoa Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands (Savai'i and Upolu); two smaller, inhabited islands (Manono Island, Manono an ...

. The volcano was discovered along with West Mata and other volcanoes in 2008 by a team of

NOAA The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...

scientists when they visited the region in a

research vessel A research vessel (RV or R/V) is a ship or boat designed, modified, or equipped to carry out research at sea. Research vessels carry out a number of roles. Some of these roles can be combined into a single vessel but others require a dedicated ...

Geography

The volcano can be found about southwest of Samoa and north of a more active volcano, Curacoa which had a significant eruption in 1973. In the surroundings of the volcano can be found the Mata volcanic group which consists of multiple volcanic structures which vary in activity including

, Northern Matas, Tafu-Maka and

Niuatahi Niuatahi or also called Volcano O is a submarine volcano located in the far northern territory of Tonga. Since the cone in the middle is named Motutahi, the volcano is sometimes referred to as Niuatahi-Motutahi. Despite not having any record of a ...

Structure

In terms of

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

, East Mata is very similar to West Mata, both in terms of shape and size, considering they both are

rift zones A rift zone is a feature of some volcanoes, especially shield volcanoes, in which a set of linear cracks (or rifts) develops in a volcanic edifice, typically forming into two or three well-defined regions along the flanks of the vent. Believed t ...

that have taken a similar process to form. Rift zones form by the spreading of the

lithosphere A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust (geology), crust and the portion of the upper mantle (geology), mantle that behaves elastically on time sca ...

as the magma upwells towards the surface.

Geologic setting

East Mata including the Mata group can be found in the Lau Basin, or more specifically the northeastern (NE) Lau Basin. The NE Lau Basin is bordered by multiple rift zones or spreading centres which are hydrothermally active like the NE Lau Spreading Center (NELSC), the Mangatolu Triple Junction (MTJ) and the Fonualei Rift Spreading Center (FRSC) from north to south, respectively. These hydrothermal and volcanic systems are caused by the rollback of the Tonga Trench which has also created the

back-arc 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 ...

Lau Basin. This rollback created an area of spreading centers and rift zones with active

hydrothermal vents A hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspot ...

Hydrothermal activity

Recent papers suggest that East Mata is hydrothermally active however it usually generates low-temperature and weak venting.

References

Sources