East Mata
East Mata is an hydrothermally active submarine volcano located in the northeastern Lau Basin, right beside the far known West Mata volcano, which effusively erupted in 2009. It is located roughly  north of Hihifo, Tonga. It can be found on the northern portion of the Tonga-Kermadec volcanic arc which extends from North Island of New Zealand all the way to Samoa. The volcano was discovered along with West Mata and other volcanoes in 2008 by a team of NOAA scientists when they visited the region in a research vessel.

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 West Mata, Northern Matas, Tafu-Maka and Niuatahi.

Structure
In terms of morphology, East Mata is very similar to West Mata, both in terms of shape and size, considering they both are rift zones that have taken a similar process to form. Rift zones form by the spreading of the lithosphere 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 Lau Basin. This rollback created an area of spreading centers and rift zones with active hydrothermal vents.

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

See also
 List of volcanoes in Tonga

References

Sources
 
 
 

Volcanoes of Tonga
Seamounts of the Pacific Ocean
Submarine volcanoes