West Mata
West Mata | |
---|---|
Summit depth | −1,174 m (−3,852 ft)[1] |
Height | ~2,900 m (9,514 ft)[2] |
Location | |
Group | Mata volcanic group |
Range | Tofua volcanic arc |
Coordinates | 15°06′00″S 173°45′00″W / 15.10000°S 173.75000°W[1] |
Country | Tonga |
Geology | |
Type | Fissure vent |
Last activity | 2016[3] |
History | |
Discovery date | 2008[1] |
West Mata is an active
At the time of exploration, West Mata was the deepest undersea volcano eruption ever recorded, nearly −1,200 m (−3,937 ft) below the surface of the ocean. Following this record eruption, several research expeditions have been conducted to study the volcano and its history. Its study has provided important insights into the geology, chemistry, and biology of
Geography
West Mata can be found in the northeastern portion of Tonga, in between Fiji and Samoa. It is located approximately 200 km (124 mi) southwest of the Samoan Islands and around 600 km (373 mi) northeast of the Lau Islands of Fiji.[1]
Structure
With data from bathymetric surveys, the structure of the West Mata volcano was made more clear. The West Mata vent has a common structure with most volcanic structures in the area, mostly dominated by a prominent rift zone that extends away from the summit, which is the peak of a conical structure with a circular base on the seafloor. Therefore, meanwhile the northeast and southwest flanks are rugged, the northwest and southeast flanks are rather smooth. This structure can also be seen on the East Mata volcano. The rift zones on the flanks consist of stair-like lava platforms piled on each other. The east-northeast rift zone curves towards the east as it deepens, and the west-southwest rift zone is west‐oriented towards its end. The summit area of West Mata is a narrow ridge aligned with those two rift zones. There are no structures similar to a crater at the summit although remnants of a former caldera seem to exist. Other conical volcanic features are limited and can only be found on the lower parts of both rift zones.[7]
Geologic setting
The
The Lau Basin consists of an area of oceanic crust which separates the now remnant and extinct Lau-Colville Ridge volcanic arc and the Tofua volcanic arc with very active volcanism. The seaward rollback of the Tonga Trench is thought to be the main reason of the diverging action in this region. The basin lies above the westward-dipping seismically active area of subduction where the Pacific Plate slips under the Australian Plate.[9]
West Mata, specifically, is located in the northern part of the Lau Basin, defined as the Northeastern (NE) Lau Basin. The NE Lau Basin borders several spreading centers on the west, including the
The NE Lau Basin has one of the highest upper mantle temperatures in the world, has one of Earth's coolest slab thermal parameters (which is caused by the age and the speed of slab convergence), and has among the highest slab water flux values of any oceanic subduction zone. These factors cause the area's tectonism and volcanism to be complex compared to other places and cause the large amount of volcanic systems that exist in the NE Lau Basin.[11]
Composition
Most volcanic extrusions in the NE Lau Basin region structures usually erupt dacite lavas, some with unusual morphologies, which are quite rare in submarine volcanoes. Other than dacitic lavas, rift zones in the region have been also found to erupt basaltic andesite compositions.[11]
However, in the Mata volcano group, the main composition of eruptions in the Matas consists of mostly boninite, which is a type of extrusive rock usually seen in the Izu-Bonin Island Arc.[11]
Fauna
West Mata and the surrounding NE Lau Basin are home to many hydrothermal vents, meaning that the area hosts a hydrothermal vent environment, which hosts organisms that use hydrothermal vents to supply their living needs. These environments can be seen in many
Hydrothermal ecology
The hydrothermal ecology of the Lau Basin is home to many endemic organisms, including the Lamellibrachia columna which shows similarity to Lamellibrachia satsuma that can be found in Japan;[13] Neobrachylepas relica, a close relative to the Brachylepadomorpha which was extinct since the Miocene;[14] and more. In West Mata, these organisms were not observed, pointing to the diversity of the Lau Basin's ecology. Instead, a hydrothermal environment consisting of three species of
Activity
The volcano has known to be both hydrothermally and eruptively active in recent history, the most active in between its neighboring volcanoes.[15] According to depth differences in West Mata's flanks, it was pointed out that West Mata had an eruption which lasted from 1996 to 2008 at a depth of 2,750 m (9,022 ft).[16]
In November 2008, during a
Both vents, Hades and Prometheus, had different eruption styles. Hades was erupting with frequent magma bursts; meanwhile, Prometheus was showing a rapid degassing eruption. These eruptions both generated broadband signals which were recorded by
Following the main eruption, several papers suggest that in 2010–11 lava flows were recorded that covered an area of 1,300 m (4,265 ft) by 700 m (2,297 ft) at 2,950 m (9,678 ft) below sea level according to bathymetry depth differences.[3] The same papers also note that a year later, West Mata had an eruption between 2012 and 2016 at a depth of 2,650 m (8,694 ft). It was discovered the same way as the 2010–11 eruption, via bathymetry depth differences and bathymetric surveys.[3]
See also
- Niuatahi – another volcano in the Northeastern Lau Basin
- List of volcanoes in Tonga
References
- ^ a b c d "West Mata". Global Volcanism Program. Smithsonian Institution. Retrieved January 25, 2023.
- ^ Murch et al. 2022, p. 3.
- ^ a b c Chadwick Jr. et al. 2019, p. 14.
- NOAA. p. 34. Retrieved 26 March 2023.
- ^ "Deep Ocean Volcanoes". Ocean Today NOAA. Archived from the original on February 17, 2023. Retrieved March 26, 2023.
- ^ "Eruption of the world's deepest undersea volcano". EarthSky. 25 October 2018. Archived from the original on August 18, 2022. Retrieved March 26, 2023.
- ^ Clague et al. 2011, p. 5.
- ^ Hawkins 1995, p. 64.
- ^ Hawkins 1995, p. 63.
- ^ Embley & Rubin 2018, p. 2.
- ^ a b c Embley & Rubin 2018, p. 3.
- ^ Southward 1991, p. 859.
- ^ Southward 1991, p. 866.
- ^ Newman & Yamaguchi 1995, p. 222.
- ^ NOAA. Archivedfrom the original on January 26, 2023. Retrieved January 26, 2023.
- ^ Chadwick Jr. et al. 2019, p. 16.
- ^ Chadwick Jr. et al. 2019, p. 2.
- NOAA. Archivedfrom the original on February 28, 2023. Retrieved January 26, 2023.
- ^ Dziak et al. 2015, p. 1482.
- ^ Caplan-Auerbach et al. 2014, p. 5930.
Sources
- Clague, D. A.; Paduan, J. B.; Caress, D. W.; Thomas, H.; Chadwick Jr., W. W.; Merle, S. G. (2011). "Volcanic morphology of West Mata Volcano, NE Lau Basin, based on high-resolution bathymetry and depth changes". Geochemistry, Geophysics, Geosystems. 12 (11): 0–21. S2CID 129252981.
- Hawkins, J. W. (1995). "The Geology of the Lau Basin". Backarc Basins. Vol. 578. pp. 63–138. ISBN 978-1-4613-5747-6.
- Embley, R. W.; Rubin, K. H. (2018). "Extensive young silicic volcanism produces large deep submarine lava flows in the NE Lau Basin". Bulletin of Volcanology. 80 (4): 0–23. S2CID 135093528.
- Murch, A. P.; Portner, R. A.; Rubin, K. H.; Clague, D. A. (2022). "Deep-subaqueous implosive volcanism at West Mata seamount, Tonga". Earth and Planetary Science Letters. 578 (1): 0–43. S2CID 245313519.
- Southward, E. C. (1991). "Three new species of Pogonophora, including two vestimentiferans, from hydrothermal sites in the Lau Back-arc Basin (Southwest Pacific Ocean)". Journal of Natural History. 25 (4): 859–881. .
- Newman, W. A.; Yamaguchi, T. (1995). "A new sessile barnacle (Cirripedia, Brachylepadomorpha) from the Lau Back-Arc Basin, Tonga; first record of a living representative since the Miocene". Bulletin du Muséum National d'Histoire Naturelle, Section A. 17 (1): 221–244. S2CID 131791539.
- Chadwick Jr., W. W.; Rubin, K. H.; Merle, S. G.; Bobbitt, A. M.; Kwasnitschka, T.; Embley, R. W. (2019). "Recent Eruptions Between 2012 and 2018 Discovered at West Mata Submarine Volcano (NE Lau Basin, SW Pacific) and Characterized by New Ship, AUV, and ROV Data". Frontiers in Marine Science. 6 (2019): 0–25. .
- S2CID 43900021.
- Dziak, R. P.; Bohnenstiehl, D. R.; Baker, E. T.; Matsumoto, H.; S2CID 20487668.