Eifuku

Eifuku
Bathymetic image of NW Eifuku as viewed to the northeast
Eifuku is located in North Pacific
Eifuku
Location
Coordinates21°29′06″N 144°02′35″E / 21.485°N 144.043°E / 21.485; 144.043[1]

Eifuku (Japanese: 永福) and NW Eifuku (北西永福) are two seamounts in the Pacific Ocean. The better known one is NW Eifuku, where an unusual hydrothermal vent called "Champagne" produced droplets of liquid CO
2. Both seamounts are located in the Northern Marianas and are volcanoes, part of the Izu-Bonin-Mariana Arc. NW Eifuku rises to 1,535 metres (5,036 ft) depth below sea level and is a 9 kilometres (5.6 mi) wide volcanic cone.

Both Eifuku seamounts are hydrothermally active, with numerous vent sites found on NW Eifuku including the "Champagne" vent site, where there are a number of white smokers. Diverse ecosystems dominated by mussels live in proximity and around the hydrothermal vent sites.

Geography and geology

The Eifuku seamounts are located northwest of Farallon de Pajaros island in the Northern Marianas. Geologically, both Eifuku seamounts are part of the Northern Marianas volcanic arc[2] and are grouped within the Northern Seamount Province.[3] The Northern Marianas are part of the c. 2,500-kilometre (1,600 mi) Izu-Bonin-Mariana Arc between Japan and Guam,[4] which owes its existence to the subduction of the Pacific Plate underneath the Philippine Plate[5] that began in the Eocene. About 40 submarine and island volcanoes make up the Northern Marianas arc.[6]

NW Eifuku and Eifuku are small volcanoes at the northwestern end of a volcano chain that also includes Daikoku;[1] NW Eifuku is the smallest of these.[7] Daikoku also features hydrothermal venting[8] and has been considered a twin cone with Eifuku.[9] Eifuku proper is composed of boulders, dykes and lava domes.[10] The occurrence of volcanic breccia, hydrothermal muds, sandstone and sulfides has been reported but without a clear attribution to either Eifuku or NW Eifuku.[11]

NW Eifuku seamount rises to 1,535 metres (5,036 ft) depth below sea level[1] and has a roughly conical outline, with a basal width of 9 kilometres (5.6 mi).[12] Its summit is formed by a lava dome that is surrounded by jagged rocks. A ridge, which likely corresponds to a dyke in the crater, runs from the summit and features old and mostly inactive hydrothermal vents. Rocks with columnar joints, lava spines and pillow basalts are found in the summit region.[13] The southwestern slope of NW Eifuku and its summit are cut by the scar of a sector collapse.[1] A northwest-southeast trending fracture may underlie the seamount and could be responsible for the mass wasting observed on the seamount.[14] The venting at "Champagne" appears to indicate that there is degassing magma.[3]

Composition

Rocks erupted by Eifuku range from basalt to andesite[1] that define either a potassium-rich calc-alkaline[15] or a tholeiitic suite.[16] The basalts contain clinopyroxene, olivine and plagioclase and feature abundant vesicles despite the great depth of the volcano.[3] This composition may occur on either NW Eifuku or Eifuku or both seamounts.[11] Sulfur mineralizations exist in the form of crusts, large deposits and also as infill within other rocks.[17] Silica and iron oxides form fluffy sediments.[12]

Hydrothermal vents

Chimneys and white smokers on Eifuku

Both Eifuku[10] and NW Eifuku are hydrothermally active, with NW Eifuku displaying white smokers[1] and hydrothermal vents dispersed over several sites on the volcano.[18] There are several sites, including diffuse venting at the summit,[19] a low-temperature area at 1,570 metres (5,150 ft) depth and high-temperature vents at 1,610 metres (5,280 ft) depth which include the so-called "Champagne" site[20] about 80 metres (260 ft) west-northwest of the summit.[21] Two other vent sites northeast and north of "Champagne" are known as "Cliff House" and "Sulfur Dendrite", respectively.[22] Additional vents are "Yellow Cone" and "Yellow Top" which are low-temperature iron-rich vents[23] and the latter of which is located south of the summit.[24] A sixth vent site is known as "Bacto Balls".[25] There are anecdotal reports of liquid sulfur.[26] The seawater above NW Eifuku has anomalous composition, a sign of hydrothermal degassing.[21]

Champagne vent

Milky white bubbles rising from the ground
Carbon dioxide bubbles rising from Eifuku volcano

The "Champagne" vent was discovered either in 2004 by the ROPOS remotely operated vehicle (ROV) or[18] by a NOAA expedition in 2003.[a][1] It lies west of the summit[18] in the sector collapse scar[1] and features both focused (white smokers that form chimneys) and diffuse venting. Temperatures of the discharge reach 105 °C (221 °F)[2] in gas-rich fluids that contain H
2S.[18] The chimneys are formed by sulfur.[27]

"Champagne" is known for being one of only three sites on Earth[b] where liquid CO
2 is emitted. The CO
2 rises from the pumice and sulfur deposits on the ground[20] through crevices,[22] and it forms cold droplets with a milky skin[18] that stick to surfaces such as ROV tools. The bubbles do not merge and their discharge increases when the seafloor is disturbed by a ROV.[31] They ascend slowly[21] owing to their buoyancy under the conditions at the vent. They appear to originate from a layer underneath the ground surface, as disturbing the vent leads to increasing exhalations.[22] The name "Champagne" is based on the appearance of the exhalations.[32]

Apart from CO
2, they contain sulfur compounds and small amounts of hydrogen and methane. CO
2 makes up about 87% of the droplets, which are rimmed by CO
2 clathrates,[18] the concentrations per unit mass are about twice the solubility of CO
2 under the environmental conditions[2] and considerably larger than at other known CO
2 venting sites.[33] Eifuku's CO
2 output appears to be a significant component of global volcanic CO
2 flux, or at least of submarine volcanic CO
2 flux.[14] Based on isotope ratios, much of this CO
2 is derived from the subduction of carbonates rather than from the mantle.[18] The emission rate may not be steady over time, as output varied between different expeditions.[14]

Biology

Mussel beds at Eifuku volcano

Several ecological communities have been found at NW Eifuku, at 1,550 metres (5,090 ft) depth[2] and with distinct microbiotas:[34]

The properties of exhaled fluids strongly influence the ecosystems surrounding hydrothermal vents,[41] and the environment of NW Eifuku has been used as an example for an ecosystem under heavy CO
2 concentrations.[42] Compared to other hydrothermal vent sites in the Pacific Ocean, mussels at NW Eifuku grow more slowly and have eroded shells, but they also are less subject to predation by crabs[43] and their body condition is not uniformly inferior.[44]

Orange coloured microbial mats are widespread on Eifuku's summit region and around the vents.[12] Barnacles, bivalves, nudibranchs, octocorals including bamboo corals, sea stars and sponges occur on Eifuku seamount. The fish species Randall's snapper[13][45] and an unidentified species of the fish genus Grammatonotus were observed on Eifuku.[46]

Notes

  1. ^ Authors of a 2016 NOAA report into Eifuku say they are not aware of any previous ROV dive.[13]
  2. ^ Two other sites are in the Okinawa Trough[28] and additional reports come from Vailulu'u seamount[29] and North Su in the Manus Basin.[30]
  3. ^ Including a species discovered on Eifuku at the "Golden Lips" and "Champagne" sites, Provanna exquisita.[35]
  4. ^ Including a species discovered at Eifuku and Myojin Knoll, Munidopsis myojinensis.[37]
  5. ^ Including a species discovered at Eifuku and Myojin Knoll, Alvinocaris marimonte,[38] and Rimicaris cambonae discovered at Eifuku.[39]

References

  1. ^ a b c d e f g h "NW Eifuku". Global Volcanism Program. Smithsonian Institution.
  2. ^ a b c d e f g h i Limen & Juniper 2006, p. 450.
  3. ^ a b c Stern, R. J.; Basu, N. K.; Kohut, E.; Hein, J.; Embley, R. W. (1 December 2004). "Petrology and Geochemistry of Igneous Rocks collected in Association with ROV Investigations of Three Hydrothermal Sites in the Mariana Arc: NW Rota-1, E. Diamante, and NW Eifuku". AGU Fall Meeting Abstracts. 43: V43F–07. Bibcode:2004AGUFM.V43F..07S.
  4. ^ Metaxas 2011, p. 104.
  5. ^ Metaxas 2011, p. 105.
  6. ^ Kurzawa et al. 2019, p. 240.
  7. ^ Stern 2024, p. 8.
  8. ^ Cantwell, Kasey; Newman, Jim (2016). Okeanos Explorer ROV dive summary, EX1605L3, June 26, 2016 (Report).
  9. ^ Bloomer, Sherman H.; Stern, Robert J.; Smoot, N. Christian (1 May 1989). "Physical volcanology of the submarine Mariana and Volcano Arcs". Bulletin of Volcanology. 51 (3): 217. Bibcode:1989BVol...51..210B. doi:10.1007/BF01067957. ISSN 1432-0819. S2CID 129715492.
  10. ^ a b "Eifuku Vent". Global Magmatic and Tectonic Lab. University of Texas Dallas. Archived from the original on 9 July 2021. Retrieved 4 July 2021.
  11. ^ a b Hein, J. R.; Fleishman, C. L.; Morgenson, L. A.; Bloomer, S. H.; Stern, R. J. (1987). Submarine ferromanganese deposits from the Mariana and Volcano volcanic arcs, West Pacific (Report). pp. 13–14.
  12. ^ a b c Makita et al. 2016, p. 5744.
  13. ^ a b c Cantwell & Newman 2016, p. 3.
  14. ^ a b c Lupton et al. 2006, p. 17.
  15. ^ Pearce, J. A.; Kempton, P. D.; Nowell, G. M.; Noble, S. R. (1 November 1999). "Hf-Nd Element and Isotope Perspective on the Nature and Provenance of Mantle and Subduction Components in Western Pacific Arc-Basin Systems". Journal of Petrology. 40 (11): 1582. doi:10.1093/petroj/40.11.1579. ISSN 0022-3530.
  16. ^ Kurzawa et al. 2019, p. 242.
  17. ^ de Ronde, C. E.; Hein, J. R.; Embley, R. W.; Stern, R. J. (1 December 2004). "Hydrothermal Mineralization Along the Volcanically Active Mariana Arc". AGU Fall Meeting Abstracts. 54: V54A–04. Bibcode:2004AGUFM.V54A..04D.
  18. ^ a b c d e f g Lupton, J.; Lilley, M.; Butterfield, D.; Evans, L.; Embley, R.; Olson, E.; Proskurowski, G.; Resing, J.; Roe, K.; Greene, R.; Lebon, G. (1 December 2004). "Liquid Carbon Dioxide Venting at the Champagne Hydrothermal Site, NW Eifuku Volcano, Mariana Arc". AGU Fall Meeting Abstracts. 43: V43F–08. Bibcode:2004AGUFM.V43F..08L.
  19. ^ Chadwick, W. W.; Embley, R. W.; de Ronde, C. E.; Stern, R. J.; Hein, J.; Merle, S.; Ristau, S. (1 December 2004). "The Geologic Setting of Hydrothermal Vents at Mariana Arc Submarine Volcanoes: High-Resolution Bathymetry and ROV Observations". AGU Fall Meeting Abstracts. 43: V43F–06. Bibcode:2004AGUFM.V43F..06C.
  20. ^ a b c d Tunnicliffe et al. 2009, p. 344.
  21. ^ a b c Lupton et al. 2006, p. 3.
  22. ^ a b c Lupton et al. 2006, p. 4.
  23. ^ Davis & Moyer 2008, p. 2.
  24. ^ Makita et al. 2016, p. 5743.
  25. ^ Davis & Moyer 2008, p. 4.
  26. ^ Stern 2024, p. 7.
  27. ^ Tunnicliffe et al. 2009, p. 345.
  28. ^ Hsu, Feng-Hsin; Su, Chih-Chieh; Lin, Yu-Shih; Lee, Hsiao-Fen; Chu, Mei-Fei; Lan, Tefang; Wu, Shein-Fu; Chen, Song-Chuen (May 2024). "Geochemical indications of hydrothermal fluid through sediments within the Geolin Mounds and Mienhua Volcano hydrothermal fields, southernmost Okinawa Trough". Deep Sea Research Part I: Oceanographic Research Papers. 207: 9. Bibcode:2024DSRI..20704293H. doi:10.1016/j.dsr.2024.104293.
  29. ^ Brewer, P. G.; Dunk, R. M.; Peltzer, E. T. (1 December 2005). "The Characteristics, Behavior and Fate of a Stream of Liquid CO2 Released Into the Ocean". AGU Fall Meeting Abstracts. 44: V44A–07. Bibcode:2005AGUFM.V44A..07B.
  30. ^ Kedzior, Stine; Buß, Antje; Schneider, Bernd; Schneider von Deimling, Jens; Sültenfuß, Jürgen; Walter, Maren; Mertens, Christian; Rehder, Gregor (September 2016). "Geochemical observations within the water column at the CO 2 -rich hydrothermal systems Hatoma Knoll and Yonaguni Knoll IV, in the southern Okinawa Trough: CO 2 -RICH VENT GEOCHEMISTRY". Journal of Geophysical Research: Oceans. 121 (9): 6619. doi:10.1002/2016JC012003. S2CID 133336199.
  31. ^ Stern 2024, p. 9.
  32. ^ a b Davis, R. E.; Moyer, C. L. (1 December 2004). "Epsilon-Proteobacterial Dominance in Microbial Mats Located at the Champagne Hydrothermal Vent Site on NW Eifuku Volcano, Mariana Arc". AGU Fall Meeting Abstracts. 41: V41B–1388. Bibcode:2004AGUFM.V41B1388D.
  33. ^ Lupton et al. 2006, p. 12.
  34. ^ Davis, R. E.; Moyer, C. L. (1 December 2005). "Extreme Spatial Variability in Microbial Mat Communities from Submarine Hydrothermal Vents Located at Multiple Volcanoes along the Mariana Island Arc". AGU Fall Meeting Abstracts. 51: V51C–1509. Bibcode:2005AGUFM.V51C1509D.
  35. ^ Chen, Chong; Watanabe, Hiromi Kayama (14 July 2022). "A new provannid snail (Gastropoda, Abyssochrysoidea) discovered from Northwest Eifuku Volcano, Mariana Arc". ZooKeys (1112): 128. Bibcode:2022ZooK.1112..123C. doi:10.3897/zookeys.1112.85950. PMC 9848648. PMID 36760627.
  36. ^ Metaxas 2011, p. 107.
  37. ^ a b Tsuchida, Shinji; Hendrickx, Michel E.; Kado, Ryusuke; Watanabe, Seiichi (29 March 2007). "A new species of vent associated Munidopsis (Crustacea: Decapoda: Anomura: Galatheidae) from the Western Pacific, with notes on its genetic identification". Zootaxa. 1435 (1): 31. doi:10.11646/zootaxa.1435.1.3. ISSN 1175-5334.
  38. ^ Hiraoka, Retori; Komai, Tomoyuki; Tsuchida, Shinji (February 2020). "A new species of Alvinocaris (Crustacea: Decapoda: Caridea: Alvinocarididae) from hydrothermal vents in the Izu-Bonin and Mariana Arcs, north-western Pacific". Journal of the Marine Biological Association of the United Kingdom. 100 (1): 97. Bibcode:2020JMBUK.100...93H. doi:10.1017/S0025315419001097. ISSN 0025-3154. S2CID 213034894.
  39. ^ Methou, Pierre; Chen, Chong; Komai, Tomoyuki (8 February 2024). "Revision of the alvinocaridid shrimp genus Rimicaris Williams & Rona, 1986 (Decapoda: Caridea) with description of a new species from the Mariana Arc hydrothermal vents". Zootaxa. 5406 (4): 501–518. doi:10.11646/zootaxa.5406.4.1. PMID 38480132.
  40. ^ Limen & Juniper 2006, p. 452.
  41. ^ Limen & Juniper 2006, p. 449.
  42. ^ Klapper, Regina; Widdicombe, Steve (2013). ECO2 Briefing Paper No. 2: Potential impacts of CO2 leakage from sub-surface storage on seabed biology (Report). Kiel, Germany.
  43. ^ Tunnicliffe et al. 2009, p. 347.
  44. ^ Rossi & Tunnicliffe 2017, p. 61.
  45. ^ Metaxas 2011, p. 108.
  46. ^ Anderson, Johnson & Nonaka 2018, p. 77.

Sources