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Bathymetric map of Micronesia-Marshall Islands, with seamounts
Bathymetric map of Micronesia-Marshall Islands, with seamounts

The Marshall Islands are the site of a number of seamounts. These volcanoes form several groups, including the Ralik Chain, the Ratak Chain and some seamounts around Anewetak.[1] These seamounts are in turn part of a larger province that extends from the South Pacific to the Mariana Trench and is characterized by unusually shallow ocean ground.[2]

These seamounts and volcanoes do not have simple hotspot-like age progressions, with some volcanoes being younger than one would expect from age progression and having more than one active episode. In some places, a middle Cretaceous and a late Cretaceous episode of volcanic activity have been determined by radiometric dating. Despite this, some hotspot-based genesis models have been formulated, often implying that French Polynesian hotspots are responsible for the formation of seamounts,[1] with the Society hotspot, Rurutu hotspot, Rarotonga hotspot and the Macdonald hotspot being candidate hotspots responsible for the development of the Marshall Islands seamounts.[3] Such linkages are in part supported by geochemical data.[4] Some discrepancies between the age and position of such seamounts and the predictions of the hotspot model may reflect the activity of short-lived hotspots linked to large mantle plumes that produce more than one hotspot.[5]

Name Other names Etymology Coordinates Depth below sea level Age Volume Details
Aean̄-Kaņ[6] Marovoiy[7] A taboo fishing spot at Eniwetok[8] 14°52.98′N 160°27.38′E / 14.88300°N 160.45633°E / 14.88300; 160.45633[9] 850 metres (2,790 ft)[9] Mid-Cretaceous[10] 10,389 cubic kilometres (2,492 cu mi).[9] Since the Eocene manganese nodules developed on the seamount,[11] which may have been created by the Macdonald hotspot.[10]
Neen-Koiaak[6] According to legend, the fastest runner in the Marshall Islands[8] 14°22.62′N 161°01.16′E / 14.37700°N 161.01933°E / 14.37700; 161.01933[12] 1,025 metres (3,363 ft)[12] 102 million years[12] 7,083 cubic kilometres (1,699 cu mi)[12] Samples dredged from Neen-Koiaak include hawaiite[13] containing clinopyroxene, olivine and plagioclase.[14]
Wōd-Eņ Rok[6] South-Wod-En[15] A coral head[16] 15°13.20′N 163°00.00′E / 15.22000°N 163.00000°E / 15.22000; 163.00000[15] 76 million years[15] While its position makes it a candidate member of the Ralik hotspot trail, it appears to be too old.[17] There is some geochemical similarity to the Rurutu hotspot.[4]
Wōd-Eņ Iōn̄[6] North-Wod-En,[18] Nazimova[7] A coral head[16] 16°06.00′N 163°02.40′E / 16.10000°N 163.04000°E / 16.10000; 163.04000[18] 86 million years[18] While its position makes it a candidate member of the Ralik hotspot trail, it appears to be too old.[17] There is some geochemical similarity to the Rurutu hotspot.[4]
Ļewa[6] A person who received canoe building knowledge, one of the first two[16] 14°01.80′N 163°07.80′E / 14.03000°N 163.13000°E / 14.03000; 163.13000[19] 100 million years[19] Part of the Ralik Chain,[20] Albian-age fossils have been dredged from this seamount.[21]
Ļōbbadede[6] Lobhadode[22] A chief from Bikini[16] 13°52.80′N 163°51.60′E / 13.88000°N 163.86000°E / 13.88000; 163.86000[22] 94 million years[22] Depending on the plate reconstruction model chosen, Lobbadede appears to coincide with the location of the Macdonald hotspot.[10] Limestone and fossils of Campanian-Cenomanian age have been found on Lobbadede,[3] which appears to have had a second volcanic episode in the Cretaceous.[20]
Wōden-Kōpakut[6] Ratak[23] A coral head[16] 13°56.40′N 167°28.80′E / 13.94000°N 167.48000°E / 13.94000; 167.48000[23] 1,320 metres (4,330 ft)[24] 85 million years[23] or 82.2 ± 1.6 million years[25] Part of the Ratak Chain with Limalok,[20] it was also active during the late Cretaceous[21] and has a well developed summit platform.[26] One reconstruction of plate motion places Woden-Kopakut close to the Rurutu hotspot.[1] Hawaiite has been dredged from the seamount and contains iron oxides, plagioclase and zeolites.[27]
Radik[6] A chief on Ujlan[8]
Ļainjin[6] A legendary navigator[8] 11°09.00′N 161°03.00′E / 11.15000°N 161.05000°E / 11.15000; 161.05000[28]
Ļōjemeja[6] A chief in Ujlan[8] 11°26.40′N 161°05.40′E / 11.44000°N 161.09000°E / 11.44000; 161.09000[29] 1,750 metres (5,740 ft)[30] Steep upper flanks, and a volcanic pinnacle is found between the summit and a sediment-covered terrace.[30]
Ļami[6] According to legend an Eniwetok giant[8] 11°54.60′N 161°24.60′E / 11.91000°N 161.41000°E / 11.91000; 161.41000[31] 1,295 metres (4,249 ft)[30] 86 million years[31] Slumps and terraces, terraces that appear to be congruent with these on Lomilik, surround this seamount. Its summit plateau is covered by sediments, sediment-filled basins and volcanic knolls.[30]
Peto-Eņ[6] A taboo channel at Eniwetok[8] 12°22.80′N 161°19.20′E / 12.38000°N 161.32000°E / 12.38000; 161.32000[32]
Lomilik[6] A place at Eniwetok with good fishing opportunities[8] 11°42′N 161°37′E / 11.700°N 161.617°E / 11.700; 161.617[33] The summit has volcanic knobs and sediment-filled basins in between. The north flank has a terrace and the rest of the slopes is covered with slumps, talus and sediments.[30]
Litōrmālu[6] A legendary navigator[8] 10°53.40′N 161°27.60′E / 10.89000°N 161.46000°E / 10.89000; 161.46000[34]
Ļo-Wūliej[6] A cape at Eniwetok[8] 12°09.60′N 162°15.60′E / 12.16000°N 162.26000°E / 12.16000; 162.26000[35]
North Ļāānṃōjānjān[6] Reference to shipbuilding techniques[16] 13°07.80′N 162°47.20′E / 13.13000°N 162.78667°E / 13.13000; 162.78667[36] 1,090 metres (3,580 ft)[30] Has a rugged appearance with little sediment.[37] It also features several terraces and two large slumps.[30]
South Ļāānṃōjānjān[6] Reference to shipbuilding techniques[16] 12°41.56′N 162°37.17′E / 12.69267°N 162.61950°E / 12.69267; 162.61950[38] 1,395 metres (4,577 ft)[38] 1,611 cubic kilometres (386 cu mi)[38] Has a rugged appearance with little sediment.[37]
Bwewa Kaņ[6] Named after canoe keels[16] 13°33.60′N 164°25.20′E / 13.56000°N 164.42000°E / 13.56000; 164.42000[39] 88 million years[39] Part of the Ralik Chain, may have been formed by a hotspot together with a stage of Wodejebato.[17]
Lōjabōn-Bar[6] A strong traditional personage at Bikini[16] 13°09.00′N 164°30.00′E / 13.15000°N 164.50000°E / 13.15000; 164.50000[40]
Wōdejebato[6] Sylvania[41] Bikini's most feared sea god[16] 11°55.95′N 164°51.72′E / 11.93250°N 164.86200°E / 11.93250; 164.86200[41] 1,290 metres (4,230 ft)[41] 82 million years[41] 12,476 cubic kilometres (2,993 cu mi)[41]
Look[6] 12°12.00′N 166°13.80′E / 12.20000°N 166.23000°E / 12.20000; 166.23000[42] 999 metres (3,278 ft)[37] 140 million years[42] Look is the oldest known seamount.[43] Flat-topped seamount that can be considered a guyot[44] and is located between the Ratak Chain and the Ralik Chain,[45] and fairly old. Its geochemistry is intermediate between these two chains as well, which may indicate that volcanism was strongly influenced by the crust.[46] Look Seamount is dotted by volcanic cones and has a rilled appearance[47] as well as slumps; the summit is covered by sediment that mostly buries small volcanic pinnacles and sediment-filled depressions.[37]
Ruwitūn̄tūn̄[6] 11°49.80′N 167°00.00′E / 11.83000°N 167.00000°E / 11.83000; 167.00000[48] 1,215 metres (3,986 ft)[37] 66 million years[48] Flat-topped seamount that can be considered a guyot;[44] basins and volcanic knolls dot its summit platform and some pinnacles contain craters.[37] Fossils indicate that Ruwituntun developed either during or before the Albian.[21]
Ļāwūn-Pikaar[6] Bikar[49] Legendary chief in Pikaar[16] 12°09.60′N 168°51.60′E / 12.16000°N 168.86000°E / 12.16000; 168.86000[50] Ankaramite-like rock containing clinopyroxene and degradation products of olivine and mellilite has been dredged[27]
Ļōkōto-N̄ōrn̄ōr[6] 13°06.00′N 169°26.40′E / 13.10000°N 169.44000°E / 13.10000; 169.44000[51]
Jebo[6] 11°03.00′N 170°39.60′E / 11.05000°N 170.66000°E / 11.05000; 170.66000[52]
Pali[6] Name given by the government of Micronesia.[53] Probably Cretaceous[54] The seamount is surrounded by a sediment cover and might feature slumps. Hyaloclastite and phosphorite have been dredged from it.[55]
Likelep[6] A site on Ujlan[8] 10°36.00′N 160°28.80′E / 10.60000°N 160.48000°E / 10.60000; 160.48000[56] 1,545 metres (5,069 ft)[57] 82 million years[56] Biotite, hornblende and plagioclase have been dredged from Likelep, and the seamount is of Campanian age. Likelep may be part of a seamount trail[58] and is part of the Ujlān volcanic complex.[59] A sediment cap and volcanic structures are found on its top, with a volcanic cone protruding through the sediment. Slumps occur on its flanks and a seamount farther north is connected to Likelep.[57]
Lalibjet[6] A sea god[8] 10°08.40′N 159°55.20′E / 10.14000°N 159.92000°E / 10.14000; 159.92000[60] 1,439 metres (4,721 ft)[61] 74 million years[60] May have been produced by the Rarotonga hotspot together with Eniwetok[62] and is part of the Ujlān volcanic complex.[59] Part of the sediment cap on its summit appears to have been removed by a slump.[57]
Ujlān[6] Ujelang[63] 9°46.80′N 160°25.20′E / 9.78000°N 160.42000°E / 9.78000; 160.42000[63] 1,250 metres (4,100 ft)[57] 80 million years[63] Seamount with three separate summits.[47] Ujlan may be part of a seamount trail[58] and is part of the Ujlān volcanic complex.[59] The southwestern flank has a terrace.[57]
Ļōtab[6] A descendant of Litōrmālu[8] 10°13.80′N 160°43.20′E / 10.23000°N 160.72000°E / 10.23000; 160.72000[64] 1,557 metres (5,108 ft)[61] 80 million years[64] Lotab may be part of a seamount trail[58] and is part of the Ujlān volcanic complex;[59] it also features traces of mass failures[57] and on the northeastern flank it is connected to another seamount.[61]
Ļajutōkwa[6] A navigator[8] 10°28.80′N 160°46.80′E / 10.48000°N 160.78000°E / 10.48000; 160.78000[65] 1,585 metres (5,200 ft)[30] 81 million years[65] Lajutokwa may be part of a seamount trail[58] and is part of the Ujlān volcanic complex.[59]
Lo-En[6] Hess[66] Named after the hibiscus tree[8] 10°06.00′N 162°52.20′E / 10.10000°N 162.87000°E / 10.10000; 162.87000[66] 113 million years[66]
Mij-Lep[6] A gap between islands on Ujlan[8] 8°48.60′N 163°12.60′E / 8.81000°N 163.21000°E / 8.81000; 163.21000[67] 1,105 metres (3,625 ft)[61] 106 million years[67] A number of pinnacles, including a flat topped one on the summit, cover Mij-Lep.[61]
Ļemkein[6] 9°18′N 166°05′E / 9.300°N 166.083°E / 9.300; 166.083[33]
Ļewōnjoui[6] 10°32.31′N 166°27.83′E / 10.53850°N 166.46383°E / 10.53850; 166.46383[68] 2,985 metres (9,793 ft)[68] 1,441 cubic kilometres (346 cu mi)[68]
Ļōkkwōrkwōr[6] Erikub[69] 9°09.00′N 170°00.00′E / 9.15000°N 170.00000°E / 9.15000; 170.00000[69] 1,400 metres (4,600 ft)[26] 87 million years[69] Alkali basalts and hawaiite have been dredged, which contain clinopyroxene, olivine derivatives and plagioclase and show evidence of having been eroded above the water surface[27]
Litakpooki[6] 8°18.60′N 160°38.40′E / 8.31000°N 160.64000°E / 8.31000; 160.64000[70]
Ṃaanjidep[6] A chief from Jalwoj[16] 6°43.80′N 169°19.80′E / 6.73000°N 169.33000°E / 6.73000; 169.33000[71] 2,215 metres (7,267 ft)[61] The depth probably does not refer to the actual summit.[61]
Ļoṃjenaelik[6] A chief from Arno[16]
Ļōmōļkā[6] A chief from Mile[16] 6°37.80′N 172°21.60′E / 6.63000°N 172.36000°E / 6.63000; 172.36000[72]
Limalok[6] Harrie[73] A chiefess from Mile[16] 5°36.00′N 172°21.60′E / 5.60000°N 172.36000°E / 5.60000; 172.36000[73] 68 million years[73]

See also

References

  1. ^ a b c Bergersen 1995, p. 605.
  2. ^ Koppers et al. 2003, p. 9.
  3. ^ a b Bergersen 1995, p. 607.
  4. ^ a b c Koppers et al. 2003, p. 25.
  5. ^ Koppers et al. 2003, p. 39.
  6. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao Hein, James R.; Wong, Florence L.; Mosier, Dan L. (1999). "Bathymetry of the Republic of the Marshall Islands and vicinity". Miscellaneous Field Studies Map.
  7. ^ a b Asavin, A. M.; Daryin, A. V.; Melnikov, M. E. (21 December 2014). "Microrhythmic distribution of Co, Mn, Ni, and La contents in cobalt-rich ferromanganese crusts from the Magellan Seamounts". Geochemistry International. 53 (1): 23. doi:10.1134/s0016702915010024. ISSN 0016-7029.
  8. ^ a b c d e f g h i j k l m n o p Hein et al. 1990, p. 245.
  9. ^ a b c "Aean Kan Guyot". Seamount Catalog. Retrieved 24 June 2018.
  10. ^ a b c Bergersen 1995, p. 610.
  11. ^ Hein, James R.; Zielinski, S.E.; Staudigel, Hubert; Chang, Se-Won; Greene, Michelle; Pringle, M.S. (1997). "Composition of Co-rich ferromanganese crusts and substrate rocks from the NW Marshall Islands and international waters to the north, Tunes 6 cruise". Open-File Report. ISSN 2331-1258.
  12. ^ a b c d "Neen-Koiaak Guyot". Seamount Catalog. Retrieved 24 June 2018.
  13. ^ Koppers, Staudigel & Wijbrans 2000, p. 142.
  14. ^ Koppers, Staudigel & Wijbrans 2000, p. 145.
  15. ^ a b c "South-Wod-En Guyot". Seamount Catalog. Retrieved 24 June 2018.
  16. ^ a b c d e f g h i j k l m n o Hein et al. 1990, p. 246.
  17. ^ a b c Koppers et al. 2003, p. 21.
  18. ^ a b c "North-Wod-En Guyot". Seamount Catalog. Retrieved 24 June 2018.
  19. ^ a b "Lewa Guyot". Seamount Catalog. Retrieved 24 June 2018.
  20. ^ a b c Haggerty & Premoli Silva 1995, p. 935.
  21. ^ a b c Haggerty & Premoli Silva 1995, p. 938.
  22. ^ a b c "Lobbadede Guyot". Seamount Catalog. Retrieved 24 June 2018.
  23. ^ a b c "Rataka Guyot". Seamount Catalog. Retrieved 25 June 2018.
  24. ^ Davis et al. 1989, pp. 5757–5758.
  25. ^ Davis et al. 1989, p. 5770.
  26. ^ a b Davis et al. 1989, p. 5757.
  27. ^ a b c Davis et al. 1989, p. 5761.
  28. ^ "Lainjin Seamount". Seamount Catalog. Retrieved 25 June 2018.
  29. ^ "Lojemeja Seamount". Seamount Catalog. Retrieved 25 June 2018.
  30. ^ a b c d e f g h Hein et al. 1990, p. 5.
  31. ^ a b "Lami Seamount". Seamount Catalog. Retrieved 25 June 2018.
  32. ^ "Peto-En Seamount". Seamount Catalog. Retrieved 25 June 2018.
  33. ^ a b Hyeong et al. 2013, p. 294.
  34. ^ "Litormalu Seamount". Seamount Catalog. Retrieved 25 June 2018.
  35. ^ "Lo-Wuliej Seamount". Seamount Catalog. Retrieved 25 June 2018.
  36. ^ "North Laanmojanjan Seamount". Seamount Catalog. Retrieved 25 June 2018.
  37. ^ a b c d e f Hein et al. 1990, p. 4.
  38. ^ a b c "South Laanmojanjan Seamount". Seamount Catalog. Retrieved 25 June 2018.
  39. ^ a b "Bwewa-Kan Seamount". Seamount Catalog. Retrieved 25 June 2018.
  40. ^ "Lojabon-Bar Seamount". Seamount Catalog. Retrieved 25 June 2018.
  41. ^ a b c d e "Wodejebato Guyot". Seamount Catalog. Retrieved 25 June 2018.
  42. ^ a b "Look Seamount". Seamount Catalog. Retrieved 25 June 2018.
  43. ^ Hubert Staudigel; Anthony A.P. Koppers (1 January 2015). Seamounts and Island Building. p. 420. doi:10.1016/B978-0-12-385938-9.00022-5. ISBN 9780123859389. {{cite book}}: |journal= ignored (help)
  44. ^ a b Hein et al. 1990, p. 2.
  45. ^ Koppers et al. 2003, p. 24.
  46. ^ Koppers et al. 2003, p. 27.
  47. ^ a b Hein et al. 1990, p. 3.
  48. ^ a b "Ruwituntun Seamount". Seamount Catalog. Retrieved 25 June 2018.
  49. ^ Davis et al. 1989, p. 5759.
  50. ^ "Lawun-Pikaar Seamount". Seamount Catalog. Retrieved 25 June 2018.
  51. ^ "Lokoto-Nornor Seamount". Seamount Catalog. Retrieved 25 June 2018.
  52. ^ "Jebo Seamount". Seamount Catalog. Retrieved 25 June 2018.
  53. ^ Hein et al. 1992, p. 1.
  54. ^ Hein et al. 1992, p. 7.
  55. ^ Hein et al. 1992, p. 4.
  56. ^ a b "Likelep Guyot". Seamount Catalog. Retrieved 25 June 2018.
  57. ^ a b c d e f Hein et al. 1990, p. 6.
  58. ^ a b c d Koppers et al. 2003, p. 20.
  59. ^ a b c d e Hein et al. 1990, p. 1.
  60. ^ a b "Lalibjet Seamount". Seamount Catalog. Retrieved 25 June 2018.
  61. ^ a b c d e f g Hein et al. 1990, p. 7.
  62. ^ Bergersen 1995, p. 612.
  63. ^ a b c "Ujlan Guyot". Seamount Catalog. Retrieved 25 June 2018.
  64. ^ a b "Lotab Seamount". Seamount Catalog. Retrieved 25 June 2018.
  65. ^ a b "Lajutokwa Guyot". Seamount Catalog. Retrieved 25 June 2018.
  66. ^ a b c "Lo-En Guyot". Seamount Catalog. Retrieved 25 June 2018.
  67. ^ a b "Mij-Lep Seamount". Seamount Catalog. Retrieved 25 June 2018.
  68. ^ a b c "Lewonjoui Guyot". Seamount Catalog. Retrieved 25 June 2018.
  69. ^ a b c "Erikub Seamount". Seamount Catalog. Retrieved 25 June 2018.
  70. ^ "Litakpooki Seamount". Seamount Catalog. Retrieved 25 June 2018.
  71. ^ "Maanjidep Seamount". Seamount Catalog. Retrieved 25 June 2018.
  72. ^ "Lomolka Seamount". Seamount Catalog. Retrieved 25 June 2018.
  73. ^ a b c "Limalok Guyot". Seamount Catalog. Retrieved 25 June 2018.

Sources