The Samoan archipelago has many features that are consistent with a plume-driven hotspot model, including the currently active submarine volcano Vailuluʻu that anchors the eastern extremity. However, the chain's proximity to the northern end of the Tonga trench, and the presence of voluminous young volcanism on what should be the oldest (~5 my) western island Savaiʻi has induced controversy regarding a simple plume/hotspot model.[2] The Samoan archipelago was most likely created by the Pacific Tectonic Plate traveling over a fixed hotspot. The Samoa hotspot trail is in part coincident with a large group of islands and seamounts 1,700km (1,056mi) long, which were probably formed by the same hotspot, but also intersect with older seamounts along the hotspot highway left by the Macdonald, Rurutu, and Rarotonga hotspots and feature substantial postshield volcanism, probably owing to tectonic phenomena triggered by the subduction of the Pacific Plate under the Australian Plate at the nearby Tonga Trench.[3][4][5][6][7]
Vailuluʻu is a volcanicseamount discovered in 1975. It rises from the sea floor to a depth of 593m (1,946ft) and is located between Taʻu and Rose islands at the eastern end of the Samoa hotspot chain. The basaltic seamount is considered to mark the current location of the Samoa hotspot. The summit of Vailuluʻu contains a 2,000m (6,600ft) wide, 400m (1,300ft) deep oval-shaped caldera. Two principal rift zones extend east and west from the summit, parallel to the trend of the Samoan hotspot. A third less prominent rift extends southeast of the summit.[2]
Rose Atoll and Malulu seamount are likely remnants of where the path of either the Macdonald or Rarotonga hotspots crossed the path of the Samoa hotspot.[8][9][10] Some seamounts in western Samoa ("Samoan Seamounts"[11]), which were emplaced together with Tuvalu between 63 and 42 million years ago are likely remnants of the Rurutu hotspot.[12] These are also known as the "interloper seamounts".[13] Other undated seamounts in Samoa have been linked to the Rurutu hotspot on the basis of geochemical evidence.[14]
Due to its positioning in the South Pacific Ocean, the Samoan archipelago is frequently hit by tropical cyclones between November and April.Samoa has an equatorial climate, with an average annual temperature of 26.5°C (79.7°F) and a main rainy season from November to April, although heavy rain may fall in any month.[23]
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The terrain of the larger islands consists of a narrow coastal plains with volcanic, rocky, rugged mountains in the interior. The Natural resources include hardwood forests, fish, and hydropower. The smaller islands are remnants of eroded volcanictuff rings, some are just a coral reef atop the eroded cone of a defunct volcano.[25]
The highest mountains are: Mt Silisili (Savaiʻi) at 1,858m (6,096ft), Mount Fito (Upolu) at 1,113m (3,652ft), Lata Mountain (Taʻū), 3,170ft (970m); Matafao Peak (Tutuila) at 2,141ft (653m), Piumafua (Olosega) at 2,095ft (639m), and Tumutumu (Ofu) at 1,621ft (494m). Mount Pioa (Tutuila), nicknamed the Rainmaker, is 1,718ft (524m).[27]:3 American Samoa is also home to some of the world's highest sea cliffs at 3,000ft (910m).[28]
Smith-Vaniz, William F. (1987). "The Saber-Toothed Blennies, Tribe Nemophini (Pisces: Blenniidae): An Update". Proceedings of the Academy of Natural Sciences of Philadelphia. 139 (1): 5. JSTOR4064893.
"Samoan Hotspot Trail". Archived from the original on December 23, 2010. Retrieved 2009-12-01.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
Jackson, Matthew G.; Hart, Stanley R.; Konter, Jasper G.; Koppers, Anthony A. P.; Staudigel, Hubert; Kurz, Mark D.; Blusztajn, Jerzy; Sinton, John M. (December 2010). "Samoan hot spot track on a "hot spot highway": Implications for mantle plumes and a deep Samoan mantle source". Geochemistry, Geophysics, Geosystems. 11 (12): 19. Bibcode:2010GGG....1112009J. doi:10.1029/2010GC003232. S2CID131425199.
Koppers, Anthony A. P.; Russell, Jamie A.; Roberts, Jed; Jackson, Matthew G.; Konter, Jasper G.; Wright, Dawn J.; Staudigel, Hubert; Hart, Stanley R. (July 2011). "Age systematics of two young en echelon Samoan volcanic trails". Geochemistry, Geophysics, Geosystems. 12 (7): 5. Bibcode:2011GGG....12.7025K. doi:10.1029/2010GC003438. hdl:1912/4769. S2CID54947952.
Koppers, A. A.; Konter, J. G.; Jackson, M. G. (2013-12-01). "Insights Into the Origin of the Longest-lived Hotspot in the Pacific: Clues from the Tuvalus". AGU Fall Meeting Abstracts. 13: V13F–2668. Bibcode:2013AGUFM.V13F2668K.
Finlayson, V.; Konter, J. G.; Konrad, K.; Price, A. A.; Koppers, A. A. P.; Jackson, M. G. (2016-12-01). "Identification of a Hawaiian-Emperor Style Bend in the Tuvalu Segment of the Rurutu Hotspot". AGU Fall Meeting Abstracts. 52: DI52A–05. Bibcode:2016AGUFMDI52A..05F.
Duncan, R.A. (1985). Brocher, T.M. (ed.). Radiometric ages from volcanic rocks along the New Hebrides-Samoa lineament. Investigations of the nonhern Melanesian borderland. Vol.Series 3. Circum-Pacific Councilfdr Energy and Mineral Resources Earth Science. pp.67–76.
Connell, Laurie; Barrett, Anne; Templeton, Alexis; Staudigel, Hubert (30 November 2009). "Fungal Diversity Associated with an Active Deep Sea Volcano: Vailulu'u Seamount, Samoa". Geomicrobiology Journal. 26 (8): 597–605. doi:10.1080/01490450903316174. S2CID128549578.
Hart, S. R.; Coetzee, M.; Workman, R. K.; Blusztajn, J.; Johnson, K. T. M.; Sinton, J. M.; Steinberger, B.; Hawkins, J. W. (30 October 2004). "Genesis of the Western Samoa seamount province: age, geochemical fingerprint and tectonics". Earth and Planetary Science Letters. 227 (1): 37–56. Bibcode:2004E&PSL.227...37H. doi:10.1016/j.epsl.2004.08.005. ISSN0012-821X.
Koppers, Anthony A. P.; Russell, Jamie A.; Roberts, Jed; Jackson, Matthew G.; Konter, Jasper G.; Wright, Dawn J.; Staudigel, Hubert; Hart, Stanley R. (July 2011). "Age systematics of two young en echelon Samoan volcanic trails". Geochemistry, Geophysics, Geosystems. 12 (7): n/a. Bibcode:2011GGG....12.7025K. doi:10.1029/2010GC003438. hdl:1912/4769. S2CID54947952.
Sims, Kenneth W. W.; Hart, S. R.; Reagan, M. K.; Blusztajn, J.; Staudigel, H.; Sohn, R. A.; Layne, G. D.; Ball, L. A.; Andrews, J. (2008). "238U-230Th-226Ra-210Pb-210Po, 232Th-228Ra, and 235U-231Pa constraints on the ages and petrogenesis of Vailulu'u and Malumalu Lavas, Samoa". Geochemistry, Geophysics, Geosystems. 9 (4): n/a. Bibcode:2008GGG.....9.4003S. doi:10.1029/2007GC001651. hdl:1912/3263. ISSN1525-2027. S2CID54637043.
Sudek, Lisa A.; Templeton, Alexis S.; Tebo, Bradley M.; Staudigel, Hubert (30 November 2009). "Microbial Ecology of Fe (hydr)oxide Mats and Basaltic Rock from Vailulu'u Seamount, American Samoa". Geomicrobiology Journal. 26 (8): 581–596. doi:10.1080/01490450903263400. S2CID85954222.
Workman, R. K.; Hart, S. R.; Jackson, M.; Regelous, M.; Farley, K. A.; Blusztajn, J.; Kurz, M.; Staudigel, H. (2004). "Recycled metasomatized lithosphere as the origin of the Enriched Mantle II (EM2) end-member: Evidence from the Samoan Volcanic Chain". Geochemistry, Geophysics, Geosystems. 5 (4): n/a. Bibcode:2004GGG.....5.4008W. doi:10.1029/2003GC000623. hdl:1912/462. ISSN1525-2027. S2CID13987904.