Malumalu

Malumalu seamount lies in American Samoa and forms a topographic structure together with Savaii, Upolu and Tutuila close to the Tonga Trench which lies about 100 kilometres (62 mi) south.[1] Malumalu lies about 66 kilometres (41 mi) south of Ofu island[2] and is also known as "Southeast Bank".[3]

The seamount is a young volcano at the eastern end of a lineament that begins on Tutuila.[4] This lineament has been named the "Malu trend" and contrasted to the "Vai Trend" farther northeast which runs between Ofu, Ta'u and Vailulu'u,[5] comparable to the "Kea" and "Loa" trends in Hawaii.[6] Malumalu is not much older than Vailulu'u,[7] which has erupted in historical time.[1] Actinide isotope ratios indicate the occurrence of at least three volcanic events in the last 300,000 years, including at least two in the last 150,000 years and at least one in the last 8,000 years.[8] According to one model of the behaviour of the Samoa hotspot volcanic activity at Malumalu will decline in the next 10,000 - 100,000 years as the mantle plume is pushed farther northeast to Vailulu'u by mantle flow generated by the Tonga slab.[9]

References

1. Workman et al. 2004, p. 5.
2. Sims et al. 2008, p. 3.
3. Wright, Dawn J.; Roberts, Jed T.; Fenner, Douglas; Smith, John R.; Koppers, Anthony A.P.; Naar, David F.; Hirsch, Emily R.; Clift, Leslie Whaylen; Hogrefe, Kyle R. (2012), "Seamounts, Ridges, and Reef Habitats of American Samoa", Seafloor Geomorphology as Benthic Habitat, Elsevier, p. 792, doi:10.1016/b978-0-12-385140-6.00058-x, ISBN 9780123851406
4. Hart, Stanley R.; Staudigel, Hubert; Konter, Jasper; Jackson, Matthew G.; Russell, Jamie A.; Koppers, Anthony A. P. (1 June 2008). "Samoa reinstated as a primary hotspot trail". Geology. 36 (6): 437. Bibcode:2008Geo....36..435K. doi:10.1130/G24630A.1. ISSN 0091-7613.
5. Reinhard et al. 2019, p. 1486.
6. Reinhard et al. 2019, p. 1487.
7. Workman et al. 2004, p. 8.
8. Sims et al. 2008, p. 13.
9. Sims et al. 2008, p. 16.

Sources

• Reinhard, Andrew A.; Jackson, Matthew G.; Blusztajn, Jerzy; Koppers, Anthony A. P.; Simms, Alexander R.; Konter, Jasper G. (2019). ""Petit Spot" Rejuvenated Volcanism Superimposed on Plume-Derived Samoan Shield Volcanoes: Evidence From a 645-m Drill Core From Tutuila Island, American Samoa" (PDF). Geochemistry, Geophysics, Geosystems. 20 (3): 1485–1507. Bibcode:2019GGG....20.1485R. doi:10.1029/2018GC007985. hdl:1912/24119. ISSN 1525-2027.CS1 maint: ref=harv (link)
• 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. (April 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.CS1 maint: ref=harv (link)
• Workman, R. K.; Hart, S. R.; Jackson, M.; Regelous, M.; Farley, K. A.; Blusztajn, J.; Kurz, M.; Staudigel, H. (April 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.CS1 maint: ref=harv (link)