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Tafuna-Leone Plain

From Wikipedia, the free encyclopedia
View of the Tāfuna Plain from A'oloau.

The Tafuna-Leone Plain forms the largest contiguous expanse of level, developable land in American Sāmoa.[1] It is the only significant flat land on Tutuila Island.[2] Much of Tutuila Island, especially its mountainous northern region, consists of older volcanic formations characterized by low permeability. In contrast, the Tafuna-Leone Plain in the southwest is composed of more recent volcanic rocks with higher permeability.[3]

Most of the lowland rainforest on the Tafuna-Leone Plain has been cleared, with only a few remaining fragments scattered across the area.[4] Adjacent to the Fatuoaiga Catholic Church Center and the Tia Seu Lupe Historic Monument at Ottoville, a 20-acre reserve protects the island's last remaining lowland rainforest on Tutuila.[5][6][7]

It is the largest expanse of level terrain on Tutuila Island, covering approximately 35 square kilometers (13.5 sq. mi.). Formed by extrusive volcanic activity that overlaid an older eroded surface, it contains the island's only extensive aquifer.[8]

Geography

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Its terrain includes numerous hills rising more than 183 meters (600 ft.), formed by Holocene volcanic eruptions overlying a preexisting barrier reef. Much of the island's industry and population are concentrated on the plain's relatively flat areas. Pago Pago International Airport occupies a low-lying section in the southeast, where rainfall averages approximately 118 inches per year. Between 1970 and 2004, annual precipitation at the airport varied by as much as 46 inches above average (in 1981) and 61 inches below average during the 1997–98 El Niño event. Urbanization—consisting of low buildings and paved roads—occurs primarily in the eastern portion near the airport.[9]

Located on Tutuila Island's southwestern coast, the Tafuna-Leone Plain exhibits the island's gentlest topography, featuring approximately 200 meters of relief. The landscape formed during the Holocene, when volcanic eruptions buried portions of an older barrier reef.[10]

References

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  1. ^ Amerson, A. Binion and W. Arhur Whistler (1982). “Wildlife and Wildlife Habitat of American Samoa: Environment and ecology”. U.S. Fish and Wildlife Service. Page 18.
  2. ^ South Pacific Regional Environment Programme (1999). Coastal Management Profiles: A Directory of Pacific Island Governments and Non Government Agencies with Coastal Management Related Responsibilities. SPREP's Climate Change and Integrated Coastal Management Programme. Page 21. ISBN 9789820401983.
  3. ^ Trubble, Gordon W. (2008). Ground Water on Tropical Pacific Islands: Understanding a Vital Resource. United States Geological Survey. Page 28. ISBN 9781411318595.
  4. ^ Amerson, A. Binion and W. Arhur Whistler (1982). “Wildlife and Wildlife Habitat of American Samoa: Environment and ecology”. United States Fish and Wildlife Service. Page 41.
  5. ^ Stanley, David (1999). Moon Handbooks Tonga-Samoa. David Stanley. Page 177. ISBN 978-1-56691-174-0.
  6. ^ Stanley, David (2004). Moon Handbooks South Pacific. David Stanley. Pages 479-480. ISBN 978-1-56691-411-6.
  7. ^ Stanley, David (1996). South Pacific Handbook. David Stanley. Pages 412-413. ISBN 978-1-56691-040-8.
  8. ^ United Nations (1995). Guidebook to Water Resources, Use and Management in Asia and the Pacific. Volume 1. United Nations Economic and Social Commission for Asia and the Pacific. Pages 6-7. ISBN 9789211197051.
  9. ^ Izuka, Scot K. and Thomas W. Giambelluca (2005). Potential Evapotranspiration on Tutuila, American Samoa. United States Geological Survey. Page 3. ISBN 9781244045378.
  10. ^ Riegl, Bernhard M. and Richard E. Dodge (2008). Coral Reefs of the USA. Springer Science+Business Media. Page 746. ISBN 9781402068478.