Saint Peter and Paul Rocks

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Coordinates: 00°55′1″N 29°20′7″W / 0.91694, -29.33528

Scientific Station of the Saint Peter and Saint Paul Islets. This image is credited by the SECIRM, Brazilian Federal Government

The Saint Peter and Saint Paul Islets, officially the Arquipélago de São Pedro e São Paulo, is an archipelago of the State of Pernambuco, in Brazilian Federation. It is an archipelago of small islands and rocks in the Equatorial Atlantic Ocean, 870 km from the Fernando de Noronha Island and 1,010 km from the city of Natal on Brazil's northeastern coast. The islets expose serpentinized mantle peridotite on the top of one of largest megamullion of the world, being the unique abyssal mantle exposure above sea level. All of the islets and rocks are designated an environmental protection area. The main economic activity around the islets is tuna fishing.

[edit] Setting

Locality map

Map of the Saint Peter Saint Paul Iselets, after Motoki et al. (2007)

The Saint Peter and Saint Paul Islets are situated in the equatorial region of the Atlantic Ocean, approximately 1,010 km to the ENE of the city of Natal, State of Rio Grande do Norte, Brazil. The total emerging area is about 13,000 m² and the maximum altitude is 18 m. They are composed of 5 islands and numerous rocks.

• Belmonte Island (Sudoeste, Southwest): 5,380 m²
• Challenger Island (São Paulo, Sudeste, Southeast): 3,000 m²
• Nordeste Island (São Pedro, Northeast): 1,440 m²
• Cabral Islet (Noroeste, Northwest): 1,170 m²
• South Islet: 943 m²

No islet has permanent fresh water.

[edit] Biology

Only the largest of the islets, Southwest Rock, 80m by 40m, is vegetated with mosses and grasses. The other rocks are mostly barren, except for algae and fungus that can tolerate the salt spray. The rocks are inhabited by sea birds, including the Brown Booby (Sula leucogaster), Brown Noddy (Anous stolidus), and Black Noddy (Anous minutus), as well as crabs (Grapsus grapsus), insects and spiders.

[edit] History

On the morning of February 16, 1832 the rocks were visited by Charles Darwin on the first leg of his voyage of the HMS Beagle around the world. Another famous person to visit the rocks was Ernest Shackleton in his last expedition to Antarctica that occurred in 1921-1922.

In 1942, during World War II, the islands were declared part of the Federal Territory of Fernando de Noronha (that also included Rocas Atoll).

In early 1960, the rocks served as the starting-point and terminus for the first submerged circumnavigation of the world by the American nuclear-powered submarine USS Triton (SSRN-586).

On October 5, 1988, the Federal Territory was dissolved and added to the Pernambuco state.

[edit] References

• Andrade, F.G.G., Simões, L.S.A., Campos, T.F.C., Silva, A.J.C.A. 2007. Padrão estrutural da foliação milonígica do Arquipélago de São Pedro e São Paulo. Anais do 11º Simpósio Nacional de Estudos Tectônicos, 5th International Symposium of Tectonics of the SBG. Natal, 233. (in Portuguese)
• Beach, Edward L. 1962. Around the World Submerged: The Voyage of the Triton, 102-105, 257. LCC: 62-18406; ISBN: 1557502153 (paperback)
• Beach, Edward L. November 1960 (Vol. 118, No. 5). "Triton Follows Magellan's Wake" National Geographic Magazine. 585-615
• Bonatti, E. 1990. Subcontinental mantle exposed in the Atlantic Ocean on St Peter-Paul islets. Nature, 345, 800-802.
• Campos, T.F.C., Virgens Neto, J., Amorim, V.A., Hartmann, L.A., Petta, R.A. 2003. Modificações metassomáticas das rochas milonitizadas do complexo ultramáfico do Arquipélago de São Pedro e São Paulo, Atlântico Equatorial. Geochimica Brasiliensis, 17-2, 81-90. (in Portuguese)
• Campos, T.F.C., Virgens Neto, J., Costa, L.S., Petta, R.A., Sousa, L.C., Silva, F.O. 2007. Sistema de diaclasamento do Arquipélago de São Pedro e São Paulo (Atlântico Equatorial) como indicador de movimentação destral associado à falha transformante de São Paulo. Anais do 11º Simpósio Nacional de Estudos Tectônicos, 5th International Symposium of Tectonics of the SBG. Natal, 238. (in Portuguese)
• Campos, T.F.C., Virgens Neto, J., Srivastava, N.K., Petta, R.A., Harmann, L.A., Moraes, J.F.S., Mendes, L., Silveira, S.R.M. 2005. Arquipélago de São Pedro e São Paulo e São Paulo, soeerguimento tectônico de rochas infracrustais no Oceano Atlântico. Sítios Geológicos e Paleontológicos do Brasil, SIGEP 002, UNB, 12p. [1], Access, on December 31, 2006. (in Portuguese)
• Hékinian, R., Juteau, T., Gracia, E., Udintsev, G., Sichler, B., Sichel, S.E., Apprioual, R. 2000. Submersible observations of Equatorial Atlantic Mantle: The St. Paul Frature Zone region. Marine Geophysical Research, 21, 529-560.
• Melson, W.G., Jarosewich, E., Bowen, V.T., Thompsonm G. 1967. St. Peter and St. Paul rocks: a high-temperature mentle-derived intrusion. Science, 155. 1532-1535.
• Moraes, J.F.S., Linden, E.M., Moraes, F.A.B. 1997. Planta topográfica do Arquipélago de São Pedro e São Paulo, escala 1:500. CPRM - Serviço Geológico do Brasil.
• Motoki, A., Sichel, S.E., Baptista Neto, J.A., Szatmari, P., Soares, R., Melo, R.C., Petrakis, G.H. 2007. Características geomorfológicas do Arquipélago de São Pedro e São Paulo, Oceano Atlântico Equatorial, e sua relação com a história de soerguimento. Revista Brasileira de Geomorfologia. (in Portuguese, in submission)
• O'Brian, Patrick: H.M.S. Surprise, W.W. Norton & Company, New York, 1973, Chapter 5, page 117.
• Savi, D.C., Sichel, S.E. Possibilidade de catástrofe no Arquipélago de São Pedro e São Paulo e suas implicações sobre a soberania do mar Brasileiro. Pesquisa Naval, 19. (in Portuguese, in press)
• Sichel, S.E., Motoki, A., Esperança, S., Maia, M., Mello, S.L.M., Horan, M.F. 2007. Geophysical and geochemical indications for existence of cold upper mantle beneath the Equatorial Atlantic Ocean. Revista de Sociedade Brasileira de Geofísica. (in Portuguese, in submission)
• Souza, José Eduardo Borges de: O arquipélago de São Pedro e São Paulo, Rio de Janeiro, Revista do Clube Naval, Ano 115, N° 340, Out/Nov/Dez 2006. p. 70-72, ISSN 0102-0382.
• Thompson, Geoffrey: St. Peter and St. Paul's Rocks (Equatorial Atlantic) and the Surrounding Sea Floor, Woods Hole, Woods Hole Oceanographic Institution, 1981 (Technical Report) (Woods Hole Oceanog. Inst. Tech. Rept. WHOI-81 -98) [2]
• Tressler, Willis L.: Rochedos São Pedro e São Paulo (St. Peter and St. Paul Rocks), Washington, U. S. Navy Hydrographic Office, 1956 (Technical Report, TR-31).
• Virgens Neto, J., Campos, T.F.C. 2007. A influência da zona de fratura São Paulo no contexto estrutural do Arquipélago de São Pedro e São Paulo - Atlântico Equatorial. Anais do 11º. Simpósio Nacional de Estudos Tectônicos, 5th International Symposium of Tectonics of the SBG. Natal, 294-295. (in Portuguese)
• Wiseman, J. D. H. 1966. St Paul's Rocks and the Problem of the Upper Mantle. Geophysical Journal of the Royal Astronomical Society, 11, 519-525. (in Portuguese)

[edit] External links

• St. Peter and St. Paul rocks (WWF)
• Information and pictures from landing, February 2001
• Darwin's description from Voyage of the Beagle