Romanche dig

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Tectonic plates with continents in the background
Romanche Trench in the middle of the Atlantic. The red arrows show the direction of movement of the adjacent panels.

The Romanchegraben , also known as Romanche Rinne or Romanche Depth , is an approximately 965 km long and 19 km wide deep-sea channel in the center of the Atlantic Ocean (Atlantic Ocean) with a maximum depth of 7730 m.

geography

The Romanche Trench is located between the Sierra Leone Basin in the north and northeast, the South Atlantic Ridge in the east and southeast, the Northern Brazilian Basin in the south and southwest and the North Atlantic Ridge in the west and northwest. There it lies at the equator as the junction of the North and South Atlantic Ridge , the two halves of the Mid-Atlantic Ridge , between about 2 ° north and south latitude and 16 and 20 ° west longitude .

geology

The Romanchegraben is a large transform fault that displaces the mid-Atlantic ridge, the junction between the South American plate in the west and the African plate in the east, by several hundred kilometers. The mean annual movement at the disorder is 1.7 cm. The mid-Atlantic ridge dissolves as it approaches the transform fault into several mutually offset sections and becomes indistinct, only to disappear 30 km in front of it. In contrast to the otherwise normal oceanic crust consisting of basalt , it is assumed that the ocean floor around the trench consists of serpentinized peridotite .

Oceanic circulation

As an interruption of the Mid-Atlantic Ridge, the Romanch Trench is important for the spread of bottom water in the Atlantic area. Since the way to the north is blocked by the whale ridge in front of Namibia , cold Antarctic bottom water formed in the Antarctic with a temperature of around 1.5 ° C in a volume flow of 3.6 Sverdrup (3.6 × 10 6  m³ / s) flow into the eastern part of the Atlantic.

Discovery story

The Romanchegraben was discovered in 1883 by a French expedition who named it after their ship. The researchers were on their way back from Tierra del Fuego , where they had operated a weather station and a geomagnetic observatory in Orange Bay as part of the First International Polar Year 1882/83 and observed the transit of Venus on December 6, 1882.

See also

literature

Individual evidence

  1. ^ E. Bonatti, M. Ligi, G. Carrara, L. Gasperini, N. Turko, S. Perfiliev, A. Peyve, PF Sciuto: Diffuse impact of the Mid-Atlantic Ridge with the Romanche transform: an ultracold ridge-transform intersection . In: Journal of Geophysical Research . tape 101 , B4, 1996, ISSN  0148-0227 , pp. 8043-8054 , doi : 10.1029 / 95JB02249 .
  2. ^ Elisabeth Helmke: On the way with the research ship "Polarstern". Weekly report No. 2, ANT XXI / 5, FS "Polarstern" May 16, 2004. (PDF) (No longer available online.) Formerly in the original ; Retrieved June 30, 2011 .  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Toter Link / epic.awi.de  
  3. ^ R. Schlitzer, W. Roether, U. Weidmann, P. Kalt, HH Loosli: A meridional 14 C and 39 Ar section in northeast Atlantic deep water . In: Journal of Geophysical Research 90, Issue C10, 1985, pp. 6945-6952, bibcode : 1985JGR .... 90.6945S .
  4. ↑ Reinhard A. Krause: Data instead of sensations. The path to international polar research from a German perspective . In: Reports on Polar and Marine Research (= Reports on Polar and Marine Research ). Volume 609, 2010. doi: 10.2312 / BzPM_0609_2010

Coordinates: 0 ° 0 ′  N , 18 ° 0 ′  W