Continental shelves/South west African continental shelves

From Wikiversity
Jump to navigation Jump to search
This bathymetric map displays the south Atlantic sea floor features. Credit: M. C. Geraldes, A. Motoki, A. Costa, C. E. Mota and W. U. Mohriak.{{fairuse}}
This orthographic map of Africa has the countries outlined. Credit: Martin23230.{{free media}}

The countries on the southwestern coast of Africa include (north to south) Cameroon, Equatorial Guinea, Gabon, Republic of the Congo, Democratic Republic of the Congo (Zaire), Angola, Namibia, and South Africa.

On the orthographic map of Africa on the left South Africa is the southern-most country outlined. Going northward along the southwest coast are South Africa, Namibia, Angola, Democratic Republic of the Congo (Zaire), Republic of the Congo (Congo), Gabon, Equatorial Guinea, and Cameroon.

Cameroon continental shelves[edit]

Image shows more continental shelves off Cameroon. Credit: Xiaohui Xiao, Timipere Jenakumo, Charlie Ash, Huyen Bui, and Oludayo Fakunle, and Sophia Weaver.{{fairuse}}
Map shows location of Bonga Field off Nigeria. Credit: Sara Scoville-Weaver.{{fairuse}}

The map on the right shows the location of Bonga Field off Nigeria where colors browns to gray approximately represent areas near or above sea level during the last ice age (currently 1,000 meters up to sea level).

Angolan continental shelves[edit]

This is a gravimetric depth map of the Kwanza river continental shelves off shore Angola. Credit: Maryline Moulin, Daniel Aslanian, Jean-Louis Olivet, Isabelle Contrucci, Luis Matias, Louis Géli, Frauke Klingelhoefer, Hervé Nouzé, Jean-Pierre Réhault, and Patrick Unternehr.{{fairuse}}

As with other bathymetric maps yellow is 2,000 to 1,000 meters depth and orange to red is 1,000 meters to sea level. This latter depth zone represents those areas most likely near, at or above sea level during the last ice age. The region of the map is centered on the Kwanza river continental shelves off shore Angola.

Namibian continental shelves[edit]

The south west African continental shelf is off shore of Namibia and Angola. Credit: EMGEPRON.{{fairuse}}

As with other near surface continental shelves, those off-shore of Namibia, in the sea-floor map on the right, yellow is 2,000-1,000 meters in depth, orange is 1,000 to near sea level, and red is just below sea level. Orange to red is 1,000 meters up to just below sea level. During the last ice age, features in orange to red were likely just below to above sea level.

South African continental shelves[edit]

Bathymetric features of the South African continental shelves are shown. Credit: David Barratt and Richard Tilzey.
Map is of the Agulhas Bank south of Africa. Credit: Fama Clamosa.{{free media}}

Several features apparently could have substantial portions at or above sea level due to the previous ice age during the last 50 kyrs. These include the Madagascar Ridge, the Mozambique Plateau, the Southwest Indian Ridge, and the Del Cano Rise. The Kerguelen Plateau is closer to and likely an extension of the Antarctic continental shelves.

In the image on the left the light blue colors correspond to the zone from 1,000 meters to sea level.

See also[edit]