American-Antarctic Ridge
Encyclopedia
The American-Antarctic Ridge (AAR) is a tectonic spreading center
between the South American Plate
and the Antarctic Plate
. It runs along the seafloor from the Bouvet Triple Junction
in the South Atlantic Ocean
southwestward to a major transform fault
boundary east of the South Sandwich Islands.
Divergent boundary
In plate tectonics, a divergent boundary or divergent plate boundary is a linear feature that exists between two tectonic plates that are moving away from each other. Divergent boundaries within continents initially produce rifts which produce rift valleys...
between the South American Plate
South American Plate
The South American Plate is a continental tectonic plate which includes the continent of South America and also a sizeable region of the Atlantic Ocean seabed extending eastward to the Mid-Atlantic Ridge....
and the Antarctic Plate
Antarctic Plate
The Antarctic Plate is a tectonic plate covering the continent of Antarctica and extending outward under the surrounding oceans. The Antarctic Plate has a boundary with the Nazca Plate, the South American Plate, the African Plate, the Indo-Australian Plate, the Scotia Plate and a divergent boundary...
. It runs along the seafloor from the Bouvet Triple Junction
Bouvet Triple Junction
The Bouvet Triple Junction is a geologic triple junction of three tectonic plates located on the seafloor of the South Atlantic Ocean, named after Bouvet Island....
in the South Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
southwestward to a major transform fault
Transform fault
A transform fault or transform boundary, also known as conservative plate boundary since these faults neither create nor destroy lithosphere, is a type of fault whose relative motion is predominantly horizontal in either sinistral or dextral direction. Furthermore, transform faults end abruptly...
boundary east of the South Sandwich Islands.