Northeast Georgia Rise

Northeast Georgia Rise
Centred in the Georgia Basin, Northeast Georgia Rise is located northeast of South Georgia, west of Islas Orcadas Rise, south the Falkland Ridge and north of the South Sandwich Trench. North or Northwest Georgia Rise, barely visible just north of South Georgia, also affects ocean circulation but has a different tectonic history.
Summit depth	2 km (1.2 mi)
Height	3 km (1.9 mi)
Summit area	400 km × 400 km (250 mi × 250 mi)
Location
Location	Northeast of South Georgia Island
Coordinates	52°30′S 31°00′W / 52.5°S 31.0°W / -52.5; -31.0Coordinates: 52°30′S 31°00′W / 52.5°S 31.0°W / -52.5; -31.0
Country	International
Geology
Type	LIP, hotspot volcano
Age of rock	100 to 94 Ma

The Northeast Georgia Rise is an oceanic plateau located in the South Atlantic Ocean northeast of South Georgia Island and west of the Falkland Plateau.

The rise is separated from South Georgia Island by the Northeast Georgia Passage. The Georgia Basin surrounds the northern end of the rise. The Agulhas-Falkland Fracture Zone (AFFZ) stretches across the Atlantic north of the Northeast Georgia Rise. A group of small seamounts north of the rise are aligned with a gap in the AFFZ. East of this gap the AFFZ is a single ridge with an average height of 2,500 m (8,200 ft) but west of the gap the AFFZ is a double ridge with an average height of 1,500 m (4,900 ft).

On the eastern flank of the rise is a prominent ridge, the Soledad Ridge, about 1,000 m (3,300 ft) tall. It has the same orientation as the southeastern part of the rise. It is a basement-feature in which bottom-water have scoured a channel. Both the Northeast Georgia Rise and the Islas Orcadas Rise east of it, are seemingly dissected by transverse valleys that extend to the fracture zones of the Mid-Atlantic Ridge.

The Northeast Georgia Rise is made of oceanic crust that formed when Africa and South America spread apart after the Gondwana breakup. 100 Ma the Northeast Georgia Rise was part of the Agulhas Plateau-Northeast Georgia Rise-Maud Rise large igneous province (LIP) in what today is the southwestern-most Indian Ocean south of South Africa. This LIP, often called the southeast African LIP, formed at the triple junction where Gondwana passed over the Bouvet Hotspot and broke-up into Antarctica, South America, and Africa. This volcanism lasted until 94 Ma after which seafloor spreading detached the Northeast Georgia Rise and Maude Rise from the Agulhas Plateau and the Northeast Georgia Rise migrated westward to its current location and Maud Rise south towards the Weddell Sea.