A lot of the stuff we sea above ground...........are features that form from below........like the Hawaiian islands..........

Islands on or near the Mid-Atlantic Ridge[edit]

The islands, from north to south, with their respective highest peaks and location, are:

Northern Hemisphere (North Atlantic Ridge):

1. Jan Mayen (Beerenberg, 2277 m (at 71°06′N 08°12′W), in the Arctic Ocean
2. Iceland (Hvannadalshnúkur in the Vatnajökull, 2109.6 m (at 64°01′N 16°41′W), through which the ridge runs
3. Azores (Ponta do Pico or Pico Alto, on Pico Island, 2351 m, (at 38°28′0″N 28°24′0″W)
4. Saint Peter and Paul Rocks (Southwest Rock, 22.5 m, at 00°55′08″N 29°20′35″W)

Southern Hemisphere (South Atlantic Ridge):

1. Ascension Island (The Peak, Green Mountain, 859 m, at 07°59′S 14°25′W)
2. Saint Helena (Diana's Peak, 818 m at 15°57′S 5°41′W)
3. Tristan da Cunha (Queen Mary's Peak, 2062 m, at 37°05′S 12°17′W)
4. Gough Island (Edinburgh Peak, 909 m, at 40°20′S 10°00′W)
5. Bouvet Island (Olavtoppen, 780 m, at 54°24′S 03°21′E)

A fissure running along the Mid Atlantic Ridge in Iceland

Rock outcrop in Iceland, a visible surface feature of the Mid-Atlantic Ridge, the easternmost edge of theNorth American plate. It is a popular destination for tourists in Iceland.

Geology[edit]

For a general explanation of mid-oceanic ridges, see mid-oceanic ridge and seafloor spreading

The ridge sits atop a geologic feature known as the Mid-Atlantic Rise, which is a progressive bulge that runs the length of the Atlantic Ocean, with the ridge resting on the highest point of this linear bulge. This bulge is thought to be caused by upward convective forces in the asthenosphere pushing the oceanic crust and lithosphere.

This divergent boundary first formed in the Triassic period, when a series of three-armed grabens coalesced on the supercontinent Pangaea to form the ridge. Usually, only two arms of any given three-armed graben become part of a divergent plate boundary. The failed arms are called aulacogens, and the aulacogens of the Mid-Atlantic Ridge eventually became many of the large river valleys seen along the Americas and Africa(including the Mississippi River, Amazon River and Niger River).

The ridge is about 2,500 meters (8,200 feet) below sea level, while its flank is about 5,000 meters deeper.^[10]

The Fundy Basin on the Atlantic coast of North America between New Brunswick and Nova Scotia in Canada is evidence of the ancestral Mid-Atlantic Ridge.

See also[edit]

• Atlantis Massif