An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Of or pertaining to the Atlantic Ocean.

M.E., from L. Atlanticum (mare) "the Atlantic (ocean)," from Gk. Atlantikos "of Atlas," adj. of → Atlas, in reference to Mount Atlas in NW Africa. So called because it lay beyond that mountain.

An immense chain of underwater mountains that runs down the middle of the Atlantic Ocean. The MAR, approximately 500-1000 km wide, extends 16,000 km from Iceland to the Antarctic Circle. The MAR is so high that it actually rises above sea level in many places, forming volcanic islands. The Azores, Ascension, St. Helena, and Iceland all arise from this great Atlantic range. The chain results from the movement of the continental plates. As these plates slowly separate, they leave gaps in the → Earth's crust. This allows molten rock from beneath the Earth's crust to reach the surface and forms a ridge. The MAR is a part of the global → mid-ocean ridge system.

→ mid-; → Atlantic; → ridge.

A region of the Earth where the inner → Van Allen belt comes closest to the Earth's surface. It is due to the fact that the → geomagnetic field is offset from the center of the Earth. The region is centered near 25 degrees South 50 degrees West, close to the Atlantic coast of Brazil. The excess of trapped energetic particles in that region presents a problem for satellites in orbit around the Earth.

→ south; → Atlantic; → anomaly.