's separation (animated) A ridge under the northern Atlantic Ocean was first inferred by
Matthew Fontaine Maury in 1853, based on soundings by the
USS Dolphin. The existence of the ridge and its extension into the South Atlantic was confirmed during the
expedition of HMS Challenger in 1872. A team of scientists on board, led by
Charles Wyville Thomson, discovered a large rise in the middle of the Atlantic while investigating the future location for a
transatlantic telegraph cable. The existence of such a ridge was confirmed by sonar in 1925 and was found to extend around
Cape Agulhas into the
Indian Ocean by the
German Meteor expedition. In the 1950s,
mapping of the Earth's ocean floors by
Marie Tharp,
Bruce Heezen,
Maurice Ewing, and others revealed that the Mid-Atlantic Ridge had a strange
bathymetry of valleys and ridges, with its central valley being
seismologically active and the
epicenter of many
earthquakes. Ewing, Heezen and Tharp discovered that the ridge is part of a long essentially continuous system of
mid-ocean ridges on the floors of all the Earth's oceans. The discovery of this worldwide ridge system led to the theory of
seafloor spreading and general acceptance of
Alfred Wegener's theory of
continental drift and expansion in the modified form of
plate tectonics. The ridge is a feature whose contribution to the breakup of the
supercontinent of
Pangaea, in the period from about 200 to 160 million years ago, is considered in the modelling of such breakup in modern tectonic theory, where subduction and mantle plumes mechanisms are hypothesised to be primary, although historically this was contentious. ==Notable features==