Cromwell Current (redirected from Pacific Equatorial Undercurrent)

Cromwell Current [′kräm‚wel ‚kər·ənt]

(oceanography)

An eastward-setting subsurface current that extends about 1½° north and south of the equator, and from about 150°E to 92°W.

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Cromwell Current 

a subsurface equatorial countercurrent in the eastern Pacific. It moves to the east under the South Trades Current from 154°–150°W long, to the region of the Galapagos Islands, approximately between 2°N lat. and 2°S lat. Length, more than 6,500 km; width, approximately 300 km. It is located at depths of 100–400 m; on the northern and southern ends and in the east, it is shallower and narrower (30 m at 2°N lat and 2°S lat.). The current line at 140°W long, lies at a depth of 100 m and off the Galápagos at 50 m.

The Cromwell Current travels at 150 m per sec in the west and at approximately 70 m per sec in the east. Water discharge is more than 30 million cu m per sec. A compensation current, the Cromwell is an important component in the circulation of water in the equatorial Pacific. The current was discovered in 1952 by an American expedition on the H. M. Smith, headed by the oceanographer T. Cromwell, after whom it was named. In 1961 a Soviet expedition on the vessel A. I. Voeikov located the Cromwell Current at 154°W long, and established its speed there at a depth of 100 m at 93 m per sec (occasionally reaching 143 m per sec).