Cromwell current
Encyclopedia
The Cromwell Current is an eastward-flowing subsurface current that extends the length of the equator
in the Pacific Ocean
.
The Cromwell Current was discovered in 1952 by Townsend Cromwell
, a researcher with the Honolulu Laboratory. It is 250 miles (400 km) wide and flows to the east. It is hidden 300 feet (100 m) under the surface of the Pacific Ocean
at the Equator
it is relatively narrow in depth compared to other ocean currents being only 100 feet deep. It has 1000 times the volume of Mississippi River
and its length is 3500 miles (6000km).
The Cromwell current was listed in the 1964 edition of the Guinness Book of World Records.
, a keen surfer, swimmer and oceanographer, discovered the current that now bears his name whilst researching drifting in the equatorial region of the Pacific Ocean
. He died in 1958 when his plane crashed en route to an oceanography
expedition.
The following year Townsend Cromwell led a research party to investigate how the currents of the ocean varied as a function of depth. They discovered a fast flowing current that flowed eastwards in the deep surface layers.
islands. (This is called upwelling) However during El Nino years the current does not upwell in this way. The waters around the islands are therefore considerably warmer during el nino years than during normal years.
. Upwelling, however, is a sporadic phenomenon; it fails to occur on a regular basis and so the food supply comes and goes. The penguins have several adaptations to cope with this, including versatility in their breeding habits.
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
.
The Cromwell Current was discovered in 1952 by Townsend Cromwell
Townsend Cromwell
Townsend Cromwell was an oceanographer who discovered the Cromwell current whilst researching drifting in the equatorial region of the Pacific Ocean. He died in 1958 when his plane crashed while he was en route to an oceanography expedition....
, a researcher with the Honolulu Laboratory. It is 250 miles (400 km) wide and flows to the east. It is hidden 300 feet (100 m) under the surface of the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
at the Equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
it is relatively narrow in depth compared to other ocean currents being only 100 feet deep. It has 1000 times the volume of Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
and its length is 3500 miles (6000km).
The Cromwell current was listed in the 1964 edition of the Guinness Book of World Records.
Townsend Cromwell
Townsend CromwellTownsend Cromwell
Townsend Cromwell was an oceanographer who discovered the Cromwell current whilst researching drifting in the equatorial region of the Pacific Ocean. He died in 1958 when his plane crashed while he was en route to an oceanography expedition....
, a keen surfer, swimmer and oceanographer, discovered the current that now bears his name whilst researching drifting in the equatorial region of the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
. He died in 1958 when his plane crashed en route to an oceanography
Oceanography
Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean...
expedition.
Discovery
In 1951 researchers on board the U. S. Fish and Wildlife Service research vessel were indulging in a spot of long line fishing. They noticed that the gear deep under water drifted eastwards. This was unusual because the surface currents of the pacific ocean flow westwards on the equator. (They follow the direction of the winds).The following year Townsend Cromwell led a research party to investigate how the currents of the ocean varied as a function of depth. They discovered a fast flowing current that flowed eastwards in the deep surface layers.
Detailed data
- Depth: The surface currents flow west. There is reversal point about 40 m down, where the water starts to flow east. The current goes down to about 400 m.
- Flow rate:The total flow is up to around 30 000 000 cubic meters per second. The top speed is around 1.5 m/s (this is about twice as fast as the westerly surface current)
- Length:13,000 km
Interaction with El Niño
El Niño is a reversal of the normal situation in the Pacific Ocean. Surface water is blown westwards by the prevailing winds and deeper water is forced upwards to replace it. Every now and then, the surface water sloshes back across the ocean, bringing warm water temperatures along the eastern coasts of the pacific. In non-El Niño years, the Cromwell current is forced to the surface by underwater volcanoes near the GalapagosGalápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
islands. (This is called upwelling) However during El Nino years the current does not upwell in this way. The waters around the islands are therefore considerably warmer during el nino years than during normal years.
Effect on wildlife
The Cromwell Current is both oxygen and nutrient rich. A large number of fish are concentrated in it. Upwelling occurs near the Galapagos islands. This brings food supplies to the surface for Galápagos PenguinGalapagos Penguin
The Galapagos Penguin is a penguin endemic to the Galapagos Islands. It is the only penguin that lives north of the equator in the wild; it can survive due to the cool temperatures resulting from the Humboldt Current and cool waters from great depths brought up by the Cromwell Current...
. Upwelling, however, is a sporadic phenomenon; it fails to occur on a regular basis and so the food supply comes and goes. The penguins have several adaptations to cope with this, including versatility in their breeding habits.
See also
- Lomonosov currentLomonosov currentThe Lomonosov current is a deep current in the Atlantic Ocean.The Lomonosov current was discovered in 1959 during the 5th cruise of the research vessel Mikhail Lomonosov by an expedition of the Marine Hydrophysical Institute of the Ukrainian SSR Academy of Sciences, based in Sevastopol...
— deep current in the Atlantic OceanAtlantic OceanThe Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area... - Ocean currentOcean currentAn ocean current is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis effect, cabbeling, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...
- Oceanic gyres
- Physical oceanographyPhysical oceanographyPhysical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters.Physical oceanography is one of several sub-domains into which oceanography is divided...