Cromwell Current facts for kids
The Cromwell Current (also called the Pacific Equatorial Undercurrent) is a special ocean current. It flows deep under the surface of the Pacific Ocean right along the equator. Unlike the surface currents that usually flow west, the Cromwell Current flows strongly to the east!
This hidden river in the ocean was found in 1952 by a researcher named Townsend Cromwell. It's about 250 miles (220 nmi; 400 km) wide. It starts about 300 feet (91 m) below the ocean's surface. Even though it's very long (about 3,500 miles (3,000 nmi; 5,600 km)), it's quite shallow, only about 100 feet (30 m) from top to bottom. This powerful current can flow as fast as 1.5 meters per second (about 3.4 miles per hour). It carries an amazing amount of water – about 1,000 times more than the Mississippi River!
How We Found This Hidden Current
In 1951, some researchers were out fishing in the Pacific Ocean. They were using long fishing lines that went deep underwater. They noticed something strange: their fishing gear was drifting east. This was very unusual because the ocean's surface currents at the equator usually flow west, pushed by the winds.
The next year, in 1952, Townsend Cromwell led a team to investigate this mystery. They wanted to see how ocean currents changed at different depths. That's when they discovered this fast-moving current flowing east, deep below the surface. It was a big surprise!
How the Cromwell Current Works
Explaining exactly how the Cromwell Current works can be a bit tricky, but here are the main ideas:
- No Coriolis Force: The current is right on the equator. At the equator, a force called the Coriolis force (which usually pushes moving things like water or air) is zero. This means the water can flow straight from a high-pressure area in the west to a low-pressure area in the east. The strong trade winds blowing from east to west help create this pressure difference.
- Staying on Track: If a bit of water in the current tries to move away from its path (either north or south), the Coriolis force (which starts to act away from the equator) quickly pushes it back into the main eastward flow. This helps keep the current tightly focused along the equator.
Facts About the Current
- Depth: The water at the very top of the ocean flows west. But around 40 metres (130 ft) down, the water starts to flow east. The Cromwell Current goes down to about 400 metres (1,300 ft) deep.
- Speed and Flow: The fastest part of the current moves at about 1.5 meters per second (3.4 mph). This is about twice as fast as the surface currents that flow west. The total amount of water flowing through it is huge – about 30,000,000 cubic metres (1.1×109 cu ft) every second!
- Length: This amazing underwater river stretches for about 13,000 kilometres (7,000 nmi; 8,100 mi) across the Pacific Ocean.
How It Connects with El Niño
El Niño is a natural event that changes ocean conditions in the Pacific. Normally, strong winds push warm surface water to the west. This allows cooler, deeper water to rise up in the east (a process called upwelling).
During an El Niño year, these normal patterns change. The warm surface water "sloshes" back across the ocean, making the eastern Pacific much warmer. In regular years, the Cromwell Current is forced to the surface near the Galápagos Islands by underwater mountains. This brings cool, nutrient-rich water up. But during El Niño years, this doesn't happen. That's why the waters around the Galapagos are much warmer during El Niño events.
Its Effect on Ocean Life
The Cromwell Current is very important for ocean life. It carries a lot of oxygen and nutrients, which are like food for tiny ocean plants and animals. Because of this, many fish gather in the current.
Near the Galapagos Islands, the current causes upwelling. This brings all those good nutrients and food supplies to the surface. This is super important for animals like the Galápagos penguin. However, this upwelling doesn't happen all the time. So, the penguins' food supply can come and go. Luckily, these clever penguins have learned to adapt their breeding habits to deal with these changes in food availability.
Possible Effect on Climate
Scientists are still studying how much the Cromwell Current affects the world's climate. It's a huge movement of water, so it likely plays a role, but we don't fully understand it yet.
See also
In Spanish: Corriente de Cromwell para niños
- Lomonosov Current
- Ocean current
- Ocean gyre
- Physical oceanography
