They also knew plates move apart most markedly at subduction zones, which typically occur at active continental margins — where the boundary between a continent and the ocean is also a tectonic plate boundary. That's why the Pacific Ocean expands faster than the Atlantic: Most of the Pacific sits atop one tectonic plate, and its boundaries line up almost perfectly with the continental ones on the east and west sides, the North American and Eurasian plates.
Subduction at these boundaries causes the earthquakes and volcanic eruptions that characterize the region's aptly named "Ring of Fire. The Atlantic Ocean, however, sits atop four major plates with boundaries that don't match continental borders — the boundaries occur in the middle of the ocean.
So scientists were flummoxed as to how its seafloor was expanding. But the new research suggests the upwelling of material from deep within the mantle could be the engine of that Atlantic expansion.
Catherine Rychert, a geophysicist from the University of Southampton and a co-author of the new study, said this process started million years ago. But someday, the rate of expansion could speed up.
However, it is likely the rate will change over millions of years because it has varied in the past," Rychert told Insider. For you. World globe An icon of the world globe, indicating different international options. Get the Insider App. Click here to learn more.
Scientists and geographers broadly separate the Atlantic in terms of north and south. The North Atlantic and South Atlantic each have distinct ocean currents that influence weather around the world. The ocean doesn't sit still like water in a sink. It moves more like a conveyer belt that's driven by changes in temperature and salinity over large areas. Both quick-moving surface currents and slower-moving deep ocean currents circulate water around the globe.
The seawater is constantly trying to find a balance. Warm water is less dense than cold water, so as water cools, it sinks, and warm water replaces it.
Water with high salinity—more salt—also moves into waters with lower salinity. Those factors drive the conveyer belt, a process also called thermohaline circulation. Warm water is heated by the Gulf Stream, a warm air current that originates in the Gulf of Mexico. The warm water then moves north, where it forces cooler water to sink and move south. As the current moves toward Antarctica, upwelling pushes cold water back to the surface, pushing the watery conveyer belt around the world.
Scientists estimate that it takes the conveyer belt about years to make one trip. That's because a wind stream called the African Easterly Jet is formed from the difference in the Sahara's dry, hot air and the humid cooler air to the west and south. The jet pushes westerly winds over Africa's west coast, where they sometimes pick up ocean water and form thunderstorms. Hurricanes are fueled by warm waters, and warmer Sahara summer winds drive some of the biggest hurricanes seen in the U.
Those that form off the coast of Africa must survive wind shear horizontal winds to hit the East Coast with full force. Occasionally, as with Hurricanes Florence and Harvey , storms weaken as they make their way across the Atlantic Ocean but are then refueled by warm waters off the East Coast or in the Gulf of Mexico.
The Atlantic Ocean is home to a diverse array of sea life, both those we can observe at the surface, and those all but hidden from human eyes. In December , National Geographic published photos from a deep-sea dive led by ocean research group OceanX. Images revealed the Northeast Canyons and Seamounts Marine National Monument , a federally protected marine area off the coast of Massachusetts, and it is teeming with biodiversity.
The Geological Society Plate Tectonics. Pioneers of plate tectonics What is a plate? Plate margins Plate tectonics of the UK. While humans have never known a world without it, the Atlantic Ocean is a relatively new addition to the planet.
It started out a smaller lakes and marshlands through the center of a now-scattered supercontinent called Pangea, eventually growing and stretching into the massive body of water we know today. Wegener believed that the major land masses, or continents, on Earth slid around each other and the perimeters of the oceans, as if they were two distinct types of crust on our planet.
This model can then better account for the growth of the Atlantic Ocean, but also for the various points of growth and destruction underneath the Pacific Ocean as well.
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