Earth’s current largest ocean, the Pacific, blankets a lot more than 30% of the planet’s surface, stretching 12,000 miles (19,000 kilometers) at its widest point, between Colombia and the Malay Peninsula, based on the Intergovernmental Oceanographic Commission of UNESCO (IOC UNESCO (opens in new tab)). But that titanic sea represents only the remnants of the biggest ocean in Earth‘s history.
Just what exactly was the biggest ocean ever to exist on our world?
That might be Panthalassa, a world-spanning sea that surrounded the supercontinent Pangaea from about 300 million to 200 million years back, Brendan Murphy, a geology professor at St. Francis Xavier University in Nova Scotia, told Live Science.
“The largest ocean usually happens when supercontinents form, because in the event that you only have one large supercontinent, then you’ve only got one ocean that exists around it,” Murphy said.
Related: Will there ever be another Pangaea?
Which has likely happened multiple times, Murphy said, but those single world oceans could have been comparable in proportions. The newest supercontinent was Pangaea, where today’s continents fit together, like the jigsaw-like bits of Africa and SOUTH USA. Another supercontinent, Rodinia, combined Earth’s landmasses in another configuration about 650 million years back, based on the Smithsonian Institution (opens in new tab); geologists debate whether another supercontinent arose among, Murphy said.
Panthalassa could have stacked at the very least another 1,860 miles (3,000 kilometers) onto the Pacific’s width, Murphy said. To place that into perspective, in the event that you were traveling by jet plane over the equator, it could take 10 hours to cross the Pacific but 15 to span Panthalassa, he explained. Or think about it in this manner: At its widest point, the Pacific could fit a lot more than five moon diameters; Panthalassa’s additional width would accommodate nearly yet another moon.
By surface, Panthalassa dwarfed the Pacific, covering approximately 70% of Earth’s surface (opens in new tab), in accordance with a 2022 review in the journal Earth-Science Reviews (opens in new tab), or nearly 140 million square miles (360 square km). The Pacific’s 30% of the Earth’s surface results in a lot more than 63 million square miles (165 million square km), in accordance with IOC UNESCO (opens in new tab).
Visualizing Panthalassa because the Pacific padded with an increase of than 1,800 extra miles captures the geological history, too: Pangaea split up in large part because of the opening of the Atlantic Ocean, at the trouble of Panthalassa. Its remnants became the Pacific, so that you can picture Panthalassa because the Pacific pasted onto the Atlantic, which today ranges between about 1,800 miles, between Brazil and Liberia, and 3,000 miles (4,800 km), between THE UNITED STATES and North Africa, in accordance with IOC-UNESCO.
Technically, however, Earth likely had a straight larger ocean at one point but one not defined by continents. About 150 million years after Earth formed, it had oceans but no continents yet, so an unbroken sea covered the earth, based on the Smithsonian. That could mean the ocean spanned the nearly 24,901 miles (40,075 km) of Earth’s equatorial circumference and the entire 197 million square miles (510 million square km) of Earth’s surface (opens in new tab).
Right now, though, scientists consider Earth’s oceans to become a single “world ocean,” considering that the waters interconnect at various points, based on the MarineBio Conservation Society (opens in new tab). The Atlantic mingles with the Pacific in the bottom of SOUTH USA, for instance, and contacts the Indian Ocean beneath Africa, Murphy said.
Nevertheless, as defined by continents, the Pacific has held the title of the world’s largest ocean since Pangaea’s demise around 200 million years back. But if current projections of tectonic plate movements hold true, Australia will split the Pacific in two on the next 70 million years, Murphy said. Simultaneously, the Atlantic will widen, taking the crown of Earth’s largest ocean.
Originally published on Live Science.
Michael Dhar is really a science editor and writer located in Chicago. He’s got an MS in bioinformatics from NYU Tandon School of Engineering, an MA in English literature from Columbia University and a BA in English from the University of Iowa. He’s got written about health insurance and science for Live Science, Scientific American, Space.com, The Fix, Earth.com among others and contains edited for the American Medical Association along with other organizations.