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Andy Nguyen
By Andy Nguyen April 28, 2023

Antarctica doesn’t contain the planet’s oceans, and Earth isn’t flat

If Your Time is short

  • Sea level is uneven across the planet. 
  • Several factors influence the ocean’s varied topography, including underwater mountains, underwater cliffs and undersea currents. 
  • Gravity holds the ocean down to the planet.

The Earth is not flat, but that hasn’t stopped conspiracy theories that argue otherwise.

An April 20 Facebook post from an account promoting flat Earth theories adds to the pile, claiming the ocean is held within a bowl-like container.

The post features a photo of a small string of islands in the middle of the ocean alongside a topographic diagram of the ocean floor. 

Text superimposed over the image claims "the ocean isn’t spherical."

"The ocean has no elevation features to its surface hence why we have SEA-LEVEL," the post’s caption said. "The continents are large islands that are popping above the ocean level; therefore, they are ‘dry land,’ inside contained, flat water with elevation features."

The caption adds that the container for the world’s ocean is Antarctica, which "wraps 360° around the Earth" and keeps the water from escaping. 

The post was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Meta, which owns Facebook.)

None of the post’s claims are based in reality. 

According to NASA, the ocean does have topographical features — water at sea level is not perfectly uniform across the Earth.

Scientists can measure uneven sea levels by using a satellite to bounce radar waves off the water’s surface. By measuring the time it takes for the radar wave to return, scientists can calculate variations in sea level height.   

The height differences aren’t plainly perceptible to the human eye as they happen across many miles of oceans, according to NASA. Several factors contribute to the variations in the sea level height. Ocean currents tilt the sea because of moving water and undersea mountains displace water by pushing it up. 

The Earth’s uneven, ellipsoid shape and gravitational force affect the ocean’s height differences. Because Earth’s mass is unevenly distributed, the planet’s gravity is also uneven and the planetary surface is bumpy. 

Gravity is also why the ocean remains on the Earth, pulling it downward toward the planet’s center like everything else in the world. 

Antarctica is not a ridged region that encircles the world and contains the ocean — it is an ice-covered continent in Earth’s southern hemisphere. 

The post’s assertion that Earth’s continents are just large islands is also wrong. 

A continent’s size makes it too big to be considered an island despite being surrounded by water, according to National Geographic. Continents also don’t sit entirely above sea level, with multiple areas on Earth sitting well below it.

Our ruling

A Facebook page promoting flat Earth conspiracy theories claimed that the ocean is "flat" and "contained" by land features that jut up from a flat (not spherical) earth.

Sea level is uneven across the planet. Several factors influence the ocean’s varied topography, including underwater mountains, underwater cliffs and undersea currents. 

The ocean is held in place by Earth’s gravity, which pulls it down toward the planet’s center. 

We rate this claim False.  

Our Sources

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Antarctica doesn’t contain the planet’s oceans, and Earth isn’t flat

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