If the Earth stopped spinning, the oceans would run to the poles and most of Europe would go under the sea

How fast you are moving right now#

The ground under London is carried east at 1,044 km/h, because the planet turns once every 23 hours 56 minutes. At the equator the speed is 1,674 km/h; at the poles, nothing.

You feel none of it. The air, the sea and everything around you travel at the same speed, and only a change of speed can be felt.

Since you opened this page, you have travelled 0 km.

If it stopped in an instant#

No force could do this, so this part is pure thought experiment. Suppose the rock stopped and nothing else did. The air would keep going east at the speed the ground had a moment before: 1,044 km/h over London.

Between 43.0° north and 43.0° south, the band shaded on the globe, that wind would be faster than sound. The strongest gust ever measured, on Barrow Island off Western Australia in April 1996, was 408 km/h.

The sea would keep going too, and so would anything not fixed to bedrock. That is why every careful answer to this question moves straight on to the gentle version.

Where all that motion would have to go#

A turning planet stores energy the way a flywheel does. For the Earth it is about 2.1 × 10²⁹ joules. Stopping the spin means putting all of it somewhere.

That is as much energy as the Sun sends out into space, in every direction, in 9 minutes, and as much as the whole of humanity uses, at today's rate, in about 345 million years.

The gentle version: the seas run to the poles#

Now let the spin wind down slowly enough that nothing is thrown about. Scroll, and the day gets longer.

Today the level surface of the ocean is about 21 km farther from the centre of the Earth at the equator than at the poles. About half of that comes from the spin flinging everything outward, half from the pull of the bulge of rock the spin built long ago. As the spin fades, the first half disappears, and the water runs downhill, towards the poles.

By the time the day lasts 48 hours, Once the spin is gone, the seas at both poles stand about 5.6 km above today's level and the water at the equator 3.4 km lower. Land shrinks from 30% of the surface to 24%: the north loses more than the tropics gain.

Why the water moves more than the rock#

The ocean settles on a level surface, shaped by gravity and the spin together. Take the spin away and that surface changes shape: at the equator it sinks by 11,060 m compared with the poles.

The rock moves too. The Earth is elastic, like a very hard rubber ball: its surface follows part of the change, and its reshaped mass shifts gravity as well. Together they cancel about a third of the change. Geophysicists measure these shares from the tides the Moon and the Sun raise in the solid Earth twice a day; it is the same arithmetic. So the sea moves against the land by about 69% of the change.

The moved water has weight of its own. Piled at the poles, it pulls more water after it and presses the sea floor down, which adds about a sixth to the effect. The cut through the planet shows the result along London's meridian.

The air drains too#

Air settles on the same level surfaces as water, so it would leave the equator as well. The tropical land would stand kilometres above the new sea, and the air there would be as thin as on today's high mountains. On the globe, yellow is ground where breathing is hard and red where it is as thin as on the highest peaks today.

Quito would stand 6,200 m above the new sea. Of the people who live in towns of more than 15,000 today, 20% live where the sea would cover them, and 4.9% where the ground would stand more than 4,000 m above it, about the height of El Alto in Bolivia, often called the highest large city in the world.

2,500–5,000 m 5,000–8,500 m

The new roof of the world depends on how much the rock gives#

Measured from the new sea, the volcanoes near the equator gain kilometres and the Himalaya gains less. Which summit ends up highest depends on how the planet answers.

On rock that flexes, Everest keeps first place at 10,188 m, only 227 m above Kangchenjunga. On perfectly rigid rock, Huascarán in Peru would lead with 11,105 m. The 2010 article gives Chimborazo in Ecuador 13,615 m.

The map everyone shares, and the oceans it leaves out#

In 2010 Witold Fraczek, a researcher at Esri, the mapping company, published the version of this map that still circulates: one continent wrapped around the equator between two polar oceans that part southwest of Kiribati. The article ends by saying that the sea of a still Earth would become a perfect sphere.

Let the sea settle into a sphere while the rock keeps its bulge, and a single continent does appear: rebuilt that way here, it covers 57% of the planet. But the sea follows a level surface, and the rock's own bulge pulls on the water. Even if the rock kept its shape, that surface would stay flattened by about 10 km. On rock that flexes, as the Earth's does, three oceans still cross the equator: the Pacific through a gap 1,740 m deep, the Indian Ocean 1,600 m and the Atlantic 1,420 m. On perfectly rigid rock the Pacific and the Indian Ocean would still get through, a few hundred metres deep, and the Atlantic would be on the point of closing. Switch between the three versions on the globe.

Over thousands of years, the old coasts come back#

Rock is elastic only in the short run. Over longer times the mantle under the crust flows, like very thick tar, and the bulge the spin once held up begins to sink.

Models of how the Earth's shape follows a change in its spin put that adjustment at roughly a thousand to ten thousand years. As the bulge sinks, the seas flow back from the poles. When the rock has fully caught up, the sea stands against the land almost where it does today; only the stiff outer shell might keep a trace of the old bulge.

A day that lasts a year#

Without the spin, the only thing that moves the Sun across the sky is the Earth's trip around it. One day lasts a year: about six months of light and six of darkness, almost everywhere.

The Sun also runs the other way. The orbit carries it eastward against the stars, so it rises in the west and sets in the east.

At two places the Sun would never rise or set. They face the poles of the Earth's orbit, and there the Sun would graze the horizon all year, going once around it; the air bends its light enough to keep the whole disc just in view. If the spin stopped right now, they would be at and : the two gold rings on the globe.

Your year-long day#

Weather without a spin#

Hurricanes and typhoons need the spin to turn. That is why they almost never form near the equator, where its effect on the winds is weakest: NOAA says a storm must be at least 300 miles (about 480 km) from the equator for the spin to set it turning. In the stopped world that would be true everywhere.

Winds would blow mostly from the night side to the day side and rise under the Sun. Climate models of slowly turning, Earth-like planets find that this builds a thick lid of cloud on the sunlit side, which reflects much of the light: in one study, slowing the turn from one day to 256 days cooled the planet's average surface by 20 °C. That model had no axial tilt and no sea ice, and its planets still turned, if slowly; a fully stopped Earth was not among the cases run.

A pendulum shows the spin directly. At London the plane of its swing turns 283° a day. Without the spin it would swing back and forth along the same line for ever.

You would weigh a little more#

The spin pulls you slightly outward. Without it, at London a person of 70 kg would weigh 94 grams more; at the equator, about 240 grams more.

A small change, and one of the few in this story you could feel in your own body.

The Earth is slowing down, but it will not stop like this#

The real Earth is slowing, braked mostly by the tides the Moon raises. Records of ancient eclipses show the day growing, on balance, by about 1.8 thousandths of a second each century. Rock layers in China laid down 1.4 billion years ago record a day of about 18.7 hours.

At today's rate the day gains one hour every 200 million years. No known process could take the spin away entirely.