Could Earth actually stop spinning?

No known process could stop it suddenly. Tidal friction from the Moon is slowing it very gradually, lengthening the day by roughly 1.7–2.3 milliseconds per century, so the day gets longer over hundreds of millions of years, but Earth will not stop.

Where would be the safest place if Earth stopped?

Near the North or South Pole, where the ground is barely moving to begin with. The further from the equator, the slower everything would be thrown.

What would happen if Earth stopped spinning slowly instead?

A gradual stop would be survivable at first but would transform the planet: one day would last a year, and as the equatorial bulge relaxed, oceans would drain toward the poles, leaving a giant equatorial continent.

What If Earth Stopped Spinning for One Second?

Q: How fast is Earth spinning?

At the equator the surface moves at about 1,670 km/h (465 m/s). The speed drops with latitude: about 1,280 km/h in Madrid or New York, and close to zero at the poles.

You're already moving incredibly fast

Right now, you feel perfectly still. You aren't. Earth turns once on its axis roughly every 24 hours, and the ground under your feet travels with it. At the equator that means covering about 40,000 km in a day, a speed of roughly 1,670 km/h, or 465 metres every second.

You don't notice because everything around you (the floor, the air, your coffee) is moving at the same speed. Motion only becomes obvious when something changes speed. That's the whole problem with this question.

Place	Latitude	Speed of the ground
Quito, Ecuador	~0°	~1,670 km/h
Mexico City	~19°	~1,580 km/h
Madrid / New York	~40°	~1,280 km/h
London	~51°	~1,040 km/h
Reykjavík	~64°	~730 km/h
North Pole	90°	~0 km/h

The rule is simple: speed = 1,670 km/h × cos(latitude). The closer you are to a pole, the smaller the circle you travel each day.

What happens, second by second

Let's imagine the rock of the planet freezes in place for exactly one second, then starts turning again. Everything that isn't part of the solid Earth obeys Newton's first law: it keeps going.

0.0 s: the ground stops. You, the air around you and every loose object are still travelling east at your local speed. In Madrid that's about 356 metres per second: faster than a passenger jet at cruising speed.
0.1 s: everything slides east. People, cars, trees and anything not anchored deep in bedrock are thrown sideways. Most buildings would be sheared from their foundations.
0.5 s: the sky becomes a weapon. The atmosphere keeps moving too. Near the equator, air rushing over the stopped ground at ~465 m/s would be faster than the speed of sound (~343 m/s): a supersonic wind stronger than any hurricane ever recorded.
1.0 s: the planet starts turning again. This doesn't help. The ground now slams back up to speed under everything that was already thrown, which is a second impact in the opposite sense.
Minutes to hours later: the oceans, also moving east, pile against the eastern edges of the continents as enormous tsunami-like surges.

Would anyone survive?

Survival would depend almost entirely on latitude. Near the equator, nothing on the surface would be moving slowly enough. In mid-latitudes like Europe or the United States, the speeds are still hundreds of metres per second.

The only relatively safe zones would be very close to the poles, where the ground barely moves to begin with. A research station in Antarctica would feel a strong jolt; a city at the equator would not survive. People deep underground in mines or bunkers anchored to bedrock would also have a better chance, since they'd stop with the rock.

What if Earth stopped slowly instead?

A sudden stop is the dramatic version. A gradual stop over years would be survivable at first, but it would remake the planet in stranger ways:

One day would last a year. Without rotation, the Sun would rise and set only once per orbit: about six months of daylight followed by six months of night.
The oceans would move to the poles. Spinning makes Earth bulge at the equator; the equatorial radius is about 21 km larger than the polar one. Without the spin, gravity would pull water toward the poles, leaving two polar oceans and one huge continent around the middle. A well-known GIS analysis by Esri mapped exactly this.
Climates would split in two. The day side would bake for months while the night side froze.

Could it actually happen?

No. There's no known process that could stop Earth suddenly; the energy involved is enormous. But Earth is slowing down very gradually. Tidal friction from the Moon acts like a gentle brake, lengthening the day by roughly 1.7–2.3 milliseconds per century. That's why, hundreds of millions of years ago, a day was only around 21–22 hours long. The slowdown is far too slow to ever bring the planet to a stop before the Sun changes dramatically billions of years from now.

FAQ

How fast is Earth spinning?

About 1,670 km/h at the equator, about 1,280 km/h at Madrid or New York's latitude, and almost zero at the poles.

Would we feel it if Earth stopped slowly?

Not directly; we only feel changes in speed. A very slow stop would show up as longer days, shifting oceans and changing climate rather than a jolt.

Where would be safest?

Near the North or South Pole, or deep underground anchored to bedrock.

Is Earth's spin really slowing down?

Yes, very slightly, mainly because of tides raised by the Moon. Days get a couple of milliseconds longer every century.

Sources & further reading

NASA. "What would happen if the Earth stopped rotating?" (NASA Ask an Astronomer / Space Place)
Fraczek, W. (Esri, 2010). "Why Does the Earth Have Two Polar Oceans… If It Stopped Rotating?" GIS analysis of a non-rotating Earth.
Stephenson, F. R., Morrison, L. V. & Hohenkerk, C. Y. (2016). "Measurement of the Earth's rotation: 720 BC to AD 2015." Proceedings of the Royal Society A.

This is a hypothetical scenario explained with real physics. Numbers are rounded for clarity. Spotted an error? Tell us and we'll fix it.