It seems like a thought that has crossed the mind of most people, but what would happen if the Earth stopped spinning right this very moment? That question is discussed in an article by Gizmodo's Sploid, and the short answer is nothing good.
The Earth rotates at different speeds, depending on your position on the globe. The equatorial regions spin faster, around 465 meters per second, while that speed slows to 368 meters per second around San Francisco, and continues decreasing toward the poles. If the Earth were to stop spinning, the force of momentum would send everything perched upon the Earth's crust flying eastward at that speed, turning human bodies into "supersonic tumbleweed," as a Vsauce video states. Storms would be generated by the sudden stop in the Earth's spin, with winds faster than those observed near atomic bomb detonations. The friction of air moving against the stopped Earth would also generate massive fires. That wind would cause "unprecedented" erosion events to the Earth's crust.
Universe Today reports that the sun would freeze in place in the Earth's sky, essentially making a day last a whole year. Only the Earth's path around the sun would change day into night, leading to six months of day followed by six months of night anywhere on the planet. When the Earth stops spinning, it will also become a more perfect sphere, loosing the 32 km bulge that centrifugal force exerts upon its equatorial regions.
The relationship between land and sea would change on an Earth that had stopped spinning as well, as The Inquisitr previously reported. Without inertia keeping water in the Earth's lower basins, it would at first flood dry-land areas, before eventually draining to the polar regions, where the Earth's gravity is stronger. The tsunamis that would flood those areas would be kilometers high - the stuff of disaster movie CGI.
If the Earth stops spinning though, so would the molten core of the planet, and this would have fatal implications for anything that managed to survive the devastation on the Earth's crust. The rotation of the Earth's core produces the planet's magnetic field, which shields life on the surface from harmful ionizing radiation produced by the Sun. No spinning Earth means no magnetic field, effectively dooming any biological life on the planet.
There's little cause for alarm though. While the Earth's rotation is almost imperceptibly slowing down, a process that results in the necessity of "leap seconds" in the functioning of atomic clocks, the probability that the Earth will stop spinning anytime soon is near zero.
[Images via Gawker/Sploid]