geophysics library

Geophysics is the study of the forces that shape the Earth from a global perspective. Learn about gravity, plate tectonics and other topics.

Featured Article: What if there were no gravity on Earth?

Have you ever wondered what would happen if we were able to flip a switch and turn the Earth's gravity off for a day? The end result may surprise you. See more »

Articles 21-35 of 35

What are the four fundamental forces of nature?

What are they? We'll give you a hint -- or four. Earth, wind, water and fire aren't among them, but our old friend and force gravity is.

What causes high tide and low tide? Why are there two tides each day?

If you've ever been to the beach you may have noticed the waterline growing or shrinking as the day wears on. There are two of these tides each day, but what causes tides and why are there two of them each day? Find out in this article.

What if a main water supply were infected with some form of bacteria?

The United States has an abundant supply to clean drinking water available in homes and businesses. But what if that water turned out not to be so clean? And what about the water supply around the world?

What if there were no gravity on Earth?

Have you ever wondered what would happen if we were able to flip a switch and turn the Earth's gravity off for a day? The end result may surprise you.

What is a geomagnetic substorm?

On February 17, NASA launched a rocket with a record-setting five satellites onboard. The $200 million mission is to discover the source of an atmospheric phenomenon known as the geomagnetic substorm.

What is wastewater agriculture?

Though it may seem disgusting to some, people all over the world must use waste water to irrigate their crops. Can you get sick from wastewater irrigation?

What would happen if I drilled a tunnel through the center of the Earth and jumped into it?

Let's say that it were possible to bore a tunnel from one side of the Earth, through the center of the Earth and out the other side. If I were to jump into the tunnel on one side of the Earth, what would happen? Find out in this article.

Why can't we manufacture water?

Water is just hydrogen and oxygen, so why can't we do what nature does and combine the two? Unfortunately, it's not that simple, and the results can be rather ... explosive.

Why do scientists think we're nearing the end of the world?

In a purely symbolic but still unsettling move, the Bulletin of Atomic Scientists has moved the minute hand on its Doomsday Clock two minutes closer to midnight. Midnight is the end of the life as we know it.

Why does the North Pole move?

You probably know that the North Pole does not stay in the same spot. The North and South Poles can actually change positions. What causes this? Find out in this article.

Why is Arctic ice melting 50 years too fast?

It used to take three years to get through the thick ice of the Northwest Passage. Now, you can sail from New York to Korea without hitting any ice at all. Where is all the ice going, and what are the ramifications of it melting 50 years too fast?

Wild World: Disappearing Lake Quiz

A lake in South America suddenly disappeared and left scientists wondering where all the water went. Is it possible that a lake can abruptly vanish? And if so, what are the causes behind this watery mystery?

Wild World: Glacier Quiz

It seems that when we hear about glaciers these days, it's because they're shrinking. Is it because of natural, cyclical climate changes or because humans are destroying the environment?

7 Wonders of the Natural World

The 7 wonders of the natural world capture the imagination with their natural power and beauty. There is nothing that man can create that can match the beauty nature can create. Learn about all 7, including the great barrier reef.

Will we ever run out of magma?

A common misconception is that magma comes from the Earth's molten core. It really comes from the mantle, the layer between the core and the crust. Will it ever run out?