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

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We bet you're looking up the longest river in the U.S. to settle a bet: Is it the Missouri River or the Mississippi River? It depends how you measure.

By Marie Look

The smallest state in the U.S.A. isn't the same as the state with the lowest population. In fact, the five smallest by each measure are completely different.

By Yara Simón

Subsidence, or the decline in the elevation of land surface, is creating a problem for some coastal cities as sea levels rise.

By Jesslyn Shields


Each year, Earth sees two equinoxes and two solstices. But how much do you actually know about these events? Take the quiz and find out!

By Alia Hoyt

Water surrounds us, falling from the sky and pouring from faucets, and yet many of us never ask where it comes from. The answer stretches way back — before tides and thunderclouds to the big bang.

By Jonathan Atteberry & Ian O'Neill, Ph.D.

Do you ever play that game in which you select the items you'd bring if you got stuck on a desert island? Along with that treasured bootleg recording of your favorite band, we think that an endless supply of water should be at the top of your list. Here's why.

By Jonathan Atteberry

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?

By Tracy V. Wilson


Huge walls of cascading water never cease to capture our attention with their majesty. Ready to marvel at nature? Check out some of the most beautiful waterfalls in the world.

By Rick Mayda

Few Americans like the switching between Daylight Saving Time and Standard Time, but there's conflict on whether to switch permanently to DST or to ST. What are the pros and cons of permanent DST?

By Allison Troutner

It's possible that the giant, deadly serpent hanging out at the bottom of Fosse Dionne spring is just a legend, but divers have disappeared trying to find out, so who knows?

By Jesslyn Shields

Deep underneath Antarctica, there lies a hidden lake. Roughly the size of North America's Lake Ontario, the buried landmark has inspired curiosity and controversy for decades.

By Mark Mancini


Some say UFOs, while others say a meteor strike formed the Carolina Bays. Whatever created these isolated ponds and wetlands across North and South Carolina left a wondrous ecosystem that is in dire need of protection.

By Allison Troutner

For more than 40 years, scientists have tried to figure out what's causing large parts of Canada to be "missing" gravity. The force of gravity around Hudson Bay is lower than surrounding areas. Learn about two theories that may explain the phenomenon.

By Jacob Silverman

On a planet that is 70 percent water, people don't have enough clean, safe water to drink. We're in a water crisis, and water rights are becoming a big issue. What happens if we just plain run out?

By Josh Clark

Have you ever read "Journey to the Center of the Earth" and wondered if it were possible to do it? Well, scientists are in the process of giving it their best shot. How hard is it to dig a hole this deep, and what might they find?

By Patrick J. Kiger


It's not just the size that differentiates a lake from a pond. The real distinctions flow much deeper.

By Sharise Cunningham

Famine might bring to mind historical tragedies or modern media coverage of tiny children with swollen bellies. But how does the unimaginable -- a widespread loss of food -- actually happen?

By Jessika Toothman

In its purest form, it's odorless, nearly colorless and tasteless. It's in your body, the food you eat and the beverages you drink. All forms of life need it. What substance is more necessary to our existence than any other? Water.

By Shanna Freeman

One iceberg sank the unsinkable Titanic, and another exploded in front of an expedition. These floating chunks of ice carry their bulk deceptively below the surface of the water. What else are they hiding?

By Ed Grabianowski


Glaciers are rivers of ice and are the largest moving objects on Earth. Learn about glaciers and find out how much freshwater are frozen in glaciers.

By Ed Grabianowski & Desiree Bowie

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.

By Josh Clark & Jennifer Walker-Journey

You've probably heard of the Tropics of Cancer and Capricorn, but do you know the difference?

By Michelle Konstantinovsky

You've probably heard of the Tropics of Capricorn and Cancer, but do you know the difference?

By Michelle Konstantinovsky


The Arctic Circle is a region marked by frigid temperatures, strange sunlight and glaciers galore. And for hundreds of thousands of people, it's also home sweet home.

By Mark Mancini

The autumnal equinox is the day Earth is perfectly angled to the sun, so the day and night are of equal length. Well, almost.

By Kathryn Whitbourne