Geophysics

A seismograph can accurately measure the movement of the Earth during a quake. How does a seismograph work, though, and what is the Richter scale that is associated with earthquakes? Learn the answers to these questions in this article.

By Sascha Bos

Water is one of the most abundant substances on the planet. About 70 percent of our planet is covered by oceans, but just how much water is there on Earth?

By HowStuffWorks.com Contributors & Yara Simón

Gravity is a force that we experience every minute of our lives, but hardly notice or give a passing thought to in our daily routines. Have you ever wondered what gravity is and how it works? Learn about the force of gravity in this article.

By Julia Layton & Austin Henderson

The polar ice caps have been in the news recently because of their alleged shrinking due to global warming. How much would the oceans rise if the ice caps melted completely?

By Marshall Brain & Sascha Bos

A map is a type of language, a graphic way of representing information, whether it's to show population density or tell you how to get from Point A to Point B. Here's how they're made.

By Tracy V. Wilson & Alia Hoyt

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?

By Julia Layton

The Earth is incredibly heavy. How do scientists determine the weight of the Earth?

By HowStuffWorks

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 Earth is split up into 24 time zones based on longitudinal lines. But those lines all converge at the North and South poles, so what's the time there?

By Mark Mancini

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

By Sharise Cunningham

The world has only had time zones since the late 1800s. Some people think we should eliminate them and have just one universal time instead.

By Patrick J. Kiger

Ice volcanoes form when it's freezing cold outside and choppy water is forced to erupt through a hole in the ice around a body of water, cascading down into the classic shape of a volcano.

By Jesslyn Shields

Since its discovery in 1870, the Wyoming cone geyser Old Faithful has wowed spectators with its predictable eruptions, but its eruptions are not quite as predictable or prodigious as they once were.

By Mark Mancini

The stratosphere is one of Earth's five atmospheric layers that also includes the troposphere, mesosphere, thermosphere and exosphere.

By Mark Mancini

The Ancient Earth visualization map shows the movement of the planet's tectonic plates in a really cool way.

By Patrick J. Kiger

Prior to the mid-1990s, the magnetic north pole traveled at speeds of around 9 miles per year. Now, it's 34 miles annually. What accounts for the acceleration?

By Mark Mancini

Sastrugi are gorgeous snow formations found in the polar north, but they're also no fun to travel over.

By Jesslyn Shields

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

We argue that living well requires wine and cheese, but what does living at all require? You might be surprised to find out that there's no single definition.

By Kate Kershner

Of course you know what gravity is. It's the force behind Wile E. Coyote plummeting off the face of a cliff and you stumbling spastically in front of your crush. But did you know it can bend light and help us detect hidden cosmic phenomena, too?

By Robert Lamb

The Caspian Sea is the largest lake in the world, but it's gradually shrinking thanks to a changing climate.

By Jesslyn Shields

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

The unique, annual sea ice phenomenon is created when pure, salt-free river water hits cold, saline seawater near the beaches of Hokkaido.

By Christopher Hassiotis