Forces of Nature

Human activities (such as leaving a campfire unattended, discarding lit cigarettes, debris burning and intentional arson) are among the top causes of wildfires.

By Jessika Toothman & Yara Simón

At some point in your life, a coach may have enthusiastically told you to "fight fire with fire." Coach, of course, was speaking metaphorically. Do firefighters actually employ this strategy?

By Robert Lamb

There are obvious craters on Earth (and the moon) that are evidence of a long history of massive objects hitting planet Earth. But what would happen if an asteroid hit Earth today?

By Marshall Brain & Sarah Gleim

Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides from power plants, cars and factories. Find out how acid rain is produced, how it affects natural and man-made objects and how governments aim to reduce it.

By Sarah Dowdey

Earthquakes and their resulting aftershocks can be devastatingly destructive. Earthquakes are caused when a fault in the Earth's crust slips, which releases energy waves in the ground. Find a list of 12 of the most destructive earthquakes in history.

By the Editors of Publications International, Ltd.

Before barometers and thermometers, people looked to the land and local lore to predict rain or shine. Have sophisticated statistical models and measuring tools changed the art of forecasting the weather that much?

By Robert Lamb

We've all probably looked up and wondered why the sky is blue instead of, say, brown. The sky is blue because of the way Earth's atmosphere scatters light from the sun.

By Nicholas Gerbis

Folks in Montana usually expect snow or rain to fall from the sky, not ash. But the 1980 eruption of Mount St. Helens in Washington flung ash across state lines. What is this gritty, gray stuff?

By Robert Lamb

San Francisco has a new airport that's supposed to stand up to the rigors of an earthquake. Does that mean that planes can land while a massive quake is shaking the city?

By Katherine Neer

Auroras are stunning natural light shows that are visible only in certain parts of the world at certain times of the year. Where can you go to see one?

By Craig Freudenrich, Ph.D.

If a tornado was heading your way, you'd probably head for the hills. But for some people, it's just the beginning of a chase.

By Ed Grabianowski

Did bunnies just attack that sailboat, or was it a narwhal playing with a school of fish? Are you going crazy, or are you just watching the clouds?

By Jessika Toothman

Witch homicide aside, Dorothy was lucky that her home safely traveled to Oz after the tornado. Many people who lived through the storms on our list were left with nothing.

By Jessika Toothman & Nicholas Gerbis

Mount Vesuvius, located near Naples, Italy, is one of the world's most iconic active volcanoes, renowned for its historic eruption that buried Pompeii. Discover its history, significance, and natural beauty.

By Cristen Conger

The birds stop chirping, and the wind chimes are silent. This eerie calm that's invaded your neighborhood is just a temporary pause before the shrills and shrieks of the incoming storm.

By Jessika Toothman

You might think of weather as something that happens around your life. It could prevent you from taking a bike ride or inspire you grab an umbrella on your way out. But there's more to weather than its ability to thwart the best-laid plans.

By Robert Lamb

We tend to think of the ground beneath our feet as terra firma, but sometimes it's as stable as a house of cards. What happens when the Earth opens up to swallow homes, cars and people?

By Jacob Silverman

The raging wildfires in southern California have claimed lives and destroyed hundreds of homes. Learn how wildfires start and spread, and find out what firefighters do to battle the blaze.

By Kevin Bonsor

Around 1,800 thunderstorms are occurring on the Earth at any given time. But how do they form, and what causes them?

We hear about humidity in just about every weather report on the nightly news. There are several different ways meteorologists measure humidity, but relative humidity is the most common measurement. What is relative humidity, though?

By Nathan Chandler

Flooding has claimed more lives than any other natural disaster. Find out how a gentle stream becomes a raging torrent.

By Tom Harris

Volcanoes are some of nature's most awe-inspiring displays, with everything from exploding mountaintops to rivers of lava. Learn how all the different types of volcanoes work.

By Tom Harris

An earthquake is one of the most terrifying phenomena that nature can dish up. We generally think of the ground we stand on as "rock-solid" and completely stable. An earthquake can shatter that perception instantly, and often with extreme violence.

By Tom Harris & Patrick J. Kiger

Whether you're planning an outdoor wedding or a Saturday morning tag sale, it's nice to know ahead of time what the sky is going to do. But does checking the 10-day forecast do any more good than praying for sunshine?

By Robert Lamb

Ball lightning can float through the air, pass through walls and even kill you. What could it be, and why are scientists finally accepting this strange meteorological phenomenon?

By Maria Trimarchi & Austin Henderson