When you look at a mountain, or a valley, do you wonder how it got there?
When you look at a map of the world, have you ever noticed how the continents look as though they could almost fit together like a puzzle?
Earth is very old – over 4.5 billion years old. And the land on our planet is constantly moving and changing. It’s happening right NOW!
It’s weird to think about, right? I mean, we know about the water cycle, so we know water on Earth is moving and changing. And we know about wind and changing weather, so we know there’s lots going on in the atmosphere. Plants and animals are growing and moving. That’s no surprise. But sometimes we don’t think about how the very ground beneath us is also moving and changing.
Being the good scientific thinkers you are, I know you’re saying, “WHAT?!? That sounds a little CRAZY! What’s your EVIDENCE?” So, recently I traveled to the country of Iceland to gather some photographic evidence for you.
Iceland has many mountains because it sits between two continental plates. Since it is right at the edge of two plates, the ground here moves A LOT. This movement causes friction, which creates heat, melting rock underground.
The underground natural heating creates some weird and wonderful phenomenon around Iceland, like mud pots….
The liquid rock under Iceland, called magma, sometimes breaks through the surface of the earth. We call this a volcano.
When it erupts, the liquid rock from under the earth pours onto the top of the earth and creates more land. As the lava cools, it mounds up higher and higher and can become a very tall mountain, or it can spread out.
I saw many different types of volcanic landscapes in Iceland – beautiful and fascinating! In some areas, the land was still very hot. I had to watch out where I stepped.
Other areas had cool ground but their tumultuous history left behind magnificent scenery.
Seismologists, scientists who study earthquakes, know that there’s usually some movement of the earth before a volcano erupts. Engineers have built monitors to detect the earth’s movement. Engineers and scientists work together to increase our understanding of the geosphere. Warning systems are in place to tell people when a volcano is about to erupt so they can move away from the area.
When those large blocks of earth, continental plates, move away from each other, they can crack the earth wide open. We call this action of the geosphere an earthquake. Sometimes it creates a small crack in the ground.
Other times, it can create a very deep and wide crack, creating a valley. In the picture below, I’m inside one of those cracks caused by an earthquake, looking at what the inside of the earth looks like.
While movement of the geosphere can create beautiful landscapes, it also has an impact on the biosphere. People are often affected by the earth’s movement and changes, not only in Iceland, but in areas around the world, especially near areas where two continental plates meet.
On April 25, 2015, a strong earthquake was felt in Nepal, a country north of India. It broke apart buildings and roads. It started an avalanche on Mount Everest. This has had tragic consequences for thousands of people. Over 2000 people have died.
The Bardarbunga volcano recently erupted in Iceland. The eruption went on for several months! Lava poured down its sides creating more land, and changing the landscape around it. Any human-made buildings or roads quickly got swallowed up by the lava.
As with Iceland, the Hawaiian Islands were created by volcanoes, and they continue to erupt.
The geosphere is active indeed, constantly changing the shape of the land and the lives of the people who live nearby.