The slow cooling of our planet causes the molten iron in the outer core to flow and swirl fast as heat is transported to the mantle, and this gives Earth its magnetic field. The magnetic field is like a magnet that acts at a distance, and even though we cannot see it with our eyes, it does lots of important jobs on our planet. The heat escaping from the core also makes material move around in different layers of our planet — from the rocky mantle to the rigid plates on the surface, where you and I live.
This movement can cause the plates on the surface to rub together, which creates earthquakes and volcanoes. This will make life on Earth very difficult for human beings and other life forms.
When the Earth has cooled completely, the movement in the mantle will also stop eventually. Then, the plates on the surface will no longer move and there will be fewer earthquakes and volcanic eruptions. You might think that this would be good for people — especially those living in places like Tokyo — but volcanic eruptions also produce fertile soil for farming, and gases that make up the air that we breathe.
Electrically and thermally insulating, the mantle is like a rock-wool blanket around the core. The minerals of the mantle are the stony part of the planet.
But as you delve deeper on this "thought field trip", things suddenly and drastically change. With more than half your journey ahead of you, you cross a boundary from the stony mantle into the metallic core. It is initially liquid in its upper stretches, and then solid right the way to the centre of the Earth. The chemistry changes too, with iron forming almost all of the core, segregated into Earth's dense inner sphere. The boundary between the metallic core and rocky mantle is a place of extremes.
Physically, Earth's metallic liquid outer core is as different to the rocky mantle that overlies it as the seas are from the ocean floor here near Earth's surface. One might just about imagine an inverted world of storms and currents of flowing red-hot metal in the molten outer core, pulsing through channels and inverted "ocean" floors at the base of the mantle. The flowing of metal in the outer part of the core gives Earth its magnetic field, protects us from bombarding solar storms, and allows life to thrive.
How Earth's core came about has puzzled Earth Scientists for many years. Experiments on mixtures of silicate minerals and iron, cooked up in the laboratory, show that iron sits in tiny isolated lumps within the rock, remaining trapped and pinned at the junctions between the mineral grains.
This observation has led to the view that iron only segregates very early in the life of the planet, when the upper part of the rocky mantle was in fact super-hot and molten. Don't forget to check out the Wonder text above to find out what the Earth's core is made of! Welcome, jordy! We appreciate you visiting Wonderopolis and leaving a comment!
We hope you liked this Wonder! It's great to hear you learned something new with us, Joseph! We're glad you're hanging out in Wonderopolis! Unfortunately, the heat and pressure at the Earth's core are so intense that you and your boring machine would be melted and crushed by infrared, visible, and ultraviolet light before you got even close to the center of the Earth. We suppose it depends on where you begin digging from, Joseph! For example, if you started digging the tunnel in Texas, you'd end up reaching the Indian Ocean on the other end!
If you began in Argentina, you may end up in China! Check out this fun tunneling tool online to explore opposite sides of the world! We're glad you enjoyed the topic, Bp, and that you learned something new with us!
Thanks for hanging out in Wonderopolis! Thanks for asking, Stefan! We research Wonder questions using the Internet, books from the library and by asking experts in the field of the topic we're researching! Thanks for stopping by Wonderopolis! The hottest temperature has varied, depending on the time period in Earth's history.
Hi, bob! We like ponies, too! We're really glad we learned some new things with each of you! Sorry you didn't like the video, John!
Perhaps there are other Wonders you might like better! Thank you for sharing your thoughts about this Wonder of the Day! Thanks for hanging out with us in Wonderopolis! We're really glad you joined us for this Wonder of the Day! We hope to hear from you again soon! It's great to hear you learned something new with us, Kyle!
Hi, K.! Thanks for joining the discussion and sharing your opinion! We appreciate your comment! Thanks for commenting, Cam! There actually is gravity in space! We are undergoing some spring clearing site maintenance and need to temporarily disable the commenting feature.
Thanks for your patience. Drag a word to its definition. You have answered 0 of 3 questions correctly and your score is:. Want to add a little wonder to your website? Help spread the wonder of families learning together. We sent you SMS, for complete subscription please reply. Follow Twitter Instagram Facebook. What is Earth's core made of? How hot is Earth's core? How thick is Earth's core? Tags: See All Tags alloy , core , crust , earth , geology , gold , iron , liquid , magma , magnetic , mantle , metal , nickel , platinum , pressure , science , solid , uranium.
Wonder What's Next? Try It Out Ready to dig a little deeper? Explore the following activities with a friend or family member: What do other people believe Earth's core is made of? Take a poll of ten classmates, friends, neighbors, or family members. Ask each of them what they believe Earth's core is made of and why.
When they answer, share what you learned from today's Wonder of the Day with them. How many of them were correct? Want to learn more about Earth's layers? How about learning more about them while also learning a new rap song? Check out Layers of the Earth Rap and sing along while you learn! Up for a challenge? Write a short story about your trip to the center of Earth. Use your imagination! You could be a miner who keeps digging for years until you reach Earth's core.
Or perhaps you're a spelunker who explores caves and stumbles upon a portal that takes you straight down to the center of Earth. The sky is the limit! Or is Earth's core the limit? You decide! Share your exciting story with a friend or family member.
Did you get it? Test your knowledge. What are you wondering? Wonder Words solid crust core iron dense thick liquid mantle nickel magma primarily deepest alloy composition tectonic noticeable gigantic uranium Take the Wonder Word Challenge. Join the Discussion. Jan 30, The outer core is a liquid mix of iron and nickel, but the inner core is solid metal. Currents in the mantle can push hot, molten rock up through the surface of the Earth. Where it breaks through the crust, there is often a violent explosion called a volcanic eruption.
These eruptions create mountains called volcanoes. Hot rock inside the Earth melts into a liquid called magma. Sometimes, currents in the magma push upward toward the surface, creating an underground fountain called a magma plume.
0コメント