What makes the outer core

Although it might be hard to imagine. Some scientists even believe Earth's inner core rotates faster than the rest of the planet. Movement within Earth's liquid outer core occasionally changes the location of Earth's magnetic North and South Poles. You can cite Wonderopolis as the author and use your date accessed instead of publication date. We're glad this Wonder helped with your project!

Hi, bill. Though scientists have not actually been to Earth's core, they have done a lot of research to learn more about it!

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We appreciate hearing your feedback about games! Thanks for joining the discussion, James. Sorry for the confusion. We made a slight edit to the Wonder text, as we didn't mean to imply that iron is the heaviest material on Earth.

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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!

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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. The speed of sound through the core as measured from the velocity at which seismic waves travel across it and the density of the core are quite similar to those seen in of iron at high pressures and temperatures, as measured in the laboratory.

Iron is the only element that closely matches the seismic properties of the earth's core and is also sufficiently abundant present in sufficient abundance in the universe to make up the approximately 35 percent of the mass of the planet present in the core.

The earth's core is divided into two separate regions: the liquid outer core and the solid inner core, with the transition between the two lying at a depth of 5, kilometers 3, miles. Therefore, If we can measure the melting temperature of iron at the extreme pressure of the boundary between the inner and outer cores, then this lab temperature should reasonably closely approximate the real temperature at this liquid-solid interface.

Scientists in mineral physics laboratories use lasers and high-pressure devices called diamond-anvil cells to re-create these hellish pressures and temperatures as closely as possible. Those experiments provide a stiff challenge, but our estimates for the melting temperature of iron at these conditions range from about 4, to 7, kelvins about 7, to 13, degrees F.

As the outer core is fluid and presumably convecting and with an additional correction for the presence of impurities in the outer core , we can extrapolate this range of temperatures to a temperature at the base of Earth's mantle the top of the outer core of roughly 3, to 5, kelvins 5, to 9, degrees F at the base of the earth's mantle. The bottom line here is simply that a large part of the interior of the planet the outer core is composed of somewhat impure molten iron alloy. The melting temperature of iron under deep-earth conditions is high, thus providing prima facie evidence that the deep earth is quite hot.

Gregory Lyzenga is an associate professor of physics at Harvey Mudd College. He provided some additional details on estimating the temperature of the earth's core:. How do we know the temperature? The answer is that we really don't--at least not with great certainty or precision. The center of the earth lies 6, kilometers 4, miles beneath our feet, but the deepest that it has ever been possible to drill to make direct measurements of temperature or other physical quantities is just about 10 kilometers six miles.

Ironically, the core of the earth is by far less accessible more inaccessible to direct probing than would be the surface of Pluto. The center of the Earth is made up of two layers, the outer core and the inner core. The outer core is the third layer of the Earth. It is the only liquid layer, and is mainly made up of the metals iron and nickel, as well as small amounts of other substances. As Earth spins on its axis, the iron inside the liquid outer core moves around.

The magnetic North Pole moves up to 64 kilometers 40 miles every year. Geomagnetic pole reversal s, for instance, happen about every , to , years. Geoscientists cannot study the core directly. All information about the core has come from sophisticated reading of seismic data, analysis of meteorites, lab experiments with temperature and pressure, and computer modeling.

Most core research has been conducted by measuring seismic waves, the shock wave s released by earthquake s at or near the surface. The velocity and frequency of seismic body waves changes with pressure, temperature, and rock composition. In fact, seismic waves helped geoscientists identify the structure of the core itself. S-waves are unable to transmit through fluids or gases. In the 20th century, geoscientists discovered an increase in the velocity of p-wave s, another type of body wave, at about 5, kilometers 3, miles below the surface.

The increase in velocity corresponded to a change from a liquid or molten medium to a solid. This proved the existence of a solid inner core. Most meteorites are fragments of asteroid s, rocky bodies that orbit the sun between Mars and Jupiter. Asteroids formed about the same time, and from about the same material, as Earth. In the lab, the most valuable tool for studying forces and reactions at the core is the diamond anvil cell.

Diamond anvil cells use the hardest substance on Earth diamonds to simulate the incredibly high pressure at the core.

The laser is beamed through two diamonds squeezing a sample between them. Complex computer modeling has also allowed scientists to study the core. In the s, for instance, modeling beautifully illustrated the geodynamo—complete with pole flips. The core is the hottest, densest part of the Earth. Illustration by Chuck Carter. Buried Treasure. Although the inner core is mostly NiFe, the iron catastrophe also drove heavy siderophile elements to the center of the Earth.

In fact, one geoscientist calculated that there are 1. By studying geoneutrinos, scientists can better understand the composition and spatial distribution of materials in the mantle and core. Subterranean Fiction. Inge Lehman. She was the first woman to receive the prestigious William Bowie Medal, the highest honor awarded by the American Geophysical Union.

Bullen discontinuity. Coriolis force. Curie point. Also called the geosphere. Media Credits The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. Media If a media asset is downloadable, a download button appears in the corner of the media viewer.

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