Earthquake waves reveal a solid, 450-mile-wide ball of metal that forms the Earth’s innermost core

Scientists have used powerful waves of earthquakes to measure the Earth’s innermost layer and found that the center of our planet is a 450-mile (725-kilometer) wide ball of solid iron-nickel alloy.

Previously, many researchers believed that the Earth had four distinct layers—the crust, mantle, liquid outer core, and solid inner core. But in the past two decades, scientists have suggested that the inner core is actually composed of two layers, referred to as the inner core and the innermost inner core.

Now, in a paper published in Nature Communications (Opens in a new tab) on Tuesday (February 21), researchers looked at seismic, or seismic, wave data from around the world to measure this innermost inner core.

When an earthquake strikes, it releases waves of energy that move through the rocks. These waves move at different speeds depending on the types of minerals the rock is made of and whether the rock is harder or softer. Certain types of seismic waves cannot move through a liquid, so they bounce off a layer of liquid. Studying the way seismic waves move through the Earth can reveal distinct layers deep within the planet’s surface.

For example, scientists have previously used seismic waves to discover churning liquid iron in Earth’s outer core, which creates the planet’s magnetic field. The seismic waves also exposed the inner core, which, despite the heat, remains solid under enormous pressure.

In the new paper, researchers have observed, for the first time, seismic waves bouncing back and forth from a strong earthquake to the other side of the globe, like ping-pong balls, said study lead author Thanh Son Pham(Opened in a new tab), a geophysicist at the university. Australian National in Canberra, he told Live Science in an email.

In particular, the seismic waves generated by a magnitude 7.9 earthquake near the Solomon Islands in 2017 reverberated across the entire diameter of the Earth several times. Seismic networks in the Alaskan peninsula and the European Alps helped researchers to see the shockwaves, and these backscattering enabled the researchers to observe the two distinct layers within the Earth’s inner core.

3D view showing a cross section of an earthquake and its epicenter. (Image credit: Naeblys via Getty Images)

The researchers noted that as the earthquake waves traveled through the innermost core, in an area about 450 miles in diameter, they moved at different speeds depending on the angle at which they were traveling. In the outermost layer of the inner core, the faster waves moved pole-to-pole and the slower ones in the equatorial direction. Meanwhile, in the deeper layer, the waves moved more slowly at an angle of about 50 degrees away from the Earth’s axis.

The different behavior of waves moving through the outermost layer of the inner core versus the innermost inner core, Pham says, suggests that although they may be chemically identical (made of an alloy of iron and nickel), the crystal structures of these layers are different.

“This study reinforces the evidence for the existence of an inner metallic sphere with a distinct texture from the outer mantle of Earth’s inner core,” said Pham.

The Earth’s structure evolved as it cooled after the planet formed about 4.6 billion years ago. As the Earth cooled, heavier elements, such as iron and nickel, migrated inward, forming the inner and outer cores, while lighter elements rose up—such as silicon, which makes up much of the rock on Earth’s surface.

Pham said the new view of Earth’s innermost inner core could indicate that an event early in the planet’s history influenced its formation, and that this idea could change what we know about when and how the inner core formed.

However, there is currently no way to know what kind of event could have created the distinct layer within the inner core, or when, Pham said. Scientists think the Earth’s core formed about a billion years ago, but the details of the evolution of the core are not well understood. . It is therefore difficult to say when an event other than the innermost core took place. But as the global network of seismometers grows, more seismic data will likely help reveal more details about the growth of the inner core.

“The exact timeline for the potential global event is highly uncertain,” Pham said. “Answering these questions can go a long way in understanding Earth’s evolution.”

What Are The Main Benefits Of Comparing Car Insurance Quotes Online

LOS ANGELES, CA / ACCESSWIRE / June 24, 2020, / Compare-autoinsurance.Org has launched a new blog post that presents the main benefits of comparing multiple car insurance quotes. For more info and free online quotes, please visit https://compare-autoinsurance.Org/the-advantages-of-comparing-prices-with-car-insurance-quotes-online/ The modern society has numerous technological advantages. One important advantage is the speed at which information is sent and received. With the help of the internet, the shopping habits of many persons have drastically changed. The car insurance industry hasn't remained untouched by these changes. On the internet, drivers can compare insurance prices and find out which sellers have the best offers. View photos The advantages of comparing online car insurance quotes are the following: Online quotes can be obtained from anywhere and at any time. Unlike physical insurance agencies, websites don't have a specific schedule and they are available at any time. Drivers that have busy working schedules, can compare quotes from anywhere and at any time, even at midnight. Multiple choices. Almost all insurance providers, no matter if they are well-known brands or just local insurers, have an online presence. Online quotes will allow policyholders the chance to discover multiple insurance companies and check their prices. Drivers are no longer required to get quotes from just a few known insurance companies. Also, local and regional insurers can provide lower insurance rates for the same services. Accurate insurance estimates. Online quotes can only be accurate if the customers provide accurate and real info about their car models and driving history. Lying about past driving incidents can make the price estimates to be lower, but when dealing with an insurance company lying to them is useless. Usually, insurance companies will do research about a potential customer before granting him coverage. Online quotes can be sorted easily. Although drivers are recommended to not choose a policy just based on its price, drivers can easily sort quotes by insurance price. Using brokerage websites will allow drivers to get quotes from multiple insurers, thus making the comparison faster and easier. For additional info, money-saving tips, and free car insurance quotes, visit https://compare-autoinsurance.Org/ Compare-autoinsurance.Org is an online provider of life, home, health, and auto insurance quotes. This website is unique because it does not simply stick to one kind of insurance provider, but brings the clients the best deals from many different online insurance carriers. In this way, clients have access to offers from multiple carriers all in one place: this website. On this site, customers have access to quotes for insurance plans from various agencies, such as local or nationwide agencies, brand names insurance companies, etc. "Online quotes can easily help drivers obtain better car insurance deals. All they have to do is to complete an online form with accurate and real info, then compare prices", said Russell Rabichev, Marketing Director of Internet Marketing Company. CONTACT: Company Name: Internet Marketing CompanyPerson for contact Name: Gurgu CPhone Number: (818) 359-3898Email: [email protected]: https://compare-autoinsurance.Org/ SOURCE: Compare-autoinsurance.Org View source version on accesswire.Com:https://www.Accesswire.Com/595055/What-Are-The-Main-Benefits-Of-Comparing-Car-Insurance-Quotes-Online View photos