The solid interior of the Earth is only a billion years old, new research finds.
Modern Earth Like a layered cake, with a solid outer crust, warm, viscous coating, liquid outer core and solid inner core. It is slowly rising like a solid inner core fluid Iron In major cooling and crystallization. This process helps to power the churning motion of the liquid outer core, which in turn creates a magnetic field that surrounds the Earth and helps protect the planet from harmful cosmic radiation.
In other words, the interior is very important.
But little is known about the history of this 1,500-mile-wide (2,442-kilometer) Iron Ball. It is estimated to be between half a billion years old and over a billion billion years old, about 4.5 billion years old. Now, researchers have cut a small piece of iron between two diamonds and blasted it with lasers to reach a new estimate of 1 billion to 1.3 billion years old – a range of dates that coincides with a measurable reinforcement. Earth’s magnetic field It happened around the same time.
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“The earth is unique among us Solar system “It has a magnetic field, and it’s habitable,” study author Jung-Fu Lin, a geologist at the University of Texas at Austin, told LiveScience. “Ultimately our results can be used to think about why our other planets. The solar system does not have a magnetic field.”
Geodinemo
The Earth’s magnetic field is governed by what scientists call “geodinamo.” It is the movement of the outer core, rich in iron, which turns the planet into a giant, if somewhat disjointed. Geology is responsible for the earth North Pole And the invisible ield of the South Pole and magnetism that defects and traps particles flowing from the sun. These particles would otherwise slowly strip the earth of its atmosphere.
Part of the movement of the inner core is driven by heat, known as its thermal energy source. As the earth’s core slowly cools, it crystallizes from within. This crystallization process releases energy rays which can give more power to the movement of the static-liquid outer core. This release from crystallization has been called the creative source of geodynamics, Lynn said.
Lynn and her team wanted to use experimental evidence to deduct energy from each of these sources. Knowing the amount of energy released will allow them to estimate the age of the inner core.
To do this, the researchers recreated the core conditions on a small scale. They heated a piece of iron just 6 microns thick (the length of a red blood cell) to 4,940 degrees Fahrenheit (2,727 degrees Celsius), and squeezed the sample between two diamonds to match the extreme pressure. The origin of the earth then they measured the conductivity of iron under these conditions.
A young core
This measure of conductivity allowed the researchers to calculate the thermal cooling of the available cores to power the grounds. They found that geodinemo drew about 10 terawatts of energy from the cooling core – only one-fifth of the heat dissipated by the Earth from its surface into space (46 terawatts, Living science previously reported).
One, they calculated the amount of energy loss, researchers could calculate the age of the Earth’s interior, Lynn said. Knowing the rate of energy loss allowed researchers to calculate how long it would take to get today’s massive size solid mass from molten iron fungi.
The results of 1 billion to 1.3 billion years suggest that the main part of the Earth is actually relatively young, Lynn said.
This estimate is not as young as some estimates, as published in the journal in 2016 Nature Who used similar methods but found that the original was only 700 million years old. Lynn said the new experiment uses more reliable ways to control the temperature that produces pressure and temperature, making small estimates not possible.
Ancient magnetic rocks revealed that the magnetic field suddenly became stronger 1 billion and 1.5 billion years ago, a 2015 study in the journal Nature Found. Lynn said the new-age lines move forward nicely with the evidence, as the crystallization of the inner core would have “boosted” the magnetic field.
There are still questions about how heat circulates in the main, Lin said. Unlike the sample tested by them, the original is not just iron – it also contains lighter elements. Carbon, Hydrogen, Oxygen, Silicon and sulfur. But the extent of these light elements is unknown, making it difficult to know how they change the conductivity of the inner core. Lina and her team are doing the same thing now.
“We are trying to understand how the existence of such light elements would affect the thermal transport properties of iron in such high pressure, high temperature conditions.”
The researchers reported their findings in the journal August 13 Physical Review Letters.
Published in Original Living Science.
