Scientists may have underestimated the number of layers on Earth. According to recent findings, the Earth’s solid inner core may contain a buried layer, or “inner-inner core”. Although the exact composition of this layer is unknown, it may be related to changes in iron’s structure at high pressure and temperature. The study was led by a doctoral student in seismology, named Jo Stephenson, from Australian National University in Canberra. It shows that the inner core is more complicated than was previously thought.
Stephenson said that It’s more than just a heavy iron ball.
Earth’s Complex core
Two different parts make up the core of the planet. The Earth’s liquid outer core is made of liquid metals and begins approximately 1,800 miles /2,897 kilometers below the surface. Its temperature ranges from 2,204 to 4,982 degrees Celsius Fahrenheit (4,000 to 9,000 degrees). The core changes to solid iron and also a bit of nickel at a depth of roughly 5,150 km or 3,200 miles below the surface of the Earth.
The first signs that anything intriguing might be buried deep inside the inner core date back to the 1980s. Scientists utilize earthquake waves to create photographs of the core because there is no means to reach the inner core. It’s because the temperatures are comparable to those at the sun’s surface. Scientists can reconstruct an image of what the waves that have passed through using small changes that are carried by them from an earthquake that is detected on the opposite side of the planet.
Strangely, waves moving through the core of the planet parallel to the equator move more slowly than waves moving through it from north to south. According to Stephenson, this is a recurrent finding for which there is no explanation. Anisotropy is the scientific name for this peculiarity.
Deep Mysteries Of The Layers Of The Earth
In the early 2000s, scientists realized that something appeared to be different at the very center of the inner core. The anisotropy appeared to differ from the rest of the inner core at this level.
Stephenson with her colleagues assembled a dataset of roughly 100,000 earthquake waves that had passed through this inner level of the core. They then applied an algorithm that looks for the best physical explanation of what is happening. They discovered that the anisotropy in the slow direction is now 54 degrees off the equator in the inner-inner core, beginning roughly 400 miles from the Earth’s center.
According to Stephenson, this isn’t simply noised in the data; there is actually something there. But identifying what is causing this is difficult. Working with mineral physicists, the researchers are currently developing models of the inner-inner core to try to explain this transition.
The planet’s inner core is expanding and cooling, therefore the structure of the inner-inner core may have something to do with how iron crystallizes as it cools or it may also be caused by changes in how the metal behaves under extreme pressure and temperatures.
Before the team’s findings can be properly verified, there is still a great deal of research and observation to be done. Having said that, the researchers’ findings do well to match up with an earlier study that also paid attention to the Earth’s innermost core.
Understanding the structure of our planet and its history can help us relate geological changes of the present to those that took place before people could observe them.
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