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According to a study published today in Australia, the inner core of the Earth is solid but softer than expected, which should help us understand how our planet was formed.
Holographic expert Hrvoje Tkalcic and the Than-Son Pham doctoral candidate of the Australian National University (ANU) were able to detect the so-called J or Osborn waves in the inner core of the Earth. They move through solid objects.
"It turns out that, if our results are correct, the inner core shares some similar elastic properties with gold and platinum," Tklacic said in an ANU statement.
"The nucleus of the Earth is like a time capsule, and if we understand it well, we will understand how the planet was formed and how it evolved."
The J waves of the inner core of the Earth are so small and so weak that we can not observe them. The ability to detect them directly has always been a challenge for seismologists since scientists first declared that it was solid in the 1930s and 1940s.
Scientists Applied the Correlation Method wave-field that observes the similarities between the signals arriving at two different receivers after a powerful earthquake instead of observing the waves arriving directly.
This is a technique. that the same team had the custom to measure the thickness of the Antarctic icecap.
"We abandoned the first three hours of the seismograph and we focused on what happened between three and ten hours after an earthquake, and we wanted to avoid the larger signals," said the scientist. .
Scientists, who worked with a global network of stations, compared the seismographs of each pair of observatories for each major earthquake to detect their similarities.
"From these similarities, we build an overall correlogram, that is, a kind of Earthprint," said the expert.
The research, published in the journal Science Magazine, can be used to demonstrate the existence of J waves and infers the speed of shear waves, also called shear waves or S waves, in the inner core of the Earth, which still has many mysteries.
"For example, we still do not know what is the exact temperature in the Earth's inner core or its age or rapidity of solidification, but with these new advances in global seismology, we can realize it," said the seismologist.
Tklacic He added that the understanding of the Earth's core has direct consequences on the generation and maintenance of geomagnetic fields, because without them, there would be no life on the surface of the planet, the statement added.
In 2015, scientists from the University of Illinois (USA) and Nanjing (China) developed studies suggesting that the inner core of the Earth contains crystals of alignment different, formed under different conditions, and that the planet could have undergone a dramatic change during this period.
The Earth's core, which lies more than 5,000 kilometers away, began to solidify about a billion years ago and continues to grow about 0.5 millimeters a year .
"It turns out, if our results are correct, that the inner core of the Earth shares similar elastic properties with gold and platinum," Tklacic said in a statement. ANU. (SPECIAL)
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