In a new study, scientists say that they have found evidence that the shape of the Earth’s inner core may have changed over time. More interestingly, this change seems to have happened not only on the geological time scale, but only in the last twenty years.
Although we examine and model our own planet as much as possible, the world’s inner core still manages to maintain a large part of its secrets. Considering that the farthest point of the Earth is 12,263 meters (or about 12 kilometers) and a region under our feet, it is not surprising that it is not very surprising. However, we can learn about the center by looking at the seismic waves passing through Earth and the magnetic field lines of the planet which is the result of the conditions in the core.
As technology and techniques used develop, there are great breakthroughs in this regard and there are a few surprising details. For example, in 2022, a team found the data collected during the nuclear tests in the 1960s and 70s, and found that the inner core returned in the opposite direction compared to the surface, at least one-tenth at least once a year (ie returned from the surface). In addition, the core seemed to be released rather than relatively fixed.
John E. Vidale, the author of the study and Professor of Earth Sciences, said in a press release that at that time, “The inner core is not fixed – it moves under our feet and seems to go back a few kilometers and forth every six years, and added: ün One of the questions we are trying to answer It was also: Does the inner core move gradually or is it mostly fixed compared to everything else in the long term? We are trying to understand how the inner core is formed and how it moves over time – this is an important step to better understand this process. ”
Later studies showed more evidence that the return of the seeds has slowed down compared to the rest of the Earth since 2010. Vidale and his team tried to examine the changes in seismic waves as the world’s core turns at different speeds.
In the new study, the team confirmed that the inner core has returned faster and more slowly than the rest of the world in the last few decades; This study analyzed the inner core -core transition (PKIKP) seismic waves recorded by Eielson (ILAR) and Yellowknife (YKA) series in the north of North America on the South Sandwich Islands between 1991 and 2023. Here, we expand the cluster of these recurrent earthquakes and compare couples when the same position of the inner core occupy the same position, while non -returned changes in the YKA between 2004 and 2008, these do not appear in ILAR. ”
Researchers examined the 168 recurrent earthquake pairs that occurred before and after the core returned to the same position and analyzed whether the changes in seismic waves were caused by rotation rate or other factors. According to the team, some of the change in seismic waves was caused by changes in the form of the nucleus.
The team concludes and concludes “observed wave form changes and changes specified in other studies, local deformation or material changes ve and adds:“ YKA, the most likely explanation of the changes observed in PKIKP waves, [outer core] traxes and [core-division topography] connection [the inner core limit] and the viscose deformation of the shallow IC. ”
The team states that more “exotic” changes, such as throwing out the melt, are not unlikely and more research is needed: “Here, we argue that there is an additional change in addition to the more dominant signal of all IC’s differential rotation. Therefore, we offer a solution to a long -standing debate – both rotation and non -rotation changes are available, and the second deserves a careful examination to see what moves in the nucleus. ”
The study was published in Nature Geoscicece magazine.
