According to a team of researchers, the inner core of Earth might have altered its form over the last two decades.
The inner core is generally considered spherical, yet its borders might have distorted by over 100 meters in certain areas, as indicated by Professor John Vidale, who headed the study.
The Earth's core acts as the vital organ of our planet, generating a magnetic field that shields life from being incinerated by the Sun's radiation.
The solid inner core rotates separately from both the fluid outer core and the remainder of the globe. If this movement ceased, our planet would resemble desolate Mars, which lost its protective magnetic shield eons ago.
This transformation might occur at the boundary between the solid inner core and the intensely hot liquid metallic outer core.
The study appears in the scientific journal Nature Geoscience. Initially, the researchers aimed to understand why the inner core appeared to slow down relative to Earth's rotation around 2010 before accelerating once more.
Grasping the functioning of the Earth's core is crucial for comprehending the magnetic field that shields our planet, as well as determining if this shield might weaken or vanish.
The interior of our planet remains a vast enigma. Located approximately 4,000 miles beneath the Earth's surface, the core has eluded scientific attempts to explore it directly until now.
Therefore, to attempt unlocking its mysteries, certain scientists assess the seismic waves generated by earthquakes as they propagate throughout the Earth.
How the waves propagate can indicate the kind of materials they have traversed, even within the inner core, thus aiding us in visualizing what exists under our feet.
The latest study examined seismic wave patterns from earthquakes occurring repeatedly in identical locations between 1991 and 2023. This allowed researchers to demonstrate the changes happening within the Earth’s inner core over this period.
Professor Vidale, an Earth scientist from the University of Southern California, discovered additional proof supporting the idea that the inner core decelerated circa 2010 during those periods.
However, his team also discovered indications of alterations in the form of the inner core.
This phenomenon seems to occur at the interface between the inner and outer cores, particularly when the inner core approaches its melting temperature. The fluid motion within the outer core along with gravitational forces caused by variations in density could lead to such deformations.
Professor Hrvoje Tkalčić from the Australian National University, who did not participate in the research, commented that the paper offers "a compelling idea that warrants further investigation."
He mentioned that this could enable researchers "to develop more accurate assessments of certain critical material characteristics, like the viscosity of Earth’s inner core, an area still shrouded in mystery within contemporary scientific understanding."
As time progresses, the liquid outer core gradually turns into the solid inner core; however, it will take billions of years for this process to be complete.
This outcome would most likely signal the conclusion of earthly existence, yet by that time, our planet will probably have already been consumed by the Sun.
Professor Vidale's research is among the studies conducted globally by specialists examining and debating the processes occurring within the Earth's core.
"Generally, in science, our aim is to examine things until we comprehend them," Professor Vidale states.
"Most likely, this discovery has zero impact on our everyday routines, yet we are keen to comprehend what transpires at the center of the Earth," he remarks.
The alterations might be linked to shifts in Earth's magnetic field.
"The magnetic field experienced sudden changes known as 'jerks' during different periods over the last several decades, and we want to determine if this is connected to observations at the inner core boundary," he stated.
Professor Vidale advised against overstating the implications of these findings, suggesting that they do not indicate the Earth's core will cease rotation anytime shortly.
He further mentioned that numerous uncertainties remain.
"We’re not entirely certain that our interpretation of these modifications is accurate," noting that the limits of scientific understanding are continually evolving, and similar to numerous—if not all—researchers, he acknowledges having been incorrect previously.