Seismic wave investigations have been used to study Earth’s structure and innermost inner core for decades. Earthquake shock waves are measured as they pass through the core. Scientists can determine denser places by measuring speed anisotropy. Moreover, these findings have led to the current geological model, which has four layers: a crust and mantle (mostly silicate minerals) and an outer core and inner core (nickel-iron).

RSES and ANU seismologists:

ANU seismologists say a recent study revealed Earth’s deepest inner core. The scientists discovered an “innermost inner core”—a solid metal ball—in Earth’s inner core in a Nature Communications study. These findings may illuminate Earth’s evolution and lead to five-layer geological models instead of four.

ANU Research School of Earth Sciences (RSES) postdoctoral fellow Thanh-Son Pham and Professor Hrvoje Tkalcic led the study. They stacked seismic wave data from 200 magnitude-6 or more significant earthquakes throughout the past decade. Seismic stations globally recorded the triggered waveforms, which went directly through the Earth’s center to the antipode before returning to the earthquake’s source.

Earth's Innermost Inner Core
Credit: Argonne National Labs

New Data Shows Earth’s Innermost Core Has Layers:

Anisotropy measurements of Earth’s inner core based on these waves’ travel times revealed previously-unrecorded data about Earth’s interior structure. This included the possible presence of a layered structure in the innermost part of the inner core. “The existence of an internal metallic ball within the inner core, the innermost inner core, was hypothesized about 20 years ago,” said Dr. Pham in an ANU press release. “We now provide another line of evidence to prove the hypothesis.”

Seismic waves show how iron atoms align at high temperatures and pressures or form crystals. The scientists observed that the bouncing seismic waves repeatedly investigated areas near the Earth’s center from different angles. By evaluating seismic travel timings, they extrapolated that the core’s innermost crystalized structure has an outside layer.

These discoveries may explain how waves speed up or slow down as they penetrate the innermost inner core. Dr. Pham:

“By developing a technique to boost the signals recorded by densely populated seismograph networks, we observed, for the first time, seismic waves that bounce back -and forth up to five times along the Earth’s diameter. Previous studies have documented only a single antipodal bounce. The findings are exciting because they provide a new way to probe the Earth’s inner core and its centermost region.”

Earth’s inner core and its centermost region

According to Professor Hrvoje Tkalcic:

One Alaska earthquake caused seismic waves that “bounced off” in the South Atlantic before returning to Alaska. The ANU team suggests a massive global event may have changed Earth’s inner core crystal structure. Hence, Prof. Tkalcic stated studying Earth’s deep interior could reveal its evolutionary history:

“This inner core is like a time capsule of Earth’s evolutionary history – it’s a fossilized record that serves as a gateway into the events of our planet’s past. Events that happened on Earth hundreds of millions to billions of years ago. There are still many unanswered questions about the Earth’s innermost inner core, which could hold the secrets to piecing together the mystery of our planet’s formation.”

On the Whole:

Lastly, seismic wave studies by ANU studies discovered Earth’s “innermost inner core,” a solid metal ball. Scientists discovered Earth’s internal structure by stacking seismic wave data from 200 magnitude-6 or more significant earthquakes during the past decade. These findings may also lead to five-layer geological models instead of four and explain how waves speed up or slow down when they penetrate the innermost core. The discovery may disclose Earth’s evolutionary history by probing its inner core and center.


Published by: Sky Headlines

Our Planet’s Inner Core “Stopped” its Rotation and may be Reversing it!

According to a recent study, deep in the center of the Earth, the inner core may have stopped and could also reverse its Rotation. Scientists have claimed that the inner core of Earth’s oscillation overlaps with periodic changes in the Earth’s surface system and that there is an interaction between different layers of the Earth.

What is the science behind the Earth’s inner core rotation?

The inner core spans roughly 746 miles and consists mainly of pure, solid iron.
The outer core is primarily surrounded by water, molten iron, and nickel, which creates the Earth’s magnetic field. When the outer core moves, it creates an electrical current that causes a magnetic field. This motion of the inner core surface also makes the outer core rotate.

What Yi Yang and Xiaodong Song said about Earth’s inner-core Rotation?

However, scientists can only study the Earth’s Rotation indirectly. Researchers Yi Yang and Xiaodong Song analyze seismic waves caused by earthquakes. Xiaodong Song, a geophysicist at Peking University in Beijing, said:

“We see strong evidence that the inner core has been rotating faster than the surface, [but] by around 2009, it nearly stopped,”

Moreover, he stated,

“Now it is gradually moving in the opposite direction.”
This research was published in the Nature Geoscience journal on Monday.

Based on their study of seismic waves caused by similar earthquakes dating back to the 1960s. Both researchers also stated that the inner core’s spin might be “paused” between 2009 and 2020. There is also a possibility that this core might be reversed “by a small amount.”

Is Earth’s “inner core” spinning for the first time?

This is not the first time the Earth’s inner core is moving. Before this statement, an American-born seismologist specializing in analyzing seismograms to explore features within the Earth also analyzed this inner core rotation.

What was John Vidale’s research?

John Vidale, a Dean’s Professor of Earth Sciences at USC Dornsife College of Letters, Arts, and Sciences, also showed the inner core’s spin between 1969 and 1974. Vidale made a statement about his research: “The inner core is not fixed. It’s moving under our feet, and it seems to be going back and forth a couple of kilometers every six years,”

Moreover, he stated: “One of the questions we tried to answer is, does the inner core progressively move or is it mostly locked compared to everything else in the long term? We’re trying to understand how the inner core forms and moves over time. This is an important step in better understanding this process.”

What will be the effect of inner core rotation on Earth’s surface?

Hold on! if you are worried about the Earth’s inner core spin. You don’t have to. This doesn’t mean that the Earth is going to stop spinning. Experts say that this pause and reversal effect of the inner core will play a vital role in studying Earth’s surface system. The inner core rotation plays a vital role in creating the Earth’s magnetic field, which protects life on the Earth from dangerous solar radiation. It could also affect the length of the day and the Earth’s distribution of heat.


Published by: Sky Headlines