Envato Elements
The core in the center of the earth
A new analysis of 168 pairs of “repeated earthquakes” indicates that the shape of the earth’s inner core is changing subtly.
In an innovative discovery, scientists found that the earth’s inner core not only changes its speed of rotation, but also seems to change shape. The revelation, in the journal Nature Geoscience, suggests that nucleus’ subtle deformations affect the way seismic waves travel through the planet, offering new knowledge about the internal functioning of the earth.
According to the geophysicist John Vidale, from the University of Southern California, this discovery challenges the previous assumptions about the behavior of the core. “Detecting a process that was not doly documented is an emotion,” Vidale told. “The next step will be certifying that we are right and improve our models.”
The earth’s inner nucleus, a solid iron and nickel sphere with about 2440 kilometers wide, is wrapped in a cast external nucleus. It plays a crucial role in planetary processes, from influencing the duration of one day to generating the Earth’s protective magnetic field.
Scientists have long known that the inner core rotates at a different speed From the rest of the planet, a phenomenon known as super rotation. However, recent investigations indicate that the rotation rate has slowed down and now new evidence suggests that the nucleus itself may be deforming.
Since scientists cannot directly observe the nucleus, they are based on the seismic waves of earthquakes, which travel through the planet and provide indirect tracks on their internal structure. In analyzing these waves, researchers can Follow the core changes over time.
Vidale and his team studied 168 pairs of “repeated earthquakes” – Seismos that occurred in the same place and under similar conditions. Comparing seismic data from times when the core was in the same rotational position, changes in rotation as the only cause of wave variations were excluded. Instead, your findings suggest that the form of the inner core is changing.
The cause of these deformations remains uncertain. Vidale proposes that the changes in form may be due to the attraction of denser regions within the Earth or the convective currents in the external nucleus that exert pressure on the surface of the inner core. Given that the inner core is close to its melting point, these changes may be relatively small but significant enough to alter seismic wave patterns.
Vidale and his colleagues plan to continue to monitor the behavior of the inner core, as it is expected to return to its position from the early 2000s in the coming years. Scientists expect this period to give more clues about how the nucleus influences the earth’s rotation and magnetic field.
