Jakarta, CNBC Indonesia – The structure of the Earth turns out to be different from what is taught in school lessons. This is because a study discovered a hidden layer in the Earth’s core.
Previously, we knew the Earth’s layers consisted of the crust, mantle, outer core and inner core. Several years ago, University of Australia geophysicist Joanne Stephenson and colleagues found evidence of two distinct layers in the inner core. Science Alert, Thursday (16/2/2023).
The research team used algorithms to trawl and match thousands of models from the inner core. It does this by observing decades of data on seismic wavelengths traveling deep within the Earth.
They managed to find several models of anisotropy in the Earth’s inner core. Differences in material composition change the nature of seismic waves, giving rise to several possibilities.
Some models show seismic waves in the inner core channel more rapidly parallel to the center of the planet. While others are related to a mixture of faster wave-making materials parallel to the axis of rotation of the Earth.
In addition, they also found a degree of difference at certain angles. The slow direction changes to a 54 degree angle with the fast wave direction running parallel to the axis.
Stephenson said his team found evidence to suggest changes in the structure of iron. So there are likely two separate cooling events.
In fact, there have been allegations of the presence of other layers in the Earth’s core before. This refers to evidence of iron crystals making up the innermost core that have different structural alignments.
“We are limited to the global distribution of earthquakes and recipients, specifically the polar antipodes,” the research team wrote in their paper. They also explained that missing data made their conclusions uncertain.
(tib)
