the Earth’s core started in Rotate in the opposite directionafter a cycle of swinging which lasts approx 70 years old. This is the conclusion reached by the researchers Yang and Song Peking University, in a New study Posted in January 23, 2023 on me Natural Earth Sciences. It is a contrast that does not directly affect our daily lives – So we have nothing to fear! – But what justifies the difference in the duration of the day every 60-70 years and fluctuations Earth’s magnetic field. In this article we will see what this difference entails direction of rotation And what studies have been conducted in this field in recent years.
Previous studies on the rotation of the Earth’s core
To better contextualize the importance of this work, let’s do a very brief review on Earth’s internal structure. the nucleusthe innermost layer, is divided into two parts: internal And external. outer core liquid And here it is Earth’s magnetic field. Inside there is a large metal object around it 70% of the moon who takes a name The inner core — is the hero of this new study.
The fact of its rotation Not stable over time It’s not new: in one study Based on the seismic waves of 1996, it was observed that the rotation of the core was Slightly faster of the crust and mantle. In numerical terms, we are talking about The first time in a year – that is, at least, until 2009. In that year, various analyzes showed how much the core was I stopped With respect to the mantle and crust, only to resume rotation but in opposite direction.
What does reversing the direction of rotation involve?
Reading the new study that has emerged from researchers Song and Yang, we try to understand the possible effects of this oscillation in the nucleus.
First of all, the authors A patterns – drawing. To do this they analyzed a file Travel times of seismic waves that they must cross the inner core by following the same path: analyzing it lost time Between one and the other it is possible to obtain information about the rotation of this mineral layer.
Their analyzes revealed that rotation It follows a long cycle of approx 70 years oldwith every direction changes About 35 years old. However, the inner core is closely related to both Coat (as a matter of cuteness) that al outer core (for magnetic letter). So changing their rotation could affect the motion of these other two layers, justifying (most likely):
- changing the length of the day which occurs cyclically every 60-70 years;
- Earth’s magnetic field fluctuations.
In any case, these are hypotheses that, in order to prove them, need confirmation Additional studies. Actually, these are the lyrics John Vidala California seismologist who was not directly involved in the study:
This is a very careful study by excellent scientists who used a lot of data […] However, none of the existing models can properly explain all the available data
