The Earth's inner core may have stopped rotating and even reversed its direction of spin in recent years, according to a study published on Monday in the journal Nature Geoscience. The reason for the reversal is unknown.
The study found that the slowing or near stoppage occurred as recently as 2009. Similar events were also found to have occurred in the 1970s and were predicted to occur again in the 2040s, with the authors noting that the core changes direction about every 35 years.
Though there is still much debate to be had on the topic, Song and Yang's research is very valuable. While some believe that the changes in core rotation and direction are happening even more frequently, we know for certain that data on seismic monitoring has yielded much better results than in previous years. The more scientists learn, the more exciting the field gets.
Song and Yang's research is flawed, and includes misinterpretations of how to measure and view seismic signals. Their results provide an inconsistent explanation of what we know to be true. More data needs to be collected to reach a consistent and scientifically agreed upon conclusion surrounding exactly which parts of the core are rotating and why changes in that rotation occur.