Terror data from a 2016 earthquake in the tectonic plates of South America and Africa, deep below the Atlantic Ocean, showed that the quake first accelerated to the northeast, then suddenly turned and hit the fault line again going west, according to a study published Monday in the journal Nature Geoscience.
The episode, in an area known as the Romanche fracture area, is visualized in this graphic animation by Imperial College London.
Beyond initial discovery, research informs how seismic events can move and change.
“Scientists and people who use hazard maps both benefit from learning that earthquake faults have a variety of ways of unfolding than previously documented,” said John Vidale, a University of Southern California professor who was unrelated. with the study.
The so-called “boomerang earthquake” may be among the first of its kind.
“There are some hints that a small number of these reversible earthquake faults have occurred on the ground, but complete evidence is scarce,” Hicks said, “so I think our study probably provides the clearest example of one so far. “
Double earthquakes can cause stronger tremors in the ground
Hicks warns that because evidence is so scarce, this finding does not mean that those living near earthquake hotspots should start preparing for dual earthquakes.
“We are not sure if what we have seen along a specific type of tile boundary can also occur in different types of defects in the ground,” he said.
If this kind of earthquake were to occur on the ground, Hicks said, it could cause stronger tremors, as the direction of an earthquake could affect its strength.
“However, since we have measured only one of these types of earthquakes in detail, then it will certainly require more scientific analysis of other earthquakes before our result begins to directly affect seismic hazard patterns and mitigation.” them, “he said.
The documentation in the latest study on both the change in direction and the rate of breakdown faster than expected “challenges our ability to understand how friction works and also to predict the expected oscillation in future earthquakes,” Vidale said.
It is also significant that the study highlights this earthquake as it moves at “supershear” speeds.