Shock data from a 2016 earthquake in the South American and African tectonic plates, deep in the Atlantic Ocean, show that the first earthquake plunged northeast, then turned abruptly. and again hit the fault line to the west, according to a study published Monday in the journal Nature Geosciences.
The episode, in an area called the Romanche fault zone, is visualized in this graphic animation from Imperial College London.
In addition to the initial discovery, research shows how seismic events can move and change.
John Vidale, a professor at the University of Southern California who was not involved in the study, said: “Scientists and people using hazard maps all benefit knowing that earthquake faults have multiple ways to open up. out than in previous documents.
The so-called “boomerang earthquake” may be one of the first of its kind.
Hicks said: “There is some suggestion that a small number of this earthquake-induced cracks have occurred on land, but the thorough evidence is very little, so I think our study has. can provide the clearest example to date ”.
Double earthquakes can cause stronger tremors on land
Hicks warns that because the evidence is so sparse, the finding does not mean that people living near earthquake hotspots should begin preparing for the double earthquake.
“We are not sure whether what we observed along a particular type of plate boundary could also occur over different types of faults on land,” he said.
If this type of earthquake happens on land, Hicks said, it could cause more powerful tremors, as the direction of the quake could affect its strength.
“However, since we have only measured one of these types of earthquakes in detail, it will likely require more scientific analysis of other earthquakes before our results begin,” he said. has a direct impact on seismic risk models and their mitigation, ”he said.
Documentation of recent research on both directional changes and faster than expected fracture rates “challenges our ability to understand how friction works and to predict expected vibrations. In future earthquakes, “Vidale said.
It is also important that research emphasizes this earthquake as moving at “supersonic” speeds.