Earthquakes can apparently turn around and hit an area with a second pass — an event known as a “boomerang earthquake” — in rare circumstances.
Scientists recently found evidence of the “boomerang earthquake” in a new study, highlighting an event that happened in the Atlantic Ocean back in 2016.
The earthquake — which took place at the Romanche fracture zone — happened between Brazil and the west coast of Africa. There was a 7.1 magnitude earthquake in August 2016. The tremor traveled one direction and then it came back around for a second strike, bringing an increase of speed on the second strike, according to ScienceAlert.
“Whilst scientists have found that such a reversing rupture mechanism is possible from theoretical models, our new study provides some of the clearest evidence for this enigmatic mechanism occurring in a real fault,” said Stephen Hicks, lead researcher and seismologist from Imperial College London.
“Even though the fault structure seems simple, the way the earthquake grew was not, and this was completely opposite to how we expected the earthquake to look before we started to analyze the data.”
The earthquake had two phases. The first traveled eastward before coming back around and going westward.
This, of course, is the first reported incident of a boomerang earthquake. It’s so rare that it’s unlikely to find one again unless researchers seek it out, according to National Geographic.
Evidence is growing of these events. But more research is needed to discover more.
“The theory says that it’s there, but it’s quite difficult to see that (in the real world),” said geophysicist Louisa Brotherson, a Ph.D. researcher at the University of Liverpool in the U.K., who simulates earthquakes.