Researchers from Nature Geoscience have proven that boomerang earthquakes exist after recording one of the quakes under the Atlantic Ocean.
In 2016, underwater seismometers to monitor a fracture zone near the Mid-Atlantic Ridge were installed, after a “back-propagating rupture” (boomerang quake) was detected. Regular earthquakes generally shake in the direction the temblor is travelling but a boomerang quake spreads shaking across a wider area.
Months later, a 7.1 magnitude earthquake was recorded in the Romanche Fracture Zone, which bisects the Mid-Atlantic Ridge.
This quake first travelled upward and eastward along the fault before switching direction and creating the geologic equivalent of a sonic boom.
According to the researchers, the quake generated seismic waves when it began to travel in the opposite direction at a top speed of 17,702 kilometres per hour, which created what geologists refer to as a supershear event.
The origin of how boomerang quakes occur is still not clear, and they are still quite rare.
According to National Geographic, scientists have previously argued that quakes such as the magnitude 9.0 Tohoku earthquake that hit Japan in 2011 may have had a boomeranged rupture.
However, confirmation of their existence will help researchers detect supershear earthquakes and learn to detect boomerang quakes on land.