A magnitude 8.2 earthquake struck southern Mexico on September 7, 2017, killing 98 and injuring hundreds of individuals. A new study now reveals that the tremor, also known as the Tehuantepec earthquake, was even more powerful than initially thought.
According to the research published in the journal Nature Geoscience on October 1, part of the tectonic plate responsible for the earthquake has completely split apart.
“If you think of it as a huge slab of glass, this rupture made a big, gaping crack,” study author Diego Melgar, from the University of Oregon told National Geographic.
“All indications are that it has broken through the entire width of the thing.”
The researchers said that no one actually knows why the split occurred because the plates should bend like plastic. They said that the event contradicts the models that they have and admitted that they do not yet have an explanation on how this was possible.
The earthquake’s epicenter occurred 28 miles deep in the Cocos plate, a relatively young plate at 25-million-years-old and is warmer compared with other tectonic plates.
The tremor produced a crack that measures 199 miles long, about 60 miles wide and goes to a depth of about 16 miles into the Earth. The tectonic plate that goes into Mexico spans about 37 miles wide and the tremor caused it to split in two.
Shallower cracks that happen at the top half or top third of a tectonic plate is relatively common but one that splits a plate in half is considered an anomaly.
“Anytime you bend something it’s prone to cracking. These kinds of cracks, we see all over the world but we don’t see them propagating all the way through the tectonic plate,” Melgar said, according to IFLScience.
“What is rare about this one is that it sort of keeps going down the entire plate, and that is something we haven’t seen before,” said Melgar.
An earthquake of this nature also occurred in Sanriku, Japan in 1933. It generated a 94-foot tsunami that killed more than 1,500 people and destroyed more than 7,000 homes.
The Mexican earthquake generated a 6-foot tsunami, which researchers said was likely limited in size because the quake occurred between the trench (the deepest part of the ocean) and the land.
One of the biggest risks posed by powerful earthquakes is the occurrence of tsunamis. Researchers said that it was fortunate that the 2017 Mexican quake occurred at the trench. Otherwise, the devastation could have been far worse.