- A magnitude 9.5 earthquake struck about 3,800 years ago in northern Chile, according to a new study.
- This caused a megatsunami that sent crashing waves from Chile towards New Zealand, according to the study.
- The nearby coasts were uninhabitable for 1,000 years due to the devastating impact of the tsunami.
According to a new study, archaeologists have found evidence of the largest earthquake in human history, which triggered a 5,000-mile-long megatsunami that devastated coastlines for a millennium, LiveScience reported.
The magnitude 9.5 earthquake struck about 3,800 years ago in northern Chile, the study in the Science Advances Journal determined.
The study said it was a megathrust earthquake, which is when one tectonic plate is forced under another. These earthquakes often cause tsunamis that are more destructive than the earthquakes themselves.
The earthquake triggered an extremely powerful tsunami that created waves 20 meters high and stretched from northern Chile to New Zealand, according to the study.
The tsunami sent car-sized boulders crashing down up to 620 miles inland, according to a statement from the University of Southampton, rendering nearby coasts uninhabitable for 1,000 years.
Archaeologists found evidence of marine sediments “very high and far inland”, Professor James Goff of the University of Southampton said, according to the statement. “So it wasn’t a storm that brought them there,” he added.
Archaeologists also excavated ancient man-made stone structures found beneath tsunami deposits on Chile’s northern coast, LiveScience reported.
The structures were lying upside down, facing the sea, suggesting they had been toppled by the tsunami’s undertow. “The local population has nothing left,” Goff said in the statement.
“Our archaeological work revealed that enormous social upheaval ensued as communities moved inland beyond the reach of the tsunamis,” Goff continued. “It took over 1,000 years before people came back to live on the coast, which is an incredible amount of time considering they depended on the sea for food.”
The study was able to conclude that the tsunami reached Australasia after Goff and his research team discovered a large number of boulders, some the size of cars, inland on Chatham Island in New -Zealand. The boulders date back to around the same time as the earthquake, according to the study.
“In New Zealand, we said these rocks could only have been moved by a tsunami from northern Chile and it would take something like a magnitude 9.5 earthquake to generate it,” said Goff in the release. “And now we have found it.”
Prior to this study, the largest earthquake ever recorded was in 1960. The Valdivia earthquake, which struck southern Chile, was placed at a magnitude of 9.4 to 9.6. It caused a tsunami that reached Hawaii and claimed up to 6,000 lives.