Experts from the United States Geological Survey say the recent strand of earthquakes to hit countries along the North and South American pacific coasts are not related. United States Geological Survey (USGS) seismologist John Vidale spoke to USA Today about the quakes that shook up Chile, Panama, and Southern California in recent weeks.
“The odds are overwhelming that they're not related," Vidale said, adding that the quakes were too far apart to be linked to one another.
The only common thread between the earthquakes is their occurrence on the Ring of Fire, a semi-circle of tectonic plate boundaries spanning from New Zealand to Southern Chile where seismologists says 90% of the world’s earthquakes take place. The USGS says 4,000 earthquakes occur each day around the world.
The USGS does note, however, that there is a good chance the latest 8.2 earthquake in Chile will be followed by a significant aftershock.
“The biggest risk is aftershocks for the 8.2 in the same area where the 8.2 occurred. They’ll become less frequent with time, but the risk still exists for days and weeks,” said seismologist Kate Hutton.
The likelihood of another 8.2 quake happening in coming months is low given that an earthquake of that size tends to happen only once a year. Seismologists are still aware of the possibility that the recent 8.2 quake could have been a foreshock to an even larger approaching earthquake.
"This earthquake is of a size that happens somewhere about once a year," said Robert Muir-Wood, a scientist who works in catastrophe modeling. "The location is no particular surprise — the Chile subduction zone is the world's most active, and northern Chile has not seen really big subduction zone earthquakes for some decades, unlike southern Chile."
A subduction zone is where two tectonic plates come together, with one riding over the other. Chile is home to an extremely active subduction zone, where the Nazci plate slides under the South American continental plate at about three inches per year.
Here is a map of the infamous Ring of Fire: