The Chile Earthquake’s First Tsunami Waves Strike

A TIDE GAUGE off the shore of Coquimbo, a Chilean seaside city less than 100 miles from the epicenter of tonight’s 8.3 moment magnitude earthquake, has logged wave heights in excess of 14 feet. This comes about 90 minutes after the quake struck at 7:54pm local time.

NOAA’s Pacific Tsunami Warning Center has predicted wave heights exceeding 36 feet along the Chilean coast, and smaller events elsewhere in the Pacific. Outside of Chile, French Polynesia, a group of over 100 islands in the middle of the south Pacific, is in the most danger. There, NOAA warns of tsunami waves from three to nine feet.

That may not sound like a lot, but even small tsunami waves, which have the full force of the ocean behind them, can be destructive. The agency also included smaller tsunami warningsfor just about any nation that touches Pacific waters.

At 7:54pm local time, an 8.3 moment magnitude earthquake struck about 10 miles off the coast of central Chile. So far, the USGS has no reports of damage, nor of tsunamis.

But that doesn’t mean things are necessarily peachy. “It’s still very preliminary,” says Dale Grant, a geophysicist at the USGS National Earthquake Information Center in Colorado. “I’m sure there’s been a lot of communication disruption in that area.” Although there are no large cities in the immediate vicinity of the quake, the epicenter is about 150 miles from Chile’s capital city, Santiago.

The National Tsunami Warning Center has warned that Chile’s shorelines could experience tsunamis exceeding nine feet. “That might not sound like much, but a tsunami wave has all the weight of the ocean behind it,” says Scott Langley, an electronics technician with the National Tsunami Warning Center in Alaska. “This isn’t something you want to go out and ride with your surfboard.”

Since the initial quake, the USGS has reported four aftershocks, ranging from 5.7 to 6.4 moment magnitude.

This story is being updated as details develop.

1 Update: 8:05pm ET 8/16/15 The National Tsunami Warning Center has issued preliminary warnings that tsunami waves threaten many islands in the south pacific—primarily French Polynesia—and just about every country with a Pacific shore.

2 Update: 8:15pm ET 8/16/15 The USGS is now showing five aftershocks, all occurring within 50 minutes of the original quake.