Thursday, April 03, 2014

Recent earthquakes in Chile, Panama, California likely not related, experts say



7:58 PM, April 2, 2014




Chileans return home to survey damage after earthquake: After being evacuated from low-lying coastal areas, Chileans in the north return home to survey damage after Tuesday's magnitude 8.2 earthquake. Nathan Frandino reports.


Chileans return home to survey damage after earthq...



Magnitude 5.1 earthquake strikes Los Angeles


By Doyle Rice

USA TODAY






An 8.2-magnitude earthquake hit Chile late Tuesday, killing at least six people and generating tsunami waves that might ripple as far as Indonesia.




People walk along a cracked road in Iquique, northern Chile, on April 2, 2014 a day after a powerful 8.2-magnitude earthquake hit off Chile's Pacific coast. An 8.2-magnitude earthquake hit Chile late Tuesday, killing at least six people and generating tsunami waves that might ripple as far as Indonesia. / Aldo Solimano/AFP/Getty Images




Recent earthquakes in Chile, Panama and Southern California have people wondering. … Are they related?

Expert say it’s unlikely. “The odds are overwhelming that they’re not related,” said John Vidale, a seismologist with the University of Washington-Seattle, about the deadly magnitude-8.2 quake near Chile late Tuesday and the magnitude-5.8 quake near Panama on Wednesday.

The two quakes are too far apart -- more than 2,000 miles -- to be connected with each other, he said.

“There’s no way that last month’s Los Angeles quakes were related” to the ones this week in Central and South America, he said.

What all the quakes do share in common is their location along the notorious “Ring of Fire,” the world’s greatest earthquake belt, according to the U.S. Geological Survey (USGS).

Also known as the “circum-Pacific seismic belt,” the ring is found along the rim of the Pacific Ocean from New Zealand to Chile. It’s where 81% of the world’s largest earthquakes occur. This includes the catastrophic quake and resulting tsunami in Japan that killed thousands of people in 2011.

“There is no evidence of linkages in activity between different regions around the Ring of Fire,” said Robert Muir-Wood, a scientist with RMS, a catastrophe modeling firm.

The quakes also are probably not harbingers of a bigger one to come. “Most quakes have about a 5% chance of being followed by a bigger quake, most of the time just a little bigger,” Vidale said.

Chances of a bigger quake in these areas do not reach alarming levels, he said, “with the exception of Chile, where even aftershocks could be damaging and a bigger earthquake might be catastrophic.”

The 8.2 quake near Chile Tuesday evening was unusually strong, Vidale said.

“This earthquake is of a size that happens somewhere about once a year,” Muir-Wood said. “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 a place where two plates of the Earth’s crust come together, one riding over the other.

Chile is one of the world’s most earthquake-prone countries because the Nazca tectonic plate just off the coast in the Pacific Ocean plunges beneath the South American plate, pushing the towering Andes mountains to ever-higher elevation. Nowhere along this fault is the pressure greater than in far northern Chile.

Despite the recent spate of quakes, Muir-Wood said, “activity overall has been quieter since 2011.” Worldwide, there are roughly 4,000 earthquakes each day, according to the U.S. Geological Survey, most small and undetectable.

The quakes in the Los Angeles area last month were not that strong. “California has gone for an unusually long period without a significant earthquake loss,” Muir-Wood said.

On average, Southern California gets about 10,000 earthquakes each year, many too small to be felt, according to the USGS. That’s more than 27 a day.

Contributing: Associated Press


Source
.

No comments: