By Jeff Todd
GOLDEN, Colo. (CBS4) – When the earth started to rumble in southern Mexico, scientists at the U.S. Geological Survey’s National Earthquake Information Center in Golden started pinpointing all the information they could.
”As soon as we detect an earthquake we start to locate exactly where it occurred and try and constrain its size or its magnitude,” said Will Yeck with the U.S. Geological Survey.
The 7.1 magnitude quake hit near Puebla, about 70 miles southeast of Mexico City. Experts say each large scale earthquake is unique but there are similarities.
The earthquake cause is similar to an 8.1 magnitude from just 12 days ago.
“Both of them occurred as normal earthquakes where the plates were bending. This happened in the subducting plate where it’s actually bending and pulling apart,” Yeck said.
But the two recent massive earthquakes are not believed to be related.
“In this case the distance between that 8.1 and the 7.1 is pretty far — they’re about 650 kilometers apart. That’s a little farther than we normally see for an aftershock,” Yeck said.
On average, 14 earthquakes are observed around the world each year with a magnitude 7 or higher.
Exactly 32 years ago, another massive quake resulted in damage and deaths in Mexico City. It’s believed soft sediment underneath the city caused more damage than other areas.
“The shaking was larger in Mexico City,” Yeck said about Tuesday’s quake. “A lot of the reason people think 1985 earthquake was so damaging, because the shaking was amplified within Mexico City.”
Over the next few days scientists in Golden will continue to monitor aftershocks.
Jeff Todd joined the CBS4 team in 2011 covering the Western Slope in the Mountain Newsroom. Since 2015 he’s been working across the Front Range in the Denver Headquarters. Follow him on Twitter @CBS4Jeff.