Colorado earthquake is largest in four decades

Colorado earthquake: A magnitude 5.3 earthquake shook the state late Monday, with an epicenter about 180 miles south of Denver, Colorado.

By Associated Press / August 23, 2011

Trinidad, Colo.
The largest earthquake to strike Colorado in almost 40 years has shaken hundreds of people near the New Mexico border and caused minor damage to a few homes.

The magnitude 5.3 earthquake was recorded at about 11:46 p.m. MDT Monday about nine miles southwest of Trinidad, Colo., and about 180 miles south of Denver, according to the National Earthquake Information Center in Golden, Colo. The quake followed two smaller ones that hit the area earlier in the day.

The quake is the largest in Colorado since a magnitude 5.7 was recorded in 1973, U.S. Geological Service geophysicist Amy Vaughn said. That one was centered in the northwestern part of the state — about 50 miles north of Grand Junction, she said.

A few homes have been damaged and there were rockslides on Colorado Highway 12 and Interstate 25, but both highways remained open, a Las Animas County Sheriff's Office dispatcher said Tuesday.

The dispatcher, who would only give her first name as Kristina, said she was working when the biggest earthquake hit near midnight.

"Everything was shaking, but we had no power loss," she said.

She said authorities were still trying to assess the damage.

"I thought maybe a car had hit my house," 70-year-old Trinidad resident Nadine Baca said. "Then I called to my son and he said it was the third (quake) today."

Another USGS geophysicist, Shengzao Chen, said the information center had received calls from more than 70 people in Trinidad and several dozen people in New Mexico who felt the shaking. More than 30 people in Colorado Springs, about 130 miles north of Trinidad, also reported feeling the quake, he said.

A magnitude 4.6 quake was felt in the same area at 5:30 p.m. on Monday, and a magnitude 2.9 quake was recorded just before 8 a.m. Two aftershocks — one recorded at 3.5 and another at 3.8 — followed early Tuesday, more than an hour after the 5.3 quake.

The last time the area received such a series of earthquakes was in August and September 2001, when about a dozen smaller-sized temblors were recorded, Chen said.

"The area seems to be active again," he said.