When the earth shook Monday morning under Becky Romero and Elvira Garcia, the Nambé residents knew it wasn't your typical Northern New Mexico occurrence.

"We hear experimental explosions from the lab," Romero said of the Los Alamos National Laboratory. "We hear sonic booms and crashes on [N.M.] 503. But this was totally different."

Garcia, who has experienced her share of natural disasters, agreed.

"I've been through the big floods in the arroyos with the pigs rolling down," the lifelong Nambé resident said, "but I've never felt something like that."

A rare 3.8-magnitude earthquake rattled some windows and nerves in Northern New Mexico when it hit at 10:38 a.m. Monday, according to the U.S. Geological Survey.

It was centered nine miles north of Santa Fe and around 19 miles southeast of Los Alamos National Laboratory, at a depth of around 0.7 miles.

Nearby residents reported booms, rumbling walls and some photographs and knickknacks falling off shelves, but there appeared to be no discernible damage, officials said Monday afternoon.

A 3.8-magnitude temblor isn't headline news in earthquake-tested states such as California. But it's enough of a rarity to draw attention in Northern New Mexico, which sits atop the Rio Grande Rift, a 600-mile fault that occasionally produces quakes.

It "is unusual for this area, historically," Richard Aster, a professor of geophysics at the New Mexico Institute of Mining and Technology, said in an email Monday. "This is a large enough event that there may be felt aftershocks."

"A little shake, rattle and roll" is how Santa Fe County Fire Chief David Sperling described Monday's temblor after the county's fire crews fanned out to check for damage in communities and landmarks but found none. Pojoaque Pueblo and its Buffalo Thunder Resort & Casino also escaped damage, Lt. Gov. Joe Talachy said.

At Los Alamos National Laboratory, the only noticeable effect was on the lab's seismologists, said spokesperson Nancy Ambrosiano.

"We have scientists who are real excited," she said, adding the quake did not affect the lab or its operations.

The lab's seismologists put the magnitude of Monday's temblor at 3.0, Ambrosiano said.

"Since we are closer, we lean toward accepting our numbers" over the U.S. Geological Survey's, the lab spokesperson said. "They'll continue to analyze the data and discuss with other scientists."

While New Mexico isn't earthquake central, temblors aren't unknown in this part of the country. The state sees "little tickles" — earthquakes measured at magnitude 1 or 2 — three or four times a year, Ambrosiano said.

Meanwhile, there have been periodic quakes strong enough for people to feel. Two hit Socorro in 1906, including one in November of that year that shook four chimneys and caused plaster to fall off the Socorro County Courthouse, according to the U.S. Geological Survey. In 1966, a 5.1 quake struck near Dulce, the government agency said.

More recently, in August 2005, a 5.0 quake struck 25 miles west of Raton while a 4.2-magnitude temblor was reported near Carlsbad in December of the same year, survey records show.

When the shaking started Monday, Becky Romero was watching her grandchild at her Nambé home and heard dishes tinkle on her shelves.

Garcia, meanwhile, was on the telephone with her sister when the rumble hit.

"The cat ran from one room to the next," she said, adding that the quake knocked a photograph and several knickknacks off her shelves.

Groping for an analogy for Monday's quake, Garcia recalled Tremors, a 1990 film featuring gargantuan earth-burrowing creatures that shook the ground before their grotesque bodies exploded out of the earth.

"I expected one of those things to come up," Garcia said.

Contact Trip Jennings at 986-3050 or at tjennings@sfnewmexican.com.