When Waverly Person picks up the phone at the U.S. Geological Survey's earthquake hot line in Colorado, he's used to panicky voices from Los Angeles or Anchorage.
Not Glen Burnie.
But Anne Arundel residents were lighting up the switchboard yesterday after a series of rare earthquakes jostled eastern Maryland.
"All they wanted to know is: `Are we gonna have a Big One?'" said the veteran geophysicist.
Fear not. Seismologists say the "Big One" is not imminent. While as many as three quakes jostled the region yesterday, even the strongest -- a magnitude 2.0 at 9:22 a.m. -- barely tickled the state's lone seismometer.
Tuesday's deadly quake in central Iran, by contrast, measured 6.4 on the Richter scale -- or 10,000 times as powerful as Maryland's. The Southeast Asian quake that triggered the tsunamis in December was a magnitude 9.0.
While yesterday's temblor did not impress professional seismologists, it did raise eyebrows and rattle nerves in a state not used to much shaking.
"I thought at first something had exploded," said Tom Shouldice, principal of Dundalk Middle School. Government seismologists put the quake's epicenter 5 1/2 miles below the community.
Shouldice and his students heard a low rumble and felt the building shake: "We all just looked at each other like, `What's going on?'" He and a few teachers went outside expecting to see plumes of smoke or a car that had plowed into the school. It took 20 minutes before everyone realized what had happened, he said. Indeed, doubt and double takes were often the first response to the quake.
Employees at The Rose restaurant in Linthicum assumed a Dumpster was being emptied. Michelle Baublitz, a server at the Double T Diner on Mountain Road in Pasadena, dismissed the quake as a passing truck.
"It sounded like thunder," said Kelly Moore, hygiene coordinator at a Glen Burnie dental office. It was Moore's first quake and, she hopes, her last. "It's kind of creepy."
As soon as the temblor struck, staffers in the office -- where no one was holding a drill, luckily -- quickly huddled to compare notes.
Several jumped on their phones, dialing husbands, mothers and day care providers around the state. Linthicum felt it, they reported; so did Ferndale and White Marsh.
"I think you're all crazy," said Niki Smith, a dental assistant who insisted that she hadn't felt a thing.
Scientists think it's unlikely that the state will ever be rocked by an earthquake like those that periodically shake up California or Southeast Asia.
That's because at least 90 percent of all earthquakes occur along the restless boundaries between the six major slabs or "plates" that divide Earth's crust. These plates, which fit together like a giant jigsaw puzzle, constantly grind against each other as they surf on semimolten rock.
California sits atop one of these plate boundaries. The closest rift to the Eastern United States is in the middle of the Atlantic Ocean.
Maryland recorded just three quakes between 1939 and 1990. Then, in 1993, a flurry of nearly two dozen quakes rattled Howard County. None caused any damage.
The last recorded event here was a 2.0 temblor in Columbia in 2001. No quake in the recorded history of Maryland has surpassed 4.0 on the Richter scale, according to state records. Typically it takes a magnitude-6.0 quake or stronger to cause severe damage, experts say.
One of the puzzling questions facing scientists studying East Coast earthquakes is what causes them in the first place.
Won-Young Kim, an earthquake researcher at Columbia University's Lamont-Doherty Earth Observatory, said that while Maryland doesn't sit on a plate boundary, there are still underground faults. Geologists have even found one running through the center of Baltimore, roughly under the Jones Falls Expressway.
Along these seams, "there's always small tensions, small stresses," Kim said. And, occasionally, they can release their pent-up energy.
But not often. One 1990 federal study concluded that the earthquake hazards in Maryland and Delaware are the lowest on the East Coast.
Gerald Baum, a researcher at the Maryland Geological Survey, said quakes are so rare here that his office employs no full-time seismologists. Even so, he was bombarded by calls yesterday -- mostly from TV and radio reporters. "I just had a chance to take two bites of my sandwich," he said late in the afternoon.
By evening, nearly 1,000 Marylanders who felt the quake had filed online reports to the USGS at http://earthquake.usgs.gov.
Baum said he's not surprised by the reaction.
"After 9/11 people get concerned about shaking and rattling," he said. Plus, "an earthquake is in the eye of the beholder."
Sun staff writers Tricia Bishop, Anica Butler and Liz F. Kay contributed to this article.