A corner of suburban Cleveland has become the earthquake capital of Ohio, shaking on average every two weeks since New Year's Day and making people wonder: What's next?
The quakes haven't caused any serious problems, and sometimes even go unnoticed. Experts aren't sure why they are happening now, but they do know they are happening frequently: 12 were recorded in the area by July 1.
"I heard one," said Jim Farrell, 79, of Mentor, a retired plasterer with an eye for wall damage. Still, he hasn't seen any damage and hasn't felt any of the quakes recorded in Lake County and under adjacent Lake Erie.
The earthquakes have been small, measuring from magnitude 2.0 to 3.8. By comparison, the deadly quake that hit the Northridge area of Los Angeles in 1994 was a 6.7 magnitude.
Though they are happening often now, earthquakes aren't uncommon in the region. Lake County has been the site for 14 of the 20 earthquakes recorded in the state in the past two years.
The quakes result from a fault, or crack, that is under pressure, one of a number of faults in Ohio, most of which are under the sedimentary bedrock.
Ground zero for keeping track of the Lake County earthquakes is a busy classroom building on the Lakeland Community College campus, where a seismic monitor sits on the concrete floor of a tiny closet housing electric boxes.
The monitor is sensitive enough to pick up the rumblings of a heavy truck along nearby Interstate 90, according to David Pierce, an assistant geology professor who keeps tabs on readings forwarded to the statewide Ohio Seismic Network near Columbus.
To Pierce, a low-level earthquake "always feels like a semi [tractor-trailer] coming down my street and hits a rock or a speed bump," sending a boom like a burst of compressed air.
Pierce, like police and fire departments, can get dozens of calls when an earthquake strikes, often from people happy to learn that it didn't do damage and wasn't a terror attack.
Without damage or injury from the series of quakes, the question for many is: will the next one be worse?
"The official take is: we don't know," Pierce said.
The frequent quakes have prompted some caution among officials.
A top concern for some Lake County authorities is the Perry Nuclear Power Plant, which was constructed to withstand a building-shaking 6.0 earthquake and opened in 1987 just one year after a 5.0 quake in Lake County.
The biggest of the recent earthquakes, a 3.8 temblor recorded June 20, automatically set off alarms to alert a plant command post. That sent 30 inspectors on a four-hour search for any indication of cracked pipes or other damage.
None was found, Perry spokeswoman Jennifer Young said. The plant remained in operation without interruption during detailed inspections of cement walls and pipelines reinforced with shock absorbers to handle shaking.
Data indicates homeowners aren't making many changes to protect against the quakes. There is little evidence that many homeowners have made moves to buy earthquake insurance, said Gary Christy with the Westfield Group insurance.
Nine percent of the Westfield-insured homes in Lake County have earthquake insurance.
Nationwide Insurance agent Gerald Merhar in nearby Willoughby said about 15 percent of his homeowner policies have earthquake coverage riders costing about $20 a year for a frame home and $30 for brick.
Merhar, 57, whose own home has a repaired crack from a quake more than 50 years ago, recommends coverage, especially for brick homes.
"They don't shake well," Merhar said.