AN EARTHQUAKE EVERY TWO WEEKS? IT'S HAPPENING NEAR CLEVELAND
July
13, 2006 05:39 PM CDT
MENTOR (AP) -- Without
damage or injury and sometimes unnoticed, 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?
"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 12 quakes recorded in Lake
County and under adjacent Lake Erie from January
1st to July 1st this year.
Earthquake experts don't know
why the repetitive quakes have come at this time. Farrell, who has lived in Lake County for more than a half century, said
the eye-catching series of earthquakes -- measuring from magnitude 2.0 to 3.8 -- don't worry him and haven't prompted
any special safety measures at home.
By comparison, the deadly quake
that hit the Northridge area of Los Angeles in 1994 was a
6.7 magnitude.
Farrell's response is similar
to that of many people who have become accustomed to the routine of quakes, some felt and some unfelt. "You have to take a
rational approach, you have to take a practical approach," said Lake County's emergency management director, Larry D. Greene,
sitting in his bunker-like underground office and hoping increased public awareness will encourage people to be prepared.
A top concern for Greene is
the Perry Nuclear Power Plant, 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 county EMA complex designed as a command post was built more than 10 miles from the plant as
a precaution.
The biggest of the recent earthquakes,
a 3.8 temblor recorded June 20, automatically set off alarms to alert the plant command post, which 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.
The plant is programmed to shut down with an earthquake of 5.4 or higher, according to Young, who said the recent quakes didn't
prompt additional safety upgrades. "We already have a lot of things built in to account for seismic activity," she said, including
heavy-duty concrete meant to withstand shaking and prevent the release of radioactive material.
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 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, with many people already aware it wasn't damaging and happy
to confirm it wasn't a terrorist 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.
Michael Hansen, director of
the Ohio Seismic Network, shares that uncertainty. "We can't predict very much in terms of when, where or how big. We're probably
better at predicting where because we know historic areas which have been active," he said by phone from Columbus.
That, for the most part in
recent years in Ohio, means Lake County, a suburb of Cleveland that's geographically the smallest
county in Ohio. Fourteen of the 20 earthquakes recorded
in the state in the past two years have occurred in Lake County. Add adjacent Ashtabula County to Lake County
and the total is 18 of 20 Ohio quakes since July 2004.
The exceptions were both in
western Ohio: Mercer County
on March 13, 2005, and Allen County
last May.
Lake County's quakes result
from a fault, or crack, that is under pressure, one of a number of faults in Ohio,
most of them under the sedimentary bedrock. The fault is under pressure from the East Coast, pushing westward, Hansen said.
The series of Lake County quakes is matched only by a series during the
1980s in Ashtabula County,
and they may have been partly manmade as injection wells created underground pressure, Hansen said.
But in Lake County, "These are natural earthquakes,"
Hansen said.
There is little evidence that
many homeowners have made a move 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% 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," according to Merhar, who also warned that falling chimneys can cause a surprising amount of damage to the house below.