CLEVELAND, Ohio -- What appears to be a 4.8-magnitude earthquake in Canada was felt in parts of Northeast Ohio and beyond this morning.
The tremor was felt around 9:43 a.m. and reports of the quake began to light up Twitter within moments.
Tim Leftwich of Ohio Seismic Network said he was checking instruments to confirm the quake, but an Ontario-based temblor appeared to have been recorded by a French seismic network.
Earthakes are not uncommon in Ohio -- there have been more than 50 recorded in the last decade, but violent tremors are rare.
In a 2008 Plain Dealer story, experts said there are several theories, taken alone or together, that could explain Ohio's frequent quakes -- in addition to new reports blaming oil well drilling in and around Lake Erie.
Seismic activity hardly follows political boundaries, but geologists say Ohio might be especially active because of a combination of a few ancient collisions.Sylvia Hayek, a seismologist with Natural Resources Canada, said the Ohio area may also be reacting to something called glacial or crustal rebound. It's the idea that the Earth's crust is still recovering or shifting from the retreat of glaciers that moved over the continent starting about 2 million years ago.
Jim Hansen of the Ohio Seismic Network has said the first collision was probably 800 million years ago, Hansen said, when a proto-North America was rammed into by another continent, possibly a portion of a southbound South America.
The force of that crash caused a mid-continent mountain range that has since eroded, but left behind its fault lines deep in the granite of Ohio.
Other forces are still pushing on the continent, Hansen said.
“We know that North America is being gradually pushed westward as the Atlantic Ocean expands,” Hansen said. “The faults deep underground in Ohio may just be favorably oriented to failure because of that push.”