The thought that NE Ohio is an area previously free of earthquake activity is utter nonsense.
From an article back in January 2008
Still, Ohio seems increasingly prone to the shakes; there have been 25 earthquakes of magnitude 2.0 or higher over the past two years, equal to the number the five years before that. There have been about as many such quakes in Ohio so far this decade as in the previous 30 years
“We think Ohio, especially northeast Ohio and Lake Erie, is going through a period of increased seismic activity,” said Mike Hansen, coordinator of the Ohio Seismic Network.
One explanation could be that there is better monitoring equipment than in the past. But more frequent activity is a likelihood.
Ohio State University geophysics professor Ralph Von Frese said location is the key.
“We’re the earthquake capital of the Big Ten, at least,” he said. “This is earthquake country, and Ohio is situated so that we’ve experienced more than every state around us.”
So just what is it that seems to make Ohio so … shaky?
“That’s the question everyone is interested in _ and the one we can’t answer for certain,” Hansen said.
There are, however, several theories about frequent earthquakes, including the one with the 3.1 magnitude that hit Tuesday.
Geologists say Ohio might be especially active because of a combination of a few ancient collisions.
The first was probably 800 million years ago, when land masses the size of continents came together, causing mountain ranges and fault lines.
Another factor is that movement still is going on.
“We know that North America is being gradually pushed westward,” Hansen said.
Sylvia Hayek, a seismologist with Natural Resources Canada, said the Ohio area also may be reacting to something called glacial or crustal rebound. The idea is that the Earth’s crust is still recovering or shifting from the retreat of glaciers. The weight of the glaciers depressed the crust of the Earth.
When they retreated about 12,000 years ago, they caused some instability in the Earth’s crust in Ohio, Hansen and Hayek said.
And they haven’t all been small earthquakes in the past
this from the Ohio Government Dept of Natural Resources
January 31, 1986 Northeastern Ohio Earthquake
(from Summer 1986 Ohio Geology)
On January 31, 1986, many northeastern Ohio residents were startled into the realization that this area is seismically active; historically, the region has the second highest frequency of earthquake activity of any area of the state. Only Shelby County and vicinity in western Ohio have experienced more earthquakes in historic times. The 1986 northeastern Ohio earthquake has the distinction of being the most intensively studied Ohio earthquake, the first earth quake in the state for which injuries were recorded, and the nearest earthquake to a nuclear power plant in the United States. The 1986 event ranks as probably the third largest earthquake in Ohio.
and
The historic seismic activity in northeastern Ohio, which long predates the Calhio injection well and indeed any drilling or deep mining activity in this part of the state, suggests that seismic activity in this area is not a result of human activities.
and
At least 19 earthquakes are known to have occurred in the northeastern Ohio counties of Ashtabula (1), Cuyahoga (7), Lake (4), Lorain (1), Portage (3), and Summit (3) prior to the 1986 Lake County event. Most of these earthquakes, the earliest of which occurred in 1836, predate the availability of seismographs and are therefore located and rated as to intensity on the basis of newspaper and other historic accounts. These data have recently been researched and evaluated in detail by personnel from Weston Geophysical.
These accounts suggest that most of the previous seismic activity in northeastern Ohio was of relatively low intensity and associated with only minor and isolated damages such as a few broken windows and items falling off shelves. One earthquake, which occurred on March 9, 1943, had a Richter magnitude of 4.7 and an epicentral intensity of V. No significant damages were reported from this quake, which had a felt area of 220,000 square kilometers (85,000 square miles). This event was originally assigned a location beneath Lake Erie, offshore from Ashtabula County; however, recent reevaluation of the seismic records of this event by seismologists from the U.S. Geological Survey placed the epicenter on the Lake-Geauga County line, near the epicenter of the 1986 event.
If you are interested in looking at information on Ohio historical seismicity, earthquakes etc.
http://earthquake.usgs.gov/earthquakes/states/?region=OhioNote that there are two time periods since modern seismic monitoring has been in place during which there were 13 recorded earthquakes above 3.0, both of which predated the drilling of shale gas wells in Ohio by 1.2 decades.
I note that the article in question doesn’t mention what the epicenter depth for the earthquakes are. The fault system which runs through NE Ohio into the Great Lakes is thought to be responsible for earthquakes in the region and generally the epicenter is several km deeper than any well, especially the shallow shale wells.
Sounds to me like the farmer quoted has been talking to a legal team bent on extracting payment from oil and gas operators to make claims (no matter how frivolous) go away.
, yea I meant earthquakes. Sorry, I seem to be having my own Perry moment....
