CLEVELAND - Do you remember where you were 26 years ago Tuesday?
Just before noon on Jan. 26, 1986, a moderate earthquake struck northeastern Ohio. I was a college student at Kent State University and watched my textbook slide across the desk as the rest of the room shook.
Here's how the Ohio Seismic Network described the event:
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.
The January 31st earthquake struck just before 11:47 a.m. Eastern Standard Time. Although early media speculation had the epicenter located from Columbus to southern Canada, the U.S. Geological Survey quickly determined that the epicenter was east of Cleveland, and within a few hours the epicenter had been accurately located in southern Lake County just north of the Geauga-Lake County line. This Richter magnitude 4.96 (commonly rounded to 5.0) event was felt in parts of 11 states, the District of Columbia, and southern Ontario. Most of Ohio and western Pennsylvania experienced particularly strong vibrations that were noted by numerous individuals. The Division of Geological Survey received hundreds of telephone calls in the hours after the earthquake as did numerous federal, state, and local agencies.
Early rumors of mass destruction, injury, and death turned out to be false. Although newspapers reported 17 people being treated for injuries in the epicentral area, only two injuries were a direct result of the earthquake. A woman received minor cuts from falling ceiling tile in a Mentor shopping mall and a child received a minor cut from broken window glass at Lake Erie College in Painesville. The remainder of the reported injuries turned out to be people treated for anxiety and effects of cold weather after they were evacuated from buildings suspected of being damaged by the quake.
Destruction in the epicentral area was mostly minor. Merchandise fell from store shelves in Mentor, Painesville, and Chardon and buildings in these communities experienced varying degrees of cracked plaster and cracked or broken windows. Chimneys are particularly susceptible to damage or destruction from ground motion associated with moderate to strong earthquakes. There was, however, only one confirmed report of a chimney being toppled. Local newspapers reported several other chimneys that sustained cracks or that were pulled away from a home or building in the epicentral area. Many schools in Lake and Geauga Counties were evacuated after the earthquake and inspected for structural damage. None were reported to have sustained significant structural damage, although cracks in walls were reported at several schools.
There were numerous reports from Lake and Geauga Counties of changes in water wells. The most common effect was a change in color or taste of the well water. There were several reports of wells going dry and a few even increased their flow by a considerable rate.
Many people in northeastern Ohio initially interpreted the earthquake as an exploding furnace or a truck striking the building. Less mundane interpretations included a nuclear attack on New York City or the aftershock of the explosion of the space shuttle Challenger on January 28, 1986.
Perhaps the greatest concern--and controversy--was directed toward the Perry Nuclear Power Plant in northern Lake County. The plant was not operating at the time of the earthquake but was scheduled to load fuel rods on the next day. Officials at the Perry plant, which is located about 11 miles north of the epicenter, declared a precautionary site area emergency immediately after the earthquake but downgraded this to alert status within a short time. Accelerometers on site at the Perry plant recorded accelerations as high as 0.19 to 0.23 g; the plant is designed to withstand 0.15 g. These higher values, however, were at high frequencies and represented only momentary peak accelerations not capable of causing significant damages. Inspections of the Perry plant after the earthquake disclosed only minor cracks in concrete and small leaks in noncritical water pipes. Both conditions may have existed before the earthquake, according to newspaper reports.
Because of an increased
interest in earthquakes in the eastern United States, the comparatively large magnitude of the event, the potential for aftershock activity, and the proximity of the epicenter to a nuclear power plant, approximately 30 seismologists representing Lamont-Doherty Geological Observatory (Palisades, New York), University of Michigan, St. Louis University, Tennessee Earthquake Information Center, U.S. Geological Survey (Reston, Virginia; Denver, Colorado; Menlo Park, California), Weston Geophysical (Westboro, Massachusetts), University of Wisconsin, and Woodward-Clyde Consultants arrived at the epicentral area on the day after the earthquake. The primary objective of these seismologists was to place portable seismographs in the epicentral area in order to record aftershocks.
Although aftershocks are commonly considerably smaller in magnitude that the main event, the proximity of portable instruments deployed around the perimeter of an epicenter permits precise locations of focal depths for the aftershocks. Such numerous detailed seismic records can then be used to located the zone of rupture and define the direction of movement along the fault plane. (h/t Ohio.gov)"