By DANIEL RIORDAN
GOSHEN — Earthquakes in Indiana aren’t top of mind for most Hoosiers. But while the chances of a massive earthquake in these parts are slim, the damage such a freak occurrence would cause could be huge.
“It’s high consequence, low probability,” said Gary Patterson.
Patterson spends his life talking about and tracking earthquakes as the director of education and outreach for the Center for Earthquake Research and Information at the University of Memphis.
And low probability is precisely how an earthquake affecting Elkhart County can be categorized. According to the U.S. Geological Survey, the chances of a 5.0 magnitude earthquake affecting the area over the next 100 years is minuscule. It’s at less than 1 percent for the Gary area, as well as Fort Wayne.
The most talked about seismic zone in the Midwest is New Madrid. Located in Missouri and stretching over several states, including southwestern Indiana, New Madrid is a seismic zone people like Patterson keep an eye on.
New Madrid gets so much attention for what it may do in the future, because of its past. From late 1811 to early 1812, Patterson said a series of powerful earthquakes took place in the region. They were as powerful, if not more so, than the 1989 earthquake in San Francisco. That earthquake killed 63 people, caused bridges collapse and halted the start of Game 3 of the 1989 World Series for 10 days.
But not all earthquakes, even ones similar in magnitude, are alike. Patterson explained that an earthquake in the Midwest has the potential to be more powerful than one in California.
“The deep crust becomes hardened due to the cold in the Midwest,” he explained. “This causes the earthquake waves to travel a much further distance.”
Patterson said that 200 earthquakes a year are recorded along New Madrid. That makes it the most active seismic zone east of the Rockies.
It’s just the quakes are usually too small to be felt by anyone said Patterson.
Devising a plan
Patterson said its hard for Midwesterners to plan for an earthquake.
“It’s not like California where they have huge earthquakes every 60 years,” said Patterson. “So many say its better not to think about.”
That’s a mistake said Patterson.
While the chances of a massive earthquake hitting a place like Elkhart County are low, it’s still important to have a plan. But unlike other weather phenomena, there is zero warning when it comes to earthquakes.
“So depending on the time of day an earthquake occurs it’s hard to tell the damage one could cause or the amount of casualties,” said Patterson. “There are way too many variables.”
Patterson advises people to know their surroundings during an earthquake and follow the “duck and cover” rule. Find a sturdy desk and hide under it while holding on to the legs.
Much like in cases of flooding or tornadoes, having a 72-hour survival kit on hand is important. From there, it’s about devising a plan, practicing and executing that plan.
“Unless you talk about it and plan for it you can freeze when the situation arises,” said Patterson. “And that freeze can be very impactful.”
A brief history
There isn’t a long history of earthquakes in Indiana. Many Hoosiers can feel tremors from earthquakes originated out of state, but not many do any damage.
According to the U.S. Geological Survey, the most damaging earthquake to originate in Indiana took place Sept. 29, 1909 between Vincennes and Terre Haute. There were reports of buildings with cracked walls and some chimneys fell. It affected an area of 30,000 square miles.
Previously, April 29, 1899 stands out for earthquakes in Indiana. Once again it affected the southwestern part of the state. That quake was felt over a 40,000 square mile area.
Twin shocks, according to the U.S. Geological Survey, took place 15 minutes apart in 1876 and were felt over a 60,000 square-mile area.
More recently, a Nov. 9, 1968 earthquake that originated in southern Illinois affected all of Indiana. Damage was reported in the southern part of the state.
The U.S. Geological Survey reports that the great New Madrid earthquakes of 1811 and 1812 must have strongly affected Indiana but there was little information available from then.
A 5.0 magnitude earthquake hit Evansville June 18, 2012. But it wasn’t caused by New Madrid. It fell in the Wabash Valley Seismic Zone and could be felt slightly in the Goshen area.
According to the Central United States Earthquake Consortium, the affected area of the Wabash Valley zone reaches further north into Indiana, west of Indianapolis.
Patterson said if Elkhart County were to feel an earthquake its quite possible it’d come from the closer Wabash Valley zone rather than New Madrid.
For more information regarding earthquakes and seismic zones across the U.S., visit www.usgs.gov/