facebooktwitterRSS
- Advertisement -
  • Most Commentedmost commented up
  • Most Emailedmost emailed up
  • Popularmost popular up
- Advertisement -
 

« News Home

What’s underlying cause of recent Valley quakes?



Published: Sat, October 1, 2011 @ 12:10 a.m.

photo

Experts point to various factors in explaining 6 temblors in 61/2 months

By Karl Henkel

khenkel@vindy.com

YOUNGSTOWN

Thursday night’s earthquake sent shock waves through most of Mahoning County.

The quake wasn’t strong enough to create any damage, but it likely felt a lot stronger than a regular magnitude-2.5 rumble, said Michael Hansen, senior geologist at the Ohio Department of Natural Resources.

That’s because rocks underneath the ground of river valley areas are mostly made up of unconsolidated sediments that amplify ground movement.

“That makes it feel higher intensity,” Hansen said.

That could explain the booming and crashing noises heard by some throughout the Valley.

And although the initial magnitude registered a 2.5, Hansen said follow-up data could revise that number slightly higher.

“It may be 2.6 or a little bigger than 2.6, but not by much,” he said.

Geologists have recorded earthquakes with epicenters in Mahoning County just six times — and all happened in the past 61/2 months.

All have occurred west of the Mahoning River, in close proximity to Salt Springs Road.

The six earthquakes registered magnitudes ranging from 2.2 to 2.6.

According to the Mercalli Intensity Scale, earthquakes between magnitudes 2.0 and 3.0 are felt by a few people, especially those on upper floors.

But why, after a lifetime with no earthquakes centered in Mahoning County, is the area averaging a quake per month?

Experts say there are a few reasons.

“From time to time, earthquakes pop up in Ohio in places where we’ve never had them before,” Hansen said.

One such instance, Hansen said, was in Mentor, near Lake Erie, in 2006.

That region had 14 earthquakes that year and has experienced additional quakes sporadically since.

The source of the Mahoning County quakes are a buried fault of basement rocks, which Hansen estimated could be 800 million to 1 billion years old.

Jeffrey Dick, Youngstown State University Geology Department chairman, said small earthquakes on ancient fault lines aren’t unique, but what’s unusual in Mahoning County is the frequency.

Other geologic movement could be the cause of the Valley’s recent quakes.

“You can get a triggering effect from a large event,” Hansen said, referencing the magnitude-5.8 earthquake registered in Virginia on Aug. 23. “But we had some before that earthquake, so I don’t think that necessarily correlates.”

Hansen also said that the North American Plate is under constant pressure and has “zones of weakness.”

Another outside source has been highly debated within the geology field.

It’s called fracking, a process where water and chemicals are blasted into rocks thousands of feet below the ground to unlock natural oil and gas.

In Ohio and Pennsylvania, companies such as Chesapeake Energy Corp. have begun drilling for natural oil and gas in the Marcellus and Utica shales.

In Harrison County, Chesapeake has drilled one horizontal well 6,418 feet below ground levels, more than one mile deep. Ohio Buckeye Energy has begun fracturing rock in Milton.

Though the Mahoning County earthquakes had a focus more than three miles deep, some geologists, including Michael Blanpied, associate coordinator for the USGS Earthquake Hazards Program, said fracking can lead to tremors.

“That process can cause very small earthquakes,” Blanpied said in video chat on the USGS website after the Virginia quake.

Dick, however, isn’t so sure.

“I think that would be pure speculation, especially when not much fracking has occurred in Ohio,” he said.


Comments

1johnyoung(241 comments)posted 3 years ago

The geologists may be missing the boat on this one. A possible contributory factor that should be considered and evaluated is the impact of several thousand steel piles that have recently been driven to bedrock for the construction of V&M Star's new mill building. This project is in very close proximity to the epicenters of many of the recent quakes, so its geological effect should be studied.

Suggest removal:

2misterlee(118 comments)posted 3 years ago

Why are all the local news outlets interviewing Dr Dick in regards to fracking? He's the only professor at YSU who thinks fracking is safe because he's an oilman. Please interview a few unbiased people too.

Suggest removal:

3Attis(900 comments)posted 3 years ago

Fracking lies at the bottom of that massive earthquake epicentered in Virginia last month and it is the cause of the repeated earthquakes in Youngstown. This insatiable greed cracked a monument in D.C. dedicated to a founder of our country. A message? Yes, it is one from Main Street to Wall Street: people before profit.

Suggest removal:

4commoncitizen(961 comments)posted 3 years ago

Your all wrong ---it's the "grumbling" from the YSU union members about their new contract.

Suggest removal:

5cambridge(3027 comments)posted 3 years ago

A few facts from someone who lives in earth quake country.

An earth quake that registers a 2 is 100 times stronger than one that registers a 1. One that registers a 3 is 100 times stronger than one that registers a 2 and so on.

I have experienced dozens and dozens of earth quakes as high as 6.8 that have lasted a full minute and being only twenty mile from the epicenter.

The causes of earth quakes is that the plates of the earth are constantly moving and earth quakes occur daily everywhere, you just don't feel most of them.

In the Sunday San Francisco Chronicle they run the weekly almanac which includes the number of earth quakes that week. It' usually around a dozen a week and we can go a year or more without feeling one. As long as they are not 5 or more and shake for a long time and you're close to the epicenter it's not a big deal. Actually I think their kind of cool so just sit back and enjoy the ride.

Suggest removal:

6reasonable(5 comments)posted 3 years ago

Cambridge, I thought that an increase of '+1' on Richter scale implied a factor of 10 in oscillation amplitude, which corresponds to a a factor of the square root of 1000 =~32x in energy release.

Suggest removal:

7cambridge(3027 comments)posted 3 years ago

reasonable.....You are correct. Since I live where I live you would think I would have it straight. I don't understand the formula you provided but your answer is on the mark. Thanks.

Suggest removal:

8taliwacker(54 comments)posted 3 years ago

It is something that Beatres hasn't come on the TV and whined or complained about... thats a start..

Suggest removal:


News
Opinion
Entertainment
Sports
Marketplace
Classifieds
Records
Discussions
Community
Help
Forms
Neighbors

HomeTerms of UsePrivacy StatementAdvertiseStaff DirectoryHelp
© 2014 Vindy.com. All rights reserved. A service of The Vindicator.
107 Vindicator Square. Youngstown, OH 44503

Phone Main: 330.747.1471 • Interactive Advertising: 330.740.2955 • Classified Advertising: 330.746.6565
Sponsored Links: Vindy Wheels | Vindy Jobs | Vindy Homes | Pittsburgh International Airport