NH News
5:00 am
Mon July 28, 2014

Merrimack Seismograph Registers High On The Interest Scale

Merrimack Public Library Director Yvette Couser explains how the seismograph works. It's the state's only publicly-available seismograph.
Merrimack Public Library Director Yvette Couser explains how the seismograph works. It's the state's only publicly-available seismograph.
Credit NHPR / Michael Brindley

While New Hampshire may not be known for earthquakes, the town of Merrimack is now host to the Granite State’s first seismograph available for public use.

Library Director Yvette Couser got her introduction to earthquakes about two years ago.

“We were sitting in this meeting across the street at one of the meeting rooms at town hall and all of a sudden we hear this rumbling and us on the tape, it’s seven of us going, ‘Huh. What was that?’”

Watch a video of that earthquake:

“I didn’t know there were earthquakes in New England,” Couser said. “I had no clue. And I sat through one.”

Residents of the town can go to the public library to view the machine, which has been tracking seismic activity for the past few months. Click here to see the library's latest seismic reading.

The machine was installed in April, and while there haven’t been any earthquakes to speak of, she says they’ve tracked some interesting vibrations.

“We picked up the fireworks that were put off on the 6th. The fireworks here in Merrimack are shot off up the hill at the high school, so we think we picked up those recordings,” Couser said.

If you’ve never seen a seismograph before, it doesn’t look all that high tech.

There’s a computer screen that displays seismic readings, and below that is the seismograph itself, which kind of looks like a scale.

“There’s some liquid in a dish sitting in the center of it and the whole thing is covered by an upside-down fish tank,” said Couser, describing the machine.

We’re not getting a lot of activity at the moment, so we give the machine a test run.

“OK, so let’s jump on three and we’ll watch the spike,” she said to me.

“So if you’ll look, you’ll see it…so there’s a big spike,” she said. “That’s us jumping and then we land. It does take a little bit of time for the motion that we created just a couple of feet away to travel to the machine.”

The library partnered with the Weston Observatory at Boston College, which has been working for the past decade to get publically-available seismographs into schools and libraries across Massachusetts.

“And now we’re expanding out to New Hampshire and there is so much good data already flowing. It’s incredible,” said Marilyn Bibeau, administrator of the Weston Observatory and associate director of the Boston College Educational Seismology Project.

She says there is real scientific value in broadening the project’s network of seismographs into the Granite State.

“They are recording on their seismograph how the earth is shaking right underneath their feet at the moment from that earthquake across the globe. So this is leaps and bounds in giving us knowledge.”

The Merrimack library was able to raise the $10,000 it needed to purchase the seismograph through local donations.

Bibeau says she hopes the program can expand farther into the state, into Lakes Region and even as far north as Pittsburg.

But just how seismically active is New Hampshire?

“It’s fairly active, though not that many of them are significant enough to really get people’s attention,” said Rick Chormann, the state geologist.

He says one that did grab people’s attention was the earthquake in 2012 that Yvette Couser felt in Merrimack.

The 4.0 tremor originated in southern Maine, but rattled the Granite State and was felt as far away as Connecticut.

There’s no record of any earthquakes that caused significant damage here in New Hampshire, but Chormann says it’s still worth educating people about why they happen.

“Just having people tuned into planet earth and the natural processes, geologic processes is a good thing,” Chormann said.

And that’s exactly what Couser says is going on in Merrimack.

Many people in the community have already signed up to get electronic alerts any time there’s a seismic reading.

And she hopes the seismograph may even spark an interest in science among local students.

“What we want to do specifically is to partner with the Merrimack schools and have the seismologist train the teachers so that they can really see an actual seismograph machine in place working locally, down the street.”

Meanwhile, she says the library will hold training sessions this summer for staff and community members to learn how to use the data.