The Hippo


May 25, 2020








More seismic monitoring 

The Merrimack Public Library’s new seismograph isn’t the only innovation in the state’s earthquake tracking. For the past year or so, New Hampshire has been home to seismographs that are temporarily installed in underground vaults. 
The machines come from a national initiative called Earthscope, with has been moving seismographs across the country to strategic locations in order to gain an academic understanding of how the earth in North America works. 
“They are not on public display,” Chormann said. “We don’t want people there tampering with them, so it’s not advertised.”
The machines will be in the state for three years.

Getting the shakes
Watch geological activity with Merrimack library’s seismograph


 Massive earthquakes off the coast of Japan and from Mexico and Chile. Tremors caused by hydrofracking in Oklahoma. Seismic activity from Canada and across New England.

Those are only a few of the geological phenomena that have sent spikes across the screen of New Hampshire’s first public seismograph at the Merrimack Public Library. 
The machine sits in a corner of the library’s Lowell Room and looks a bit like a strange, green sewing machine inside a terrarium. It hooks up to a computer screen, and at all hours of the day, it records and sends data about seismic activity to Boston College’s Weston Observatory. The information is used by an international network of seismologists who are constantly working to pinpoint epicenters across the planet. 
“The data we are picking is being used to pinpoint where an epicenter is. Especially if we get activity in Canada and New England,  our machine is going to help them really figure out where the pulses are originating from,” Library Director Yvette Couser said. 
The library raised more than $10,000 for the seismograph after receiving a letter last fall from Weston Observatory asking for assistance with a research and educational program that benefits both scientists and the public. 
New Hampshire has a surprising amount of seismic activity considering the state isn’t near any major tectonic plate boundaries. That phenomenon remains an enigma to scientists, said Rick Chormann of the New Hampshire Geological Survey. It might be explained by ancient movement, he said. 
“Going back 400 million years there were plate boundaries here as the region was being assembled,” he said. “There could be an underlying region where there could be some activity in terms of move, but  we’re not certain.”
In late December 1940, a pair of magnitude 5.0 earthquakes in Tamworth toppled some chimneys and cracked two foundations. Granite Staters might remember rumblings from an earthquake from Virginia in 2012 and another from Maine in 2013. 
The largest New Hampshire epicenter on record dates back to a 6.5 magnitude earthquake  in 1645. 
Back then, the land was scarcely populated by people or structures, but if the state were to be hit with a comparable one now, the integrity of some infrastructure would be compromised, Chormann said. 
“If we had that today, it could do significant damage,” he said. “New Hampshire has a lot of the brick mill buildings that would not fare very well, and there is a fairly significant chance of walls collapsing — and a possibility of seeing that again.”
But when or whether it might happen is impossible to determine, he said.
“We can’t predict when an event will occur, so it’s hard to convince people to take [precautions], but at the very least, have a plan with families about where to go, what to do and how to communicate with each other to minimize destruction that will occur,” he said. 
Installed in April,  the seismograph is already providing public access to an element of science that’s usually restricted to college campuses and research facilities. 
“We had a program where the younger kids constructed a structure and tested it on a shake table. That’s engineering,” Couser said. “We did a teen event that was, ‘Would you survive a natural disaster’ — there were a lot of games, quizzes and fun things, but it was based on real situations and putting teenagers to a challenge. It’s fun, and it’s getting them to think.”
As seen in the September 18, 2014 issue of the Hippo.

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