By Mac Cerullo Staff Writer
---- — Gale Regis was walking around her house Tuesday night when she felt the structure move.
“I thought it was my washing machine, but my washing machine wasn’t on,” Regis said. “People have been telling me that they thought a plane had crashed or that it was a big, heavy truck coming down the road.”
But while the 4.0 magnitude earthquake that rattled much of New England initially confused and frightened many residents throughout Greater Newburyport, it left Regis excited,
The sixth-grade science teacher at Amesbury Middle School immediately saw a teachable moment.
Regis and her students keep track of earthquakes throughout the school year, and Tuesday’s earthquake provided a rare occasion for them to study a big quake that occurred right in their backyard.
Yesterday, Regis’ students got a chance to look at the data gathered by their classroom’s own seismograph, which Regis said can pick up seismic waves, if they’re strong enough, from anywhere in the world.
Through the data, the students not only could tell how strong the quake was and how long it lasted, but also subtle details — like the steady buildup of smaller seismic waves before the quake hit as well as a similar tapering off at the end. The students also identified a small aftershock that occurred about 20 minutes following the main quake and was too small to be felt by humans.
After examining the data, the students then took a look at a map of the Northeast indicating all the areas where the quake could be felt. The map showed that the quake had an impact on most of New England and as far as eastern New York, but also showed that it didn’t affect some areas closer to the epicenter in Maine, while other spots farther away could still feel it.
Regis explained that those areas that didn’t feel the quake might have unique features in the ground that would disperse the shock waves. She said that would also explain why many of her students could feel the quake at home, while others couldn’t.
Finally, the students plotted the earthquake and took note of where they were if and when they felt it. Regis intends to send that data to larger agencies like the United States Geological Survey for further study.
While Tuesday’s earthquake was a special occurrence for Regis and her class, the study of earthquakes in general is not. Seismology is a staple of the science curriculum at Amesbury Middle School and a more advanced study is offered at the high school as well.
“I do this all year round,” Regis said. “If there is an earthquake, we plot it.”
Earthquakes are a daily occurrence all over the world, and even though New England rarely experiences any big enough to be felt, small ones do occur frequently in the area.
In order to keep track of all the activity, Regis’ students use a live seismic monitor operated by the Incorporated Research Institutions for Seismology, or IRIS, as well as the classroom seismograph, which Regis obtained in 2006 with grant money from the Amesbury Educational Foundation, Inc.
“The original grant was $10,000,” Regis said. “Then I had fundraisers, Newburyport Five Cents Savings Bank gave me some money and I think I ended up raising about $15,000 for the seismograph.”
In January, a professional seismographer will arrive for a two-month stay to help teach the students more technical aspects of seismology.
“She’ll be coming in January and she stays for eight weeks,” Regis said. “She comes here and she goes next door, and she’s here twice a week so the kids learn about earthquakes, they do experiments, they do seismographs.”