ORONO, Maine — About five minutes after an intense earthquake devastated Port-au-Prince, Haiti, and the surrounding area late Tuesday afternoon, the seismometer in the basement of Somerset Hall at the University of Maine picked up the rippling waves of the temblor.
“It shows an incredibly strong earthquake,” said professor Alice Kelley of the department of earth sciences. The machine, installed in 2008, links UM to the New England Seismic Network based at Boston College.
Kelley uses the machine and the real-time signals it generates to teach students about the unpredictable nature of earthquakes.
“When an earthquake happens, waves travel in a ripple in all directions,” Kelley explained Wednesday. Some waves course right through the body of the Earth, she said, while others move along the surface of the planet.
“We picked up both” from the Haitian quake, she said.
The earthquake in Haiti occurred “exactly where we expect it” — at the margin between two tectonic plates, Kelley said. But mild earthquakes in New England, which happen about once a year, are something of a mystery, she added. They may be aftershocks from large quakes in other parts of the world, or rebounding depressions in the Earth’s crust caused by long-ago glaciers, or energy traveling inward from the edges of tectonic plates, she said.
Kelley said the seismometer was installed by two UM students with guidance from electrical engineers and information technology specialists at the university. It is secured to a ledgy outcropping of bedrock that ensures the accuracy of its readings.
Readings from the UM seismometer, including a record of Tuesday’s earthquake, can be found at the Web site of the Weston Observatory in Massachusetts, www.quake.bc.edu:8000/index.htm. Click on “current seismograms” and select “ORNO” from the drop-down menu.