Harvard may not be the epicenter of earth-shaking news, but it does sometimes record it.

Evidence of the March 11 earthquake that devastated Japan can be found 15 feet below ground at Oak Ridge along Pinnacle Road, where seismographs have been monitoring earthquakes since 1933. While the exterior of the Oak Ridge seismic station, officially known as Harvard University's Adam Dziewonski Observatory, looks its age above ground, below grade, paper seismographs have given way to 25 electronic instruments that record and feed data nationally and internationally as part of the New England Seismic Network and the U.S. Seismic Network.

When Harvard University moved its astronomical observatory from Cambridge to Oak Ridge in 1933 to take advantage of the location's high point and dark-night surroundings, a seismic station was created for the two seismographs that had been housed in the basement of the school's Geological Museum. Over time, increasing light in the night sky and decreasing funds eventually caused the observatory to close in 2005. But the seismic station remained, renamed to honor Adam Dziewonski, a Harvard professor who, along with graduate student Miaki Iishi, changed the prevailing view of the earth's internal structure,when they hypothesized from analyzing 30 years of seismic data that within the earth's molten cores lies a 350-mile wide solid ball.

But why study earthquakes in New England? New England doesn't have the dramatic tectonic plate activity of California and the Pacific rim, which the U. S. Geological Society's Seismic Hazard map colorfully illustrates. On that map, the entire west coast is one fiery red line, while most of Massachusetts is a serene blue with a circle of pale green in the northeast. But the blue-and-green serenity has been severely shaken a few times in recorded history, and is lightly stirred 40 or more times a year.

Henry Nourse wrote in his 1890 History of the Town of Harvard: "In the evening of Nov. 18, 1755, … occurred the famous New England earthquake, the phenomenal tremors of which were so energetic along the Nashua Valley as to create general consternation, and give peculiar point to the solemn admonitions of the ministers for a long time afterwards." According to sources at the time, chimneys toppled, walls cracked, and fine sand flowed like water from small chasms that opened in Pembroke and Salem. A miner in Sterling was reportedly killed by the tremors. John Ebel, director at the Boston College's Weston Observatory, locates the 1755 epicenter at sea off Cape Ann and assigns it a 6.0 magnitude.

Similarly, large earthquakes were reported in 1638, originating in New Hampshire and in the St. Lawrence River Valley. One of the largest known Massachusetts quakes occurred in 1727, also off Cape Ann, an area which continues to be the most seismically energetic in Massachusetts, although Littleton may surpass it in frequency.

Residents may remember the early morning tremors on Oct. 19, 2007, when a magnitude 2.5 earthquake occurred about a half mile from the Littleton Common. Another October quake, magnitude 2.0, was felt in 2004. According to a report by Ebel, Littleton experiences a felt earthquake every two years, on average. Yet Harvard doesn't. What is going on?

Littleton resident Daniel Boudillion, who likes to wander Littleton's countryside and history, attributes the Littleton phenomena to geological formations called plutons, 100-million-year-old shafts of cooled magma, of which Nashoba Hill is one. Linear stresses pressing against the cylindrical plutons cause the earth tremors.

Evidence of quaking ground in the area dates back to at least the 17th century. Nashoba (later Littleton) was the sixth "Praying Indian" town, officially formed in 1651 by Rev. John Eliot, who worked to convert Native Americans to Christianity and to create towns where the Native Americans could continue their own culture. According to Daniel Gookin, Eliot's assistant, "Near unto this town is a pond, wherein at some seasons there is a strange rumbling noise, as the Indians affirm; the reason whereof is not known. Some have conceived the hills adjacent are hollow, wherein the wind being pent, is the cause of the rumbling, as in earthquakes."

Boudillion suggests in his writings that Sachem Tahattawan, leader of the local Concord Indians, was insistent on choosing the "nashope" lands, an area that includes Nashoba Hill and Nagog Pond, because those places had special meaning to the Indians, perhaps because of the seismic rumblings there.

Without giving his source, Boudillion writes, "Nashoba is a word of many meanings. When applied to the Nashoba Praying Indian Village, it means the Place Between the Waters. (These titular waters were Nagog Pond and Fort Pond, and less significantly, Long Pond.) When applied to Nashoba Hill, it means "the hill that shakes." It is from Nashoba Hill that the early English settlers said the booming and rumblings emanated."

Modern science offers evidence of the earth's workings that Native Americans picked up by experience, though each with a different interpretation. We don't know for sure what forces and spirits Concord Indians used to explain the rumblings. But geologists' explanations are not more definitive.

In 2000, Boston College seismologist Alan Kafka wrote, "It seems to me that if we have learned anything at all during the past few decades about earthquake processes in the eastern United States, it's that there is no simple relationship between faults and earthquakes in this region."

Whatever the sources or the explanation, there has been a whole lot of shaking going on.