Following a series of small, mysterious earthquakes in the rural town of Berne, southwest of Albany, N.Y., seismologists from Lamont-Doherty Earth Observatory have placed three temporary seismometers in the area, in an attempt to understand what is driving the tremors and assess whether there is a risk of larger events. Occasional small quakes have been recorded in the area since the 1970s, but suddenly in 2009 there were 21, and 14 more since the start of 2010. The biggest was about magnitude 3–enough to be felt, but not really dangerous. None have done any damage, but some have knocked books off shelves, and in one case, caused a local farm owner to believe that a plane had crashed in his cornfield.
The Lamont Cooperative Seismic Network monitors much of the northeastern United States on behalf of the U.S. Geological Survey, and thus it registered the quakes. There are some known ancient faults in the area, but this much activity had never been seen before. Lamont seismologist Won-Young Kim, head of the network, decided to deploy the temporary seismometers near the epicenters, in hopes of detecting smaller events that might escape more distant permanent instruments, and of better locating where the activity is coming from.
Kim and his team dug holes at two local farms and a nature center and buried the instruments, tethered to aboveground solar panels and recording devices. They plan to return every few weeks in coming months to download data. They also toured the area looking for geological clues, and made a quick discovery–an unusually steep chasm several hundred feet deep, that appears to be the continuation of an ancient, long inactive fault that is known to head this way from further north. The scientists speculate that the quakes may be coming as the earth settles and shifts slowly around this fault, or related hidden weaknesses in the earth. But what danger, if any, they might pose, no one can really say at this point.
The daylong expedition was accompanied by officials from the New York Geological Survey and the state Emergency Management Office. It also aroused interest from media; New York Times reporter Peter Applebome tagged along, as did Rick Karlin of the Albany Times-Union, with their respective photographers. For more pictures and details, read the New York Times article; and the Times-Union article.
