New York isn't the first state that comes to mind, when one thinks of the word, "earthquake," but things got shaken up today, when the effects of the Virginia magnitude-5.9 quake were felt across various portions of the city. I was sitting in my living room and talking to my sister, when all of a sudden, we felt the house shake (I in an area that's predominately an "eco-friendly" landfill, and the bedrock is weak to say the least, so we felt quite the jolt on the second floor of our home this afternoon). And, while New York State experiences scattered seismic activity, most New Yorkers aren't used to being jolted in their cubicles or as they're sitting down for a bite to eat.
The United States Geological Survey (USGS) monitors seismic and other geological activity, including earthquakes, geomagnetism, and volcanic data. It provides accurate scientific information regarding seismic activity around the world, and updates data daily, and if one was to visit its site, they'd see that New York is not as inactive as previously believed; for instance, the state lies on a fault line. Although it's one that's regarded to be relatively inactive, geologists and seismologists have been observing a rising trend in the frequency of earthquakes in our area. A recent list of earthquakes includes a 5.1-magnitude earthquake on April 20, 2002 in Plattsburgh, NY and a 2.4-magnitude earthquake on January 17, 2001 in New York City.
New York has a long and interesting geology that suggests the concentrations of these earthquakes surround the area of Manhattan Island, which is primarily composed of Schist, Inwood Marble and Fordham Gneiss; providing a solid foundation for New York's historic skyline. One of the largest earthquakes occurred in 1884; observations included fallen bricks and cracked plaster, but the most extensive damages and greatest magnitudes were reported in Jamaica, NY and Amityville in western Long Island.
What does this mean for New York's future? Many leading LEO and USGS seismologists are claiming that the New York State area is long overdue for a medium to high intensity earthquake (in the magnitude-5.0-6.0 range); these types of earthquakes occur about once every century, leading many experts to believe that this minor rumble is a precursor to a larger seismic event.