Did you feel the earth move?
No, you didn't drink too much New Year's champagne, Ringwood -- that was a real earthquake you felt last night!
"Although strong earthquakes are rare in New Jersey, they certainly do happen from time to time," Zarrow noted. "Especially along the Ramapo Fault, which separates the Highlands of northern New Jersey from the Piedmont near the Newark Basin. A magnitude 2.1 earthquake is considered very minor, and would have been barely felt (if at all). Generally, an earthquake would need a Richter scale magnitude of 3.0 to be felt by most people and to cause objects on shelves to sway."
According to Zarrow, an earthquake would have to be about 4.0 on the Richter scale to cause even minor structural damage, and that would be almost 100 times stronger than the Ringwood earthquake. He added that the Richter scale is logarithmic, so each step up in magnitude is a tenfold increase in strength.
An aftershock of this earthquake, Zarrow added, is unlikely.