Aftershocks from the 4.8 magnitude earthquake that hit New Jersey and reverberated through the northeast Friday continued overnight, according to preliminary data from the U.S. Geological Survey. Officials reported nine aftershocks Hunterdon and Somerset counties between 5 p.m. Friday and 4 a.m. Saturday. Don’t worry — this is normal. Aftershocks are a series of smaller quakes that follow the larger “mainshock” of an earthquake, and the ones that happened overnight all fell below a magnitude of 2. While the main earthquake was felt as far away as Massachusetts, the overnight seismic activity w…