Gov. Phil Murphy said aftershocks would not be unusual within 24 hours. He also advised residents to use "common sense" to assess damage to their homes and buildings.

NEW JERSEY - A third, 4.0 scale rated aftershock shook up portions of the Garden State Friday after an afternoon of unusual seismic activity.

The third event, centered just outside Gladstone was recorded shortly after 6 p.m., according to the United States Geological Survey, which monitors earthquakes.

A series of smaller events hit New Jersey Friday afternoon after a "notable" 4.8 magnitude earthquake shook up the state less than two hours earlier.

The 2.0 magnitude earthquake was detected with an epicenter seven kilometers west of Bedminster, New Jersey, the USGS noted.

Three more aftershocks ranging from 1.8 to 2.2 magnitude were reported near Morris, Hunterdon and Somerset counties between about 12:30 and 1:30 p.m.

New Jersey's State Emergency Operations Center has been activated, which will allow for 24-hour agency staffing to coordinate response and recovery operations, Gov. Phil Murphy said. There is no risk of a tsunami from the quake, according to the United States Tsunami Warning System.