When you think of earthquake danger zones in the United States, it's unlikely that New Jersey is at the top of your list. However, the Garden State has been something of a hotbed of seismic activity this week.

A second minor earthquake has rattled the New York metropolitan area within several days. The 2.7 magnitude quake struck Tuesday afternoon near Hillsdale, New Jersey, northwest of the Bronx.

While earthquakes are relatively uncommon in the Northeast, the events highlight the region's ongoing seismic activity.