A magitude-2.6 quake was the last to hit around 10:01 p.m. at a depth of nearly two miles. The weakest ones to strike measured at 2.5.
The quakes occurred in the same region where a magnitude-5.3 quake hit on Saturday.
The first quake, registering at a magnitude-2.6, struck around 9:27 p.m. at a depth of less than two miles. At least 18 other quakes hit the same area within about 20 minutes.