A 2.8 magnitude earthquake rattled the area near Johannesburg in Kern County on Tuesday night, adding another small but noticeable jolt to a week already marked by repeated tremors. The U.S. Geological Survey said the quake struck at 10:32 p.m.
The shaking was centered about 11 miles west-southwest of Johannesburg and occurred at a depth of 5 miles. www.mercedsunstar.com reported that five tremors of magnitude 2.5 or higher have been recorded in the region over the last week.
Recent activity in the area
The largest quake in that stretch was a 3.5 magnitude event recorded in the same region on June 17. Other nearby quakes included a 2.9 magnitude tremor on June 17, a 2.8 magnitude quake on June 21, a 2.7 magnitude quake west-southwest of Searles Valley on June 18, and a 2.6 magnitude quake on June 17.
What the magnitude means
According to the U.S. Geological Survey, magnitude measures the energy released at the source of an earthquake and replaces the old Richter scale. Michigan Tech says quakes between 2.5 and 5.4 magnitude are often felt but rarely cause much damage.
Earthquakes can trigger fires, tsunamis, landslides, or avalanches, and they can happen anywhere. The Department of Homeland Security says they are most common in Alaska, California, Hawaii, Oregon, Puerto Rico, and Washington.
How to respond if shaking starts
Officials say the best response is to drop, cover, and hold on. That means getting down on hands and knees, covering the head and neck, and holding onto something sturdy until the shaking stops.
If you are in a car, pull over and stop with the parking brake set. If you are outdoors, stay away from buildings and do not go inside.
People indoors should stay inside and avoid doorways. If you are in bed, turn face-down and cover your head with a pillow.
The U.S. Geological Survey also warns that aftershocks can follow the main shock, along with hazards such as damaged buildings, leaking gas or water lines, and downed power lines.