5.4 magnitude aftershock rocks Southern California following strongest quake in decades

A strong aftershock shook Southern California early on Friday as residents were still assessing the damage from the July 4 quake, the strongest in the region in 25 years, which was felt by more than 20 million people.

The temblor, one of many aftershocks predicted by seismologists, struck the same desert region as Thursday’s major earthquake with a magnitude of 5.4 about 11 miles (18 km) west of Searles Valley at 4:07 a.m. local time, the U.S. Geological Survey said.’

WATCH: 6.4 magnitude earthquake rocks southern California

0:48 6.4 magnitude earthquake rocks southern California

There had already been more than 80 smaller aftershocks since Thursday’s 6.4 magnitude quake near the city of Ridgecrest, which was felt from Los Angeles to Las Vegas, USGS seismologist Lucy Jones said.

“We should be expecting lots of aftershocks and some of them will be bigger than the 3s we’ve been having so far,” Jones told reporters on Thursday. “I think the chance of having a magnitude 5 … is probably greater than 50-50,” she said.

Some residents spent much of their July 4 holiday cleaning up the mess left by the quake.

“I mopped up over 20 gallons (75 liters) of wine that fell over in addition to the beer, soda and the cooler that fell over. We have several thousand dollars worth of damage,” said shopkeeper James Wilhorn.

WATCH: Likelihood of another earthquake in southern California ‘unknown’

0:51 Likelihood of another earthquake in southern California ‘unknown’

Only a few injuries were reported, but two houses caught fire from broken gas pipes, officials said. Water gushed from zigzagged cracks in the pavement from busted water lines. Deep fissures snaked across the Mojave Desert, with passersby stopping to take selfies while standing in the rendered earth.

The quake hit the edge of Death Valley National Park about 113 miles northeast of Los Angeles at about 10:30 a.m. on Thursday. It was very shallow, only 6.7 miles (10.7 km) deep, amplifying its effect, and was felt in an area inhabited by 20 million people, the European quake agency EMSC said.

The Ridgecrest Regional Hospital, where 15 patients were evacuated earlier, appeared intact apart from some new cracks in the walls.

California Governor Gavin Newsom approved an emergency proclamation, and Ridgecrest Mayor Peggy Breeden said she had declared a state of emergency, a step that enables the town to receive help from outside agencies.

Breeden said she has asked residents to check on their neighbours in the high desert town.

“We’re a close-knit community and everybody is working to take care of each other,” she told Reuters by telephone.

WATCH: Ground split by fissures near epicentre of southern California earthquake

0:37 Ground split by fissures near epicentre of southern California earthquake

The quake is the largest in Southern California since the 1994 magnitude 6.6 Northridge earthquake, USGS geophysicist Paul Caruso said. That quake, which was centred in a heavily populated area of Los Angeles, killed 57 people and caused billions of dollars of damage.