UK & World News
Puente Hills Fault Quake 'Could Cause Disaster'
Experts have warned that a strong earthquake along the little-known Puente Hills thrust fault in California could be more damaging that one along the more famous San Andreas.
The Puente Hills thrust fault brought a 5.1 magnitude quake on Friday night, and some 100 aftershocks.
The quake was centred outside La Habra, around 20 miles (32km) east of downtown Los Angeles.
It caused some structural damage but only minor injuries were reported.
However, experts say that a 7.5 magnitude earthquake along that fault could prove more catastrophic than one along the San Andreas.
The US Geological Survey (USGS) estimates that such a quake along the Puente Hills fault could kill 3,000 to 18,000 people and cause up to $250bn (£150bn) in damage.
In contrast, a larger 8 magnitude quake along the San Andreas would cause an estimated 1,800 deaths.
The greater risk of potential damage is due to the fault line running near many vulnerable older buildings, many made of concrete, in downtown Los Angeles and Hollywood.
Seismologists also say an earthquake along the fault could be particularly hazardous because it is a horizontal fault, which means more intense shaking could be felt over a larger area than vertical faults.
The San Andreas fault runs along the outskirts of metropolitan southern California.
The shaking from a 7.5 quake in the centre of urban Los Angeles could be so intense it would lift heavy objects in the air, USGS seismologist Lucy Jones told the Los Angeles Times.
"That's the type of shaking that will hit all of downtown. And everywhere from La Habra to Hollywood," Ms Jones said.
Seismologists say a huge earthquake causing widespread devastation, referred to as The Big One, is 99% certain to hit the state within the next 30 years.