72nd Quake In A Month Hit Malibu Wednesday — What It Means For The 'Big One'

MALIBU, CA — A trio of small earthquakes struck Malibu Wednesday morning, the latest in a series of around six dozen temblors epicentered near the city in the last month, according to the U.S. Geological Survey.

The first of three quakes, a magnitude 2.7, struck around 1:46 a.m. The second and third — a 1.8 and 2.2 — both hit in quick succession around 6:22 a.m. Their depths ranged from about 6 to 18 miles.

Weak shaking during Wednesday's largest quake was felt widely across Malibu, the Santa Monica Mountains, and San Fernando Valley and as far away as Santa Ana, according to the USGS.

No injuries or damage were reported.

The epicenters were about 3.5 miles north of Point Dume in the Santa Monica Mountains, an area that has seen a total of 72 earthquakes in the last 30 days, many of them small, according to the USGS.

The biggest quake was a 4.7 on Sept. 12. Two magnitude 3.4 quakes hit the same day and a 3.2 struck the area on Sept. 13.

The Sept. 12 earthquake at the time was part of the 14th seismic sequence this year in Southern California with at least one magnitude 4 or greater quake — which broke a record for the last 65 years, seismologist Lucy Jones told the Los Angeles Times.

According to the Southern California Seismic Network, a cooperative project between Caltech and the US Geological Survey, the quake was possibly the largest one to strike in the immediate Malibu area since record-keeping began in 1932. Over the last 92 years, there have been five quakes larger than a magnitude 4.0 within 7 miles of the Sept. 12 epicenter.

The unusual increase in seismic activity doesn't mean that the "big one" is right around the corner. There's two theories: that earthquake activity increases in an area before a large temblor — or that seismic activity decreases before a big quake, the Times reported.

The Southern California Earthquake Center says that the city does not sit on a major fault and will not experience mass devastation.

“You have to have a longer or greater surface area on a fault to have a larger earthquake. You can’t have a magnitude eight on a small, little local fault,” center Director Mark L. Benthien said in a USC publication. “And the faults that these Malibu earthquakes were near, probably the largest earthquake that it could have would be a 7.0 or so.”

John Vidale, a USC professor of earth sciences, said the recent quakes can be classified as aftershocks of the 4.7 quake that struck on Sept. 12.

“We don’t expect that these earthquakes are increasing the chance of anything or decreasing the chance of anything,” he said.