Any chance that Monday's magnitude 4.4 temblor was a prelude to a larger, more powerful earthquake was reduced to 1% Tuesday morning.
The earthquake that struck in Encino at 6:25 a.m. — the most significant shaker in Southern California since a 5.5 temblor hit Chino Hills in 2008 — surprised seismologists and Angelenos alike. It was followed by several aftershocks, the largest being a magnitude 2.7.
Seismologists had warned that there was a 5% chance the quake could be a foreshock, a prelude to a more powerful temblor along the little-noticed fault deep under the Santa Monica Mountains. That probability, however, would fall to 1% by Tuesday morning, they said.
Monday's earthquake hit in the northern edge of the Santa Monica Mountains, an area responsible for the uplifting of the range over many thousands of years.
"The location is somewhat surprising. It's within the Santa Monica Mountains. We have not seen seismicity in it in recent times," said Caltech seismologist Egill Hauksson. "It has been dormant for quite some time."
The shaking was actually more dramatic farther from the epicenter on top of the soft, soil-filled Los Angeles Basin and the San Fernando and San Gabriel valleys.
That's because the quake's waves "bounce back and forth" within the basin and valleys, "so you get this bowl-of-Jello effect," Hauksson said.
A few miles away, in communities such as Westwood, Sherman Oaks and Beverlywood, the quake packed a punch.
"I kind of just grabbed a blanket and hid," Lilly Chang, 22, a UCLA psychobiology major, said after her boyfriend, Aaron Green, 28, grabbed her and jumped out of bed.
The quake caused Cristina Toth, 26 and Andresa Maia, 25, to flee UCLA's architecture building, where the two had been working all night.
"We looked at each other," Maia said, "and we just sort of ran outside."