A recent “swarm” of earthquakes to hit the Salton Sea area in Southern California has experts chattering about “the big one” yet again. While there’s no way to predict when a quake will happen, the location and frequency of these particular quakes are making seismologists question if we’re close to seeing another major quake on the San Andreas fault according to the LA Times:
The swarm began just after 4 a.m. Monday, starting earthquakes three to seven miles deep underneath the Salton Sea.
The biggest earthquakes hit later that morning, a 4.3, and then a pair later at night, another 4.3 followed by a 4.1. There was another burst of activity Tuesday night.
The earthquakes hit in a sparsely populated area, less than four miles from Bombay Beach, population 171, sitting on the edge of the Sonoran Desert. When swarms hit this area — the northern edge of the so-called Brawley Seismic Zone — it’s enough to give earthquake experts heartburn.
The Times reports that a similar “swarm” back in 1987, featuring a larger 6.3 quake in the Salton Sea area, led to a 6.6 event dubbed the Superstition Hills earthquake. Nothing that size hit the area this time, but it was still enough to bring worries for experts:
“Any time there is significant seismic activity in the vicinity of the San Andreas fault, we seismologists get nervous,” said Thomas H. Jordan, director of the Southern California Earthquake Center, “because we recognize that the probability of having a large earthquake goes up.”
As seismic activity drops, the probability of having a large earthquake also decreases.
Experts said it’s important to understand that the chance of the swarm triggering a big one, while small, was real.
“This is close enough to be in that worry zone,” seismologist Lucy Jones said of the location of the earthquake swarm. “It’s a part of California that the seismologists all watch.”
If a “swarm” or quake was to trigger a larger event in the area, it could unzip “the fault from Imperial County through Los Angeles County” according to the LA Times. The most damaging quakes in recent memory were the 1989 Loma Prieta earthquake and the 1994 LA Northeridge earthquake, both measuring above 6.5 on the scale and causing considerable damage. Predictions have cited a much larger quake in coming years, but not for the San Andreas fault. The true culprit will be the Cascadia Subduction Zone, which could spark a quake that could reach 9.2 on the scale and cause damage we’ve yet to see in the States.
(Via LA Times)