An earthquake of the variety that seismologists classify as "light" shuddered under the basin at 7:36, prompting a routine cautionary response from the LAFD and the usual suspects in the LA media corps to do their over-excited thing on social media. The initial magnitude reading of 3.7 or 3.8 was recalculated upward after several minutes, landing on 4.2. The shift under the Santa Monica Mountains west of Sepulveda Pass was perceptible over a pretty wide area; see the official shake map above. No reports of important damage were received, but as comedian Paula Poundstone quipped on Twitter, "CNN will keep trying."
USGS seismologist Lucy Jones made an interesting observation on Twitter. The number of magnitude 4-plus quakes under the Los Angeles is ramping up. In March, a quake pegged at 4.4 broke pretty close to the same area of the mountains.
The LA Basin (33.7-34.4N;117.7-118.7W) had 36 M>4 EQs from 1940-2013. We've had 3 M≥4 EQs so far in 2014. 1988 had 4. 1989 had 3— Dr. Lucy Jones (@DrLucyJones) June 2, 2014
For more resources, visit the LA Observed earthquake page
Journalists' guide to reporting on earthquakes in Southern California