A magnitude 4.4 earthquake struck the Los Angeles area Monday morning – but where exactly did it hit?
The U.S. Geological Survey says the quake was centered about 5.6 miles north-northwest of Westwood. The online report from the USGS Earthquake Hazards Program also notes that the epicenter was 6 miles northwest of Beverly Hills, 7 miles west of Universal City, 7 miles north of Santa Monica and (just for good measure) 349 miles south-southeast of Sacramento.
Initial media accounts of the quake described it as being "near Westwood," and TV coverage included a map of the Southland with a pattern of concentric circles radiating outward from Westwood. However, the precise location was 34.135°N latitude and 118.486°W longitude.
If you plug that into Google Maps, you get a cul-de-sac on the north side of the Santa Monica mountains. That cul-de-sac – the 16000 block of Meadowcrest Road – is at the far western edge of Sherman Oaks. Had the epicenter been another block or so to the north, west or south, it would have been in Encino.
We wondered why Westwood got the shout-out in favor of another neighborhood closer to the epicenter. Egill Hauksson, a seismologist at Caltech who works down the street from the USGS office in Pasadena, said the short answer was simple: Westwood is in the USGS database, while Encino and Sherman Oaks are not.
"Westwood just happens to be [the] closest city on the list," Hauksson explained. "All the real-time data processing is done automatically, so there is no human judgment about what is a more important city."
Nancy King, a USGS geophysicist based in Pasadena, said the agency's quake reports use cities as reference points because city names are easier for people to grasp than the numerical coordinates you might see on a GPS device. "Latitude and longitude don't mean a lot to many people," she said.
Monday's event may wind up being named for Los Angeles, Westwood, Sherman Oaks or Encino. But at @latimesscience, we're partial to the nickname "Shamrock Shake."