An earthquake search will bring up fairly rich results, with a map of recent seismic activity and data for each incident. Since earthquakes also pose a very real danger, the results card will actually display tips for what to do in the aftermath as well. Anything under a 2.5 magnitude, which hardy Californians would scoff at anyway, won't trigger the new feature.
As TechCrunch reports, the USGS usually posts the data within minutes of a quake in the US, and that data gets to Google seconds later. For other parts of the world, however, it can take the agency up to 30 minutes to verify and post the information. Regardless, the new "earthquake near me" search feature will work globally, but only in English for now. It's also worth noting that if you have your location turned off, or just want to check another city, searching for "earthquake San Francisco" or "earthquake Los Angeles" will bring up the same information.