When disaster strikes, you used to see or hear announcements over television and radio, but with fewer people tuned in to these old school mediums, they're less useful channels of communication. Now it's far more likely that we'll hear about the latest earthquake or flood on a real-time social channel like Twitter simply because it's what all of our friends are talking about.
Google already aims to provide quick access to disaster information via Google Public Alerts, which feeds information from official sources—like weather alerts and school closings—to search, maps, and Google Now. Recognizing the speed of social networks to convey important information in a crisis, Google is starting to add tweets to the mix.
However, this doesn't mean you'll be getting everyone's favorite earthquake jokes when you just need to know what's happening: Google will make sure they're still providing relevant information, even if the source is less official. Google explains, "Some of the more extreme Public Alerts will include tweets to help answer important questions: are schools closing? Are neighbors evacuating? What are people seeing on the front lines of a storm?"
Now that sounds like a good use of social networking.