A new Facebook feature will allow you to let friends know if you are safe during a natural disaster such as an earthquake, hurricane or tornado. It will also notify you about your friends or check them in as safe, Facebook Inc. announced Thursday.

“We’re starting with natural disasters, and then we'll expand to more types of issues over time,” CEO Mark Zuckerberg said in reply to one user's question about which disasters Facebook would cover. “This is an important area, and there’s a lot more to do here,” he said to another.

Because Facebook's news feed is driven by an algorithm, recent posts aren't shown first, which makes the network less useful during in-the-moment events, where short-messaging services such as Twitter excel.

Facebook will activate “Safety Check” after a natural disaster. If the social network suspects that you are in an affected area, based on the city you list as home or the one where it detects that you using the Internet, it will send you a notification. Users can then either say that they are not in the disaster area or that they are but they are safe, and Facebook will create a news feed, letting friends and family know.

The new feature will work on desktop computers as well as Facebook’s apps for iPhone, Android and simple feature phones. Facebook said that Safety Check originated in a disaster message board that its Japanese engineers developed after the 2011 earthquake and tsunami. Experts say that it could help or hurt, depending on the situation, but that it is certainly a step in the right direction.

“If it gives people better information, then those people are more likely to make better, informed decisions,” Dr. Joseph E. Trainor, a researcher at the Disaster Research Center at the University of Delaware, said. Trainor recently conducted several focus groups that taught him and his colleagues that the public "overwhelmingly" wants a feature such as Safety Check.

"This is a step toward giving citizens tools to think about what they want to do and how they want to respond [to natural disasters]," Trainor said. He also cautioned that public agencies might worry about potential dangers of the feature caused by Facebook users who cannot confirm the safety of family and friends, "motivating them to go looking for them. But the truth is that people are already doing that with text messages and cell phones."