Twitter announced today that it has launched a new emergency feature called Twitter Alerts, which lets credible organizations get important information out to people via notifications.
Users can sign up for alerts on an account-by-account basis. Once you subscribe to an account's alert, you will get a notification on your phone whenever that account marks a tweet as an alert. The notifications are delivered through SMS and push notifications. These tweets also appear differently on your actual Twitter timeline. Tweets marked as alerts will feature an orange bell icon.
To sign up for an account's alerts, go to its setup page, which can be found at twitter.com/username/alerts.
Twitter is only allowing handpicked accounts to issue alerts. Currently, the types of accounts that can use them are limited to law enforcement and public safety agencies, emergency management agencies, city/municipal governments and their agencies and representatives, county/regional agencies and select state, federal and national agencies and NGOs. You can see a full list of participating organizations here.
Organizations are being directed to use the alerts for things like warnings for imminent dangers, preventative instructions, evacuation directions, urgent safety alerts, info on access to essential resources, info on critical transit and utility outages and crowd and misinformation management.