Hurricane Irene knocked out power to millions of homes and businesses as it travelled up the US East Coast this weekend. Even as the winds subsided, torrential rains triggered savage flooding throughout Eastern New York state and Vermont, tearing up roads and exposing the telecommunications infrastructure to further risks. The storm’s impacts were clearly visible in the Internet’s global routing table, as tens of thousands of networks were cut off from the rest of the world.
Here are a couple screenshots from our Internet Health Portal, which we provide to the US Computer Emergency Readiness Team (US-CERT). During an emergency like Hurricane Irene, this tool provides the US-CERT with critical information about the availability of Internet services across America. Working from lists of impacted customers in each state and county, and lists of correlated outage events, we can supply a lot of useful information about the problems being experienced by enterprises in the affected area. That information can be passed along to state and local governments to aid in prioritization of disaster relief.
During Irene, this feedback was particularly important because the storm’s progress affected different regions at different times. To the left below, you can see a sequence of state-by-state plots of withdrawn routes (representing networks that have become unreachable due to power loss or infrastructure damage) along the US East Coast, from south to north. (Click on individual state plots to see details.)
As time marches on, you can see the peak window of Internet damage move north along the track of the storm. Outage counts rise with the local onset of storm winds, and fall again as restoration efforts are successful (significant outages continue in the last states affected: Vermont, New Hampshire, and Maine).
Animation: East Coast Internet Outages
Finally, here’s an animation that combines the network outage information in each zip code with the satellite imagery from Irene. It gives you a good sense of the massive scope and impact of this event. Short-duration outages are green; longer ones that linger (due to sustained power outages or infrastructure damage) are red.
Staying Connected, Preparing to Rebuild
Overall, it seems that the East Coast’s power and Internet infrastructure fared pretty well during this storm, with good evidence of restoration after the storm had passed. This is good news, given the important role Twitter now plays in ad hoc rescue coordination, and the importance of the Web for keeping people informed about what they’re facing in an emergency situation. I suspect that always-on, ubiquitous Internet access is going to fundamentally change the way people on the ground manage their affairs in the wake of disasters like Irene.
I spent 12 hours picking my way across the ruined roads and bridges of Eastern New York State yesterday, trying to get back to New Hampshire, and I can attest to the fact that the transportation network is now far more vulnerable to disruption by an event of this scale than is the cyber-infrastructure.
As we drove past legions of idle 18-wheeler trucks full of food and fuel, unable to reach their destinations, 3G mobile connectivity kept us connected to the Internet and in touch with the tweets of local emergency management officials and people back home. At one point we were even part of a stream of vehicles heading urgently for higher ground, following a report that the Gilboa Dam had failed. Thanks to Google Maps we knew where to climb to, and thanks to Twitter we knew when it was safe to come down again. You can’t eat the Internet, or burn it to keep warm, but compared to the days of the transistor radio and EBS alerts, we’ve come a long way.