Amanda Ripley is the author of "The Unthinkable: Who Survives When Disaster Strikes -- and Why." Her coverage of Hurricane Katrina helped Time win two 2006 National Magazine Awards. She has written cover stories for Time on disaster survival and the male and female brain. Ripley is also a seasoned media guest and over the years has appeared on ABC News, NBC, CNN, Fox News, CNBC, MSNBC, and NPR, among other outlets. She has briefed staff at the U.S. Senate, the State Department and the Department of Homeland Security. She can be reached at www.AmandaRipley.com.