To map the mass exodus from the Gulf Coast, ePodunk analyzed more than 40,000 messages posted on the Internet by survivors of the storm.
"Family is safe! House is lost! Kids are in Indiana with grandparents."
We looked at Web "safe lists," including those maintained by CNN, craig's list and MSNBC, and recorded data from every message in which the poster included his hometown and a city and state where he had found refuge.
An advantage of compiling data this way, rather than through official reports from agencies such as FEMA, is that these reports include not only people who were in shelters, but also those who were able to leave on their own, before and after the hurricane.
In our analysis, people reported moving to 724 cities in 46 states. Many expressed an intention to move on from their temporary quarters, so the map would likely to change with time.
Our sample, while sizeable, is not a complete picture, nor is it intended to reflect the numbers of people moving to a city. Houston, for example, experienced a much greater influx than Seattle.
However, the map does provide a graphic representation of the nationwide impact of such a huge migration. Indeed, repercussions will be felt beyond national borders. Eventual destinations mentioned in postings included Canada, Mexico, Ecuador, Guatemala and the UK.