THE GEOLOGY OF THE KATRINA DISASTER IN NEW ORLEANS - FIELD TRIPS FOR THE COMMUNITY

On the morning of August 29, 2005, Hurricane Katrina struck New Orleans. Levee failures that occurred early on that morning resulted in flooding of over 80% of the city. In the first few weeks after the event, reliable sources of information about what happened were scarce, the most reliable being the New Orleans Times-Picayune newspaper. In order to assemble the facts and better understand what happened, an independent investigation was conducted, relying on field observations and information published in the Times-Picayune. It soon became apparent that few people living in New Orleans, let alone the rest of the world, had a thorough understanding of what happened and that there was an abundance of misinformation being circulated. Thus, in early November, 2005, I began offering field trips to the devastated areas for anyone interested. They began with trips for family and friends, and later expanded to the Tulane University community, my own course on natural disasters, and to the community at large. To date, over 1000 people including New Orleans residents, people from throughout the U.S., and many foreign visitors, have participated on over 60 field trips. Because investigations into the cause of the levee failures have continued to evolve, an easily updatable field trip guide was developed and placed on the internet (http://www.tulane.edu/~sanelson/Katrina). The field trips offer a unique opportunity to discuss and observe the geologic factors that contributed to and were revealed by the disaster. Discussions include the geologic history of southern Louisiana, the subsurface geology of New Orleans proper, the geologic conditions present at the levee failure sites that contributed to the failures, and evidence observable at these sites which provide a better understanding of the causes of the failures. In addition, each trip provides a forum to discuss coastal erosion and how human interference with natural processes has made the area more vulnerable to disasters like Katrina. Overall, the field trips provide an opportunity to see the importance of geology in a region where geology is not readily apparent at the surface, but an understanding of which is critical to human lives and property.