Between hurricanes and oil rigs, the Gulf of Mexico has been a busy place in modern times. But the area was also a hub of activity 13,000 years ago, when man and woman walked on land that is now underwater.

Detail of Gulf of Mexico in vicinity of Louisiana. The light colored shelf would have been exposed at low glacial sea levels and thus available for habitation by humans.

How did these first Americans live their lives along the Gulf so many years ago? Patrick A. Hesp, designated chair of geography and anthropology, LSU Ph.D. candidate Amanda Evans, and geologist and oceanographer Graziela da Silva are using a $300,000 grant to be among the first to find out.

The grant, “Examining and Testing Potential Preshistoric Archeological Features on the Gulf of Mexico Continental Shelf,” courtesy of the Federal Minerals Management Service (MMS), enables the team to spend thirty months investigating alleged Gulf of Mexico middens, or under water archeological trash heaps, to gather information about early civilizations.

The geophysical surveys of the Gulf currently in use include decades-old data on tagged areas that may—or may not—be human artifacts. These charts, made with the best technology of their time, are used to help oil and gas companies avoid disturbing potential archeo-logical sites when laying pipe.

“[But] no one has done the next stage of proving the tagged sites,” Hesp says. “Essentially they do the geophysical surveys and find a signal they interpret as a site. Then they put a circle around it and say, ‘You can’t go there because it could be [an archeological] site.’”

Hesp expects his team’s study will help government and private concerns re-evaluate their current methodology.

The new grant has big economic implications. “Some sites marked as middens on previous surveys are erroneous,” Hesp says. “Money is wasted when underwater pipe is laid to avoid sites that don’t exist.” In a political and economic climate calling for increased offshore drilling, the team’s updating of older surveys is especially relevant.

Hesp and his colleagues use high resolution side-scan sonar, a system that efficiently creates an image of large areas of the sea floor. The system is typically used for fisheries

Chirp subbottom profile data in the Galveston area showing a large, and several small infilled valleys, and a potential site located on a preserved landform (arrowed). Data courtesy of Tesla Offshore LLC..

Hesp, a native New Zealander who completed his undergraduate and graduate degrees “down under,” first knew he would enter coastal studies when a professor took his class to the beach for a lecture. “I thought, Wow! You can get paid for being on the beach. This is phe-nomenal!” He has been studying in the sand ever since.

Hesp met Evans two years ago while teaching a graduate class in coastal resources and management. While a student, Evans was also working for Tesla Offshore LLC, a Louisiana company that conducts geophysical offshore surveys for the oil industry. The current grant came about, serendipidously, from an idea Evans had based on her work with Tesla in the Gulf of Mexico.

Evans explained that the chances of finding artifacts in high energy seas with big surf and quick erosion are low, whereas the comparatively calm Gulf is ideal. The Mississippi River provides additional benefit by delivering layers of sediment to preserve potential finds.

However, tropical cyclones can complicate research in this area. Hesp says he won’t know for some time what damage Hurricane Ike did to a site they are studying off the coast of Galveston, or whether there was damage from Hurricane Gustav to their site near Avery Island.

Until they return, the team will continue to evaluate and refine their data, ultimately seeking to learn more about the first Americans and when they reached the Gulf Coast.

One wonders: Given the continuing loss of Louisiana’s coastline, could our own civilization become the subject of future marine research?

-Renee Bacher

...from the Autumn 2008 Issue