Pictured from left: Art Berman (HGS VP) and Dr. Roy Dokka (LSU professor)
Dr. Roy Dokka, LSU professor of engineering and surface GPS geospatial expert, got a laugh out of the HGS Lunch crowd on March 25, 2009 with this tongue-in-cheek headline:
"New Orleans is not only sinking, but it’s also sliding into the Gulf!”
Dr. Dokka heads one of the most successful research programs on the LSU campus, averaging over $1MM/yr in federal competitive grants and contracts over the past five years. His current research interests center on the application of the Global Positioning System (GPS) and geodetic leveling to the study of massive subsidence that is affecting Louisiana’s coast and mid-continent, and on understanding the role that tectonism and climate play in creating landscapes.
His presentation at this HGS Lunch was entitled, “Late 20th Century Subsidence of South Louisiana: Insights into the Nature of Passive Margin Normal Faults.” As a Director at both the Center for Geoinformatics, and the Louisiana Spatial Reference Center, Dr Dokka is trying to understand present-day normal fault movement using geospatial measurement from the Louisiana delta. He said geologists understand the 3D picture of faults in the subsurface, but hardly ever study present-day fault movement. He has evidence of offshore Louisiana faults moving up to 1.25” downward per year. He has also detected breaking and rebound on growth faults. He has documented when faults release strain energy that can be detected at the surface using geospatial measurements.
Dokka said he believes the Gulf Coast is at risk for earthquakes, even though little monitoring is done to try and spot earthquakes. He pointed out the earthquakes have been measured recently due to subsidence in offshore Louisiana near the Sigsbee escarpment. He says coastal normal faults can “store” elastic energy and release “slow” 30-year-long earthquakes in the Gulf Coast.
Two warnings came up in the talk. First, Dokka expressed concern that the USGS is using his research data on the Golden Meadow fault in Louisiana as evidence that the oil and gas industry “causes” fault movement. His view is that fault movement is natural and caused by multiple forces. Second, he was concerned about permitting and building nuclear power plants in the subsiding Gulf coastline because of the unstable, and poorly understood ground surface movement.
Pictured at left: Former HGS President, John Amoruso
Pictured at right: Mac McKinney, also a former HGS President