A study released this week by a team led by a NASA researcher provides a detailed look at subsidence across New Orleans—a problem here because of our soft sedimentary soil that is prone to sinking and compacting, and because many neighborhoods are built on drained marshland. Also, levees built to mitigate flooding ironically tend to exacerbate the problem of soil compacting.
Examining subsidence rates between 2009 and 2012 using a radar strapped to a jet, the study found the most dramatic rates of subsidence in the Michoud area of New Orleans East, which dropped by about 30 millimeters, or about 1.18 inches, each year, and Norco in St. Charles Parish. Since Michoud is the site of a NASA assembly facility, and Norco is the home of a Shell refinery, rates of subsidence might be due to industrial activity.
Rates of up to .78 inches a year were seen in the Lower 9th Ward, Chalmette, Algiers, and Old Metairie.
• Study shows continued subsidence in New Orleans, but some areas sinking faster than others [The Advocate]
• There is Now a Sinkhole on Canal Street Above the Harrah's Tunnel [Curbed NOLA]
• This Research on Carbon Emissions and the Louisiana Coast Will Ruin Your Monday [Curbed NOLA]