DID WE SINK THAT MUCH?

In metropolitan New Orleans, we sink approximately 3 feet per century or about 1 inch every 2 ½ years. Along the Louisiana coast, some areas are subsiding at the rate of 6 feet per century or 1 inch per year! We will continue to subside, but for different amounts in different places. Research by Prof. Roy Dokka at LSU’s C4G indicates that the rates of subsidence are not constant, but appear to be episodic in some areas. That applies to both the surface-related differential subsidence that is due to the local soil conditions as well as to the deep-seated subsidence that appears due to consolidation of deltaic materials, the presence of geologic faults, and the bending of the lithosphere (the Earth’s crust) due to the sheer weight of the deltaic overburden.