Mississippi River Delta Subsidence Caused by Compaction
On February 17, 2008, Torbjorn E. Tornqvist of Tulane University and other researchers published a letter in the journal Nature Geoscience entitled Mississippi Delta subsidence primarily caused by compaction of Holocene strata. The research findings suggest that the Mississippi delta is sinking as much as one fifth of an inch per year, but that the sinking is mostly limited to the upper layers of sediment while the land beneath is more stable.
This research suggests that the high rate of subsidence is largely the result of compaction of the shallow sediment deposits from the last 10,000 years in the upper few hundred feet near the surface of the earth. These findings suggest that flood control structures that penetrate through the shallow sediment deposits and rest on the more stable foundation below would not subsidence as quickly.
News articles reporting on this research include: Science Daily in an article entitled Post-Katrina Rebuilding? Mississippi Delta Both Spongy and Stable published on February 22, 2008; and New York Times in an article in a section entitled Observatory with the article title Support for a Theory As to Why Land Sinks Along the Gulf Coast by Henry Fountain published on February 19, 2008.
Erich P Rapp
