Geodetic subsidence rate in coastal Louisiana

Southern coastal Louisiana is experiencing significant subsidence, leading to land loss and increasing the risk of storm-related flooding. Several processes contribute to this subsidence, with differing spatial and temporal variations. Here we report on regional subsidence as measured by a network of continuously recording, high precision GPS stations, and attempt to characterize it. Our results show that the short-term subsidence rate of parts of the Mississippi delta is considerably higher than surrounding coastal areas. Sediment compaction, low-angle faulting and regional subsidence associated with mass loading appear to be the major factors controlling subsidence in the delta. The coastal regions outside of the delta undergo slower subsidence, probably related to factors such as fluid withdrawal (ground water, petroleum and natural gas extraction).