This dissertation describes and analyzes the temporally and spatially non-linear nature of the vertical displacement of 1st order geodetic benchmarks in the lower Mississippi Valley and northern Gulf of Mexico coastal region. The least-squares method of adjusting redundant surveying observations is implemented to compute the most likely value of the most recent rates of displacement at node benchmarks within the network, along with estimates of the uncertainty of those values. Using that result, a modification of the standard method of adjusting geodetic leveling networks is developed and demonstrated to compute new elevations for the node benchmarks which accounts for both the temporal and spatial variability of the vertical displacement. The result of this re-adjustment computation is a new estimate of the current elevations of a framework of 1st order benchmarks that are generally lower than the official published values. This result has serious practical implications for the population and infrastructure within this region
