Jaap H. Nienhuis, Torbjörn E. Törnqvist, Krista L. Jankowski, Anjali M. Fernandes, Molly E. Keog

GSA Today

Published date June 14, 2017

A New Subsidence Map for Coastal Louisiana

I think it’s a point worth making that we are finding here that what people recently have considered worst case scenarios are actually conditions that we already see right now.

Torbjörn Törnqvist, a geologist at Tulane University and a co-author on the new paper


  • States that coastal Louisiana has experienced catastrophic rates of wetland loss over the past century, equivalent in area to the state of Delaware
  • States that land subsidence in the absence of rapid accretion is one of the key drivers of wetland loss
  • Argues that accurate subsidence data should therefore form the basis for estimates of and adaptations to Louisiana’s future
  • States that Jankowski et al. (2017) recently determined subsidence rates at 274 sites along the Louisiana coast
  • Presents a new subsidence map based on these data and calculate thats, on average, coastal Louisiana is subsiding at 9 ± 1 mm yr−1