Modern-day tectonic subsidence in coastal Louisiana

Research Article| April 01, 2006 Modern-day tectonic subsidence in coastal Louisiana Roy K. Dokka Roy K. Dokka 1Center for GeoInformatics and Department of Civil & Environmental Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Roy K. Dokka 1Center for GeoInformatics and Department of Civil & Environmental Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA Publisher: Geological Society of America Received: 21 Sep 2005 Revision Received: 02 Dec 2005 Accepted: 11 Dec 2005 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2006) 34 (4): 281–284. https://doi.org/10.1130/G22264.1 Article history Received: 21 Sep 2005 Revision Received: 02 Dec 2005 Accepted: 11 Dec 2005 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Roy K. Dokka; Modern-day tectonic subsidence in coastal Louisiana. Geology 2006;; 34 (4): 281–284. doi: https://doi.org/10.1130/G22264.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Subsidence is leading to the slow inundation of communities and wetlands of Louisiana, Mississippi, Texas, and Alabama (United States) by the Gulf of Mexico. The prevailing paradigm considers subsidence to be the result of young sediment compaction and/or consolidation and human activities. This paper describes the results of a test of this theory based on an examination of historic motions of benchmark in the Michoud area of Orleans Parish, Louisiana. This methodology allowed for an assessment of vertical change at different levels over time relative to a precise vertical datum (North American Vertical Datum of 1988, NAVD88). Data do not support the current theory on the origins of subsidence; they demonstrate that tectonic causes dominate in the study area. During 1969– 1971 and 1971–1977, tectonism was responsible for −16.9 mm/yr and −7.1 mm/yr of subsidence, respectively. These contributions account for 73% and 50% of the total subsidence during these intervals. The change in deep subsidence is attributed to renewed motion along a large normal fault (Michoud fault). Over the same time intervals, intermediate depth subsidence due to compaction of Pleistocene to middle Miocene strata was constant (−4.6 mm/yr). Similarly, subsidence due to shallow processes, i.e., sediment compaction and groundwater offtake, was −1.5 mm/yr and −2.5 mm/yr. Subsidence associated with petroleum extraction was not a factor due to the lack of local production. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.