HR: 1330h
AN: G43A-03 INVITED     [Abstracts]
TI: Present-day deformation along the Northern Gulf of Mexico as observed by continuous and episodic GPS observation
AU: * Sella, G F
EM: sella@earth.northwestern.edu
AF: Department of Geological Sciences, Northwestern University, 1850 Campus Drive, Evanston, IL 60208 United States
AU: Dokka, R K
EM: rkdokka@c4g.lsu.edu
AF: Center for Geoinformatics, Louisiana State University, South Stadium Drive, Baton Rouge, LA 70806 United States
AU: Dixon, T H
EM: tdixon@rsmas.miami.edu
AF: Department of Marine Geology and Geophysics, RSMAS-University of Miami, 4600 Rickenbacker Csway, Miami, FL 33149 United States
AU: Hossain, I
EM: imtiaz@c4g.lsu.edu
AF: Center for Geoinformatics, Louisiana State University, South Stadium Drive, Baton Rouge, LA 70806 United States
AB: Characterizing the northern Gulf Coast as a passive plate margin based on the lack of seismicity, low relief, and geological history does not reflect all the processes that are at work. Additional processes include: gravitational loading and consequent flexure from the Mississippi deltas (and earlier rivers), compaction of thick Quaternary sediments, growth normal faulting, salt migration, and local fluid withdrawal. The net effect of these processes results in significant horizontal and vertical deformation. This deformation contributes to coastal land loss that reaches maximum rates in Louisiana of 35-40 square kilometers a year. To ascertain present day rates of horizontal and vertical motion along the northern Gulf of Mexico we have analyzed GPS data from both our own GULFNET network consisting of 18 continuously operating stations (CGPS) and 25 episodic stations that have been monitored every two-three years. In addition we have also included over 20 NGS CGPS sites. Results from the continuous GPS sites provide limits on southward directed horizontal displacement with respect to the stable interior of North America, with maximum rates of 5 mm/yr. Subsidence estimates from CGPS generally are up to 15mm/yr
DE: 8105 Continental margins and sedimentary basins
DE: 8107 Continental neotectonics
DE: 8110 Continental tectonics--general (0905)
SC: Geodesy [G]
MN: 2005 Joint Assembly