Viscoelastic Deformation Due to Sediment Loading in the Ganges-Brahmaputra Delta and in the Bay of Bengal.

Thursday, 18 December 2014
Mikhail Karpytchev1, Valérie Ballu1, Pierre Valty2, Stephane Calmant3, Junyi Guo4, Fabrice Papa3, Melanie Becker5, Faisal Hossain6 and C.K. Shum7, (1)LIENSs/Université La Rochelle, La Rochelle, France, (2)IGN Institut National de l'Information Géographique et Forestière, Paris Cedex 13, France, (3)IRD, Toulouse Cedex 09, France, (4)Ohio State University Main Campus, Division of Geodetic Science, School of Earth Sciences, Columbus, OH, United States, (5)University of the French West Indies and Guiana, University of the French West Indies and Guiana, Fouillole, Finland, (6)University of Washington Seattle Campus, Civil and Environmental Engineering, Seattle, WA, United States, (7)Byrd Polar Research Center, The Ohio State University, Columbus, OH, United States
Sedimentation is a major cause of long-term subsidence in the Ganges-Brahmaputra Basin.
 We estimate the vertical crustal velocities induced by sediment discharge in
 the Ganges-Brahmaputra-Meghna Delta (GBMD) by using a realistic viscoelastic Earth model.
 The ancient sediment loading is inferred from the available chronostratigraphic data and
 the present-day loading is estimated from the river discharges.
 The model is constrained by geological data and the GPS vertical velocities.
 The contribution and spatial pattern of the present-day elastic subsidence in the GBMD is compared
 with that due to Holocene sedimentation and with the subsidence rates induced by sediment compaction.
 The model provides new insights on possbile links between the climate changes, the river discharges
 and the relative sea level variations along the GBMD coast.