Tectonics and sedimentation are closely related in Bangladesh. The Ganges and Brahmaputra Rivers drain most of the Himalayan Mountains bringing ~8% of the world’s annual sediment supply to Bangladesh. These sediments have built the world’s largest delta at the NE corner of the Indian plate. This delta, in turn, is being overridden by two plate tectonic boundaries, the Burma Arc to the east and the uplifted Shillong Plateau to the north. The Shillong Plateau a piece of Indian basement that may represent the beginning of a forward shift of the Himalayan Mountains to the south. The Burma Arc is the northward extension of the plate boundary that experienced the 2004 M9.3 Sumatra-Andaman earthquake and tsunami. Both of these boundaries are partially buried by the sediments of the Ganges-Brahmaputra Delta. This both obscures the boundaries and preserves a record of the tectonics in the sediments.
Details on both the scientific issues and the methods we use to investigate them are on the pages for:
Rivers & Sediments
Tectonics & Geophysics
Figure 1A) Drainage basin of the Ganges, Brahmaputra and Meghna (M) Rivers. The rivers, shown in yellow drain most of the Himalayan Mountains. B) Topography of the area surrounding the Ganges-Brahmaputra Delta. Bangladesh is outlined in red. The Hinge Zone is the edge of Indian Shield. Farther east is where the very thick sediments of the delta have extended the continental margin. The major plate boundaries are shown at black lines with triangles on the upper side of the thrust.