Natural forces formed the Bay of Bengal; the bay continues to shape the features of its basin
A. About 118 million years ago, the formation of the Bay of Bengal and its sedimentary basins was started in the early Cretaceous period, during the seafloor spreading between Antarctica and India. During Paleocene epoch greater India’s tectonic plate collided with Eurasian plate and later it continued its northward drift, resulting in the Himalayan uplift.
B. Unlike most of the boundaries between Oceanic and Continental crust on the planet, the Bay of Bengal’s oceanic-continental boundary is located onshore, several hundred kilometers inshore beneath present-day northern Bangladesh, because the large volume of sediments shed following the uplift of the Himalayas. The delta— called the Bengal delta is still active.
C. Sedimentation through Ganges-Brahmaputra-Meghna rivers system continues to date, extending into the deeper waters of the bay. The world’s largest submarine fan— called the Bengal fan starts off the GBM river mouth and the submarine canyon Swatch of No Ground.
D. The fan system and a thick uniform abyssal plain occupy almost the entire bay, in many places underwater valleys dissect this plain. The seabed is characterized by a broad U-shaped basin gently sloping southward with its opening to the Indian Ocean.
E. The sea level change, waves and various weather phenomena are reshaping the coastal areas.
F. Rapid erosion, influenced by wind, waves, and currents, results into redistribution of rock, soil and other earth materials of coastal wetlands in the Bay of Bengal.
G. Sediments, composed of fragments of animals, plants, rocks and minerals, are a product of erosion. Sedimentation in the Bay of Bengal is dominated by deposits from the rivers, derived mainly from the Himalayas and other lower plain and mountain ranges.
Version: August 2019