3. River Deltas

Using Google Earth complete the following questions:

3.1 Find the Niger River Delta (04 º 30' N 06 º 6' E) and examine the shoreline. Now, find the shoreline of the Ganges-Brahmaputra River Delta (21 º 45' N 89 º 15'E). Which of these locations do you think is a wave dominated shoreline? Which do you think is a tide dominated shoreline? Justify your answers by providing observations about the configuration of each coast.

3.2 Go back to the Niger River Delta, and fly out to an eye altitude of approximately 1000 km. Notice how the shoreline in the area of the Niger delta protrudes into the Atlantic Ocean. Also, examine the bathymetry in front of the subaerial part of the delta. Integrating your knowledge of plate tectonics, sea level history during the last 18,000 years, and coastal processes describe the plate tectonic setting, and provide several descriptive sentences explaining what events and processes have contributed toward the long-term (last 18,000 years) evolution of this coast.

3.3 Now, go back to the Ganges-Brahmaputra River delta and fly out to an eye altitude of approximately 1500 km. Examine the configuration of the many rivers and drainage networks delivering sediment to the delta. Where do the rivers originate? Why do the largest of the rivers extend to the north and then suddenly turn toward the east or west? What type of plate tectonic setting exists where the rivers originate? Explain whether you think that this tectonic setting can influence the availability of sediment to the rivers and ultimately the long-term evolution of the delta.