The Atlantic Ridge has mountains and deep valleys in the hemispheres, north and south.
The East Pacific Rise has no large mountains or valleys because the Pacific Rises oceanic crust is moving away from the east.
Water Erosion
Wind Erosion
Glacier Erosion
Sea Erosion
Soil Erosion
The Congo and Niger rivers have interesting irregular courses, and instead of going just in a certain direction, they circle around big areas. This is due to the shape of the landscape, and also because of the types of rocks in the surrounding areas where these two rivers flow.
The shape of the landscape is crucial in the course of a river, since every river is moving through the lowest parts where there isn't obstacles, so these rivers have followed that pattern and it turned out to give them irregular course. Also, the types of rocks on their way are very important, so these rivers managed to get through the sediment rocks as they are easy to erode, but haven't been able to break through the igneous rocks that are much harder.
It lies on the Indian Ocean side of the continent, almost entirely within the Eastern Hemisphere – hence the name “East Antarctica”. The region includes the South Magnetic Pole, the Geographic South Pole, the Ross, Scotia and Weddell Seas and the Shackleton Ice Shelf.