Tag: rivers, coasts and glaciation

Slumping in simple terms is recurring downward movements of rock debris. Slump is slipping of one or several units of debris with a backward rotation with respect to the slope over which the movement takes place. Thus, it is the process by which the weathered materials do not move downward but sink in situ.

The factors that determine the deposition of sediments are the length of the rivers, volume of water, amount of sediments, and the slope of the river and the earth's surface.

When gravity alone causes rock or sediment to move down a slope, the erosion is called mass movement. This process is also known as mass wasting. It is a process where a mass of rock debris down the slope under the direct influence of gravity. Weathering is not essential for mass movement, though it helps mass movement. Mass movement has two major classes namely:

Solifluction is a process covered under the slow mass movements. It is a process that involves slow downslope flowing of soil mass or fine-grained rock debris saturated or lubricated with water. It is because permafrost (ground that remains completely frozen) is impermeable to water, soil overlying may become oversaturated and slide downslope under the pull of gravity. Thus, in periglacial regions along the slopes, some small layers of soil accumulated because of the movement of the soil are known as solifluction. 

Sea cliffs are usually formed by the process of weathering and erosion. In coastal areas the sea waves erode away the base of the headland. The part of rock that remains form a sea cliff.

A headland is an area of land that extends into a large body of water. It is often a cliff or other elevated landform overlooking a sea or ocean. It is formed when a softer rock in pushed or eroded inwards, the hard rocks sticks out in the sea. 

Landforms like flood levees, flood plains and deltas are formed because of the depositional works of the river.

Sea forms create erosional and depositional landforms. Steep rocky coast rising almost vertically above sea water is called sea cliff which is very precipitous with overhanging crest. Sea canes are formed by the mechanical erosion of rocks by the action of sea. A lagoon is a shallow body of water separated from a larger body of water by barrier islands or reefs. They form in areas with small tidal range.