Climatic and Geomorphic Processes

Wave Processes

Weathering

Mass Movement

Fluvial Processes

Aeolian Processes

The attack of rocks in situ.

Agents of erosion are not involved.

Uses energy to produce physically or chemically altered materials from surface or near surface rock.

Can be significant and influence coastal landforms.

Types of weathering

Physical/mechanical

Chemical

Biological

The breakdown of rock into smaller fragments by the exertion of a physical force without chemical alteration.

Freeze-thaw, pressure release, thermal expansion, salt crystallisation

Where chemical reactions attack individual minerals in the rock, breaking bonds and producing new chemical compounds.

Oxidation, carbonation, hydrolysis, hydration, solution

Biological weathering is the break down of rock in situ by living or once-living organisms. It often speeds up mechanical or chemical weathering through the actions of plants, bacteria or animals.

Tree roots, organic acids

Occurs when forces acting on a slope material, mainly the resultant force of gravity, exceed the forces trying to keep the material on the slop, predominantly friction.

Rock fall - rocks may become detached from the slope and fall to the foot of the cliff under gravity.

Slides - these may be linear with movement along a straight line slip plane, such as a fault or a bedding plane between layers of rocks, or rotational also known as slumps with movement taking place along a carved slip plane.

Erosion

Abrasion

Attrition

Hydraulic action

Pounding

Solution

Transportation

Solution

Suspension

Saltation

Suspension

Deposition

Happens when:

Where the rate of sediment accumulation exceeds the rate of removal

When waves slow down immediately after breaking

At the top of the swash, where for a brief moment the water is no longer moving

During the backwash, when water percolates into the beach material

In low-energy environments, such as those sheltered from winds and waves e.g. estuaries

Processes that relate to rivers and streams

Erosion in the upper catchment is the main source of a river's sediment load.

Transportation by traction, suspension, saltation and solution

Deposition drops the largest particles first, then the finest being carried further to sea. The meeting of fresh water and salt water causes flocculation of clay particles. These fine, light materials clump together due to electrical charges between them in saline conditions and they then become heavier and sink to the sea bed.

Aeolian processes involve erosion, transportation, and deposition of sediment by the wind. These processes occur in a variety of environments, including the coastal zone, cold and hot deserts, and agricultural fields.

Erosion - Wind is able to pick up sand particles and move them by deflation.

Transportation - moving air is able to transport material using the same mechanisms as water moving in rivers and waves.

Deposition - material carried by wind will be deposited when the wind speed falls, usually as a result of surface friction. In coastal areas this occurs inland, where friction from vegetation and surface irregularities is much greater than open sea.