geomorphic processes

Geomorphic processes

• Geomorphic processes in costal landscape include:
• weathering
• mass movement
• erosion, which includes hydraulic action, abrasion, solution, attrition
• transportation, including, traction, saltation, suspension, solution.

weathering

• there are 3 different types of weathering: mechanical (or physical), chemical and biological
• Mechanical weathering:
• An example of mechanical weathering is freeze-thaw, this is repeated cycles of water trapped in rock cracks, freezing and thawing, meaning the water expands and contracts, widening the crack. this causes rock fragments to break away.
• 2. Chemical weathering:
• some examples of chemical weathering include:
• hydrolysis, also known as acid rain, alters the chemical composition of the rock.
• oxidation, when oxygen reacts with iron-rich minerals, this causes them to crumble.
• 3.Biological weathering:
• weathering caused by animals and plants (e.g. plant roots cracking a rock)

mass movement

• sliding: rocks or lose material sliding downhill along a slip plane, often triggered by shaking (e.g. earthquakes) or heavy rain
• slumping: usually involves the collapse of weak rock , usually caused by heavy rainfall, when the sediment gets weighted down by the water.
• common forms of mass movement are:
• landslide-blocks of rock quickly sliding downslope, usually lubricated by water
• rockfall-bits of rock falling off the cliff face, usually as a result of freeze-thaw
• mudflow-saturated material (such as clay) flowing downhill, can involve elements of sliding or slumping
• rotational slip/slump-slumping of material, usually along a curved plane, often lubricated by water.

Erosion

• there are 4 processes that make up erosion:
• hydraulic action-waves crash against the cliff base, creating a wave cut notch, the water also compresses air into the rock causing it to crack and break.
• abrasion-pebbles and other materials picked up by the sea are thrown against the cliff face.
• solution-dissolved material and rocks such as limestone and chalk
• attrition- rocks and boulders roll around the sea bed, bumping into each other and becoming smaller and rounder.

Transportation

• movement of materials from one place to the other.
• usually involves:
• traction- large particles rolling around the sea bed
• saltation-bouncing/hopping motion by pebbles to heavy too be suspended
• suspension-particles suspended within water
• solution-chemicals dissolved in water