Centrifugation is the process by which a centrifuge is used to separate components of a complex mixture.
Destructive waves erode our coast in a number of ways: This is a combination of weathering and mass movement. Weathering is the wearing away and breakdown of rock due to atmospheric processes and biota plants and animals. Examples of mass movement: Erosional Wave cut-notch and wave cut-platforms The waves erode the base of the cliff through the processes of hydraulic action, abrasion and solution.
This forms a notch between the high and low tide mark. The cliff face is weakened by weathering such as freeze thaw action. The notch continues to get bigger until it can no longer support the material above and it collapses.
The cliff retreats inland leaving behind a wave cut-platform which can be seen at low tide. Headlands and bay formation Headlands and bays are formed where there are alternative bands of more resistant hard rock and less resistant soft rock. The waves erode the cliff face through the processes of hydraulic action, abrasion and solution.
The less resistant rock is eroded at a quicker rate than the more resistant rock. This forms headlands, harder pieces of land which stick out into the sea and bays, curved inlets.
The shape of the coastline refracts the waves forming sheltered bays with sandy beaches. The destructive waves attack the headlands. Eventually the coastline will become straight and the processes will start again.
Dependent on the arrangement of rocks depends on the type of coastlines we get. If the layers of hard and soft rock are at right angles to the coastline you will get a discordant coastline. If the same type of rock is along the stretch of coast with a less resistant rock behind we get a concordant coast.
Caves, arches, stacks and stumps Erosion and weathering can produce the erosional landforms of caves, arches, stacks and stumps.
The waves through the processes of hydraulic action, abrasion and solution erode cracks and weaknesses in the cliff face making them bigger, this forms caves.
The processes continue until the erosion breaks through the headland, this feature is known as an arch. Over time the arch will get bigger and will not be able to support itself and due to gravity will collapse forming a stump. Over time the stack will be subject to erosion forming a stump.
Old Harry Rocks in Dorset stands at the tip of a chalk headland between the bays of Studland and Swanage and is an excellent example of a stack.
He once had a wife who is now a stump. Bitesize Transportation Once eroded material is moved along the coast by waves, this is known as transportation. There are 4 main processes by which material is transported by waves.
These processes contribute sediment to larger overall processes called longshore drift LSD. LSD is the zigzag movement of sediment along the beach.
This process is reliant on the waves hitting the beach at an angle. These waves are driven be the prevailing winds. The swash carries sediment up a beach at an angle, and then due to gravity, the backwash pulls the sediment straight back down the beach. This process continues moving the sediment along the beach.
Over time this can change the shape of the beach. LSD carries the sediment along the beach until there is a change in the direction of the coast for example a river estuary. LSD carries the sediment in a straight line out into the sea. Deposition of the sediment will occur where the waves enter a sheltered or shallow area or where there is little wind.
The sediment over time builds up and salt marshes can form in the sheltered area behind. The secondary wave direction can change the shape of the spit giving it a hook like appearance, these are known as laterals.
The spit cannot form completely across an estuary as the river current is too strong. Our example is Spurn Point.
If the spit grows across a bay it is known as a bar. A spit which connects an island to the mainland is known as a tombolo Beaches Beaches are common features of a coastline.This is because of sediment cells – these cells form the basis for shoreline management plans (SMP).
The Holderness coast is part of a sediment cell from Flamborough Head to The Wash. This whole cell is considered but it is broken into to sub cells. What is a sediment cell? A sediment cell is a length of coastline within which the movement of sediment is largely self contained.
Within all marine processes of erosion, transportation and deposition operate. These particles can sediment at the bottom of the tube into what’s known as a pellet, and this isolated specimen, or the remaining solution, the supernatant, can be further processed or analyzed. The principle component of a centrifuge is the rotor, which is the moving part that spins at high speeds.
coastline dynamics within a sediment cell: Eastern England A year record of coastline dynamics within a sediment cell: eastern England.
3. 4 Anne-Lise Montreuil. partial boundary with sediment transfer continuing in to The Wash . blood cell washing, positive angle to sediment cells rapidly at the bottom of the tube For decanting, the rotor holds centrifugally User-Friendly Design • Save time with pre-set programs in automatic mode • Manual mode available to wash the cells step-by-step, allowing closed monitoring of washing process • Tube racks with red and.
The main cell boundaries are Flamborough Head to the north, a fixed chalk headland, and Gibraltar Point spit in the south, which is a partial boundary with sediment transfer continuing in to The Wash and southern North Sea.