Erosional landforms Nature of eroded coastlines determined by two factors: direction, strength and frequency of waves and geology of coastline Cliffs: produced by coastal erosion. wave action undermines land leading to slumping/rock falls. produces a steep ‘edge’...
corals = tiny marine animals (polyps). reefs formed from millions of them living together in colonies. skeletons are calcium carbonate cups and they join to form a stony, hard mass of limestone. next one grows on top of the generation that just died, reef grows up...
Coastal features found on tidal mud flats in tropical and sub-tropical areas. Features: stilt roots — anchor plant in soft mud, slows wave movement and encourages more mud deposition; extending coastal area into sea and reducing erosion risk. conical breathing...
coastal management has 3 aims: protect coastline from erosion. protect coast from seawater flooding. conserving fragile ecosystems sustainable coastal management has to consider the 3 main aspects of sustainable development: environmental, economic and social...
Most from plate boundaries, hot spots and fault lines Some can be non-tectonic, caused by human activity putting too much stress on faults (e.g. reservoir construction) Plates try to move, get stuck and stress builds. They break free but causes pressure release...
Results from build-up of molten material emitted onto surface through fissure in crust. Active volcanoes: erupted in last 80 years Dormant volcanoes: inactive but may be active again Extinct volcanoes: will not erupt again Primary hazards: Gases water vapour...
movement is mainly through the air in rock and debris falls. slides and flows move on the surface both down and out. more rapid are more dangerous. slide is distinguished from a flow by being a solid mass moving along a single failure plane or fracture zone. ...
largest landslip in Europe. physical causes: mountain composed of alternating permeable sandstones and impermeable shales which dip slightly towards valley. shales (finely bedded mudstones) can be crumbled easily so little strength. upper layer gets slippery...
April 2013, had landslides when 135million tonnes of rock and rubble moved into the open pit. slide was of solid bedrock that broke from upper half of slope with waste rock from mine that has been piled above, weight putting additional stress on slope. rock slid...
area suffered highest death toll from mass movements in recent times in December 1999 when 30,000 died in towns along Caribbean coast. actual number is unknown as many people swept out to sea. mass movements fuelled down steep valleys on the north side of the sierra...
Global distribution of areas most at risk from large scale tropical atmospheric disturbances and small-scale atmospheric disturbances hazardous tropical cyclones are very large low-pressure systems with wind speeds above 119km/h and deep low pressure (880mb),...
a tornado is a violent, rapidly rotating and fast moving, narrow, funnel shaped column of cloud that extends from base of a cumulonimbus cloud to the ground. the wind makes it most violent type of storm. stronger winds than cyclones, 500 km/h. have very low pressure...
Waves Size depends on: wind speed, length of time wind blows in constant direction and length of fetch California: very big waves as come from Aleutian Islands, 4000m fetch so time for wave energy to build up. Mediterranean: very small waves as surrounded by...