EXAM Flashcards
What is a natural hazard?
A natural event that threatens people or has the potential to cause damage destruction or death
What are tectonic hazards?
Involve the movement of the earth’s crust
What are atmospheric hazards?
Hurricanes
What are geomorphological hazards?
Earths surface
What are biological hazards?
Involve living organisms
How can tropical storms be reduced?
- Monitoring
- Prediction
- Protection
- Planning
How can buildings be protected against tropical storms?
- hurricane straps
- storm shutters
- emergency generator
- tie down wind borne objects
- reinforce garage doors
- remove trees close to building
- salt marshes and wetlands and mangroves
- trees
- coastal flood defences
- no building on low lying areas
What is the tropical storms case study?
Typhoon Haiyan
Case Study for TS:
When? Where? Category? Killed?
- 8 November 2013
- Philippines
- Category 5
- 6190
What were the long term responses to the TS?
- no build zone along Eastern Visayas coast
- New storm surge warning system
- mangroves replanted
What are the main UK mountain ranges?
- Grampians in mid Scotland
- Antrim Plateau in northeast Ireland
- Cambrian Mountains in mid Wales
- The pennines through mid England
- Cumbrian Mountains in LD
- Mourne Mountains just south of belfast
What does wave energy depend on?
- wind speed (more energy transferred)
- How long wind has been blowing (more energy)
- The fetch (the maximum distance of open sea that wind can blow over)
What are the characteristics of c waves?
- found in bays and spits
- sandy beaches
- more in summer
- larger swash than backwash
- gently sloping beaches
- low wave frequency
- low wave height
- low energy
- gently sloping front
What are the characteristics of destructive waves?
- short wave length and high frequency
- steep wave front
- high wave front
- wave over height of one metre
- Steep slope
- strong backwash, restricted swash
- exposed bays
- pebble beaches
- winter
What’s mass movement?
The downhill movement of large amount of rock, soil or mud under the influence of gravity
What is the difference between sliding and slumping?
Sliding is straight, slumping is concave, so material is rotated to face the cliff
What causes deposition?
- low energy sheltered bays c waves
- sediment updrift (e.g eroding headland)
- large expanses of flat beach
- spit
- engineered structures trap stuff
What conditions does a sand dune need to form?
- a large flat beach
- supply of sand
- large tidal range so sand can dry
- onshore wind
- obstacles like drift wood
What are Embryo dunes?
Newly formed sand dunes close to the sea
What’s marram grass?
A plant that has long binding roots
What is saltation
How sand is bounced along by the wind
What’s a crest?
The top of a dune
Whats a water table
The upper horizontal limit of wet sand
What’s a dune slack?
Where there is a trough or low point in a line of dunes
What’s a leeward slope?
The slope that faces away from the wind
What’s the windward slope?
The slope that faces towards the wind
What’s dune succession?
The change in vegetation with increased distance inland
What are the three methods of sand transportation?
- Suspension
- Saltation
- Creep
What are the types of hard engineering in rivers?
- damns and reservoirs
- Channel Straightening
- Embankments or Levees
- Flood relief Channels
What are the types of soft engineering in rivers?
- Flood plain zoning
- Flood warnings
- Afforestation
- River restoration
How is a coastal spit formed?
1) Sudden change in the coastline (headland)
2) Longshore drift carries stuff (usually from sw in uk)
3) at change, energy is reduced so sediment is deposited in the sea as it has no where else to go
4) salt marsh formed behind as water dries up
5) change in wind direction causes curved head
How is a bar formed?
When spits join from two head lands
What is a spit?
A long, narrow piece of land that has one end joined to the mainland and projects out to sea
What is a bar?
A bay bar is a ridge of sand or shingle that stretches across a bay, forming a lagoon behind it
What is a submerged offshore bar?
A raised area of seabed that lies offshore
What is a tombolo?
A spit that joins an island to the mainland
What is a concordant coast?
Alternating layers of hard and soft rock running parallel to the coastline
What is a discordant coast?
Alternating layers of hard and soft rock running at right angles to the coast
Headland process thing
1) wave crest in deep water
2) waves near headland reach shallow water
3) as it approaches it begins to take the shape of discordant coastline
4) frictional drag slows down lower part of wave making it higher and steeper
5) concentrates wave energy on the headlands and increases erosion
6) waves crashing and retreating on headlands creates a lateral current across bays
7) this along with fewer waves as they are refracted away results in low energy waves depositing material in bays
How is a caved formed?
1) large crack is enlarged by pressure on/off effect of ha
2) crack grows into a notch and then a cave as destructive waves continue to erode it
How did is an arch formed?
3) over time cave becomes larger. Wave refraction draws waves to all sides of headland so caves form back to back
4) sea breaks through cave backs forming a natural arch. The base of the arch is widened as notches form
How is a stack formed?
5) weathering continues to weaken top of arch making to less stable
6) top of arch eventually collapses
7) this leaves a pillar of detached rock called a stack
How is a stump formed?
- notches form at the base of the stack making it unstable
* !stack eventually topples leaving only its base called a stump
Ex of spit
Spurn head, yorkshire
Bar
Slapton sanda, devon
Offshore bar
Hordle cliff, Lymington
Tombolo
Chesil beach, Dorset
