Summer Test Long Questions Flashcards
(16 cards)
How is a soil creep formed?
Soil creep occurs as soil moves very slowly down gentle slopes at a speed of about 1cm per year. This is the slowest form of mass movement. We only its effect on the landscape form the clues it leaves after the many years. E.g tree trunks and fences bending , terracetles , soil builds up behind walls causing them to bulge and break , poles may lean in the direction of soil creep
What is the formation of a landslide
A landslide is a fast mass movement. It is the sudden movement of rock, soil and debris down a slope due to gravity. It happens when the stability of the slope is weakened by factors such as heavy rainfall , deforestation , and/or human activities like construction of roads , rail and buildings. These factiors reduce friction and support , causing materials to slide downhill
Name and explain the formation of one mechanical weathering feature.
Freeze thaw action -
Freeze thaw action occurs in areas where temperatures regularly changes between freezing and thawing ( high altitude and low latitude) . During the day water seeps into the joints (cracks) in the rock. By night the temperatures drop below freezing point (0ºC) . The water freezes and expands. This makes the crack bigger and puts strain on the rock. Over time after repeated freezing and thawing of water , over many years , the rock spilts. Sharp jagged pieces , called scree , break off. They roll down the mountainside and collect in piles at the bottom of the slope
Name and explain the formation of one chemical weathering feature.
Stalagmites , stalactites and pilars are formed from carbonation. Water with calcium carbonate drips into the cave. Evaporation of water droplets on the ceiling and cave floor , leave calcite behind. Calcite continues to build over millions of years on the cave ceiling and floor forming stalacites and stalagmites. When stalacites and stalagmites meet a pillar is formed. E.g the ailwee caves and the doolin caves the burren Co.Clare
Describe te formation of a surface karst landscape
Limestone pavement (Clints + grikes) - limestone pavement is created when glaciers strip away soil , exposing limstone.rainwater dissolves that rock , forming grooves called grikes and flat slabs called Clints. E.g the burren Co. Clare formed by carbonation
Describe the formation of one feature made by erosion.(rivers)
Waterfall form in the youthful stage f. River due to differential erosion , where soft rock erodes faster than hard rock. Hydraulic action is the main force , with moving water wearing away the softer rock , while abrasion uses the rivers load to further erodes the bed and bank , shaping the plunge pool. As the river carries its load over the fall , it deepens the plunger pool. Solution erodes the back wall , creating and overhang of hard rock that eventually collapses into the plunge pool. This process repeats , causing the waterfall to retreat upstream forming a gorge through headward erosion .
Describe the formation of one feature made by deposition (rivers)
Levees are found along the old stage of a river. Levees are raised banks that help prevent flooding. They develop through the process of deposition. Flooding occurs during heavy rainfall or snowmelt , the rivers water level rises and overflows its banks. As the floodwater spreads out , it slows down losing energy and dropping the heaviest sediments closest to the riverbanks. Over time , repeated flooding deposits more and more sediment , gradually building up raised embankments (natural levees) . Lighter material like silt and clay are carried further away , helping form fertile floodplains beyond the levees. E.g the river Liffey (co.Dublin)
Name and explain two positive and two negative about human interaction with rivers
2 positive -
Sport and recreation - rivers are sued for activities like fishing , kayaking , rafting and swimming , providing leisure opportunities for local communities and tourists
Transport - rivers serve as natural highways for boats and ships , allowing for the movement of goods and people. Historically , major cities were developed along river for this reason.
2 negative -
Flooding - following heavy rainfall or storms rivers can break their banks causing flood damage to properties, land and crops. There is also a risk to farm animals.
Displacement - regular / repeated flooding can force communities to relocate.
Environmental damage - rivers can become polluted due to agricultural activities causing damage to marine life and water supply.
Name and explain two positive and two negative about dam construction
Positive impacts -
HEP generation - provides renewable electricity , reducing fossil fuel reliance
Water supply and irrigation - ensure stable water access for drinking farming and industry.
Negative impacts -
displacement - flooding forces communities to relocate
Environmental damage - alters ecosystem , disrupts fish migration and causes erosion. Salmon migration is effected.
E.g the ardnacrusha dam on the river Shannon (co.Clare)
Why does flooding happen and how can we reduce / prevent it?
Why has it increased? -
population growth - more people are living in towns built along rivers
Building on floodplains - county councils have allowed construction of housing estates on floodplains.
Clearing of trees for houses and farmland- trees which would have absorbed water from rainfall , much of which now runs - off into rivers.
Heavier rainfall due to climate change.
How to reduce flooding -
Dredge slit form the bed of rivers - this will prevent the river from bursting its banks.
Don’t build on floodplains.
Reforestation - plant more trees which will absorb rainwater during heavy downpours.
Explain the formation of one coastal erosion feature
Sea cliffs form through erosion by destructive waves. Hydraulic action occurs when waves crash against the cliff , compressing air and water into cracks , weakening the rock. Abrasion happens as rocks and pebbles carried by the waves wear down the cliff face. This erodes the base , creating a wave -cut notch. Over time , the cliff retreats as the overhanging rock collapses , leaving a wave - cut platform at the base. Eg. Cliffs of Moher , co.clare
Explain the formation of one feature of coastal deposition
A beach forms between the low water make and the high water mark through the deposition of materials like sand , shingle and pebbles. They are formed by constructive waves , when material is transported , moved and deposited along the coast by longshore drift. When waves loose energy , especially in sheltered bays , they deposit material , gradually building up the beach. Storm beaches form when powerful storm waves with a strong awash throw large pebbles and boulders high up the shore , creating a steep ridge above the normal high tide line . E.g. sandy mount beach , Co.Dublin.
What are the processes of coastal erosion?
Hydraulic action ; is the force of fast flowing water that breaks up the bed and banks of the river , almost like a power hose.
Compressed air ; air trapped in cracks by powerful waves , causes pressure , causing the rock to weaken and break
Abrasion ; stone carried by the river (load) hit against the bed and banks of the river , wearing it away
Solution ; when river water dissolves the rocks over which it flows.
Attrition ; when stones roll along the bed o collide with each other. River stones become round and smooth over time
What are the waves types?
Destructive waves - erosion
Constructive waves - deposition
Human interaction with coast - two positive , two negative
2 positive -
Tourism - coastal landscapes can be very scenic and a tourist attraction generating income for the local communities e.g. cliffs of moher
Leisure activities - beaches provide opportunities for sport and recreation. Cliffs can be used for rock climbing and diving.
2 negatives -
Coastal erosion - due to constant crashing waves the cliff face can erode and break down. This may force coastal communities to relocate.
Coastal pollution - people can dispose of waste material ( e.g. plastic , sewage, litter , oil) at sea which can damage aquatic life and the environment.
How can we protect the coast?
Rock armour - large boulders of resistant rock (basalt) are placed to protect the coast from crashing waves. These are quick, cheap and simple way to protect the coast.
Sea walls - curved walls that defending the land and reflect the waves back out to the sea (expensive to build)
Gabions - there wire cages filled with stones and stacked up to protect the coast from the sea.
Groynes - they are large wooden or concrete walls placed at right angles to the beach. They prevent longshore drift
