Flashcards in Topic 2 Deck (89):
What is erosion?
The wearing away of rocks.
What are igneous rocks?
Formed by molten rock turning solid either on the Earth’s surface or beneath it.
What are metamorphic rocks?
Formed by a change of structure of existing rocks by exposure to extremes of heat and pressure.
What are sedimentary rocks?
Formed but the erosion of existing rock and the fragments produced being cemented together to form new rocks.
What is till?
A loose mixture of sediment of different sizes that is a result of erosion by ice. It is also called ‘boulder clay’.
What is hydraulic action?
He breaking up of rock material caused by water compressing air in cracks within rock surfaces, before releasing it explosively. Also known as quarrying.
What is attrition?
The wearing down of rock material by fragments rubbing together during transport.
What is abrasion?
The wearing away of rock surfaces by pieces of rock held in the water. Also known as corrasion.
What is corrosion?
The dissolving in water of soluble rock material, like limestone (calcium carbonate). Also known as solution.
What is the process of erosion on a cliff?
Wave-cut notch -> cave -> arch -> stack
What is a wave-cut notch?
A slot cut by wave action at the bottom of a cliff.
What is a cave?
A wave-cut inlet of a cliff.
What is a arch?
An offshore pilar of rock linked to the mainland at the top.
What is a stack?
An isolated offshore pillar of rock.
What is a wave-cut platform?
A flat area of land at sea level left as a cliff retreats.
What is load?
The material carried by water as it moves.
What is solution?
Rock material dissolves in the water. It will return to its solid state if the water evaporates.
What is suspension?
Material 'floating' in the water as it moves.
What is saltation?
Material being bounced along the surface by moving water.
What is traction?
Material being rolled or dragged along the surface by the water.
What is a spit?
A feature formed by longshore drift at a change in coastline direction when deposition continues into the sea.
What is swash?
The flow of water up a beach as a wave breaks on a shore.
What is backswash?
The flow of water back into the sea after a wave has broken on a beach.
What is an estuary?
Where a river enters the sea?
What is hard engineering?
Involves building structures either parallel to the coast or at right angles to it.
What is soft engineering?
In the UK, the placing of beach material in front of an eroding coast or by regarding the cliff face.
What are examples of hard engineering?
What are examples of soft engineering?
Wetland creation or protection
What is a Shoreline Management Plan (SMP)?
A detailed set of strategies for the future management of a stretch of coastline.
What is cost-benefit analysis?
A consideration of the balance between the advantages and disadvantages of implementing a particular strategy.
What is hold the line?
Using coastal protection methods to prevent erosion.
What is retreat the line?
Accepting that erosion will take place and putting strategies in place that will protect people as it happens. Also called managed retreat.
What are values?
The things people believe that are important to the way they live. Our values inform the attitudes we have to different issues.
What are stores?
Where water remains in one place or the same physical state (liquid, solid, gas).
What are flows?
The transfer of water between stores, in the same state or involving a change in state.
What are examples of flows?
Interception - Falling water hitting the Earth's surface.
Evapotranspiration - Transfer of water vapour from the Earth's surface and from vegetation.
Infiltration - Water passing into the soil from the Earth's surface.
Surface runoff - Water flowing across the Earth's surface, usually as rivers and streams.
Through-flow - Water moving slowly through the soil.
Groundwater flow - Water moving through the rocks.
What is the water table?
The upper level of groundwater.
What is a aquifer?
Store if water in porous rocks that is extracted for human use.
What is annual regime?
Pattern of water discharge throughout the year.
What is long profile?
A line graph along the length of a river showing its gradient changes from source to mouth.
What is discharge?
The volume of water flowing through a section of river at a given time. It is measured in cubic meters per second (cumecs).
What is bedload?
The material that is carried by a river by traction and saltation.
How are meanders and a floodplains formed?
1. Water flow is fastest on the outside of a bend. Erosion creates a river cliff.
2. Water flow is slowest on the inside of a bend. Deposition creates a point bar.
3. A combination of 1 and 2 causes the river to move, or meander, across its valley.
4.In times of high rainfall or snow melt, the river flows onto the valley floor and deposits material to form the floodplain.
5. Deposition is usually greatest close to the river banks. This forms a levee.
What is a river channel?
The area that contains the flowing water.
What is a river cliff?
A steep-sided river bank.
What is a point bar?
A shallow river beach, also called a slip-off slope.
What is a levee?
A river bank higher than the level of the flood plain.
How are ox-bow lakes formed?
Ox-bow lakes are created when the inside bends of a meander join. The water flows straight across, cutting off the meander to leave it as an ox-bow lake.
What is bankfull stage?
When a river fills its channel.
What is baseflow?
The normal rate of discharge of the river.
What is stormflow?
The rate of river discharge following a period of abnormally high rainfall.
What factors affect flooding?
The soil is saturated from previous rainfall.
Removal of forests causes rapid soil erosion.
A very steep drainage basin.
A wide drainage basin with many tributaries.
Storm drains feed directly into the river system.
Heavy rainfall in early spring.
What are the costs and benefits of tree planting and crop growth to prevent flooding?
Tree planting and crop growth
Slows surface runoff.
Reduces river flow.
Loss of farmland and jobs.
Produce sold and jobs created.
Environment sometimes improved.
What are the costs and benefits of protection of river banks to prevent flooding?
Protection of river banks
Prevents bank erosion.
Reduces river transport load.
Lost use of some grazing land.
Increases carrying capacity of river downstream.
What are the costs and benefits of managed flooding to prevent flooding?
Stores excess flood water.
Releases it slowly.
Equalises river flow.
Takes land out of year-round use.
A natural-looking barrier.
What are the costs and benefits of river straightning to prevent flooding?
Speeds river flow past protected area.
Disrupts anglers and other leisure users.
More silting further down stream.
Sale of extracted gravel.
What are the costs and benefits of river deepening and widening to prevent flooding?
River deepening and widening
Increases river carrying capacity near protected areas
Reduces river levels in non-flood times - disrupts leisure use of river.
Sale of extracted gravel.
New habitats created at river's edge.
What are the costs and benefits of dam construction to prevent flooding?
Stores excess flood water.
Controls its release.
Equalises river flow.
Loss of farmland.
Housing and communities destroyed.
Water for irrigation and electricity generation.
What are the costs and benefits of raising river banks to prevent flooding?
Raising river banks
Increases river carrying capacity near protected area.
Loss of river views.
Disrupts river access.
Increases flow to places downstream.
Increases local property values.
Reduces insurance costs.
What are the costs and benefits of flood plain zoning to prevent flooding?
Flood plain zoning - a protection method
River flood naturally.
Different types of land use banned dependent on risk.
Loss of land for housing development.
Low-cost land for reserved for recreation and car parks.
How does global atmospheric circulation effect climate in the UK?
The weather we get depends on the position of the polar jet stream and its influence on the air mass we experience at any one time. Due to the Earth's rotation, weather systems usually pass over the UK from west to east.
As the jet stream is constantly changing position and the weather systems that follow it also shift, it is not possible to make simple statements about regional differences.
How does air pressure effect climate in the UK?
In low-pressure situations rising air cools and as it does it loses its ability to retain moisture as a gas. The water vapour condenses to form water droplets. These join together and, when large enough, fall as rain or snow.
High pressure produces sinking air. This heats as it sinks, increasing its ability to hold water vapour. Such air is 'stable', with no precipitation. As skies are often clear, they bring cold conditions in winter and hot in summer. Diurnal temperature ranges are high.
As low-pressure systems blow off the Atlantic Ocean form west to east, it is the west that experiences the greatest rainfall. This is helped by the fact that the air rises to travel over hills and mountains before sinking down their eastern sides.
High-pressure areas (anticyclones) often settle over Europe for weeks. Their influence, therefore, is felt a little more in the east of the UK than the west.
How does latitude effect climate in the UK?
This is the distance a place is form the Equator. Because the Earth is curved, the angle at which the Sun's rays hit the Earth (the angle of incidence) reduces with distance from the Equator. This means that the heating effects also reduce. This loss is further affected by the greater distance the rays have to pass through the atmosphere causing increased reflection back to space.
In both summer and winter, the north of the UK is colder than the south. This is partly the result of latitude but the influence of altitude is at least as important. In fact, there is also an east to west difference, with the east, on the whole, being warmer than the west. Latitude is of great importance when considering differences between areas close to and far from the Equator. The 600-mile length of the UK (just over 8 degrees of latitude) is of less influence.
How does altitude effect climate in the UK?
The height above sea level of a location. With height, air becomes less pressurised so incapable of holding so much heat. The loss is 9.8oC for every 1000 m under a clear sky but only about 3.3oC when in cloud. This is due to the ability of the increased proportion of water vapour in the atmosphere to absorb heat.
Highland regions will be colder than lowlands. Loosely, this suggests that the influence of latitude will reduce the further south-east one travels. Two places geographically very close to each other can have greatly different temperatures.
At 16:00 on 25 February 2017 the forecast for Ben Nevis (1344 m) was -4oC while, at its foot, Fort William (24 m) was +8oC, a temperature range of 12oC.
How does distance from the sea effect climate in the UK?
Sea areas are less effective conductors of heat than land areas. So they have a lower range of temperatures and winds blowing off the sea will have a modifying effect on coastal areas. In winter, they will help make such areas milder. In summer, they will have a cooling influence. These effects are lost with distance from the sea.
As the Uk is an island, the simple influence here is that the further inland a place is, the warmer it will be in the summer and the colder in winter. However, we are also influenced by our nearness to the and mass of mainland Europe, where summer temperatures in the east are very high and winter temperatures very low. The effect of this is sometimes seen in the eastern UK being colder in winter and hotter in summer than the west.
What is the polar jet stream?
A band of strong winds between 9 and 12 km above the Earth. It forms along the interface between high- and low- pressure air masses.
What is a air mass?
A large volume of air having the same temperature and moisture properties.
What is climate?
Average weather conditions taken over a period of at least 30 years.
What is isolation rate?
The amount of solar energy received per square centimetre per minute.
What is diurnal range?
The difference between night-time and daytime temperatures.
What is the weather?
Day-to-day changes in atmospheric conditions.
What is a warm front?
A surface divide between a cold and warm air mass; temperature rise as the front passes over.
What is a cold front?
A surface divide between a warm and cold air mass; temperature fall as it passes over
What is a occluded front?
A front in which the divide between warm and cold air masses is above the ground. There is little temperature change as the front passes over.
What are isobars?
Lines connecting points of equal air pressure. The closer together they are the stronger the wind.
What is conventional rain?
Precipitation from thunderstorms caused by air rising over a hot land surface.
What are the difference between summer and winter weather conditions?
Hot or warm days, warm nights.
Clear skies and Sun high in the sky.
Chance of convectional rain.
Cool days and cold nights.
Clear skies and Sun low in the sky.
Frost and fog formation.
What is a monsoon?
A wind that reverses its direction from winter to summer.
What are cyclones?
Intense low-pressure systems. Known as hurricanes and cyclones in different parts of the world.
What are the responses to cyclones?
Prediction and monitoring of the track of the event, its intensity and potential to damage property. Access to satellite technology to do so rapidly.
Training of emergency services and their ability to respond speedily when a cyclone hits.
Educating people on how to respond in the event of a cyclone. Includes the ability to read printed advice.
The ability of individuals to prepare for an event; to protect property and to store emergency food, water and other items.
Development of infrastructure (transport and communications) that is resistant to the event.
Building dwellings that are capable of standing up to the strong winds.
The ability to use national government funds to respond immediately to provide food and shelter to affected people and, in the longer term, to repair the damage.
A reliance on aid from outside the country.
What is quaternary?
The geological period of time stretching from about 2.6 million years ago to the present day.
What are glacial periods?
Times of colder temperatures when greater areas of land are covered by ice.
What are inter-glacial periods?
Warmer times when the ice cover retreats.
What are the consequences of climate change?
Changing rainfall and temperature patterns. Some farming areas will no longer be productive. In other areas farmers will need to change their crops and animals.
Habitats will alter, with some plant species dying out to be replaced by others. Broken food chains will result in some wildlife migrating or dying out.
Providing drinking water will become more difficult in some areas. Other areas will have too much water, causing flooding.
People may be forced out of the areas in which they live as conditions become more difficult. They will try to migrate to other areas.
As weather conditions change, some places will become unpopular as holiday destinations. Others will become more popular. Employment opportunities will change.
What are the effects of climate change on coastal areas?
Global warming reduces the amount of water stored as a solid on land. This loss of 'white' ice and snow reduces the amount of reflected heat. Temperatures rise more. As liquid water heats it also expands. This increases the volume of water in our seas and oceans. So, sea levels rise. in some places, the sea-level rise will be accompanied by more severe storms than at present. This all contributes to increasing risks of coastal flooding.
What are the potential challenges to the coast?
Increased costal erosion.
Higher river discharges.
More and more intense rainfall.
What are the agreements to reduce climate change?
2005: Kyoto Protocol - an agreement to reduce greenhouse gas emissions in 1997.
2012: Doha Amendment - limit global temperature increase to below 2oC until at least 2020.
2015: Paris Agreement - aim to reduce increases to 1.5oC this century and for richer countries to provide help to poorer ones.
Why does the UK government need to respond to climate change?
Increased flooding from heavy downpours.
Extremely wet winters are five times more likely.
Flood risk from rising sea levels.
A rise from 330,000 to 1.2 million houses in danger of flooding by 2080.
Increased summer heatwaves put pressure on health services.
At least 25 million people with water supply deficits by the 2050s.