Topic 4 UK Physical Flashcards
Define bedding plane
the surface between two layers (or strata) in sedimentary rock
What does the term bio-chemical weathering mean?
the process of rocks being broken down by chemicals produced by living things, such as acidic droppings
What does the term biological weathering mean?
the process of rocks being broken down by living things
Define carboniferous limestone
deposited rocks that were formed between 363 and 325 million years ago
What does the term bio-physical weathering mean?
the process of rocks being physically broken up by living things such as tree roots
Define the term clint
the large blocks of rock on a limestone pavement, separated by grykes
Define the term clitter slope
the trail of deposited rocks from the action of freeze thaw weathering on tors
What does the term dip slope mean?
land that follows the same gentle slope as the layers of rocks underneath
Define the term erosion
the wearing away and removal of material by a moving force, such as a river, a breaking wave or a glacier
What does the term errartic mean?
a rock or boulder that differs from the surrounding rock, brought from a distance by glacial action
What does the term freeze thaw weathering mean?
the process of rocks breaking up from repeated freezing and thawing
Define the term geology
the different types of rocks that make up an area
Define the term glacial
a period of time with lower average temperatures causing widespread glaciations
Define the term gorge
a steep, narrow valley with rocky sides
Define the term granitic
granitic a rock with a similar composition to granite: high in silica, with quartz crystals.
What is a gryke?
a vertical joint, enlarged by weathering, between the blocks in a limestone pavement
Define the term interglacial
a period of time between two glaciations with higher average temperatures
Define the term joint
a vertical crack within a layer of rock
Define a term landslip
the movement of rocks or soil down a slope due to gravity
What is meant by the term limestone pavement
a horizontal or gently sloping area of limestone, comprised of large blocks (dints) separated by deep eroded fissures (grykes)
Define metamorphic rock
a rock formed from other rock changed by extreme pressure or heat. It is usually formed from layers or bands of crystals and is very hard
Define the term scarp slope
a steep slope that cuts through the layers of rock underneath
What does scree mean?
angular rock pieces created by freeze thaw weathering
What does the term sediment mean?
material such as mud, sand and pebbles carried and deposited by rivers or waves
Define the term sedimentary rock
rock formed of small particles that have been eroded, transported, and deposited in layers, such as sandstone or from the remains of plants and animals
What does soil creep mean?
the slow gradual movement downslope of soil, scree or glacier ice
What is meant by strata?
distinctive layers of rock
What does the term sub-aerial processes mean?
acting on the Earth’s surface, including weathering and mass movement
Define the word till
sediment deposited by melting of glaciers or ice sheets
Define the term topography
the shape and physical features of an area
What does the term tor mean?
a block of granite found at the top of a hill
Define the term weather
the day-to-day conditions of the atmosphere, e.g. temperature, precipitation, cloud cover, etc
Define the term weathering
the breakdown and decay of rock by natural processes acting on rocks, on cliffs and valley side
Define the term abrasion
caused by the river picking up material in the river and rubbing it against the bed and banks of the channel in the flow
What is afforestation?
the planting of trees where there were none before, or they had been cut down
Define alluvium
fine sediments which are deposited by rivers
What are antecedent conditions
conditions in a drainage basin in the period before a rainfall event, such as saturated or frozen ground
What is an arch?
the rock bridge formed over a passage through a headland eroded by the waves
Define the term attrition
a type of erosion where particles carried by rivers or waves are worn down as they collide with each other, so they become smaller and rounded
Define backwash
the movement of a wave down a beach back to the sea
What does bankful mean?
the discharge or contents of the river which is just contained within it banks. This is when the speed, or velocity, of the river is at its greatest
What is a bar?
a ridge of sand or shingle across the entrance of a bay or river mouth
What is a bay?
an area of sea, curved in shape which has been eroded between two headlands
Define a beach
a sloping area of sand or pebbles between the low and high water marks
What is beach replenishment?
the process of adding sand or shingle to widen or improve a beach
What does the term berm mean?
a ridge of sediment found towards the back of a beach
Define the term channel
refers to the bed and banks of the river
What is a concordant coast?
the type of coast where the rock type runs parallel to the coastline
Define a constructive wave
a gently breaking wave with a strong swash and weak backwash. It adds more material to the beach than it removes
Define the term corrosion
chemical erosion caused by the dissolving of rocks and minerals by water
What is a cost-benefit analysis?
a way of reaching a decision by comparing the costs of a project with the benefits it will bring
Define the term cove
a small bay with a narrow inlet
What is deforestation?
permanently removing forest so the land can be used for something else
Define a delta
formed where layers of sediment are deposited at river mouths faster than the sea can erode them. Deltas are usually roughly triangular in shape, and the river splits into several channels.
What is deposition?
a process where sediments are dropped by the river, glacier or waves that carried them
Define a destructive wave
a strong wave that removes material from the coastline
Define discharge
the amount of water flowing in a river, made up of its volume and speed, and measured in cubic metres per second (m3/sec, or cumecs)
What is a discordant coast?
a coast where bands of hard and soft rocks lie at right angles to the coastline forming headlands and bays
Define dissipate
to reduce wave energy, which is absorbed as waves pass through, or over, sea defences
Define distributaries
a smaller river channel created where a river splits, often to form a delta
What is a drainage basin?
the area of land drained by a river and its tributaries
Define an estuary
the mouth of a river which broadens into the sea and is affected by tides
What is evaporation?
the changing of a liquid into vapour or gas. Some rainfall is evaporated into water vapour by the heat of the sun
Define a flood plain
the flat land in the valley floor each side of a river channel, which is sometimes flooded
Define a gabion
a large wire basket filled with rocks used to prevent coastal erosion
Define gradient
how steep a slope, river channel or valley is
What is groundwater flow?
movement of water through the rocks in the ground
What is ground water?
stored underground in rocks and soil
What is a groyne?
a wooden barrier built at right angles to the coast, used to break waves and reduce the movement of sediment along the coast
What is hard engineering?
strategies using artificial structures (e.g. concrete) to prevent river or coastal flooding
Define helicoidal flow
a continuous corkscrew motion of water as it flows along a river channel
What is a headland?
an area of more resistant rock jutting out into the sea from the cliff-line
What are high and low water marks?
the points reached on a coast by the highest and lowest tides
Define holistic management
takes into account all social, economic and environmental costs and benefits. In coastal management this means looking at the coastline as a whole instead of an individual bay or beach.
Define hydraulic action
this results from the sheer force of moving water wearing away the river bed and banks, or waves wearing away sea cliffs
What is a hydrograph?
a graph showing changes in a river’s discharge and rainfall over time
Define interlocking spurs
areas of higher land jutting out of steep valley sides in a river’s upper course
Define lag time
the difference in time between the peak rainfall and the river’s peak discharge on a hydrograph
Define a lagoon
a fresh water lake formed when a bay is cut off from the sea by a beach bar
Define lateral erosion
erosion where a river cuts sideways into its banks
What are levees?
the naturally raised bank of sediment along a river bank, which may be artificially strengthened or heightened
Define the term long profile
the shape and gradient of a river bed from source to mouth
What is longshore drift?
the movement of material along a beach transported by wave action
Define a long term response
reaction that happens in the weeks, months and years after an event
What is a meander?
a bend formed in a river as it winds across the landscape
Define the middle course of a river
the journey pf a river from tis source in hills or mountains to mouth is sometimes call the course of a river. (this can be split into upper, middle and lower course)
What is the mouth of a river?
the point where a river leaves its drainage basin and reaches the sea
What are mudflats?
flat coastal areas formed when mud is deposited by rivers and coasts
What is the ‘neck’ (of a meander)?
the narrow strip of land between the two closest banks of a meander
Define an oxbow lake
a semi-circular lake on a river flood plain, which has been cut off by a meandering river
Define a plunge pool
a hollow in the river bed caused by erosion underneath a waterfall
Define the term plunging waves
typically tall can close together, created by strong winds.
What is a point bar?
sediment laid down on the inside of a meander bend where the river flows slowly
Define the prevailing wind
direction in which the wind blows most frequently
What is a profile?
a cross section of the landscape, for example a river valley or beach
Define rip rap
large boulders of resistant rock placed at the bottom of cliffs that dissipate wave energy
Define a river cliff
a steep section of river bank, caused by fast-flowing water eroding the outside of a meander
Define river erosion
the action of water wearing away the rocks and soil on the valley bottom and sides
What does the term runoff mean?
water running across the land surface or the proportion of rainfall that flows in rivers
Define saltation
a process where sediment is transported by being bounced along a river bed or sea floor
Define a saltmarsh
an area of mud flats formed by deposition of sediment in the low wave energy area behind a spit
What is a sand dune?
onshore winds blow sand inland, forming a hill or ridge of sand parallel to the shoreline
What does saturate mean?
soil becomes saturated when it has absorbed as much water as is possible. If any more water is added, it cannot be absorbed
What is a sea wall?
a curved or straight wall built along the coastline to prevent waves eroding the coastline
What is the sediment load?
the sediment particles carried by a river
What does a Shoreline Management Plan mean?
a plan which assesses the risks to a piece of coastline and how to manage these
Define a slip off slope
the gentle slope on the inside of a meander bend formed by deposition slumping a type of mass movement where soil or rock slides down a slope, often rotating as it moves
What does soft engineering mean?
flood defences that work with natural processes to reduce the risk and impact of coastal or river flooding
Define the term solution
the process where some rock minerals slowly dissolve in water, which is slightly acid
What is the source of a river?
the starting point of a stream or river, often a spring or a lake
What is a spit?
a ridge of sand or shingle deposited by the sea. It is attached to the land at one end but ends in a bay or river mouth
Define spring-line settlement
where there is a ridge of permeable rock lying over impermeable rock; with a line of springs along the boundary between the two layers
What is a stack?
an isolated column of rock, standing just off the coast that was once attached to the land
What is a stakeholder?
a person with an interest or concern in something
Define a storm surge
an increase in the height of the sea due to a storm
What does strategic realignment mean?
the planned movement of the coastline inland because it can no longer be protected, also known as managed retreat
What is a storm hydrograph?
a graph which shows the change in both rainfall and discharge from a river following a storm
Define the term stump
a short piece of rock found at the end of a headland formed after a stack has collapsed
Define surface runoff
water running across the land surface into streams and rivers
Define suspension
the process where small particles of sediment are held up and carried along by moving water
Define swash
the movement of a breaking wave up a beach
What is throughflow?
the flow of rainwater sideways through the soil, towards the river
Define traction
the transport of sediment along a river bed or the sea floor through a rolling action
Define the term transportation
the movement of sediment by rivers, glaciers or waves
What is a tributary?
a stream or small river that joins a larger one
Define a tsunami
giant sea wave travelling at high speed
What is a V-shaped valley?
a valley with a V-shaped cross-section formed by river erosion
Define velocity
the speed at which a river flows; river velocity is often measured in metres per second
Define vertical erosion
downward erosion of the river bed
What is a wave cut notch?
a small overhang at the base of the cliff formed where wave action is greatest
What is a wave cut platform
a flat area of rock at the bottom of cliffs seen at low tide
Define the term weathering
the breakdown and decay of rock by natural processes acting on rocks, on cliffs and valley sides
Define acid precipitation
also called acid rain. When industrial air pollution causes water vapour in the atmosphere to become acidic and fall as acid precipitation topic
Define basalt
a dark coloured colonic rock. Molten basalt spreads rapidly and is widespread. About 70% of the earths surface is covering in basalt lava flows topic
Define the term cave
a hollow at the base of a cliff which has been eroded backwards by waves
Define the term cross-section
a diagram showing the shape of a feature or landscape as if it was cut through sideways
Define the term fetch
the distance a wave has travelled towards the coastline over open water, the longer the fetch the more powerful the wave
What are impermeable rocks?
that are impermeable, like clay, do not allow water to pass through them
What is infiltration?
the process whereby water soaks into the soil and rock
What is the Integrated Coastal Zone Management (ICZM)?
a way to manage the coast and the land behind it sustainably, by involving everyone involved in using it
Define interception
the process where vegetation catches rainfall on its leaves and branches
Define kinetic energy
energy generated as a result of movement
What is mass movement?
the movement of material down a slope due to gravity
Define permeable
rocks that are permeable, like chalk, allow water to pass through them
Define the term thalweg
the line of the fastest flow along the course of the river
What is transpiration?
the release of water vapour through a plant’s leaves
What is thermal expansion?
as a result of heating, expansion occurs. When sea water warms up it expands
