PHYSCIAL Flashcards
(Natural systems)
What is meant by the store and boundary of a system?
Stores is where matter or energy builds up. The boundary is the limits of the system
Name the 5 systems of the earth
Cryosphere = includes all areas where it's cold enough to freeze Lithosphere = outermost part, includes crust and upper part of mantle Biosphere = where living things are formed Atmosphere = layer of gas between earth's surface and space
How can positive feedback alter a natural system?
Positive - amplify changes in inputs or outputs
E.g temp rise - ice melts - less ice cover means less energy is reflected
(Water cycle)
One change that can cause water vapour to change?
Happens when air containing water vapour cools to its dew point
Outline impact of long term global temp change on water cycle
During cold periods - water transferred to it as snow and less water transferred away due to melting
(Drainage basins)
Outline 3 stores of water in drainage basin systems
Vegetation storage is when it’s taken up by plants.
Surface storage includes water in puddles, ponds + lakes.
Interception is when some precip lands on vegetation
Outline seasonal changes in water balance
Wet seasons - precip exceeds evapotranspiration and creates a water surplus - more runoff
In dry seasons - deficit of water
(Runoff and water cycle variations)
3 factors that can affect the amount of runoff in DB
Shape of basin
Ground steepness - less lag time
Rock + soil type - increased runoff
(Carbon cycle)
Outline the role of living organisms in the carbon cycle
Carbon is stored in the tissues of living organisms. It is transferred to the soil when living organisms die and decay. The biosphere contains approx 0.004% of earth’s total carbon
Give one effect of chance in carbon cycle on land
CC allows plants to grow - if there was no carbon in the atmosphere, plants would not photosynthesise.
If there was no decomposition, dead plants would remain and nutrients wouldn’t be recycled.
CC changes can reduce amount of carbon stored in land, e.g permafrost melting
Outline how changes in carbon cycle are affecting oceans
As part of CC, co2 is dissolve directly into oceans from the atmosphere. Co2 is used by organisms such as phytoplankton and seaweed during photosynthesis by other organisms to make skeletons. Increased Co2 can increase acidity of oceans
(Coastal systems)
Difference between high and low energy coasts
High energy: high inputs of large waves - strong winds + long fetches. Tend to have coves + rocky landforms, e.g. Cliffs, caves, stacks
Low energy: low inputs of energy - gentle waves + winds - short fetches
Characteristics of constructive waves
Low-frequency, low + long, gives them an elliptical cross profile with powerful swash
(Coastal processes)
Two processes of coastal sediment transport
Solution = substances dissolved Suspension = fine materials carried along
How can sub-aerial weathering cause breakdown of coastal rock?
Salt weathering - saline water enters cracks at high tide. As tide goes out, rocks dry and water evaporates, forming salt crystals - these expand
(Sea level change)
What are two causes of eustatic + isostatic sea level change?
Eustatic = caused by a change in volume in the sea, or by a change in the shape on ocean basins
Isostatic is caused by vertical movements of land relative to the sea. Any downward movement of land causes sea level rise locally
Coastal landforms of lowered sea levels
Raised beaches - sediment becomes vegetated
Exposes wave-cut platforms
Cliffs are no longer eroded by the sea, and get covered by vegetation - RELICT CLIFFS
Name some Landforms of coastal submergence
RIAS: Formed where river valleys are partially submerged. Have a gentle long cross profile, deep + wide at mouth
FJORDS: Drowned glacial valleys, steel sides.
DALMATION COASTLINES: Valleys lie parallel to the coast, valleys are flooded, leaving islands parallel to coastline.
(Coastal landforms)
How are stacks formed?
Weak areas in rock (joints) are eroded to form caves. Caves may join up to form arches. When arch collapses it forms a stack.
Where do salt marshes form?
Sheltered, low-energy environments, e.g behind a spit.
As silt + mud is deposited, mudflats develop - they are colonised by vegetation that can survive high salt levels
How is a headland and bay formed
Bands of alternating hard + soft rock at right angles to shoreline
Outline how spits form
Where coastline has a sudden direction change. LSD continues to deposit material across the river mouth, leaving bank of sand sticking out to sea. Occasional changes to dominant wind + wave direction may lead to spot having received end
What are shoreline management plans?
Coastline is split into stretches by sediment cells. For each cell, a plan is devised for how to manage different areas with the aim of protecting important sites without problems
Outline the sources of energy in a coastal system?
Wind
Waves
Tides
Currents
