Environmental Geoscience Flashcards
What is the environment?
The surroundings or conditions in which a person, animal or plant lives or operates. It can also be summarised as the natural world, as a whole or in a particular geographical area, especially as affected by human activity.
The environment is defined by the components that it contains. What are the hydrosphere, biosphere, cryosphere? (Other components include the atmosphere and the geosphere.)
Hydrosphere - water cycle, rain, clouds etc
Biosphere - component containing life (animals)
Cryosphere - ice, glaciers etc
An environment can also be divided into fluxes and reservoirs. What are these?
Flux - a quantifiable mass transfer and the rate of transfer, i.e. tonnes per year.
Reservoir - a quantifiable mass (in tonnes) and its residence time.
Cumulatively these form cycles, for example the carbon cycle, rock cycle or nutrient cycle.
Chicago’s environment is very unnatural. What are some human effects on this city’s natural environment?
The flow of the river reversed in 1900 so it now drains Lake Michigan into the Mississippi catchment.
Reclaimed land has been planted with non-native, non-climax species.
It has a heavily polluted atmosphere, which is very typical for cities.
Cows eat grass, foxes eat cows, foxes die on grass and release nutrients.
This is the natural cycle, what does it look like now and how do we fix the broken cycle?
Cow eats grass, human eats cows, waste goes into sea.
The broken cycle is solved by spreading fertiliser onto the fields.
What are biomes and what do they tell us? What biome type does the UK lie within?
The different spheres (geosphere, hydrosphere, atmosphere and biosphere) can be combined into discrete blocks, defined by their typical climate, biology and geography/geomorphology. These blocks are called biomes.
They tell us what could grow in terms of life if there were no human effects. The UK is classed as a temperate broadleaf forest.
What biome types are included in the Allee (1949) classification of biomes?
Tundra, grasslands, deserts.
What biome types are included in the Olsen and Dinerstein (1998) classification of biomes?
Temperate grasslands, savannahs and shrub lands or polar freshwaters/montane freshwaters.
What are biomes based on?
Whether the land is terrestrial or aquatic, but also the environments latitude, humidity, seasonality or elevation.
What is climax vegetation?
This term refers to the vexation that would be established and stable in an ecosystem or climate, free of major disturbance. Examples of major disturbance include anthropogenic effects, volcanic eruptions, wildfires or hurricanes.
What are anthropogenic biomes, or anthromes?
These are groups sorted in order of population density from urban/dense settlements to remote croplands.
Residence time =
Capacity / flow
A higher temperature typically means a longer residence time.
High flow (large flux) and small reservoir capacity =
Short residence time in the reservoir.
Low flow (small flux) and high reservoir capacity =
Long residence times in the reservoir.
What is an example of anthropogenic forcing?
Disturbance to the nitrogen cycle - N is released into land through fossil fuel burning, deposition feeds N into land where it transforms into reactive N, river fluxes transport N from land to oceans.
What is the baseline?
The quantifiable environment or defined population prior to a perturbation. Change, impact or damage are modifications to reservoirs, fluxes and populations from a baseline.
Why would we need to quantify the environment?
- describe and classify environments in a simpler fashion
- compare/contrast specific parameters across different biomes
- allows a better understanding of change/comparison to baselines
- allows scaling, small scale up to global
- better understand complex systems
In terms of the cow in the field, what are some things we can quantify?
Cow - economic value, biomass
Land - nutrient fluxes, topography
Air - temperature, humidity, wind speed
In terms of Chicago, what are some things we can quantify?
Urban climate, population density, traffic emissions, waste.
Moving averages can smooth a data plot, by reducing extreme peaks and troughs. What is a problem with this method?
If this was showing rainfall in a certain area, this will remove evidence of floods or draughts. This evidence may be vital for interpreting an environment.
How do we attempt to count our carbon emissions? (This is called the carbon count)
- count the coal burned each year, work out the C content of that coal and then translate to CO2
- measure CO2 release for a vehicle and extrapolate to all vehicles
- measure CO2 per hour of flight and multiply by the number of flights per time interval
What are the issues with the carbon count?
- variability between vehicles
- differences in jet usage for take off
- variability from types of coal
- how can we possibly count all the cars and jets in the world?
What are the proxies we use for arsenic?
Bioavailable soil arsenic - earthworms
Human exposure - toenails (record long term exposure, rather than one off high doses)
What is an environmental impact assessment?
A practical assessment application of quantitative environmental analysis. It predicts the impact of the proposed activity and any associated mitigation.
