C6.3 - Earth Systems? 🌍 Flashcards
spec approved
describe the theory of how the atmosphere was originally formed
- intense volcanic activity released gases (like CO2 and H20) = formed early atmosphere
- earth cooled and water vapour condensed to form oceans
- left behind atmosphere of mainly carbon dioxide
- with small amounts of
ammonia, methane - little/no oxygen
what kind of gases did the volcanoes release in the early atmosphere? (3 main, 2 non-main)
- huge volumes of water vapour
- carbon dioxide
- small amounts of nitrogen
and
- sulfur dioxide
- hydrogen sulfide
how has an oxygen-rich atmosphere developed over time?
- plants and algae made their own food through photosynthesis
- took in carbon dioxide + water and released oxygen
describe the four steps of the greenhouse effect
1) energy transferred by radiation from sun reaches earth’s surface
2) radiation warms up the earth’s surface
3) radiation emitted back into earth’s atmosphere
4) some is absorbed by greenhouse gases
5) others go directly into space
- this allows temperature to be regulated in the atmosphere
what human activity increases levels of greenhouse gases in the atmosphere?
- driving (release CO2)
- raising cattle (methane)
what are the uncertainties in past CO2 conc in air measurements? (2)
- Historical data is much less accurate due to the lack of accurate instrumentation and methods
- Fewer locations would also have been measured due to the lack of satellites and transport
potential effects of increased levels of carbon dioxide + methane on earth’s climate
- increase in average global temperatures
- extinction of species
- raised sea levels
how can greenhouse gas emissions be reduced?
- reduce consumption of fossil fuels BIOFUELS
- renewable energy resources
- using CARBON CAPTURE (prevent carbon dioxide from escaping)
main source of carbon monoxide?
- incomplete combustion of fuels with carbon
- ie. in vehicle engines
problem with increased amount of carbon monoxide? (and why)
- is a toxic gas
- has no colour, taste smell
- reduces amount of oxygen bloodstream can carry by binding w/ haemoglobin
- causes drowsiness/difficulty breathing/death
main source of sulfur dioxide
- burnt fossil fuels
they contain small amounts of sulfur compounds
problems of increased amount of sulfur dioxide?
- causes acid rain
- breathing difficulties
what are the products of complete combustion of fossil fuels? (4)
- oxides of nitrogen
- carbon dioxide
- oxides of sulfur
- water vapour
problem with increased amount of oxides with nitrogen?
- acid rain
- asthma
what does acid rain do to stone, metal, trees and living things
- erodes stonework, corrodes metal
- kill trees
- kill living things in rivers/lakes
main source of particulates in atmosphere?
- produced in industrial processes like metal extraction
- incomplete combustion of fossil fuels
- in vehicle engines
what are particulates?
microscopic particles of solid or liquid matter suspended in the air
problem caused by increased amount of particulates in the atmosphere
- global dimming
- small particles settle in lungs
- breathing problems (bronchitis, increase chance of heart disease)
where does tap water come from?
- water stored in lakes/reservoirs
- or in aquifiers
- from lakes/waste water
what are the 5 steps which describe how fresh water is treatd?
1) passes through screen (metal bars which trap large things like leaves + twigs)
2) passes through settlement tank (where soil + sand settle out)
3) aluminium sulfate + lime added (causes small particles of dirt to clump together + sink to bottom)-SLUDGE
4) water passed through fine sand filter (removes mud/grit)
5) chlorine added to kill bactera
6) pH checked + neutralised
what is groundwater?
water found underground in cracks/spaces in soil/sand/rock
where is groundwater stored (and where and how does it move)?
- stored in geological formations of soil, sand, rock
- moves slowly through aqufiers
where is salt water found?
sea water
what is the name of the processes used to treat salt water? (and large scale or small scale) (2)
- simple distillation for large scale
- reverse osmosis for small scale
- both are desalination processes
what factors would affect whether desalination would be worthwhile in a country? (2)
(and give an example where they use it)
- where freshwater supply is low
- cost of energy resources is low
- ie. coast on middle east
what characteristics must water have to make it potable? (3)
- Have a pH between 6.5 and 8.5.
- The dissolved substances (e.g. salts) will be present is very small regulated quantities
- Be free of bacteria or potentially harmful microbes
what does it mean if water is potable?
safe to drink
extra products of incomplete combustion of fossil fuels (in comparison w/ complete combustion) (2)
- carbon, which clubs together forming carbon particulates
- carbon monoxide
