Geography Flashcards
(17 cards)
how do scientists determine past climates
- analysing sediments from the seafloor and oxygen
- study oxygen isotope levels by extracting sediments from the sea floor
Higher concentration of light oxygen (16) equals?
the earth climate is warmer
Higher concentration of heavy oxygen (18)
The earth cimate is cooler
Why when higher concentration of light oxygen there is warmer temperature and why when higher concentration of heavy oxygen the temperature is higher
Evaporation and condensation influence the ratio of the heavy and light oxygen in oceans. water molecules are made up of two hydrogen atoms and one oxygen atom. Water molecules containing light oxygen evaporate slightly more readily than heavy oxygen atom. water vapour molecules containing the heavy variety of oxygen condense more readily
When earth experience cooler temperature what happened and what is another word for cooler temperature
Glacial period and large ice sheets where formed over continents
When earth experience warmer temperature what is another word for earth experience warmer temperature
interglacial period and continental ice sheets were melted away
how has earth’s climate change zones changed over time?
From rising sea surface and air temperatures, it is found that the tropical climate zone is expanding in coverage across earth. This then has led to an increase in places experiencing drier-than-usal conditions, affectng many human livilhoods
long term climate is affected by?
changes in earth’s orbit and angle of tilt
short term climate is affected by?
occurence of sun spot and large-scale volcanic erruptions
how does the earth’s orbit change? And how long does it take
The earth’s orbit stretches from circular to an elliptical shape and back again 100k years
how does changing in the earth’s orbit impact on the earth’s temperature
When the earth’s orbit is the most elliptic, the earth receives more solar radiation, hence higher tempeatures are experienced
how do the earth’s angle of tilt work? and how long does it take
The earth’s axis varies back and forth between 21.5 degrees and 24.5 degrees and it takes 41000 years
What impact does the earth’s angle of tilt have on earth’s temperature
When the tilt increases, the northern hemisphere will turn more towards the sun, making the temperature higher
why do sunspots affect the Variations in solar input and can also lead to small short-term changes in earth’s climate?
As it is due to cycles in the number of sunspots where periods of maximum sunspot activity correspond to times of high annual surface temperatures on earth.
how long do sunspots occur?
every 11 years
What do higher sunspot activity do? and why
higher sunspot activity is linked to higher amounts of solar radiation emmited from the sun, leading to short-term increases in average temperatures. This is because areas surrounding the sunspots radiate more energy, which compensates for the lower temperatures of the sunspot areas. Hence sunspot variation is believed to result in small short-term changes to the earth’s climate
how do athropogenic factors contribute to climate change?
Anthropogenic causes of climate change such as the burning of fossil fuels and deforestation which has resulted an unprecedented rise in global average temperatures. This are all caussed by growth in population and inustrialisation
