Geography Exam 2 Dec Flashcards
Name all 6 natural resources
Air Water Forest soil Animals Marine life
What is the Earth composed of
the Exosphere Thermosphere Mesosphere Stratosphere Troposphere
how much percent of earth’s air is found in the troposphere
95%
In what “sphere” is the ISS in
The centre of theThermosphere
The remaining 5% of air stretches to the height of about…
280km
Name 2 causes of air pollution
Industry
The burning of fossil fuels in power stations, fires, and motor vehicles.
Name all 4 consequences (what it can cause) of air pollution
Respiratory problems
Headaches
Sleepiness
or lung cancer
How does the water cycle work
Due to the heat of the sun, water on the earth’s surface evaporates while water transpires from plants. The evaporated water rises in the form of water vapor into the air cooling at about 1° C per 100m until it reaches dew point temperature where it condenses and forms clouds. Once clouds are saturated, precipitation occurs and water falls to the earth. Water will run off the land in rivers which will flow to lower areas until they either reach lakes, dams, or the sea. Some water however infiltrates the soil to form subsurface aquifers, where some of this subsurface water will reach the sea.
Name all 8 parts of the water cycle
evaporation transpiration condensation precipitation run-off surface water Infiltration subsurface outflow
What % of Earths water is found in the earth’s oceans and is salty in nature
97%
During the height of the drought Cape Town built three desalination plants. where were they
At Strandfontein, Monwabisi and the V&A Waterfront
More than 66% of the remaining water is found in
glaciers and ice caps
There is more freshwater …………. (where) than water in dams and lakes.
below the surface of the earth
What extracts subsurface water
Windmills, Wells, and pumps
Why is more rainfall occurring in the East
In South Africa, due to the cold Benguela Current in the west and the warm Mozambique Current in the east, the rainfall increases from west to east with the most abundant rainfall occurring in the east.
Why does more rainfall occur in the East?
More rapid evaporation takes place over the warm Mozambique Current therefore more clouds and more rain.
What % of South Africa receives less than 500mm average annual rainfall, meaning that drought is an ever-present risk.
66%
Future projections indicate that what will happen by 2025. There are already major problems of supply and quality, with an estimated 8 million South Africans currently having no access to potable water.
The country’s water requirements will outstrip supply unless urgent steps are taken to manage the resource more sustainably
The growing water crisis is exacerbated by
Many of South Africa’s wetlands have been lost.
Pollution of catchment areas.
Alien plant infestations are using excessive water.
Major dams in SA
Dam
River
Province
Gariep Dam
Orange River
Border: Free State and Eastern Cape
Vanderkloof Dam
Orange River
Border: Free State and Northern Cape
Sterkfontein Dam
Nuwejaar Spruit
Free State
Vaal Dam
Vaal River
Border: Gauteng, Mpumalanga and Free State
Pongolapoort Dam
Pongolo River
KwaZulu-Natal
Major dams in SA 2
Bloemhof Dam
Vaal River
Border: North West and Free State
Theewaterskloof Dam
Riviersonderend
Western Cape
Heyshope Dam
Assegaai River
Mpumalanga
Woodstock Dam
Tugela River
KwaZulu-Natal
Loskop Dam
Olifants River
Mpumalanga
Name 5 things that make forests an important resource
1) Trees protect the soil from erosion.
2) Forests are home to birds, animals and insects.
3) Forests can be a source of food.
4) Forests can be cut down to produce timber for construction, furniture, and paper. It can also be used as firewood.
5) Forests produce oxygen.
Any movement of the Earth’s crust is known as
seismic activity
A person who studies the movement in the earth’s crust is referred to as a
seismologist
The oldest instrument used to measure the magnitude of a quake is called a
seismograph
How does the equipment used to measure the magnitude of an earthquake function
A rotating drum has graph paper attached to it. When vibrations occur the arm vibrates and at the same time draws lines on the graph paper. The paper can later be removed to display an image that gives details about the magnitude and duration of the quake.
The greater the wavelength drawn on the seismograph, the stronger the earthquake. Straight lines indicate periods of no vibrations.
Some extra info on seismographs
Today seismographs are more sophisticated and some are fully computerized.
Originally the Richter Scale, drawn up by Charles Richter in 1935, was used to measure the intensity of earthquakes, but more recently the Movement Magnitude Scale has been used. These two scales both have a maximum rating of 10.
How many measurable earthquakes
It’s estimated that Earthquakes happen every 10 seconds. most of these can’t be felt
About 50 measurable earthquakes occur each and every day.
As these plates move they slip and grind against each other forming vibrations below the ground which sends shock waves in concentric circles away from the focal point. (The point where vibrations first occur)
What are they called
seismic waves
The point on the surface above the focal point is referred to as the of an earthquake
epicenter
Memorise the answer
This is where the earthquake is at its strongest. Because the earth’s crust has to settle, aftershocks, which have a lower magnitude than the main earthquake, occur.
Look at the drawings on page 4 and 5 of the earthquake study on faults
a) Fault plane
b) Focal point
c) Epicentre
d) Seismic Waves
There are 3 different types of Fault Planes. (Cracks in the earth’s crust where earthquakes occur.)
What happens in a Normal Fault
Because of tension, a crack forms in the earth’s crust. As the two sections of the crust are pulled apart, the one slides down in relation to the other, grinding against each other. A good example is the Christchurch Fault in South Island, New Zealand
What happens in A transverse fault
Transverse forces cause two sections of the earth’s crust to slide against each other at the same time grinding against each other to form vibrations. The best example is the San Andreas Fault along the California Coast in the USA.
What happens in a Reverse Fault or Thrust Fault
Converging pressure at a fault plane forces one section of the earth’s crust to thrust upwards in relation to the other. As it is forced upwards, the two sections of crust grind against each other. A good example is the Himalayan Mountains in Tibet.
In September 1969, a 6.3 magnitude earthquake struck the Ceres area in the Witzenberg Mountain Range, 130km from Cape Town. It was the most destructive earthquake in the history of South Africa. It caused widespread damage in Ceres, Wolseley, and Tulbagh. Shock waves were felt as far away as Durban. There were 12 recorded deaths.
In the last 30 years, most of South Africa’s earthquake activity is caused by mining, especially around the areas of Klerksdorp, Welkom, and Carletonville
Just read the flashcard till you memorize it
A 6.2 magnitude quake occurred on the evening of 26 September 2020 on a plate edge 2000 km SE of Cape Town, in the southwestern Indian Ocean.
It occurred at the active divergent plate boundary separating the African and Antarctic plates, which probably now have moved a few cm further apart as a consequence.
Very light shaking was reported in Cape Town.
2 days later a 2.5 magnitude earthquake around 10km north of Malmesbury was felt by residents around Cape Town, which rattled buildings for about three to four seconds.
In cities that experience high seismic activity measures are put in place to make buildings earthquake resistant.
What are they
1) Small buildings are mostly made out of timber.
2) Skyscrapers use modern technology to counter earthquakes such as:
Buildings are constructed on flexible pads that isolate the foundation from the ground so that the buildings remain steady.
Or concrete and plastic rings are placed below the buildings to channel shock waves around the buildings
Go through Kathmandu, Nepal, 25 April 2015 on the last page of the Earthquake study
Remember
The name of the earthquake The location of the earthquake Date Magnitude 5 facts about it the amount of deaths
What is a population?
A group of individuals, from the same species, who inhabit a particular area.
In what year did the human population exceed 7 billion.
2001
Population growth
Pre agriculture – only a few million
After agriculture – slow growth
After 1900 – rapid growth in population due to increases in technology and medical advances – 3 billion by 1960
Since that time the population has more than doubled and continues to increase
What is Natality
The number of individuals added to a population over a period of time due to reproduction. This is often referred to as the birth rate. A birth rate is the number of people born per 1 000 people in a year. Birth rates are often recorded as a percentage of the population.
What is Immigration
The migration of an individual into a place.
Factors that influence a reduction in the size of a population.
What is Mortality
The number of deaths in a population over a period of time. This is often referred to as the death rate. A death rate is the number of individuals that die per 1 000 people in a year. Death rates are often recorded as a percentage of the population
What is Emigration
The migration of an individual from a place
Remember
Immigration and emigration do not influence world population sizes
A Population Growth Rate is the rate at which the population changes in size.
Growth rate =
(Births in a country + immigration) – (Deaths in a country + emigration.) The answer could be either positive or negative.
Look at page 3 of population geography
How to draw a line graph
What is The biotic potential
The biotic potential is the rate at which a species produces with unlimited conditions. That is when they have unlimited food and water, safe habitat and any other conditions promoting successful reproduction.
Environmental Resistance are factors that can limit the increase of a population.
Factors that can limit the growth of a population can include:
lack of food and water lack of suitable habitat competition diseases unnatural deaths.
As a result of environmental resistance, not all members of a population will survive to adulthood or the stage when they are able to reproduce.
Each population will have a carrying capacity. This can be defined as
the maximum population size of a species that an ecosystem can support indefinitely
Look at the carrying capacity graph in Population Geography 1
What is it saying
When a population’s size is below its carrying capacity size, conditions are ideal for a population size to increase. Once the size of a population exceeds its carrying capacity, there are insufficient resources to sustain everybody so birth rates will drop and members of the population will die off until its size is once again below its carrying capacity. When resources once again increase the population can once again begins to grow.
What is Demography
the study of the size, density and distribution of human population.
Demography takes into account Birth rates, death rates, age distribution and any other factors that influence the size and growth of a population.
What is demography
Demography is the study of the size, density
and distribution of human population.
What does demography take into account
Birth rates, death rates, age distribution and
any other factors that influence the size and
growth of a population.
What are the 3 distinct periods of growth
1) The pre-agricultural period
2) The agricultural period
3) The industrial period
Name 3 facts about the pre-agricultural period
1. Characterised by the development of tools. 2. There was slow growth until the development of tools. 3. The human population was estimated to be from 5-10 million people. 4. Up to 10 000 years ago. 5. New tools and skills enabled people to adapt to new environments,
Name 3 facts about the agricultural period
From 10 000 to 1 000 years ago.
Plants and animals were used for
domestic purposes.
Advances in irrigation
made food more abundant.
Characterised by advances in
agriculture.
More food and healthier food
caused populations to increase
more rapidly to around 500 million
people.
Name 3 facts about the Industrial period
Characterised by advancement in technology.
This period saw technical advances in medicine,
Food production and sanitation. helping
to support a rapid increase in population.
The Industrial Revolution from 1760 to +/- 1840,
Further enhanced production growth.
The world’s population increased to the current
A figure of 7,8 billion people.
Is there a carrying capacity for Earth
Yes
Do you think that the Earths population will increase
It should increase over time
What did people believe in the 1700s
During the 1700s demographers believed that the human population would be stable because human Knowledge and moral constraints would make it possible to establish a world where resources are abundant.
Humans would control the earth and they would make sure that they have all the supplies in order to survive.
It was believed that if the population was to grow too
rapidly, people would stop creating offspring to limit
population sizes.
Who was the person that predicted the limit of the human population
In 1798, a British philosopher, Thomas Malthus,
became the first person to predict the limit of the
size of the human population.
In doing this he linked population ad well-being together
What else did Thomas Malthus believe
He believed that the human population exhibits
exponential growth.
In other words, the increase is proportionate
to the population already present.
What will uncontrolled population growth lead to
a) A depletion of resources
b) Increased pollution
c) Overcrowding
d) Increased unemployment
What are the larger problems that uncontrolled population growth will lead to
a) starvation
b) Increased diseases
¢) Higher crime rates
d) High poverty rates
e) wars
What will the larger problems of uncontrolled population growth lead to
These problems would then lead to:
a) Increased death rates
b) Lower birth rates
What did Thomas Malthus find to be true
His theory was found to be true in developing countries, where increased population sizes led to the
abovementioned problems.
His theory, however, did not take into account the advancements in technology and food production in developed countries.
Name 3 developed countries
USA, Canada France, England Australia, New Zealand
Name 3 developing countries
Mexico
Brazil
Pakistan
What is economic inequality
Economic inequality is the difference between individuals or populations in terms of their wealth, assets or income.
What can countries be catergorised according to
Countries can be categorised according to per capita income which is the average income per person.
