geography Flashcards
three types of volcano
active, dormant, extinct
3 layers of the earth
crust, mantle, core
what is the crust made up of
solid rock
what is the mantle made up of
magma
what is the core made up of and how hot can it get
the core is made up of iron and nickel and is it 6000 degrees celcius
where are the plates located
on the mantle
who first said the term ‘Pangaea’ to describe the earth?
alfred wegener
what is pangaea
meaning all land, used to describe the earth before it split apart into different countries.
what happens when plates collide
plates that collide with eachother have destructive (or convergent) boundaries - called subduction - crust is destroyed
what happens when plates seperate
plates that seperate have constructive boundaries - called sea-floor spreading - crust is created
what happens when plates slide past eachother
passive boundaries - cause earthquakes
three types of rock
sedimentary, metamorphic, igneous
positive effects of volcano
soil rich in minerals, tourism, geothermal energy
negative effects of volcano
sulfur dioxide, loss of human life, volcanic material mixing with water creates mud called lafar (extremely deadly)
what is the focus
the point beneath the surface where the earthquake happens
what is the epicentre
the point above the focus - greatest damage occurs here, strongest tremors etc
how to measure an earthquake?
richter scale, ranges 1/10 each in 10x stronger than last,
or seismographs
how do fold mountains form
when two plates collide
how are igneous rocks formed
cooled magma
how are sedimentary rocks formed
particles of other rocks, dead plants and animals compressed over time
how are metamorphic rocks formed
when igneous or sedimentary rocks are changed under great pressure and heat
what is the pacific ring of fire, and where it it located?
The Ring of Fire is a string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean.
5 different parts of a volcano
magma chamber, vent, crater, ash cloud, volcanic cone
how do earthquakes occur?
when plates collide or slide past eachother
short term response in event of an earthquake
evacuation,
long term response in event of an earthquake
repair
one example of an igneous rock
basalt
e.g of sedimentary rock
limestone
e.g of metapmorphic rock
marble
where does marble come from
when limestone is put under great heat and pressure
where can you locate basalt
the giants causeway,
where can you locate limestone
the burren
where can you locate marble
connemara co. galway
where is the burren
co. clare
what is quarrying
the process of using large machinery to cut large chunks out of the earths crust to extract rock
positive impact of quarrying
employment, raw materials, economic activity
negative effect of quarrying
eyesore, pollution, decrease in property value around, traffic pollution
what are the three types of economic activity
primary, secondary, tertiaryw
what is primary economic activity
people working directly with the earths materials e.g farmer
what is secondary economic activity
people who manufacture something e.g baker
what is tertiary economic activity
providing a service e.g solicitor
renewable resource
resources that can be used repeatedly without running out e.g water
non renewable resource
resources that will run out e.g oil
four stages of water cycle
Evaporation
Condensation
Precipitation
Run off
what is irrigation
the supply of water to land or crops to help growth, typically by means of channels.
what does permeable mean
water can pass through it
what does soluble mean
dissolves in water
2 types of weathering
freeze thaw and carbonation
features in the burren (underground)
swallow holes
stalactites and stalagmites and pillars
features in the burren (surface)
karst landscape/limestone pavement
clints and grikes
is carbonation chemical or mechanical weathering
chemical
carbonation method 1-4
chemical weathering is when rocks are dissolved because of a chemical reaction.
1. rainwater mixes with carbon dioxide to form a weak carbonic acid.
2. this weak carbonic acid has a huge effect on limestone rock. this is because limestone contains 80% CALCIUM CARBONATE.
3. the weak carbonic acid reacts with the calcium carbonate in the limestone and dissolves it.
4. LImestone is a permeable rock, rainwater can pass right through it.
freeze thaw method 1-3
Freeze thaw action occurs high up in mountainous areas where there is a lot of precipitation (rain, sleet, snow.) temperatures fluctuate.
1. during the day, water seeps into cracks in the rock.
2. at night, temperatures fall below freezing point. the water in the cracks freeze and expand by 9 percent putting pressure on the rock.
3. this process is continued over time, widening the cracks and joints in the rock. causing it to weaken, and eventually pieces break off. the broken rock is known as SCREE.
causes of mass movement
(human activity, gradient, water, lack of vegetation, animals
types of mass movement
soil creep, bogburst, mudflow, landslide, avalanche
Effects of mass movement
damage to local area or farmland
loss of life
harmful to the economy (e.g loss of jobs)
rare species could be killed/washed away
