global hazards info Flashcards
what is a natural hazard
it’s something which endangers living things but is caused by nature
what is a natural event
it’s something which happens due to nature. it can be dangerous or it can’t.
what are some example of extreme weather
heatwaves, flooding, thunderstorm, tornado
what is an el Niño
an el Niño is when warm water piled around Australia is pushed towards Peru due to the trade winds pushing warm water towards Peru causing cold water from deep in the ocean to rise and gets pushed towards Australia.
what causes an el nino
when the trade winds blowing from Peru to Australia get weakened, stopped or reversed.
what are the impacts of an el nino
. 30cm sea level rise around Peru. water near Peru also increase in temp by 6-8 degrees Celsius. more rainfall in south America. low air pressure in Peru. Chance of flooding
. colder water near Australia. higher air pressure, drier condition. chance of droughts
what causes a la nina
when the trade winds strengthen
what is a la nina
when the trade wind strengthen leading to warm water being pushed to Australia and cold water being upwelled towards the coast of south america.
what are the impacts of a la nina
3-5 degrees Celsius colder water off the coast of peru. higher risk of droughts at peru. high pressure wind
warmer water in autralia leading to a risk of floods. low pressured winds.
what is a drought
its when an area of land doesn’t receive any rain for a long period of time leading to mass amounts of living things to die.
name the order of layers of the earth going from the surface to the innermost layer possible.
crust, mantle outer core, inner core
what is the crust
a thin layer of rock on the surface of the earth made up of mostly rock
what is the mantle
the mantle is the second layer of the earth and it’s made of magma
what is the outer core
it’s the third layer of the earth and is made of liquid metal
what is the inner core
what is the inner core made up of solid metal like iron and it’s the 4th layer of the earth
which is lighter the oceanic crust or the continental crust
the continental crust is lighter as it’s less dense
what is a continental crust
crust found under land
whats an oceanic crust
crust found under the ocean
what are convection currents
currents formed in the mantle caused by the mantle being heated by the outer core causing the heat too rise up and push other bits of the mantle. as it reaches the top it cools then sinks back down which pushes the tectonic plates on the surface
what was the continental drift
when convection current pushed the tectonic plates making up Pangea to move; splitting it apart.
what was Pangea
it was a super continent formed 200 million years ago.
what are convergent plate boundaries
when 2 plates meet and when is forced to rise up and the other forced to go down causing the one going down to burn up.
what are collision plate boundaries
when 2 plate boundaries collide and so they both rise up
what are divergent plate boundaries
when two tectonic plates move away from each other
what are conservative plate boundaries
wen two plates move along side each other
what is an earthquake
rumbling beneath the surface of the earth which is caused by the moving of tectonic plates
what is a shield volcano
a volcano with a big width and a small height and runny lava
what’s a composite volcano
it’s the shape of a cone with steep sides and it’s made up of solidified lava and ashes.
releases poisonous gas
what’s a fissure volcano
a small volcano with gentle slopes.
what is a caldera
a volcano which creates hole which is then filled by rain to make a lake.
how do you know if an earthquake is coming
historic trends - patterns in earthquake rates
radon gas emissions- some gas may be released before an earthquake
animal behaviour- animals can pick up seismic waves made by the earthquake
how does the government protect building from falling from an earthquake
shock absorbers at the base of the building, building must be flexible and strong. they also need to have the base isolated in case of collapse
how can people know if a volcano is about to erupt
soil or water pH will turn more acidic due to sulphur dioxide.
tiltmeters measure the shape of a volcano to identify bulges before an eruption.
satellite imagery- thermal scanning can identify if the magma is rising
gas emissions- CO2 AND SULFUR DIOXIDE INCREASE BEFORE AN ERUPTION
how can people prepare for volcanic eruptions
practice evacuations, have emergency kits with water, clothes, utilities, bandages, gas masks, food and medicine
