hazardous Earth

Question 1

name a primary impact of an earthquake

Answer 1

death/injuries
damaged buildings
damaged roads

Question 2

name a secondary impact of an earthquake

Answer 2

fires
landslides
disease
tsunamis

Question 3

what happens at a collision zone

Answer 3

e.g. Himalayas

2 continental plates collide and buckle

Question 4

what are shield volcanoes?

Answer 4

they are found on constructive plate boundaries or hotspots
they have gently sloping sides and a wide base
they have basaltic magma which is thick with a low silica and gas content.
They erupt frequently, but not violently

Question 5

what are composite volcanoes?

Answer 5

they are found on destructive plate boundaries and have steep sides and a narrow base

they are made up of layers and ash

they also contain andesitic magma which contains lots of silica and gas

Question 6

why are composite volcanoes more dangerous

Answer 6

composite volcanoes eruptions involve andesitic magma which contains a lot of silica. This clogs up the volcanic vent, so pressure builds up in the volcano, along with a large amount of gas that makes it explosive

Question 7

what happens at a divergent plate boundary

Answer 7

e.g. Eurasian and North American plates

rising convection currents pull plates apart e.g. mid-Atlantic ridge

Question 8

what are the layers of the earth and their properties?

Answer 8

inner core - solid - iron 
outer core - liquid-iron
mantle - liquid
asthenosphere
crust

Question 9

why are some countries more vulnerable to cyclones?

Answer 9

physical - low -lying land / coastal areas

social - poor areas

economic - richer countries have better prediction, protection, and evacuation strategies

Question 10

what are the physical hazards of cyclones?

Answer 10

storm surges
landslides
flooding
high rainfall

Question 11

what are the impacts of storm surges?

Answer 11

large areas of low pressure allow the sea level to rise and combined with the wind, the water surges towards the land, eroding beaches, and damaging sea defenses

Question 12

how do landslides affect people and the environment?

Answer 12

soil becomes saturated due to high rainfall and slides injuring people below

Question 13

why do cyclones dissipate?

Answer 13

• they reach land
• colder temperatures
• winds blow in different directions

Question 14

what evidence is there for natural climate change?

Answer 14

tree rings= thicker rings indicate warmer, wetter weather
ice cores= indicate levels of CO2 from when the ice formed and settled
historical sources= diaries, paintings, harvest records

Question 15

what are the human causes of climate change?

Answer 15

industry
energy
transport
agriculture

Question 16

name some natural causes of climate change

Answer 16

sunspots on the sun are hotter and last between 10-100 years

volcanoes and asteroids cause large amounts of ash and sediment to rise into the atmosphere; blocking the sun and cooling the Earth. These effects last around 1-5 years

Question 17

what are the Milankovitch cycles?

Answer 17

The shape of the Earths orbit changes every 100000 years affecting the amount of sunlight it receives and can last between 20000-100000 years

Question 18

how does global and atmospheric circulation affect arid and high rainfall areas?

Answer 18

warm air creates low pressure. Rising air cannot hold as much moisture so precipitation is higher

when cool, dry air descends it creates high pressure therefore there is little precipitation

Question 19

how do ocean currents redistribute heat around the earth?

Answer 19

cold, salty, dense water sinks
as it sinks warm water from lower altitudes is pulled in
this then travels, cools, and sinks
the cycle repeats

Question 20

what happens at a conservative plate boundary

Answer 20

e.g. San Andreas fault

2 plates slide past each other

Question 21

how can you predict a cyclone?

Answer 21

satellites are used to spot a tropical cyclone forming

forecasters can predict its track and storm surge heights

Question 22

how do tropical cyclones form

Answer 22

1- 26.5C

2. high humidity - lots of moisture in the atmosphere
3. rapid cooling-rising air must condense quickly to generate power for the cyclone
4. low wind shear - if winds are blowing in different directions, the cyclone won’t form
5. Coriolis effect-strongest between 5-30 of the equator
6. low pressure

Question 23

how does the atmosphere transfer heat around the earth

Answer 23

global circulation system

warm air rises at the equator
cool air falls
cycle repeats

Question 24

how do circulation cells redistribute heat around the earth?

Answer 24

warm air rises=low pressure

cool air falls=high pressure

hot air at the equator rises, cools, then travels north and south, where it sinks
the cells meet and energy is transferred

Question 25

what are ocean currents?

Answer 25

e.g. the Gulf stream
ocean currents transfer heat around the globe
they are powered by:
-wind
- density differences (due to salinity and temperature)

Question 26

what are the key characteristics of cyclones?

Answer 26

low pressure- warm, moist air rises sucking more air up behind it

rotation - Coriolis helps rising air to spiral and drags in strong winds

structure - a cylinder of rising, spiraling air surrounding an eye of descending, high-pressure air

Question 27

why do cyclones intensify

Answer 27

temperatures over 26.5C
low wind shear
high humidity

Question 28

what’s the difference between the crusts

Answer 28

continental crust - less dense - granite

oceanic crust - more dense- basalt

Question 29

how do convection currents contribute to plate movement

Answer 29

1. the core heats the molten rock to create a convection current
2. heated rock from the mantle rises
3. at the surface the convection currents move the tectonic plates in the crust
4. it cools and flows back to the core to be reheated

Question 30

what happens at a convergent plate boundary

Answer 30

e.g. Nazca and South American plates

2 plates collide and one subducts under the other

Question 31

what’s the evidence for climate change

Answer 31

in 2015 average temperature was 1C higher than the average temperature in 1800-1900

oceans warm 0.11C per decade

Arctic sea ice covers 13% less of the sea each decade