natural hazards

Question 1

Natural Hazard

Answer 1

A natural hazard is a process where it could cause death,injury or disruption to humans or property or possession.

Question 2

Natural Disaster

Answer 2

A natural disaster is a natural hazard that has actually happened.

Question 3

Geological Hazard

Answer 3

G.H caused by land and tectonic processes. Include volcanoes and earthquakes.

Question 4

Meteorological Hazards

Answer 4

M.H caused by weather and climate + TROPICAL STORMS AND EXTREME WEATHER.

Question 5

What are the 3 different hazard risks?

Answer 5

Vulnerability
Capacity to cope
Nature to Natural Hazards

Question 6

Vunerablity

Answer 6

More people that in an area exposed to nat haz the greater the probability they will be affected by nat haz.
E.g area w high population on flood plain - flooding
Base of a volcano - volcanic eruptions.

Question 6

Capacity to cope

Answer 6

Better pop can cope w extreme event the lower the risk of them being severely affected. E.g HICs better able to cope w flooding bc they can afford to build defenses and evacuate people.

Question 7

Nature of Nat Haz

Answer 7

Type - risk from some haz are greater than others
E.g trop storm can be predicted and monitored to give people time to evacuate
Frequency - nat haz occur more often may carry higher risk.
Magnitude - more server nat haz tend to have greatest effects. E.g mag 9.0 earthquake that struck Japan in 2011 killed 15K
6.3 magnitude earthquake in Italy in 2009 killed 300.

Question 8

how thick is continetal crust

Answer 8

continetal crust is 30-50km is thicker

Question 9

How thick is oceanic crust

Answer 9

Oceanic crust is thinner (5-10km) and more dense.

Question 10

What is the name of when plates are moving in the mantle?

Answer 10

Convection Currents

Question 11

What is the name of the plates meet?

Answer 11

Plate margins or plate boundaries.

Question 12

Destructive margins

Answer 12

Two plates are moving towards eachother
When an oceanic plate meets a contintetal plate the denser oceanic plate is sub-ducted and destroyed.
Volcanoes and ocean trenches occur here.
When 2 contential paltes meet, the ground is folded upwards + fold mountains.

Question 13

Constructive margins

Answer 13

Where 2 plates are moving away from eachother. Magma rises from the mantle to fill the gap and cools + new crust.

Question 14

Conservative Margins

Answer 14

Where 2 plates are moving sideaways past eachother or are moving in the same direction but at different speeds. Crust isnt created or destroyed.

Question 15

Destructive margins - volcanoes

Answer 15

the desner oceanic plates moves down into the mantle where it melts. A pool of magma forms which then rises through cracks in the crust called vents. The magma erupts = volcano.

Question 16

Constructive margins - volcanoes

Answer 16

the magma rises up into the gap created by the plates moving apart=volcano

Question 17

Hotpsots

Answer 17

Some volcanoes that form over parts of the mantle that are really hot.

Question 18

How do pyroclastic flows happen?

Answer 18

When a volcano erupts it emits lava and gases. Some volcanoes emit lots of ash which can cover land and block out the sun.

Question 19

Destrcutive margins - earth

Answer 19

Tension builds when one plate gets stuck as it moves past the other

Question 20

Constructive margins - earth

Answer 20

tension builds along cracks in the plates as they move away from eachotherc

Question 21

conservative margin - earth

Answer 21

tension builds up when plates that are grinding past eachother get stuck.

Question 22

Shock waves

Answer 22

Plates eventually jerk past eachother sending out shock waves. Vibrations = earthakes.
The SW spread out from the focus the point in the earth where the earthake starts. the waves are stronger near the focus and cause more damage.

Question 23

Epicentre

Answer 23

the point on the earths surface straight above the focus.

Question 24

Moment magnitude scale

Answer 24

measures the amount of energy released by an earthuake
it is a logarthimic scale so mag 7 would cause 10x more ground shaking then mag 6.

Question 25

new zealand`

Answer 25

place - kaikoura new zealand
date - 14th nov 2016
plate boundary - destructive and conservative - the pacfic plate is subducting benath the australian place to the north and sliding past it to the south.
mag - 7.8 mmscale

Question 26

new zealand - primary effect

Answer 26

2 people died and over 50 injured.
10ks homes + destroyed damaged
60 ppl = emergency housing
total cost of damage was around 8.5 billion dollars.
+200km road + over 190km of rail line + destoryed.
Communcations,water,sewage + power supplies + cut off.

Question 27

NZ - secondary effects

Answer 27

earthake triggered up 100k landslides which blocked major road and rail routes
major landslide blocked the clarence river leading to flooding and evacution of 10 forms.
earthake generated a tsunami w waves of around 5m + leaving debris up to 250m land.

Question 28

nz - immediate response

Answer 28

tsunami warning was issued fast + residents of coastal areas were told to move to higher ground.
100s of ppl housed in emergency shelters.
200 of most vulnerable ppl were evacuted from kaikoura by helicopter within 24 hrs of the earthuake.
power was restored to most places within a few hours.
temporary water supplies were set up.
international warships were sent to kaikoura with supplies + food,medicine + portable toilets.

Question 29

nz- long term response

Answer 29

5.3 mil dollar funding provided by the kaikour district council to help w the rebuilding the town’s water systerms + harburs.
most road + rails routed were repaired + reopned within 2 yrs.
Kaikoura Mayoral Earthake Relief Fund set up to help residents who couldnt afford basic supplies + donations were recieved from around the world.
By march 2017, a permanet water main ad been laid in kk the new pipe was desgined to move with any future earthake so it wont break.

Question 30

nepal

Answer 30

place - gorkha nepal
date - 25th april 2015
Plate boundary - destructive - the indo-australian plate is being subducted benath the eurasian plate.
mag - 7.8

Question 31

Nep - pimary effects

Answer 31

around 9k died and 22k+ injured
estamiated 800k buildings damaged or destroyed
4mil ppl left homeless
cost of damage over 5.5bil
roads and bridges were destroyed
water tanks and pipes were destroyed leaving 2 mil people without access to clean water and sanitation.

Question 32

Nep - immediate respon

Answer 32

india and china sent teams to help residents rescue people trapped by debris but lack of tools + machinery slowed down rescue efforts.
ppl tried to recover the dead and treat the injured but damaged roads made it hard for emergency workers aid to get through.
charites = oxfam provided medicine,food and temporary water supplies
red cross set up emergency sheleters for 130k families who had lost their families.

Question 33

Nep - long term respon

Answer 33

world bank group financed 500 mil worth = projects to build earth ake resistant housing and repair roads an irrigation systems.
Some projects are still on going.
The road from nepal-tibet was reopened after 2 yrs after the earth ake many roads wre still damaged.
many heritage sites were reopened in june 2015 to encourage toursits back to the area.
water supply is being restored but 2 yrs after the event many people still didnt have access to clean water.
NGO’s are working w residents to increase their resilence to disasters for example providing alternatives energy sources.

Question 34

why do people have risk and example

Answer 34

many people live close to volcanoes or in area vunerable to earth akes some peopel dont have a choice. e.g they may not be able to afford to move or they may not know the risks.

Question 35

why do people choose to live in hazard earth ake

Answer 35

theyve always lived there - moving = leaving jobs or families.
in wealtheir countries effective monoitoring and evacuation plans can minimise risk.
the minerals from volcanoes from volcanic ash makes volcanic soil v. fertile - farers for e.g mineral rich soil around mount etna.

Question 36

managment strategy - monotiring
earth akes

Answer 36

earth akes - seismometers and lasers monitor earth movements and can be used in early warning system to give a small but vital amount of warning before a large earth ake occurs.

Question 37

managment strategies - prediction
earth ake

Answer 37

earth akes - cant be reliably predict but scientists can forecast where they may occur moinitoring the movement of tectonic plates.

Question 38

managment strategies - protection
earth

Answer 38

earth akes - new buildings can use reinforced concerte that absorb an earth ake’s energy. existing buildings and bridges can be strengthened with steel frames so they’re less likely to collaspe. automatic shut off switches can turn off gas and electricty supplies to prevent fires.

Question 39

mang start - planning both

Answer 39

future dev can avoid high risk areas
govt can plan evacution routes to get people away fast and safely.

Question 40

management strats - monitoring
v.e

Answer 40

volcanic eruptions - scientists can monitor the tell - tale signs that come before an eruption = tiny earth ake escaping gas and changes in shape of a volcano.

Question 41

mang strat - monitoring v.e

Answer 41

volcanic eruptions - can be predictied if scientists monitor volcanoes closely.

Question 42

managment strategies - protection
v.e

Answer 42

v.e - buildings can be strengthened so that they’re less likely to collapse under the weight of ash. trenches and barriers have been used to try to divert lava away from settlements but w little success.

Question 43

what does global atmospheric circulation mean

Answer 43

transfer of heat from the euator to the poles by the movement of air.

Question 44

why does air move

Answer 44

air moves due to the diffrences in air pressure winds blow from high pressure areas to low pressure.

Question 45

how is the global atmospheric circulation system divided into loops

Answer 45

each cell has warm rising air that creates a low pressure belt and cool sinking air that creates a high pressure belt.

Question 46

describe atmospheric circulation system

Answer 46

1) the sun warms the earth at the euator causing the air to rise. this creates a low pressure belt
2) as the air rises it cools and moves away from the euator
3) 30 degrees north and south of the eator the cool air sinks creating a high rpessure belt
4) at the ground surface the cool air moves either back to the eator or towards the poles. these winds curve because of the earth’s rotation this is the coriolis effect.
5) 60 degrees north and south of the eator th ewarmer surface winds meet colder air from the poles , the warmer air rises creating low pressure.
6) some of the air moves back towards the eator and the rest moves towards the poles.
7) at the poles the cool air sinks creating high pressure the high pressure air is then drawn back towards the eator.

Question 47

Global atmospheric circulation influences weather and climate

Answer 47

at the eator sun is directly overhead - earth’s surface recieves a lot of solar radiation so its hot. warm moist air rises and forms clouds = rains
by the time it reaches 30 N and S of the eator releases most of its moisture as rain. dry air = few clouds + little rainfall so deserts are often found at this latitude.
UK lies close to low pressure zone @ 60 N. warm rising air brings lots of cloud cover and rainfall often as low pressure systems carried from the atlantic by westerly winds.

Question 48

tropical storms develop..

Answer 48

between 5-30 degrees north and south of the eator when
- sea temp is 27 degrees celusis or higher
- wind shear between the higher and lower parts of atmposheric is low.

Question 49

how do trop storms develop over warm water?

Answer 49

• the warm surface water evaporates,rises and condenses into clouds. this releases and condenses into clouds huge amounts of energy , producing powerful storms. the rising air creates an area of low pressure which increases surface winds. Low wind shear prevents clouds breaking up as they rise so the storm stays intact.
• easterly winds near the eator more trop storms towards the west.
• the storms spin bc of the corralis effect.
• as the storms moves over the ocean the energy from the warm water strengthens the storm so wind speeds increase. Storms lose strength when they move over land or cooler water bc the energy supply from the warm water.
• majority of storms occur in the nothern hemisphere from aug - oct while in he southern hemisphere most storms occur from dec - april.

Question 50

Features and strucute of a trop storm - centre of the storm

Answer 50

eye - up to 50 km across and is caused by descending air . theres v low pressure,light winds, no clouds,no rain and a high temperature in the eye.

Question 51

Features and strucute of a trop storm -
they eye is surrounded by

Answer 51

eye wall - where theres spiralling rising air very strong winds storm clouds torriental rain and a low temperature.

Question 52

Features and strucute of a trop storm -
towards the edges of the storm

Answer 52

the wind speed falls, the cloud become smaller and more scattered, the rain becomes less intense and the temperature increases.