P1: Tectonic Hazards

Question 1

What is a natural hazard

Answer 1

A natural hazard is a natural process or event that poses potential risk of damage to property, and loss of life

Question 2

Types of natural hazards

Answer 2

Tectonic hazards - Tsunami, Earthquake
Geomrphological hazards - avalanche, flood
Atmospheric hazards -hail,hurricane,blizzard
Biological hazards - Wildfire, malaria, grassfire

Question 3

What is a hazard risk

Answer 3

A hazard risk is the probability of being affected by a natural event

Question 4

Factors affecting hazard risk

Answer 4

Proximity - how close you are to the event
Urbanisation - highly populated areas are at high risk
deforestation - clearing forests will increase space for lava to flow
climate change - may cause droughts in a lot more areas and flooding in others.
Farming - when a river floods they release nutrients for crops
Poverty - in poorer areas of the world people would live in areas of high risk

Question 5

Factors that influence the effect of natural hazards

Answer 5

Human - population density, emergency services, warning time, how people react, land use, community preparedness
Physical - geology/soil, magnitude of event, duration of event, frequency, time of day, ground type.

Question 6

Layer of the earth - Crust

Answer 6

Oceanic - basalt, solid, 6-10km thick, 200-400 degrees celcius., outer layer of crust
continental - Granite, solid , 50-100km, 500-1000 degrees celcius, inner layer of crust

Question 7

Layer of the earth - Mantle

Answer 7

Top = rock, Bottom = molten rock, solid and liquid, 2900km thick, 400-4500 degress celcius, flows slowly

Question 8

Layer of the earth - Outer core

Answer 8

Iron and nickel,liquid, 1250km,<3700 degrees celcius, currents generate earth magnetic field

Question 9

Layer of the earth - Inner core

Answer 9

Iron and nickel, solid, half the diameter of the earth, <5000 degress celcius/

Question 10

Lithosphere

Answer 10

The solid crust and solid mantle

Question 11

Asthenosphere

Answer 11

The solid crust is floating on the molten asthenosphere

Question 12

Three ways heat energy travels

Answer 12

Conduction
Convection
Radiation

Question 13

Why do the plates on the earth move

Answer 13

As heat rises from the core it creates convection currents in the liquid outer core and mantle.
These currents are so strong enough to move the tectonic plates- they pull and push at the crust.
Radioactive decay in the core creates the heat that is the engine of the plate techtonics

Question 14

What is a constructive plate margin

Answer 14

Where two plates move apart and molten magnma rises and then cools down to form solid rock. Lava is usually runny and spreads out before it solidifies. e.g. Mid atlantic ridge.

Question 15

What is a Destructive plate boundary

Answer 15

When an oceanic and continental plate move towards each and the oceanic plate sinks under the continental plate. The friction between the two causes strong earthquakes and tsunamis. e.g. Andes Mountains in Peru and Chile

Question 16

What is a conservative plate boundary

Answer 16

When two plates do not collide but move past each other. Earthquake occurs. San Andreas Fault.

Question 17

What is a collision plate boundary

Answer 17

They cause the material to rise upwards forming mountains. Causes destructive earthquakes, landslides. The Himalayas

Question 18

What is a volcano

Answer 18

A volcano is an opening or vent in the earths surface through which molten materials erupts and solidifies as lava.

Question 19

Details about a volcano at a Destructive plate margin

Answer 19

Composite Volcano. Lots of layers of ash and lava build around the main vent to form a strato volcano because they release carbon dioxide. At this location adesthetic magnma is made where continental rocks are melted by the magma. It is lower in temperature than the basaltic magma. e.g Montserrat

Question 20

Details about a volcano at a constructive plate margin

Answer 20

Shield Volcano. Creates basaltic magma. The emerging lava is quite runny and hotter so the shape of the volcano is low and wide. e.g. Sutney Island, Island.

Question 21

Details about a volcano at Hot Spot Inter-plate

Answer 21

Shield volcano. Magma plumes are formed at these volcanoes. These shield volcanoes have gentle oozing lava which comes out very slowly. e.g. Mauna Loa Hawai

Question 22

How are volcanoes formed at a constructive plate margin

Answer 22

The techtonic plate is melted by the upper part of the mantle and hot molten magma rises to form a gap. The slab pull allows the lava to pour out and then form solid rock. The tectonic plates are moved apart by slab pull. As more and more lava piurs out a shield volcano forms and the rising magma pours out forming another layer a bigger volcano.

Question 23

How are volcanoes formed at destructive plate margins

Answer 23

As the two plates move towards each other, the less dense one falls below. the oceanic plate is denser and gets melted below. The composite volcano is then formed.

Question 24

How are volcanoes formed at Hot spots

Answer 24

The plate moves apart in every direction and gets thin in the middle. This piece then gets torn by melting. Basaltic lava then erupts and then a shield volcano is formed.

Question 25

Hazards of volcanic eruptions

Answer 25

eruption cloud, ash fall, lava flow, debris, magma, pyrocrastic flow

Question 26

How can the effects of volcanoes be managed

Answer 26

Prediction - We could use sulphur dioxide detectors to tell us magma is rising. Volcano will change shape as magma moves up vent Protection - Concrete lahar channels can be built to divert lahar flows away from builds Planning - People may be given emegency packs.

Question 27

What is an earthquake

Answer 27

An earthquake is the result of a sudden release of energy in the earth's crust which causes seismic waves. The pressure is then released along faults sending out huge pulses of energy.

Question 28

Nepal Earthquake CS - Causes

Answer 28

There were collision plate margins between Indian plate and Eurasian plate.

Question 29

Nepal Earthquake CS - Management

Answer 29

Temporary Shelters were built.

Question 30

Nepal Earthquake CS - Primary effects

Answer 30

8,841 people died, over 16800 injured and 1 million homeless. A reduced supply of water, food, electricity. Historic buildings and temples in Kathmandu, Harar tower a UNESCO world heritage site, 20 hospitals and 50% of schools destroyed. 352 aftershocks

Question 31

Nepal Earthquakes CS - Secondary effects

Answer 31

The earthquake happened just before the monsoon season when rice is planted, 2/3 of the population depend on rice. Triggered and avalanche - 19 people died.

Question 32

Nepal Earthquake CS - Immediate responses

Answer 32

Nepal requested a lot of help from other countries. The USDEC raised $126 million to provide to rebuild most severely hit areas. Temporary shelter was set up.

Question 33

Nepal Earthquake CS - Long term responses

Answer 33

The nepal government carried out a post disaster and needs assessment, They said 23 areas need full rebuilding as they were very important.

Question 34

Italy Earthquake CS - Causes

Answer 34

There is an african plate which is crashing into the eurasian plate. Both collision plate margins.

Question 35

Italy Earthquake CS - Managements

Answer 35

There were very effective communication strategies. THere were many machines + monitoring high earthquakes.

Question 36

Italy Earthquake CS - Primary effects

Answer 36

308 people died, 1500 people critically injured, 67500 people left injured and occured at 3:36 am. 10000- 15000 buildings collapsed.

Question 37

Italy Earthquake CS - Secondary effects

Answer 37

The amount of students in l'aquil university decreased. Lack of housing increased prices. All of the business districts were cordoned off due to unsafe buildings. Aftershocks triggered landslide and rockfall.

Question 38

Italy Earthquake CS - Immediate responses

Answer 38

5000 soldiers, alphine guides, police, firefighters and volunteers were involved in the rescue. THe rescue teams worked throughout the night and the Italian red cross set up tents for those force to leave homes and they provided emergency items. Mobile kitchens provided 1000 meals a day.

Question 39

Italy Earthquake CS - Long term responses

Answer 39

The Italian government, promised to move displaced families into camps into lightweight wooden houses. THe italian government will rebuild villages to look the same as they were before as well as being earthquake proof.

Question 40

How are tsunamis formed

Answer 40

When the oceanic plate sinks below the continental plate there are earthquakes. These cause the water in the gaps to be repelled outwards. This then causes the waves to be sent towards the land.

Question 41

How can we mitigate the impacts of seismic hazards

Answer 41

Prediction - Use of seismographs, Animals can act weirdly before an earthquake Planning - educate children in schools to know what to do, Have an earthquake warning system Protection - Have strong steel frames on buildings which are flexible and stop cracking.

Question 42

Living in Hazard Prone areas - Geothermal enrgy

Answer 42

Geothermal energy is a major source of electrical power and stema is heated by hot mama in permeable rock. These then turn turbines at power stations. It is renewable which means it will never run out. 30% of Icelands energy

Question 43

Living in Hazard Prone areas - Farming

Answer 43

Lava and ash erupting from volcanoes can kill livestock and destroy crops and vegetation. after 1000s of years the weathering of this lava releases minerals and leaves behinds extremely fertile soils, which are rich in nutrients.

Question 44

Living in Hazard Prone areas - Family, Friends, Feelings.

Answer 44

Many people don't want to leave because of ancestors living here in the past. Sometimes it is easier when people monitoring the natural hazard have asid that the effects are not that severe.

Question 45

Living in Hazard Prone areas - Tourism

Answer 45

Many tourists come and visit volcanoes for the spectacular view and the very relaxing hot springs, adventure and for thrill seeking. More than 100million people come and visit volcanic sites every year. The revenue is beneficial.

Question 46

Living in Hazard Prone areas - Mining

Answer 46

Valuable minerals are found in these areas and many jobs are created in the mining industry. It is not just dormant or extinct volcanoes that are mined but active volcanoes are well.