The Challenge Of Natural Hazards - Tectonic

Question 1

What is a natural hazard?

Answer 1

A natural event that threatens people or has the potential to cause damage, destruction and death

Question 2

Examples of a natural hazard

Answer 2

Earthquake

Volcano

Tropical storm

Question 3

What factors affect the impact of a natural hazard?

Answer 3

Population - distribution and density

Frequency

Location - rock type, land relief

Magnitude

Level of development & wealth

Question 4

What are the 3 Ps?

Answer 4

Prediction

Preparation

Prevention

Question 5

What layers of the earth?

Answer 5

Inner core
Outer Core
Mantle
Crust

Question 6

What are convection currents?

Answer 6

Occurs in the mantle

Magma rises from heat and then sinks as it cools down

Question 7

What do convection currents do?

Answer 7

Build pressure

Carry plates with them

Question 8

What are the two types of crust?

Answer 8

Oceanic

Continental

Question 9

Oceanic crust

Answer 9

Newer

Thinner

Denser - sinks

Question 10

Continental crust

Answer 10

Older

Very thick

Not dense - cannot sink

Question 11

What is slab pull?

Answer 11

When denser plates sink into the mantle - due to gravity

It pulls the rest of the plate along behind it

Question 12

What is ridge push

Answer 12

Magma rises and the plates move apart

Magma cools - new material forms = more dense

Slides down away from ridge = tectonic plates move away from each other

Question 13

What is continental drift?

Answer 13

Theory discovered by Alfred Wegnar

All continents used to be combined - called Pangea

Question 14

What is evidence for continental drift

Answer 14

Continents fit like puzzle pieces

Correlation of fossils

Mountainous areas match neighbouring countries

Question 15

What is a destructive plate margin

Answer 15

Two plates collide with each other - due to convection currents

Oceanic crust is more dense - it sinks into mantle

Question 16

What natural hazards occur along a destructive plate margin?

Answer 16

Earthquake - friction between to plates causes earthquakes

Volcano - friction and heat from mantle melts rock, hot liquid rises and volcano erupts

Question 17

What is a constructive plate margin?

Answer 17

Two plates move apart

A new crust is formed - mid ocean ridge

Question 18

What natural hazards occur along a constructive plate margin

Answer 18

Volcano
Magma rises up to form a volcano filling the gaps
Magma cools as plates are pulled apart - gap forms

Earthquakes
The movement of plates causes earthquakes in the mantle

Question 19

What is a conservative plate margin?

Answer 19

Two continental plates move parallel to each other

Friction and pressure build up

Energy is released and the two plates move at different rates

Question 20

What natural hazard occurs along a conservative plate margin

Answer 20

Earthquakes

Friction from plates sliding against each other

Question 21

What are the two types of volcanoes?

Answer 21

Composite and Shield

Question 22

Characteristics of a composite volcano

Answer 22

Sticky, viscous lava
Destructive plate margins
Explosive
Travels slowly
Steep sided volcano

Question 23

Characteristics of a Shield volcano

Answer 23

Runny Lava
Constructive plate margin
Non-explosive
Travels quickly
Shallow sided volcano

Question 24

What are the seven main volcanic hazards

Answer 24

Volcanic Gases
Landslides
Lahar
Lava flows
Pyroclastic flows
Tephra
Jokulhlaup

Question 25

Volcano Case study

Answer 25

Eyjafjallajokull, Iceland

Question 26

Location of Eyjafjallajokull

Answer 26

Eruption was 100km away from the capital city of Iceland

Question 27

Magnitude of Eyjafjallajokull

Answer 27

140million3 of material was ejected in the first five days First 24 hours - 3.1 magnitude

Question 28

Date and Time of Eyjafjallajokull eruption

Answer 28

Began in March 2010 - wasn’t a threat 14th -18th April - most explosive phase and height of crisis

Question 29

Causes of Eyjafjallajokull eruption

Answer 29

The volcano had been active since 1863 Constructive plate margin runs through Iceland Slab pull + convection currents

Question 30

Primary effect of Eyjafjallajokull

Answer 30

Huge ash cloud - main hazard Ice caps melted Thick clouds of ash were omitted Ash travelled impacting neighbouring countries

Question 31

Secondary effects of Eyjafjallajokull

Answer 31

Transport was cut off Air was polluted - injuring and disturbing Jobs cut off meaning expenses stacked up - UK lost £102 million in 6 days

Question 32

Immediate responses to Eyjafjallajokull

Answer 32

Airlines closed - ash damaged plane systems Computers used to monitor the clouds movement

Question 33

Long term responses to Eyjafjallajokull

Answer 33

Food had to be imported and without transport it was difficult People began to question whether the strict guidelines were necessary

Question 34

What is an earthquake

Answer 34

A sudden or violent movement within the Earth’s crust followed by a series of shocks

Question 35

What is used to measure Earthquakes

Answer 35

Richter scale 1 = 10 times greater

Question 36

What is a tectonic hazard

Answer 36

A natural hazard caused by the movement of tectonic plates

Question 37

Epicentre

Answer 37

The point inside the crust where the pressure is released

Question 38

Focus

Answer 38

The point of origin of an earthquake within the earths crust

Question 39

Earthquake HIC case study

Answer 39

L’aquilla, Italy

Question 40

Important facts about L’aquilla

Answer 40

L’aquilla is a city in central Italy High Income country

Question 41

Magnitude and time of L’aquilla earthquake

Answer 41

6.3 on Richter scale 6th April 2009 - 3.32am

Question 42

Causes of L’aquilla earthquake

Answer 42

Destructive Plate margin 4.6 magnitude tremor shook the area

Question 43

Primary effect of L’aquilla earthquake

Answer 43

10,000 buildings destroyed Deaths were reported People were looking for safety and shelter

Question 44

Secondary effects of L’aquilla earthquake

Answer 44

Phone and power lines went down Rescuers were sent to search the rubble;e Landslides = rockfall Bridges and roads closed

Question 45

Immediate responses to L’aquilla earthquake

Answer 45

Declared a state of Emergency People were hosted in tents and hostels Free mobile calls Rescue services were stretched to the breaking point

Question 46

Long term responses to L’aquilla earthquake

Answer 46

Two field hospitals thrived Open air medical help 11 million in cost damage

Question 47

Earthquake LIC case study

Answer 47

Gorkha, Nepal

Question 48

Important facts about Gorkha earthquake

Answer 48

City in Nepal Low income country

Question 49

Magnitude and date of Gorkha earthquake

Answer 49

7.8 magnitude on the Richter scale 25th April 2015

Question 50

Causes of the Gorkha earthquake

Answer 50

Destructive plate margin Build up of stress causing sudden thrusts Tectonic forces built up movement along plates leading to earthquake

Question 51

Primary effects of Gorkha earthquake

Answer 51

Earthquake triggered Avalanche on Mount Everest Buildings were destroyed Deaths reported Belongings lost

Question 52

Secondary effects of Gorkha earthquake

Answer 52

People had no house so had to sleep outside - exposed Harvest was lost - income fluctuated - valuable food Resources were running out Tourism decreased - income decreased

Question 53

Immediate responses to Gorkha earthquake

Answer 53

People were living in tents in fields People pulled others out the rubble to help International countries shared resources

Question 54

Long term responses to Gorkha earthquake

Answer 54

Countries offered support Task force for dealing with earthquakes cam to help People were educated 5 billion cost damage

Question 55

4 ways to manage tectonic hazards

Answer 55

Planning Protection Prediction Monitoring

Question 56

Why do people live in areas at risk from tectonic hazards

Answer 56

Richer soils - good for agriculture Mining - energy and income Can’t afford to move Family and friends Not understanding risk Not high enough risk

Question 57

Plate Margin

Answer 57

A place where two tectonic plates meet