1
Q
Plate boundary
A
- the lines where tectonic plates meet are called the plate boundaries.
2
Q
Name the four types of plate boundary
A
- convergent (destructive)
- divergent (constrictive)
- transform (conservative)
- intra plate
3
Q
Where do most powerful earthquakes occur?
A
- convergent
- transform
4
Q
Where do most volcanoes occur?
A
- convergent
- intraplate (hotspots)
5
Q
What are hotspot volcanoes and where do they occur?
A
- areas on the mantle where heat rises as a thermal plume from deep in the earth, low pressure and high heat in the tectonic plate leads to the melting of rock which rises through cracks as magma to form a volcano.
- form at intra plate boundaries
6
Q
What is the mid Atlantic ridge and its hazards?
A
- divergent (constructive) plate boundary
- forms volcanic islands
7
Q
Why are some at more risk to earthquakes than others?
A
- closer to plate boundaries
8
Q
Difference between oceanic and continental plates
A
- oceanic underneath sea floor, dense basalt
- continental underneath land, less dense granite
9
Q
Why do plates move?
A
- convectional currents
10
Q
3 processes that occur at convergent boundaries
A
- subduction
- earthquakes
- volcanic activity
11
Q
What is paleo magnetism and how does it help in the study of plate tectonics?
A
- the study of the magnetism in rocks induced by the earths magnetic field
- helped back up the continental drift hypothesis and its transformation into plate tectonics.
12
Q
What is a locked fault?
A
- a fault hat isn’t slipping as the frictional force is greater than the stress on the rock
- when it does slip can cause a larger earthquake
13
Q
What is the Benioff zone?
A
- an inclined zone underneath convergent plate margins where the oceanic crust is subducted.
14
Q
Hypocentre and epicentre
A
- hypocentre point within earth where earthquake originates
- epicentre pint on earth surface where earthquake originates
15
Q
Intensity vs magnitude of earthquake
A
- intensity , severity of shaking assessed using modified mercalli scale
- magnitude, size of earthquake using Richter scale
16
Q
Describe the three types of seismic waves
A
Primary wave
- arrives first, longitudinal, travels through solid rock and fluids.
Secondary wave
- slower than p wave, transverse, only moves through solid rock
Love wave
- only travels through surface of crust, fastest of surface waves, moves form side to side as it moves forward
Rayleigh wave
- only travels through surface of crust, rolling motion, slower than love wave, ground moved up and down and side to side.
17
Q
Secondary hazards associated with earthquakes
A
- landslides
Seismic waves loosen rocks of steep slopes, loses cohesion and falls due to gravity. - liquefaction
Lowland areas where shaking sorts the ground material to the point where it acts as a fluid.
18
Q
Describe how 3 primary volcanic hazards affect people
A
- Lava flows
Burns and covers everything in its path and when moving quickly can burn humans. - emissions of gases or steam (phreatic eruption)
Can pollute water sources and cause mass fatalities as a large amount of co2 in the air reduces oxygen. - pyroclastic flow
Rock fragments and hot gases, 900 degrees Celsius can cause death and destruction of cities e.g. Pompeii
19
Q
What are jokulhlaups and why are they hazardous
A
- a jokulhlaup is a flood of meltwater issuing from underneath an ice cap or glacier, forming when a volcano erupts underneath the ice and melts the ice so it forms a lake.
- the water bursts out carrying blocks of ice, this can lead to it wiping out roads and bridges, e.g. Iceland main road along the south coast been cut and bridges washed away.
20
Q
What is meant by vulnerability
A
- the weaknesses of people in a situation where they are exposed to risk e.g. A tectonic hazard.
21
Q
What is meant by resilience
A
- the ability of a community to resist the impacts of a hazard by adapting and recovering
22
Q
What is the hazard risk equation
A
risk = hazard x vulnerability
- an equation used to show the risk to people
23
Q
What makes a hazard into a disaster
A
- the United Nations suggest 500 or more deaths is a disaster.
24
Q
Name the 2 pressures in the pressure and release model
A
- (dynamic pressures)
Lack of skills
Lack of training
Urbanisation
25
What are the main economic impacts of tectonic hazards
- damage to infrastructure
- halt to agricultural activities
- collapsed buildings less business higher unemployment less tax
26
Explain the possible link between the capacity of a country to cope with a hazard and its level of development
- urban governments of rapidly growing cities can plan ahead to reduce vulnerability
- poorer countries with poor governance such as Haiti have poor capacity and cannot reduce vulnerability
27
Why are the impacts of earthquakes generally greater than those of volcanoes
- fast speed of onset
- unpredictable
- impacts larger area
28
What does VEI stand for and what does it measure
- volcanic explosivity index
| - measures how explosive a volcanic eruption is using style of past activity, plume head and height of spreading.
29
Name the six characteristics commonly used in producing a tectonic hazard profile
- high magnitude
- speed of onset
- duration
- areal extent
- spatial predictability
- frequency
30
Explain the value of compiling hazard profiles
- allows to compare to previous events
- allows to identify a strategy to reduce vulnerability
- analyse risks
31
Identify the inequalities that make low income households and communities carry a disproportionate share of disaster costs
- low income therefore damage to infrastructure cannot be repaired, water sources polluted, diseases spread.
32
In what ways does poor governance increase vulnerability to the impacts of tectonic hazards
- lack of preparation
- poor prediction
- lack of income means poor response
33
Identify the factors that made one specific earthquake event into a disaster
- Haiti earthquake
- over 500 deaths
- dependance on aid from abroad
34
Identify two ways in which disasters can create development opportunities
- allows to reconstruct old buildings with better design
- become more resilient
- more modern city could lead to a rapidly growing city
35
Give reasons why disaster statistics are not altogether reliable
- subjective what a disaster is
| - can be unreliable
36
Spatial scale is one characteristic of a mega disaster, outline other characteristics
- fatalities
- homelessness
- fall in GDP
- dependance on aid
37
Give one recent example of a tectonic mega disaster
- Haiti 2010
38
What is a multiple hazard zone? Name one country that is particularly exposed to multiple hazard
- a place whihc is exposed to multiple hazards
| - phillipines exposed to volcanoes earthquakes tsunamis 60% of land is exposed to multiple hazards
39
Give an example of how different types of natural hazard may be linked
- tsunamis can be generated from large shallow earthquakes with an epicentre near or on the ocean floor
40
Explain why there is concern about the worlds rapidly growing mega cities
- some locations vulnerable to multiple hazards therefore hazards could cause larger economic damage due to modern infrastructure.
41
Name the four main stages in the hazard management cycle
- pre disaster
- response
- post disaster
42
What does the risk disk model attempt to explain
-
43
Explain the role of scientists as players when dealing with tectonic hazards
- scientists develop technology used to predict
| - aid rehabilitation
44
Give three examples of the human factors affecting the response to a tectonic hazard
- infrastructure (communications e.g. Mobile signal)
- media
- accessibility, ease of access to emergency
45
Identify the four stages in parks model of the disaster response curve
- pre disaster
- relief
- rehabilitation
- reconstruction
46
Describe how the parks model can help in the study of tectonic disasters
- can allow us to identify time frames for each stage
| - can use previous records to predict response curve for future events
47
Identify the four priorities of the Sendai framework for action (2015)
-
48
Evaluate the four different approaches to hazard management
-
49
give three examples of the human factors affecting the response to a tectonic hazard
-
Geog Physical AS
flashcards
Decks in class (5)
# Cards
