Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

A level GEOGRAPHGY edexcel > Tectonic hazards > Flashcards

Tectonic hazards Flashcards

1
Q

what is accretion wedge

A

-the accumulation of material at the point of subduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is aseismic building

A

buildings designed to withstand or minimise destruction during an earthquake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the asthenosphere

A

the upper mantle layer of the earth . its semi molten and approximately 200km wide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is ash

A

fine particles and dust ejected during an eruption , which can remain airborne as clouds or accumulate on the ground

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the continental crust

A

crust that forms the continents of the lithosphere , on average 35km thick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is continental drift

A

the movement of tectonic plates , due to varying weights of crust . it was originally though convection currents moved plates but now slab pull is though of as the primary driving force.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is Degg’s model

A

model shows that a hazard becomes a disaster if it affects a vulnerable population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the epicentre

A

the point on the surface , directly above the earth quakes origin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the focus

A

the place in the crust where the pressure / seismic energy is released

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the hazard mitigation cycle

A

the sequence of governance of a natural hazard: monitoring and prediction, mitigation, preparedness.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a hot spot

A

volcanoes found away from the plate boundary , due to magma plume closer to the surface.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is Jokulhaup

A

a sudden glacial flood caused by a glacier on top of or near a volcano melting due to heat from the eruption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is a lahar

A

a flow of mud and debris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the lithosphere

A

the upper crust of the earth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is a love wave

A

a surface earthquake wave with horizontal displacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is a mid ocean ridge

A

Partin oceanic plates at a constructive plate boundary creates a ridge , with new land at the base of the oceanic valley

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the oceanic crust

A

crust, usually thinner than continental crust , that forms the sea floor . it is on average 7km thick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is paleomagnetism

A

the alternating polarisation of new land created.
as magma cools, the magnetic elements within will align with the earths magnetic field , which can alternate over thousands of years.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the park model

A

a model describing the decline and recovery of a country over time, following a natural disaster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are primary waves

A

an earthquake wave causing compressions within the body of the rock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is pyroclastic flow

A

a mixture of gases and rock fragments , at high temperatures travelling at rapid speeds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is a Rayleigh wave

A

a surface earthquake wave causing both horizontal vertical displacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is a Richter scale

A

a logarithmic measure of earthquakes intensity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is a secondary wave

A

an earthquake wave causing vertical displacement within the body of rock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is a seismic wave
the energy relesed during an earthquake in the forms of primary , secondary , love and Rayleigh waves
26
what is slab pull
the force contributing to the movement of tectonic plates . slab pull is due to the weight of the plate.
27
what is subduction
oceanic plate is forced below continental plate , due to the oceanic plate being more dense than the continental plate.
28
what is a tsunami
initial vertical water displacement creates waves, with large destructive power.
29
what is the volcanic explosivity index
a measure of magnitude of a volcanos eruption
30
what is the wadati-benioff zone
a region of the subducting plate , most affected by pressure and friction, where most destructive margin earthquakes originate
31
what is a destructive plate boundary
Continental and oceanic: ● Denser oceanic plate subducts below the continental. ● The plate subducting leaves a deep ocean trench. ● Built up pressure from the melting plate cause explosive volcanoes bursting through the continental plate
32
what is a constructive boundary
Oceanic and oceanic: ● Magma rises in between the gap left by the two plates separating, forming new land when it cools. ● Less explosive underwater volcanoes formed as magma rises. ● New land forming on the ocean floor by lava filling the gaps is known as sea floor spreading (as the floor spreads and gets wider). Continental to continental: ● Any land in the middle of the separation is forced apart, causing a rift valley. ● Volcanoes form where the magma rises. ● Eventually the gap will most likely fill with water and separate completely from the main island.
33
what is ridge push
The slope created when plates move apart has gravity acting upon it as it is at a higher elevation. Gravity pushes the plates further away, widening the gap (as this movement is influenced by gravity, it is known as gravitational sliding).
34
what plate boundary does earthquakes occur at
The most powerful earthquakes occur at destructive and conservative boundaries
35
what plate boundary does Tsunami occur at
occur at destructive boundaries
36
what plate boundary does Volcanic hazards occur at
The world’s active volcanoes are found at constructive and destructive plate boundaries, and at hotspots
37
what is the equation for risk
Risk = hazard x vulnerability / capacity to cope
38
what is the PAR model
Root causes - dynamic pressures - unsafe conditions- disaster( risk - hazard x vulnerability) - natural hazard
39
what are the steps to the park's model
step 1 - Relief ( hours-day) Immediate local response ,foreign aid step 2- Rehabilitation ( days or weeks ) Services ,Temporary shelters ,hospitals set up Food and water step 3-Reconstruction ( weeks - years) Restoring , Infrastructure , future event
40
What did believe Alfred Wegener 1912
All continents were once joined in a super continent called Pangea. Continental drift caused Pangea to move apart.
41
What did say Holmes 1929
Convection in the mantle is the force behind continental drift.
42
What is a Volcanic Hotspot
An area in the mantle from which heat rises as a hot thermal plume from deep in the earth.
43
What is the lithosphere?
the rigid outer part of the earth, consisting of the crust and upper mantle.
44
What is the asthenosphere?
the upper layer of the earth's mantle, below the lithosphere.
45
Factors affecting earthquake intensity
*Duration of locked fault *Depth of hypo-centre *Timing & intensity of seismic waves
46
What Is basaltic magma
magma that has low viscosity and low silica and gas content; eruption is non-explosive
47
Rhyolitic Magma
magma that has a high viscosity and high silica and gas content; eruption tends to be very explosive
48
Explain a Composite volcanoes
large, steep-sided volcanoes that result from explosive eruptions of andesitic and rhyolitic lava and ash along convergent plate boundaries. Poses most danger to Hunan life.
49
Explain a Shield Volcanoes
Gently sloping mountains formed by thin, runny lava. Frequently eruptive.
50
What is the "Benoiff zone"
A dipping flat zone where earthquakes are produced by the interaction of a submerging oceanic crustal plate with a continental plate.
51
What is a fault
A fracture in the rocks that make up the earth's crust
52
What is an epicentre?
The point on the Earth's surface straight above the focus.
53
What are Secondary Hazards of Earthquakes
*liquefaction *landslides *tsunamis
54
What is soil liquefaction?
When an earthquake causes the ground to shake to the point of making it liquid.
55
What is a landslide?
the sliding down of a mass of earth or rock from a mountain or cliff.
56
What is a tsunami?
Convection currents in the mantle move plates towards each-other. Pressure builds up as the denser plate is forced beneath the overriding plate. An EQ occurs. Water is displaced creating a wave which spreads out. As wave approaches shore, height increases and wave length shortens
57
What are the Primary Hazards of a Volcano?
*pyroclastic flow *tephra *volcanic gases *lava flows
58
What is tephra?
rock fragments and particles ejected by a volcanic eruption
59
What are volcanic gases?
Water, sulphur dioxide, hydrogen and CO2.
60
What are the secondary impacts of a volcano?
*Jokulhlaups *Lahars
61
What are Jokulhlaups?
Sudden, violent and short-lived increase in discharge of glacial meltwater
62
What is community resilience?
The ability to cope with a hazard using your own resources.
63
Reasons Cumulative Act Effect Model
Acknowledges that pre-existing vulnerabilities in society can exacerbate the impacts of a hazard and make it into a disaster
64
Governance
The sum of the many ways individuals and institutions, public and private, manage their common affairs
65
what are the three ways of managing a tectonic hazard.
Modify the Event, Modify the Vulnerability, Modify the Loss​.
66
Explain Modifying the event .
we can't control seismic activity. how can control the design of buildings through civil engineering using micro and macro methods. Micro - strengthening individual buildings and structures. Macro- large scale support and protective measures designed to protect whole communities.
67
what are the different types of modifications in modifying the event.
- Land use zoning - Resistant buildings - Tsunami defences - Lava diversion
68
what are the advantages and disadvantages of Land use zoning
+ low cost +reduced vulnerability -stops economic - development on some high value land - strict enforcement requirement .
69
what are the advantages and disadvantages of Resistant buildings
+ can help prevent collapsing +protects people and property. - high cost for larger buildings - Low income families cannot afford this.
70
what are the advantages and disadvantages of Tsunami defences
+Reduces damages + Provides security - Very high cost -Doesn't look nice - Can be overtopped
71
what are the advantages and disadvantages of Lava diversion
+ Diverts lava away + low cost -only works for low VEI lava
72
what are the different modifications for modify vulnerability.
Hi tech scientific monitoring Community preparedness and education . Adaptation

A level GEOGRAPHGY edexcel (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions