1
Q
What is a natural hazard?
A
A natural process that threatens human life, property, or the built environment (e.g., earthquakes, volcanoes, storms).
2
Q
Where are most tectonic hazards located?
A
Along plate boundaries where plates interact (constructive, destructive, conservative).
3
Q
Why do intraplate earthquakes occur?
A
Because old crust develops weaknesses that can reactivate under pressure despite being far from boundaries.
4
Q
What are volcanic hotspots and how do they form?
A
Localised mantle plumes (e.g., Hawaii) where unusually hot magma rises and penetrates thin crust, forming chains of volcanoes.
5
Q
What happens at continental-oceanic destructive boundaries?
A
Denser oceanic plate subducts, forms deep trenches, melting produces magma → explosive composite volcanoes + fold mountains.
6
Q
What happens at oceanic-oceanic destructive boundaries?
A
Denser oceanic plate subducts, forming trenches, volcanic island arcs (e.g., Japan), and submarine volcanoes.
7
Q
What happens at continental-continental destructive boundaries?
A
No subduction due to equal density → crust buckles forming fold mountains (e.g., Himalayas).
8
Q
Key features of constructive oceanic-oceanic boundaries?
A
Magma rises through gap → sea-floor spreading → mid-ocean ridges + fissure volcanoes.
9
Q
What forms at continental-continental constructive boundaries?
A
Rift valleys (graben), uplifted blocks (horsts), volcanic activity, eventual formation of new oceans.
10
Q
What defines conservative boundaries?
A
Plates slide past each other, creating tension → earthquakes along fault lines (e.g., San Andreas fault).
11
Q
What are the Earth’s layers and major characteristics?
A
Crust (basalt/granite), Mantle (semi-molten, convection currents), Outer Core (liquid iron), Inner Core (solid iron, radioactive heating).
12
Q
What is slab pull and why is it important?
A
Subducting dense oceanic plates pull the rest of the plate downward → now considered the MAIN driver of plate motion.
13
Q
What is ridge push?
A
As new crust forms at ridges, gravity pushes plates apart down the slope.
14
Q
What is paleomagnetism evidence for plate movement?
A
As lava cools, iron minerals align with Earth’s magnetic field. Symmetrical magnetic stripes on ocean floor indicate sea-floor spreading.
15
Q
Name the two scientists linked to major tectonic theories.
A
Harry Hess (sea-floor spreading)
Dan McKenzie (slab pull/mechanical plate movement).
16
Q
Primary volcanic hazards?
A
Lava flows (low viscosity basalt = fast)
pyroclastic flows (high-speed deadly mixtures)
ash (roof collapse, aviation hazard)
volcanic gases (SO2, CO2).
17
Q
Secondary volcanic hazards?
A
Lahars (volcanic mudflows triggered by rain or melting ice)
Jokulhlaups (glacial outburst floods)
acid rain (SO2 combines with water vapour).
18
Q
Why are pyroclastic flows so dangerous?
A
Travel >100 km/h, 300°C+, cannot be outrun, destroy everything in path.
19
Q
What causes earthquakes?
A
Friction locks plates; stress builds until it is released suddenly → seismic waves.
20
Q
Difference between focus and epicentre?
A
Focus = origin inside Earth
epicentre = surface point directly above it.
21
Q
Types of seismic waves?
A
P-waves (fast, compressional, through solid/liquid)
S-waves (slower, only solids)
Love waves (horizontal shear, very destructive), Rayleigh waves (rolling).
22
Q
Secondary hazards of earthquakes?
A
Liquefaction (soil behaves like liquid)
landslides (hill collapse)
tsunamis (sea-floor uplift displaces water)
fires (burst gas pipes).
23
Q
Why does damage vary even at same magnitude?
A
Geology
building strength
depth of focus
distance from epicentre
preparedness.
24
Q
What is a hazard profile used for?
A
Comparing hazards by their physical characteristics to prioritise management and resources.
25
What are the components of a hazard profile?
Magnitude, frequency, duration, speed of onset, fatalities, economic loss, spatial predictability.
26
Why are hazard profiles less useful for multi-hazard events?
They **fail to capture secondary hazards** (e.g., tsunami worse than earthquake).
27
Define disaster according to UNISDR.
**Serious disruption** exceeding a **community’s ability to cope** using internal resources.
28
What does Degg’s model show?
Disaster = hazard + vulnerable population; hazards alone do not create disasters.
29
Why do definitions of disaster vary?
**Organisations prioritise different impacts** (fatalities, economic loss, people affected).
30
Write the hazard risk equation.
Risk = Hazard × Vulnerability ÷ Capacity to Cope.
31
What increases a population’s risk?
High vulnerability, low capacity to cope, high hazard magnitude.
32
What is resilience?
Ability of a population/system to absorb, cope with, and recover from a hazard.
33
Factors affecting resilience?
Wealth, education, governance, infrastructure strength, community cohesion.
34
What does the PAR model explain?
How **vulnerability builds through** social/economic/political processes leading to disaster.
35
List the 3 components of vulnerability in the PAR model.
Root causes → Dynamic pressures → Unsafe conditions.
36
Give an example of each PAR stage
Root causes: weak governance
Dynamic pressure: lack of training
Unsafe conditions: poor infrastructure
37
How to reduce pressure in PAR?
Address root causes (governance), reduce dynamic pressures (education), improve safe conditions (building standards).
38
How does development affect hazards?
More development = fewer deaths but higher economic losses
39
What is the Risk-Poverty Nexus?
Poverty increases vulnerability; disasters deepen poverty (a positive feedback loop).
40
Why do richer countries suffer larger economic losses?
High-value infrastructure, insurance payouts, complex services damaged.
41
Types of inequality affecting vulnerability?
Asset (quality of buildings), political (voice, leadership), social status (class, mobility), entitlement (access to services).
42
Why are urban areas particularly vulnerable?
High population density + vertical living + more infrastructure at risk.
43
How does good governance reduce vulnerability?
Land-use planning, warning systems, building codes, education, disaster plans.
44
How does corruption increase disaster losses?
Funds diverted away from mitigation → weak emergency services, poor building standards.
45
Role of planning in vulnerability?
Avoids building in hazard zones, prevents secondary hazards (e.g., deforestation increases landslides).
46
Trend in recorded hazards since 1960?
Increasing due to better monitoring + more people living in hazard zones.
47
Trend in fatalities from 1960
Decreasing due to better medical care, early warning systems, preparedness.
48
Trend in economic losses from 1960
Increasing due to development, infrastructure value, insurance costs.
49
Why is hazard data sometimes unreliable?
Government bias, remote locations, different measurement methods
50
Define mega-disaster.
High magnitude, high impact, low frequency event affecting large populations and requiring international aid.
51
Characteristics of mega-disasters?
Widespread spatial impact, large economic losses, supply chain disruption.
52
Examples of global economic disruption from hazards?
Tohoku 2011 (supply chain shock), Eyjafjallajökull 2011 (airspace closure).
53
What is a multiple hazard zone?
Area exposed to several interacting hazards (e.g., Philippines → earthquakes, typhoons, volcanoes, landslides).
54
Why are they more at risk?
Multi hazard zones
Cascading hazards, overstretched response systems, poverty, steep slopes, climate change.
55
Four stages of the Hazard Management Cycle?
Mitigation → Preparedness → Response → Recovery.
56
Examples of mitigation?
Building codes, sea walls, land-use zoning, reinforcing structures.
57
Examples of preparedness
Drills, education, stockpiling supplies, evacuation planning
58
what is modifying vulnerability
Forecasting likelihood of events using seismic data, satellite images, tiltmeters (volcanoes).
59
Examples of modifying vulnerability
Relocation, building adapted homes, diversifying livelihoods, hazard-resistant urban design.
60
Benefits and limits of modifying vulnerability
Protects lives long term, but expensive and culturally disruptive.
61
What is modifying loss?
Reducing impacts after the event using response and recovery measures.
62
Examples of modifying loss?
Insurance, international aid, rebuilding programmes, NGOs providing emergency relief.
63
Why is short-term aid essential?
Prevents disease outbreaks, provides shelter, supports survival.
64
Long-term aid advantages?
Rebuilds infrastructure, increases resilience through improved planning and building codes.
65
what are physical processes that impact the magnitude and type of volcanic eruption
magma viscosity, volatile (gas) content, and tectonic setting
66
explain magma viscosity and how it can impact the magnitude of a volcanic eruption
The "thickness" of magma determines flow resistance. High silica content increases viscosity, leading to sticky, gas-trapping magma that causes explosive eruptions.
While low-viscosity, basaltic magma results in effusive lava flows.
67
explain volatile (gas) content can impact the magnitude of a volcanic eruption
the amount of dissolved gases (water, carbon dioxide, sulfur) dictates eruptive pressure. High gas content creates intense pressure, leading to higher-magnitude explosions
68
explain tectonic setting and how it can impact the magnitude of a volcanic eruption
Destructive Boundaries: Subduction zones, where oceanic crust sinks, produce viscous, gas-rich magma leading to violent explosions (e.g., Mount St. Helens).
Constructive Boundaries: Plates moving apart allow magma to rise easily, resulting in runny, basaltic lava flows (e.g., Iceland).
Hotspots: Plumes from deep in the mantle can create massive, often effusive eruptions (e.g., Kilauea).
69
what are the two types of eruptions
effusive- Characterized by low-viscosity, low-gas, basaltic lava. Produces lava flows rather than explosions.
explosive-Driven by high-viscosity, high-gas, silicon-rich magma. Releases tephra, ash, and pyroclastic flows.
70
what are physical processes that can impact an earthquakes magnitude and focal depth
By tectonic plate interactions—specifically subduction, collision, and lateral slipping—which dictate the release of strain energy.
Shallow earthquakes (0-70 km) occur at all boundary types due to brittle faulting
While deep earthquakes (up to 700 km) occur in subduction zones via high-pressure, ductile, or mineral-phase changes.
71
what do p waves cause
They cause minor damage, often felt as a quick jolt or rattle, and can travel through solids, liquids, and gases.
72
what do s waves cause
S-waves travel slower than P-waves and move through solid rock only. They create transverse, side-to-side or up-and-down shaking, causing much more intense shaking and damage than P-waves
73
what do l waves cause
Love waves are a type of surface wave that shakes the ground horizontally, perpendicular to the direction of motion. They are generally responsible for the most severe, destructive damage, shaking buildings side-to-side.
74
what can happen after earthquakes as secondary hazards
landslides,liqufaction
75
explain liquefaction as a secondary hazard of earthquakes
The process where saturated, loose, granular soil loses its strength and stiffness due to intense shaking (like an earthquake), causing it to behave like a liquid. This phenomenon causes soil to lose its capacity to support structures, leading to sinking, tilting, or collapse of buildings
76
explain a landslide as secondary hazard of earthquakes
The downslope movement of rock, soil, and debris triggered by strong ground shaking
77
explain how tsunamis are caused by sub marine earthquakes at subduction zones
when a dense oceanic plate subducts under a continental plate, causing immense strain. When this strain exceeds friction, the upper plate snaps upward, vertically displacing a massive volume of seawater, which radiates outwards as high-speed, long-wavelength waves.
78
what is MMS as a type of scale to measure magnitude and intensity earthquakes
The Moment Magnitude Scale (MMS) is the modern standard, measuring the energy released based on fault slip and area, typically replacing the older Richter Scale.
79
what is the mercalli scale as a type of scale to measure magnitude and intensity earthquakes
Mercalli Intensity Scale measures the effects of an earthquake on humans, buildings, and the environment, ranging from I (not felt) to XII (total destruction)
80
what is the vei as a type of scale to measure magnitude and intensity of a volcano
This scale (0-8) measures the magnitude of volcanic eruptions based on the volume of material erupted, plume height, and duration.
81
what are the three scales to measure magnitude and intensity of tectonic hazards
mercalli,moment magnitude scale,volcanic explosivity index
82
what is modifying the event
Modifying the event refers to proactive, long-term hazard management strategies designed to reduce the physical magnitude, areal extent, or impact of a natural disaster before it occurs. Key techniques include engineering defenses, land-use zoning, and hazard-resistant design to control, divert, or withstand natural hazards.
83
explain convection in terms of a theory of plate tectonics
Convection currents are driven by intense heat from radioactive decay in the Earth's core.
Process: Hot, less-dense magma in the mantle rises towards the lithosphere, cools, moves horizontally, becomes denser, and sinks back down.
Role in Tectonics: Historically, it was believed these currents directly carried the overlying plates, acting like a conveyor belt. Rising currents create constructive (divergent) margins, while descending currents pull plates together at destructive (convergent) margins.
84
define disaster
A serious disruption of the functioning of a community or a society at any scale due to hazardous events interacting with conditions of exposure, vulnerability and capacity, leading to one or more of the following: human, material, economic and environmental losses and impacts.
85
define vulnrability
the susceptibility of a community, population, or environment to damage,, injury, or disruption, caused by a tectonic event (earthquake, volcano, tsunami). It reflects an inability to anticipate, cope with, resist, and recover from such hazards.
86
how does vulnerability affect tectonic hazard impact
It transforms natural events into disasters by limiting a community’s capacity to prepare, cope, and recover. High vulnerability—driven by poverty, poor infrastructure, weak governance, and high population density—leads to greater death tolls, economic destruction, and longer recovery times compared to resilient areas.
87
What are the advantages of hazard profiles
-Hazard profiles can be used to compare:
Different hazards
Same hazards with different processes - a volcano on a destructive boundary compared to one on a constructive boundary
Same hazards with different human vulnerabilities - an earthquake in a developed country compared to one in a developing country
-They can also be used to plan for future events
-They are useful when looking at one hazard such as an earthquake
88
Disadvantages of hazard profiles
-Other factors may have a greater influence on the impact
-They focus on physical factors when human factors may be the most important
-Multi-hazard events are not easily represented on a hazard profile
-They are subjective
89
How does inequality of access to education influence vulnerability and resilience to a disaster
Access to Risk Information: Higher educational levels are correlated with better understanding of warning messages and risk assessments. Lower-educated populations may not interpret warning signs correctly (e.g., retreating ocean water before a tsunami), increasing mortality rates.
Preparedness Actions: Educated individuals are better equipped to take proactive, long-term steps, such as purchasing insurance or reinforcing housing.
Recovery and Adaptability: Better-educated individuals are more adaptable in the long term, less likely to live in temporary shelters, and more likely to secure new income sources after a disaster.
Childhood Impact: Educational inequalities are magnified when schools in low-income areas close for longer periods, resulting in disproportionate learning losses and trauma, which impairs long-term community resilience.
90
How does inequality of access to healthcare influence vulnerability and resilience to a disaster
Immediate Health Risks: Lack of access to quality care, especially in rural areas, means that when disasters strike, vulnerable groups face higher mortality rates.
Service Disruption: Disasters often destroy or limit access to medical facilities. When healthcare is most needed, areas with already poor access suffer a "secondary surge" of illnesses related to overcrowded shelters, lack of clean water, and interrupted treatments for chronic conditions (e.g., diabetes or kidney issues).
Mental Health Burdens: Disasters consistently widen health disparities, with low-income groups, women, and minorities experiencing higher rates of long-term post-traumatic stress, anxiety, and depression.
91
What is governance
The way in which a country or region is run is known as governance, this also impacts vulnerability and resilience
National governance refers to how the whole country is run
Local governance is how local areas are run
92
What does it mean if a place has good governance
means it is well run and the local or national government is effective
These areas are more able to cope with hazard events and will have a faster recovery
93
What does it mean if a place has bad governance
weak or poor governance leads to increased vulnerability and impacts the area's ability to cope with a hazard event
Poor governance impacts on the ability of governments to:
Plan for hazard events using techniques such as hazard mapping and land use zoning
Educate the population about the risks and how best to protect themselves
Predict events as they do not have the technology and equipment available
Prepare by ensuring that stocks of water, food, medical equipment and shelter are available
94
Explain corruption and mismanagement as an explanation for poor governance
1. Corruption and Mismanagement (Development and Hazards)
Diversion of Funds: Funds intended for public services (healthcare, education) or disaster risk reduction (planning, infrastructure) are stolen or misdirected by officials.
Bribery and Regulations: Officials may accept bribes to ignore building codes or land-use zoning, leading to unsafe housing, such as during the 1999 Izmit earthquake in Turkey or in Haiti in 2010.
Ineffective Aid Distribution: Corrupt governments may fail to distribute foreign aid, as seen in cases of "switched-off" nations, where aid does not reach the intended beneficiaries.
95
Explain lack of investment and planning as an explanation of poor governance
Neglect of Peripheral Areas: Governments may focus investment on capital cities or prestigious projects (e.g., in the UK, focusing on London over "Left Behind" deindustrialised towns), leading to spatial inequality.
Poor Infrastructure Maintenance: Failure to maintain or upgrade infrastructure (transport,, waste disposal,, energy) leads to declining social conditions and economic opportunities, typical of "sink estates".
Lack of Long-Term Strategy: A focus on short-term political gain over sustainable development means that long-term problems (e.g., environmental degradation) are not addressed.
96
Explain isolation/accessibility as a geographical factor that can impact vulnerability
-The more difficult it is to reach and supply aid - in Nepal 2015 some of the hardest hit regions were remote rural areas and they were not reached for days
-The less likely people are to have methods of communication
-The poorer the infrastructure will be
-The fewer facilities there are such as medical assistance
97
Why is response important in the hazard management cycle
Occurs immediately after a disaster, focusing on saving lives, providing emergency aid, and securing the area. Key actions include search and rescue, medical care, and food/shelter provision.
98
Why is recovery important in the hazard management cycle
Because it Involves restoring normal life and services, often spanning months or years. This includes cleaning up, rehabilitating, and reconstructing infrastructure better than before to reduce future vulnerability.
99
Explain the three phases that follow a hazard event shown by parks model
Relief – the immediate response including search and rescue, provision of emergency medical assistance and aid
Rehabilitation – a longer phase that includes temporary restoration of services and infrastructure e.g. temporary schools and shelters are set up
Reconstruction – permanent restoration which aims to provide the same or an improved quality of life than before e.g. through the rebuilding of infrastructure using aseismic designs
100
What are the trends in economic cost of tectonic hazards from 1960
-The economic cost of disasters has increased since 1960
-As countries develop the cost of repairing infrastructure and rebuilding increases
-Increased wealth means people have more possessions and property to be damaged and destroyed
-Infrastructure is more sophisticated and expensive to replace, for example, electric grids
-As more people are affected the cost increases
101
Describe the number of tectonic disasters trends since 1960
The number of tectonic disasters has fluctuated since 1960 but has generally remained steady
The slight increase in a number of earthquake disasters does not mean there have been more earthquakes or higher magnitude earthquakes. It results from:
Greater urbanisation leads to higher population densities and increased building density
Population growth means more people are living in earthquake-prone regions
Geography Paper 1
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