Tectonics Flashcards

Question

Explain why volcanic eruptions vary in their magnitude

Answer 1

type of magma (basaltic eruptions are less explosive) gas content (more gas = more explosivity) volcano type

Answer 2

1. Asses the damage to a country/region by displaying it on a disaster response curve 2. Measures 3 factors: quality of life, level of economic activity and social stability 3. Measures 4-5 stages

Answer 3

They assist in predicting when tectonic hazards might happen, understanding the impact they could have, and figuring out how to manage and lessen their effects. These frameworks use organized ideas to make studying earthquakes and volcanoes easier and help us plan better for safety.

Answer 4

1. Shaking Ground:The ground shakes vigorously during an earthquake, and this shaking can cause buildings to sway or vibrate. If a structure is not well-designed or lacks proper reinforcement, it may not withstand this movement, leading to structural damage or collapse. 2. Energy Transfer: Earthquake waves carry a lot of energy, and when they reach a building, that energy tries to move through and around it. If a building isn't designed to absorb or distribute this energy effectively, it can experience stress and damage, making it challenging for the structure to remain intact during the seismic event.

Answer 5

Different types of plate boundaries affect how strong earthquakes can be: 1. Pulling Apart (Divergent): - Link: Earthquakes are not very strong. - Why: Plates move slowly away from each other, causing mild shaking. 2. Crashing Together (Convergent): - Link: Strong earthquakes happen here. - Why: Plates collide or one goes beneath the other, creating powerful shaking. 3. Sliding Past Each Other (Transform): - Link: Strong earthquakes can occur. - Why: Plates rub against each other, building up stress and causing significant shaking when released.

Answer 6

1. Tectonic Hazard: - Criteria: Possible danger. - Explanation: When there's a chance of something harmful, like an earthquake. 2. Tectonic Disaster: - Criteria: Real impact. - Explanation: When the harmful event actually happens and causes damage. 3. Tectonic Mega-Disaster: - Criteria: Extremely big and damaging. - Explanation: When the harmful event is exceptionally powerful and causes widespread devastation.

Answer 7

The magnitude scale measures how powerful an earthquake is overall, while the intensity scale describes its effects in specific areas. Higher magnitudes indicate more power and a higher likelihood of secondary hazards like landslides and tsunamis. The intensity scale helps understand localized impacts, such as building damage, caused by these secondary hazards.

Answer 8

Earthquakes create more disasters than volcanic eruptions because they can happen in many places globally, affect densely populated areas, and trigger additional hazards like tsunamis and landslides, making their impact more widespread and severe. Volcanic eruptions, on the other hand, are often localized and may impact fewer people.

Answer 9

The physical characteristics of volcanic eruptions, like eruption type, explosiveness, and lava flow, are crucial in determining the risk for people. The more explosive and widespread an eruption is, the higher the risk, as it can lead to lava flows, ash clouds, and other hazards that pose threats to communities. Understanding these physical traits is essential for effective risk assessment and planning for volcanic events.

Answer 10

can happen anywhere the crust is cracked small movements build up friction and strain overtime which suddenly releases causing low mag. earthquakes

Answer 11

isostatic readjustment can cause earthquakes as the crust moves up and down

Answer 12

oceanic plates: magma rising though the mantle is able to melt its way through creating volcanoes that grow from the sea bed continental plates: much thicker but get stretched enough in places for the magma from a hot spot to break through

Answer 13

molten material rises from the outer core to about 700km beneath the crust or lithosphere

Answer 14

hot spots - where magma rises through the asthenosphere and may break through the crust

Answer 15

heat radiating from the inner core causes a plate to convect (travel). the convection cells make contact with the base of the crust causing friction and so drag the crust along in the general direction of the convection.

Answer 16

the outer core is mainly liquid iron and it convects. This creates a magnetic field for the earth which flips every 100 000 years. When igneous rocks cool to form solid rocks they trap the magnetic field at a point in time. This can be used as a record.

Answer 17

at destructive plate boundaries denser oceanic plates are subducted under less dense continental plates eg at deep ocean trenches as a slab of oxeanic plate dcends it often pulls with some force the rest of the plate behind it

Answer 18

where the new crust formed at divergent plate margins is less dense than the surrounding crust and so it rises to form oceanic ridges

Answer 19

continents have moved and rotated

Answer 20

destructive: this is where here is the greatest friction and build up of pressure betwen plates | destructive plate boundaries = most destructive

Answer 21

where the magma is viscous with a high silica and gas content. These are usually found at destructuve plate margins with subduction where the subducted plate is melted usually under a continental plate

Answer 22

P (primary) waves, S (secondary) waves and L (Love) waves

Answer 23

arrives first, moves fast and throigh solid rock and fluids, compresses in the direction of travel

Answer 24

slower than P waves and moves more up and down only through solid rock

Answer 25

only travels through the surface of the crust, fastest of the surface waves and moves from side to side horizontally as it moves forward

Answer 26

Shockwaves move the ground in different ways, with S waves being the most damaging of the body waves due to high amplitude (up and down) and slow speed. Love waves are the most damaging of the surface waves, arriving after P and S waves have weakened buildings

Answer 27

crustal fracturing ground shaking liquefaction landslides

Answer 28

shockwaves travel quickly through rock and can increase stress until the rock fractures causes faults which can rupture causing damage to anything on them

Answer 29

happen quickly in short bursts and multiple directions buildings may be damaged or collapse whch presents a real threat to their inhabitants

Answer 30

occurs when shokwaves travel through loose unconsolidated material shaking it so that it acts like a fluid causes buildings to tilt or collapse and threatens underground cables or pipes

Answer 31

shockwaves loosen rock on steep slopes causing it to move downslope en mass may hit settlements or block roads

Answer 32

– Forced to a high altitude so they can be carried around the planet in the atmosphere and disrupt flight paths – can fall locally causing roofs to collapse. – can get into machinery and electronics causing them to fail

Answer 33

– Dense mixture of superheated solid particles (tephra) and poisonous gases which erupt from a crater moving down the side of a volcano. – travel at great speed of up to 700 km an hour – can cause flooding due to blocked River channels

Answer 34

- gases such as sulphur can cause acid rain when combined with water vapour damaging water and plants. – sulphur may also cool the Earth when it’s carried high into the atmosphere by blocking the sons energy. This can cause crop failures and famine.

Answer 35

– Molten magma is erupted from volcanoes flows down the sides until it calls – Basaltic lava flows fastest making it the most dangerous

Answer 36

– A mixture of water and erupted volcanic material various sizes – flow very fast (60 km an hour) down River valleys. – the water make come from rainfall, a crater lake, or the melting of snowcap on the top of a volcano

Answer 37

– Where a volcano erupts underneath an ice cap the heat will melt some of the eyes. – the meltwater builds up around the top of the volcano trapped by the surrounding ice. – eventually the warm water will melt and lift the ice away from the ground causing the water to burst out from under the ice and flow rapidly to lower ground

Answer 38

- the largest wave is not the first - long wavelength in open ocean but short in shallow water - very far in deep water but slow in shallow - low in open ocean but high in shallow

Answer 39

an undersea earthquake may cause a rapid movement of the seabed. if this is up or down then water is displaced creating a wave tsunamis can also occur due to volcanic eruptions on islands, and major landslides into the sea or underwater on the edge of continental shelves

Answer 40

A natural event that causes disruption to daily lives or death and destruction

Answer 41

A disaster occurs when the scale of an impact of a natural hazard are great. It is measured by the number of deaths (UN suggests 500+) all the cost of the damage (millions of dollars).

Answer 42

a mega-disaster occurs when they are over 2000 deaths as a result of a natural hazard and a GDP reduction of 5% or more.

Answer 43

hazard risk involves potential loss of life and injury and destruction and damage to buildings infrastructure in an area. The equation involves consideration of the hazard, degree and frequency of exposure to the hazard, vulnerability the people and systems, and the capacity to recover. Risk = Hazard x Vulnerability R = H x V

Answer 44

The ability of capacity of community or society to withstand the effects of a natural hazard through methods of adaption and recovery

Answer 45

The extent to which community could be damaged or disrupted by hazard. Is based on the human geography of a community or area. Factors include: – the location of settlements – peoples knowledge and understanding – peoples ability to prepare, react to and withstand the effects of a hazard – the presence of advance warning systems – the involvement of local people in planning and preparation.

Answer 46

– Economic development (GDP per capita) – social development – social and economic development (HDI) – political development – environmental development

Answer 47

– There are higher losses of life and developing an emerging countries then in HICS – people developed an emerging countries are more vulnerable due to low understanding link to levels education and lower levels of technology because there’s less money to spend on a size buildings, warning systems or emergency rescue and healthcare. – emerging countries have rapidly growing cities which increase rested denser populations and uncertainties over building codes and land use zoning – Corruption and government departments

Answer 48

– When the characteristics of a tectonic hazard are comparable, it is clear that developed countries have greater costs of damage than emerging or developing countries. – Richard countries have more expensive buildings, infrastructure and technology to be damaged. – developing countries may only have significant construction in urban areas, if rural areas are affected by hazard cost tend to be low. – cost to emerging countries are increasing because they have increased construction and rapid urban growth. However even low damage costs can be expensive to poor people who have to buy new construction materials, or find a new job because their place of work has been destroyed

Answer 49

- for earthquakes - logarithmic where each level has 10x the energy of the level below

Answer 50

- for earthquakes

Answer 51

- magnitude - logarithmic scale where each level has 100 times the energy of the level below it

Answer 52

- logarithmic where each level has twice the energy of the level below

Answer 53

– spatial predictability – aerial extent – frequency – magnitude – speed of onset – duration

Answer 54

an area that has never had an event will experience greater impacts as people and places will be unprepared

Answer 55

The larger the area affected by the event, the greater the impact will be as more people and places are affected

Answer 56

an event that occurs often is more likely to create cumulative impact (although rare events have more energy)

Answer 57

The greater the amount of energy released by an event, the greater the impacts are like to be

Answer 58

The faster the event occurs, the shorter the warning time and the greater the impacts as places are unprepared.

Answer 59

The longer an event lasts, the more likely that there will be greater impacts

Answer 60

– Volcanoes have very specific locations and usually give signs they are about to erupt, but earthquakes are found in broad zones and are unpredictable. – not all under seas earthquakes produce tsunamis. – Hazard profile showed differences in social and economic impacts between countries at different stages of development

Answer 61

1. population increase – more people affected. 2. urbanisation rates high – more people affected in a small area. 3. Widespread poverty – people living in risky areas in insecure housing. 4. More expensive construction and belongings in increasing the cost of damage. 5. Inequality – the increased risk of those lacking access information and services. 6. Climate change – increasing the severity of climate, weather, river and biological hazards. 7. Environmental degradation – reducing protection from natural systems. 8. More reporting – information through media

Answer 62

– over 2000 deaths or – over 200,000 people made homeless or – losses of 5% of National GDP or higher or – dependence on external aid for one year or longer – Global energy policies (nuclear power stations damaged) – global and regional economic activities (international air travel disrupted) – global pollution – multi-national losses of life – global temperatures and regional food supplies affected

Answer 63

hazards can be grouped into several categories: - meteorological (such as strong winds in a storm) - hydrological (such as river floods) - geophysical (such as tectonic and mass movements) - climatological (such as long term drought) - biological (such as a diseas)

Answer 64

- volcanic eruptions colliding with heavy rains or tropical cyclones; produces a heavy rain and tephra mix creating lahars - earthquakes in remote areas of developing countries where there are no health services may lead to outbreaks of disease, where there is no clean water and medicine

Answer 65

- predicting the TIMING of earthquakes is impossible - there is some evidence that animals and birds can sense danger but only just before - modern seismic monitoring and communications allow for warning to be given minutes before shockwaves arrive - foreshocks can be an indication of a larger event but the pattern is not certain until after - The absence of earthquakes along and known fault as a concern as it shows that stress and strain a building up instead of being released by smaller earthquakes. – earthquakes may travel along a fault line overtime until it’s possible to say which part of the fault will move next (but not when) – some faults are unknown and earthquakes catch people by surprise

Answer 66

– Volcanoes have a fixed location and this allows constant monitoring. However constant monitoring requires technology and is expensive. So many volcanoes and developing countries are not monitored. – geological evidence of past eruptions provides clues about the type of extent of future eruptions. – measurements can include gas emissions, harmonic tremors, bulging of the volcano, and the composition of magma. There are usually changes in these readings, before an eruption, which allows relatively accurate prediction of warnings to be given, although the exact magnitude is more difficult to forecast

Answer 67

– Any submarine earthquake may create a tsunami, especially if it is large magnitude on subduction zones with mega thrust. – warning systems exist in the Pacific and also in the Indian ocean (after 2004), based on size Moura readings percent buoys monitoring movement of the sea – computer modelling has been used to predict arrival times and wave heights but does not always accurately count for ocean depth or the shape of the sea floor

Answer 68

There are several groups of people (players) involved with predictable forecasting. At the forefront of these are the scientist who are working to understand the Temic processes and carry out monitoring using the latest tech technology. Prediction forecasting is hugely important to reducing future rest, although some believe it will never be possible to predict earthquakes precisely so uncertainty will always remain.

Answer 69

- pre-disaster: risk assessment mitigation/prevention preparedness 💥warning/ evacuation - response: Saving people Providing immediate assistance Assessing damage – post-disaster: Ongoing assistance Restoration of infrastructural services Reconstruction (settlement/relocation) Economic and social recovery Ongoing development activities Risk assessment/mitigation/prevention

Answer 70

- geographic information systems (GIS): shows where movement was greatest and reveals where land-use zoning could be imposed including regulations requiring hazard resistant designs - hazard zones: hazard zoning maps can forecast where the biggest dangers are. people can be prevented from living in these areas through land-use zoning. - modifying the tectonic event: earthquakes: Modifying earthquakes as difficult because of their power and unpredictable.They can be avoided by not living near plate boundaries or faults or designing buildings to withstand powerful seismic waves. volcanoes: modifying some volcanic hazards as possible, hazard learning maps forecast where the biggest danger are and land use zoning stops people living there; training crater lakes reduces the formation of lahars; lava flows can be diverted by barriers or diversion channels or sprayed with water to cool and slow movement. Tsunamis: tsunamis can be modified at the coast to prevent development near the shore (building offshore barriers, higher and stronger, using natural defences like mangrove forests)

Answer 71

involves actions and interventions by a community that will reduce the severity of a hazard, such as reducing vulnerability and increasing resilience

Answer 72

changes or responses to a hazard situation designed to help a community cope with a hazard such as taking precautions

Answer 73

– Hazard risk mapping: modelling of hazard zones within an area for example liquid action areas or Lahar routes – land use zoning: strict planning regulations to stop building in risky areas. – food supplies: increasing food production with better storage methods – monitoring and warning systems: to give people enough time to evacuate. – hazard resistant designs: any construction to be built to a specification strong enough to withstand impacts. – investment services: healthcare systems can be better prepared and education can raise the level of a community understanding of hazards and actions to take. – improved evacuation routes: to enable people to escape in time

Answer 74

– Rescue teams: fully equipped with the latest technology. – emergency relief aid: involving food, water, sanitation and shelter as well as medical care – community volunteers: local people specifically trained for emergency events to help guide and help other locals. – Insurance: large or microscale insurance to reduce financial losses for individuals and families especially lively had been lost. – evacuation: move away from the areas that may be hit again, including permanent settlement locations – development aid: long-term assistance from other countries to help rebuild what has been lost

Answer 75

zone of Earth's mantle lying beneath the lithosphere and believed to be much hotter and more fluid than the lithosphere

Answer 76

Body waves can travel through the Earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water

Answer 77

Where there is a spot of extra energy and heat a mantle plume may form which can cause a hot spot

Answer 78

the sea floor spreads outwards because it is at a different plate margin which means it is pushing away and causing different bands of rock to face different directions depending on which direction they were pointing when the earths magnetic field were at north or south

Answer 79

Where an oceanic and continental plate move towards each other

Answer 80

Where two plates (usually oceanic) pull apart

Answer 81

Where two plates move alongside each other (either in the same or opposite directions)

Answer 82

When two continental plates move towards each other

Answer 83

Where several types of plate boundary are found in a short distance

Answer 84

An example of a tectonic hazard They are often found at collision boundaries and can be explosive due to the mantle material and plate forcing their way to the surface Gentle volcanic activity is found at constructive plate boundaries as mantle material moves upwards to fill the gaps left by diverging plates

Answer 85

Constructive plate boundaries may cause small earthquakes as there is not much friction as plates diverge Conservative plate boundaries have a large amount of friction meaning they can cause strong earthquakes Converging plates (destructive and collision) create the largest amount of friction and strain with earthquake focal points following the Benioff zone to considerable depths

Answer 86

The point where an earthquake starts is termed the focal or hypocentre and may be many kilometres deep within the earth. The point at the surface directly above the focal is called the earthquake epicentre. The focal depth is the depth of the focal point.

Answer 87

The Benioff zone is a sloping region of seismic activity that occurs along a subduction zone, where one tectonic plate is forced beneath another into the Earth’s mantle. It is characterised by earthquakes that originate at varying depths, from shallow near the surface to deep within the mantle (up to 700 km). These earthquakes are caused by the friction, deformation, and melting of the subducting plate as it descends. The Benioff zone provides evidence of plate tectonics and subduction processes.

Answer 88

An upward of downward movement of crust below seawater that causes it to be disturbed causing a large wave. This is associated with an underwater earthquake which links to a destructive (form of convergent) plate boundary

Answer 89

Earthquakes can happen anywhere the crust is cracked > usually ancient faults created by previous plate movements Small movements along these old faults build up friction and strain over time which is then suddenly released causing low magnitude earthquakes > human activities like fracking and reservoirs can trigger tremors

Answer 90

Isostatic readjustment is when the Earth’s crust moves up or down because of changes in weight on top of it. For example, during the Ice Age, heavy ice sheets pushed the land down. When the ice melted, the land slowly rose back up. It’s like a sponge bouncing back after being pressed. This process can also happen when lots of sediment piles up or is washed away. It can also cause earthquakes as the crust is moved upwards or downwards as a result

Answer 91

Volcanic activity happens in the middle of oceanic and continental plates - oceanic plates are 7km thick and magma rising through the mantle from the edge of the outer core is able to melt its way through, forcing molten material to the surface. This creates volcanos that grow from the sea bed. - continental plates are much thicker but get stretched enough in places that allow the magma to break through where there is a hotspot and travel up in a mantle plume

Answer 92

Molten magma rises from the outer core boundary to about 700km below the crust (lithosphere) > there are two massive mantle plumes in the earths mantle layer, one under the pacific plate and the other under the African plate

Answer 93

Small hotspots are created where magma rises through the asthenosphere (the weak part of the upper mantle below the crust) and sometimes breaks through the crust. Molten material from the outer core/mantle boundary can then rise quickly to the surface.

Answer 94

The weak part of the upper mantle below the crust

Answer 95

The crust The mantle The outer core The Inner core

Answer 96

By studying the movement of seismic waves as they travel at different speeds through different material of different densities and some types, like S waves wont travel through liquid

Answer 97

Heat radiating from the inner core through the mantle causes it to convect (the rising motion of warmer areas of a liquid or gas, and the sinking motion of cooler areas of liquid or gas, sometimes forming a complete cycle) as it behaves like a liquid (sometimes solid under pressure). The convection cells make contact with the base of the crust which causes friction and drags the crust along in the direction of the convection.

Answer 98

The outer core is mostly liquid iron and it convects. This movement gives the earth a magnetic field which flips direction every 100 000 years. When molten rocks cool to form solid rock they trap the magnetic field in the direction of the time they cooled. Geological records of magnetic directions are symmetrical either side of constructive plate boundaries, proving that oceanic crust has been moving apart in places for a very long time.

Answer 99

At destructive plate boundaries, denser oceanic plates are sub-ducted under less dense continental plates. As a slab of oceanic plate descends it pulls the rest of the plate with it (slab pull).

Answer 100

where the new crust formed at constructive plate margins is less dense than the surrounding crust and so it rises to form oceanic ridges > this may help to move the plates away from the point of divergence

Answer 101

Mantle plumes that are responsible for pushing up the crust causing it to move or split (perhaps splitting Africa and Europe from the americas)

Answer 102

The magnetic field directions locked in rocks

Answer 103

Trenches, accretion wedges, fold mountains, continental volcanoes, earthquakes (along Benioff zones)

Answer 104

Rifts Fissures Faults Undersea ridges

Answer 105

Fold mountains Shallow earthquakes

Answer 106

Major and minor fault lines and frequent earthquakes

Answer 107

At destructive plate margins where there is more friction between two plates causing earthquakes > tsunamis are also greater at this plate boundary

Answer 108

Plates try and slide past each other which causes a build up of friction and strain

Answer 109

Magma that is viscous with high silicone and gas content which are usually found at destructive margins with subduction where the subducted plate is melted under the continental plate

Answer 110

P, S, and L waves

Answer 111

P and S waves that travel through the earth

Answer 112

L waves that travel along the surface of the crust

Answer 113

Arrives first and moves fast through solid rock and fluids > compresses and expands like a slinky in the direction of travel

Answer 114

Secondary wave that moves more slowly than P waves and only moves through solid rock > moves in an up and down motion

Answer 115

Only travels through the surface of the crust, fastest of the surface waves > moves from side to side horizontally

Answer 116

S waves are the most damaging of the body waves due to the high amplitude (up and down) and slow speed L waves are the most damaging of the surface waves, arriving after P and S waves have weakened buildings

Answer 117

Shockwaves travel fast through solid rock and can increase stress in it especially if there is different rock types. This stress causes strain which will continue until the rock fractures. This causes faults which can rupture the surface causing subsidence or uplift. Anything on these faults can get moved or damaged.

Answer 118

Shockwave ground movements include pushing and pulling (P), up and down (S) and side to side (L), which all happens in less than 60 seconds. Buildings that are not aseismic may only survive some types of shaking and will be damaged. If buildings have the same resonance (the occurrence of a vibrating object causing another object to vibrate a higher amplitude) as the seismic energy, the impact is intensified.

Answer 119

Occurs when shockwaves travel through loose unconsolidated material, shaking it so that it acts like a liquid > Christchurch 2011 Causes buildings to tilt over and collapse or the ground to crack. Underground infrastructure like cables and pipes may rupture.

Answer 120

Occur when there are steep slopes. Shockwaves loosen rock and cause it to move downwards under the influence of gravity Landslides may hit settlements directly or destroy and block transport and communications infrastructure

Answer 121

Primary happens as a result of the seismic waves, secondary happens as a result of the ground shaking

Answer 122

Ash is forced to a high altitude and can be carried around the planet via the atmosphere. A lot of ash falls locally and can cover settlements and cause roofs to collapse. It also gets into electrics and machinery causing it to fail. It may also disrupt the paths of aeroplanes.

Answer 123

Consist of superheated solid particles (tephra) and poisonous gases erupted from a crater, moving down the sides of volcanoes at great speed. Any buildings or people in the water are destroyed on impact then buried, incinerated or poisoned. They may also block river channels and cause floods.

Answer 124

One of the common gases to come out of volcanoes is water vapour which may condense locally and mix with other erupted materials. Other gases like sulphur dioxide are poisonous and can cause acid rain which damages buildings, cars and plants. It can also cool the suns heat by blocking its energy.

Answer 125

Molten magma that is erupted from volcanoes flows down the sides until it cools. Basaltic lava flows fastest but people can still get out the way so there is usually not as many deaths unless the eruption is at night or opens on the sides of volcanoes. However structures are often burnt.

Answer 126

These are a mixture of water and erupted volcanic material of various sizes which flow very fast down river valleys. The water may come from rainfall, a crater lake or snow caps on the volcano. These are a major hazard along valleys as lahars can speed up as they enter river valleys.

Answer 127

Where a volcano erupts underneath an ice cap causing the heat to melt the ice which causes water to build up around the top of the volcano trapped by the surrounding ice. Eventually the ice will be lifted away from the ground allowing the water to burst out and flow rapidly to the ground. Anything in its path is washed away or covered by volcanic and glacial deposits carried in the jokulhlaup.

Answer 128

A sequence of large waves of varying heights. > the largest wave is not the first Long wavelength in open ocean but short in shallow water Very fast in deep water but much slower in shallow water Low height in deep water but tall in shallow (up to 20x)

Answer 129

An undersea earthquake at a subduction zone may cause a rapid movement of the seabed. If this movement is up or down then a column of sea water above the epicentre is displaced creating a powerful wave. Tsunamis can also be caused by: Violent explosive eruptions of volcanic islands Major landslides or volcanic cone collapse into the sea Underwater landslides at the edges of continental shelves

Answer 130

A natural event that causes a disruption to daily lives or death and destruction

Answer 131

When the scale impact of a natural hazard is great. It is measured by the number of deaths or the cost of damage (500+ or millions of $)

Answer 132

Over 2000 deaths and a GDP reduction of 5% or more

Answer 133

Changes to a way of doing things so future hazards have less impact

Answer 134

A way of returning to normal after the impacts of a hazard

Answer 135

Risk (R) = Hazard (H) x Vulnerability (V) Hazard risk - Potential loss of life and injury, and destruction and damage of buildings and infrastructure Also considers the degree and frequency of the hazard as well as the vulnerability of the people and their capacity to recover.

Answer 136

The ability or capacity of a community or society to withstand the effects of a natural hazard through methods of adaption and recovery.

Answer 137

Adapt: Identify the risks of a potential hazard Plan what to do if the hazard occurs Implement plans to reduce the impact Recover: Stockpile essentials like food, water and medicine Collect resources for repairing and rebuilding

Answer 138

The extent to which a community could be damaged or disrupted by a hazard. It is based on the human geography of an area. - location - people’s knowledge and understanding - people’s ability to prepare, react and withstand the effects - the presence of advanced warning systems - the involvement of people in planning and preparation

Answer 139

Pressure and release model Has the causes of a hazard (poor governance, political and economic systems) as well as the pressures (things that make it worse - lack of education rapid population growth, high migration and urbanisation rates) and the living conditions on one side and the geography (location, frequency, magnitude, timing, speed of onset) and tectonics (plate movements, earthquake, volcano) on the other side with the hazard risk equation in the middle. Summarises the link between natural hazards, risk and vulnerability.

Answer 140

Economic development - GDP or GNI or capita Social development - levels of education and healthcare Social and economic development - HDI Political development - the involvement of people in decision making Environmental development - indicates a respect and maintenance of natural systems

Answer 141

Deaths are a social impact When characteristics of tectonic hazards are comparable (eg same magnitude) it shows how developing countries have a higher loss of life. People in developing and emerging countries are more vulnerable due to: - lower understanding linked to levels of education - lower levels of technology due to less money to spend on Aseismic buildings, warning systems and emergency rescue and healthcare Emerging countries like China have rapidly growing cities with denser populations and less land zoning. Corruption in government departments may also reduce the effectiveness of mitigation measures.

Answer 142

This is an economic impact Again, tectonic hazards are comparable when they have similar characteristics like the same special extent. Developed countries have greater costs of damage than emerging. Richer countries tend to have more expesive buildings, infrastructure and technology for a hazard to destroy. They also have higher insurance costs after. Developing countries often only have significant construction in urban areas and if rural areas are impacted by a hazard, costs will be low. Costs to emerging countries are increasing because they have increased construction and have rapid urban growth. However, even low damage costs can be expensive to poor people who have to buy new construction materials or find a new job because their work has been destroyed.

Answer 143

Moment magnitude scale for earthquakes Mercalli intensity scale for earthquakes Volcanic exclusivity index Tsunami intensity scale

Answer 144

Spatial predictability Areal extent Frequency Magnitude Speed of onset Duration

Answer 145

Where you can assume a tectonic hazards which affect - usually on a plate boundary An area that has never experienced an event will have greater impacts as people and places will be unprepared

Answer 146

The area affected by a hazard The larger the area the greater the impacts as more people and places are affected

Answer 147

An event that occurs often is more likely to create cumulative impacts (although rare events have more energy)

Answer 148

The greater the amount of energy released by an event, the greater the impacts are likely to be

Answer 149

how quickly the peak of the hazard event occurs, with the starting time at the first point of the process towards it becoming a hazard. The faster the event occurs the shorter the warning time and the greater the impacts as places are unprepared

Answer 150

How long an event lasts The longer, the more likely there will be greater impacts

Answer 151

Developed: incur higher damage costs becasue there is more expensive infrastructure to damage. Even small costs create problems for poorer people. Developing: incur higher death rates because people are more vulnerable: they lack awareness of hazards and live in buildings that have not been proofed and do not have access to communications or emergency services

Answer 152

Volcanoes have specific locations and usually give signs that they are about to erupt, but earthquakes are found in broad zones and are unpredictable. Also, not all undersea earthquakes produce tsunamis. Hazard profiles can also show differences in social and economic impacts between countries at different stages of development.

Answer 153

Unequal access to education Unequal access to housing Unequal access to heath care Urbanisation Unequal access to income opportunities Population density Governance Accessibility (distance or physical barriers)

Answer 154

Data collection method Recording of costs (inflation means costs are increasing over time) Multiple databases Recording of deaths Change to database content Geological timescale

Answer 155

Over 2000 deaths Over 200 000 people made homeless or Losses of 5% of national GDP or higher or Dependence on external aid for one year or longer

Answer 156

Hating 2010 which killed 300 000 people and caused a cost of 100% of GDO

Answer 157

Global energy policies Global pollution Multi national loss of life Global temperatures Regional food supply

Answer 158

nuclear power stations can be damaged releasing radioactivity which makes governments concerned about their countries energy mix

Answer 159

Volcanic ash may disrupt aircraft movements over a large area. This costs airlines money in lost trade and compensation as well as stranding tourists and goods

Answer 160

Damaged and destroyed buildings, factories and power stations emit chemicals into the atmosphere, increasing ozone depletion and global warming. Tsunamis may carry debris and contamination into the ocean where currents distribute it more widely.

Answer 161

Due to international tourism, foreigners can find themselves in disaster events. Death, upset and grief may be global or a hazard may have a big impact on more than one country > lots of Swedish nationals were killed in the 2004 Indian Ocean tsunami

Answer 162

Large volcanic eruptions send ash and SO2 particles high into the atmosphere. These particles are carried around the world, especially if the volcano is near the equator. They block and reflect the suns heat energy causing global dimming.

Answer 163

Meteorological - strong winds Hydrological - floods Geophysical - tectonics or mass movement Climatological - long term drought Biological - diseases like cholera

Answer 164

A country or region that experiences more than one of the 5 hazard groups in a short space of time. This can be deadly.

Answer 165

Volcanic eruptions may coincide with a rainy season or cyclone. This can cause lahars. Earthquakes in remote areas of developing countries where there is no health services may cause an outbreak of diseases where there is no clean water and no medicine

Answer 166

**predicting the *timing* of earthquakes is impossible** There is some evidence that animals and birds can seismic waves before they reach a location Modern seismic monitoring and communications allow for warnings to be given up to a minute before shock waves arrive Foreshocks can be an indication of a larger event but the pattern can’t be seen until after The absence of earthquakes along a fault is usually a sign that stress is building up instead of being released by smaller earthquakes Earthquakes may travel along a fault line over time so it’s impossible to say which area of the fault will be next Some faults are unknown and catch people by suprise

Answer 167

Volcanoes have a fixed location which allows for constant monitoring > however, this requires technology which is expensive as a result many are not monitored Geological evidence of past eruptions provides clues about the type and extent of future eruptions Measurements include gas emissions (SO2), harmonic tremors, bulging of flanks and composition of magma. > there are usually changes in these before eruptions which allows accurate predictions and warnings to be given, although the exact magnitude is tricky to forecast

Answer 168

Any sub marine earthquake may create a tsunami, especially if it is large magnitude in subduction zones with mega thrust Warning systems exist in the pacific and Indian oceans based on seismograph readings locating epicentres and buoys monitoring the movement of the sea Computer modelling has been used to predict arrival times and wave height but it does not always accurately account for ocean depth or the shape of the sea floor

Answer 169

There are several groups of people involved. At the forefront is scientists who are working to understand tectonic processes and monitor using the latest technology.

Answer 170

Mitigation: actions to reduce vulnerability before a natural hazard Preparedness: ways in which communities can adapt to live with a natural hazard Resilience: ability to resist, cope with, adapt to and recover from a natural hazard Response: actions taken during and after a natural hazard to reduce impacts such as evacuation, rescue, medical care and damage assessment Recovery: rehabilitation and reconstruction through restoring infrastructure, temporary housing, relocation and risk assessment

Answer 171

The key players in the management of hazards are those involved with planning for emergencies. This may be government departments, rescue teams, NGOs and the community. Expertise and involvement will vary according to the type of country.

Answer 172

Forecast where the biggest dangers are by looking at where a hazard will occur (for example where a volcano is). People can be prevented from living in these areas via land zoning.

Answer 173

Earthquakes: difficult becasue of their power and unpredictability. They can be avoided by not living in hazard zones or designing buildings to withstand waves Volcanic: hazard zoning maps show where the biggest dangers are and land use zoning stops people living there: draining crater lakes reduces the formation of lahars, lava flows can be diverted using dikes or dams and sprayed with water to slow Tsunamis: can be modified at the coast to prevent development near the shore by building off shore barriers, higher and stronger walls and using natural defences like mangroves

Answer 174

Involves actions and interventions by a community that will reduce the severity of a hazard, such as reducing vulnerability and increasing resilience.

Answer 175

Changes or responses to a hazard situation designed to help a community cope with a hazard such as taking precautions.

Answer 176

Models can be devilled to consider the future and forecast the impacts of a tectonic hazard. Models make it possible to predict the benefits of putting mitigation and adaptation measures in place. Modifying the loss involves some key players like NGOs and insurance agencies who can help during the recovery stage.

Answer 177

Hazard risk mapping can help show hazard zones within an area (liquefaction or lahar routes) Land use zoning Food supplies Monitoring and warning systems Hazard resistant design Investment in services Improved evacuation routes

Answer 178

Rescue teams Emergency relief aid Community volunteers Insurance Evacuation Development aid

Answer 179

Rocks (plates) on both sides of the fault move in the same way due to tectonic forces causing a fault to form either by extension, compression or horizontal movement (think of people in a festival crowd: everyone’s being pushed around the same way which could be away towards or horizontal to each other)

Answer 180

Crust is pulled apart creating rift valleys

Answer 181

Small cracks opening in the earths surface

Answer 182

Elevated, long, narrow bumps formed by tectonic activity. In the ocean they are created by sea floor spreading.