Tectonic Hazards and Processes EQ3 Flashcards
What are the main tectonic disaster trends?
- deaths have fallen over time due to better response, management and prediction. (More then 120,000 fallen to 20,000 in 2015
- number of reported disaster have increased then stabilised due to improvements in data coverage (can get data from more rural areas)
- number of people affected by disasters continue to rise as populations grow and more people live in risky locations
- economic looses have increased as more affluent people and more advanced technology
Why are data statistics often inaccurate?
- depends what is counted (primary deaths or secondary deaths)
- locations (rural/remote areas tend to under recorded)
- declaration on number of deaths could be ignored or over extracted (deaths of tourists in 2004 Tsunami Thailand were played down to protect there tourist industry
- statistic during disasters are hard to locate
- time trend analysis is difficult to do
What is a tectonic mega disaster?
These are large scale disasters that are usually classified as high impact, low probability (HILP) events.
E.g. 2004 Boxing Day Tsunamis and 2010 Haiti
What are the main characteristics of mega disasters?
- large scale disasters either spatial and aerial scale, or economic or human
- pose problems fro effective management (short and long term)
- countries will enquire international support in the immediate aftermath and long term recovery.
Why was the 2004 Asian Tsunami classified at a HILP?
- 14 counties affected surrounding the Indian Ocean affected
- huge economic losses and deaths toll in Indonesia and Thailand
What was the 2011 Japanese tsunami (Tohoku)?
- only Japan was directly affected, but economic impacts had global consequences
- massive disruption to ports, factories and power supplies
- nuclear meltdown at Fukushima catalyses Germany abandoning its nuclear energy programme.
Why is the 2010 Eyjafjallokull earthquake classified as a HILP event?
- 20 European countries affected due to the total or partial closure of their airspace
- The ash cloud cancelled 100,000 flight costing £1 billion.
What is a multiple hazard zone?
Multiple-hazard zones are places where a number of physical hazards combine to create an increased level of risk for the country and its population. These are disaster hotspots.
E.g. Philippines with 36.4% of population exposed to 5 separate hazards.
What are hydro meteorological hazards?
Natural process of a atmospheric nature that may cause loss life and destruction. Examples include floods, droughts, storms and tropical cyclones.
What is prediction?
Predictions includes knowing when or where a natural hazard will occur on a spatial and temporal scale. This means communities have time to prepare and evacuate.
What is forecasting?
Forecasting is a much less precise prediction which provides a percentage chance of a hazard occur. It is a lot less accurate.
How can earthquake be predicted?
It is not possible to make accurate predictions of the occurrence of earthquake. Scientists are using
- animal behaviour
- changes in radon emission
- electromagnetic variation
To attempt to predict earthquake.
How are earthquake forecasting?
Earthquake risk can be forecasted since it’s based if the statistical likelihood of an event happening at a particular location. They are based of data and evidence gathered through global seismic monitoring networks and historical networks.
Why is forecasting important?
Forecasting is important as it encourages governments to enforce better buildings regulation and no build zones in areas of high stress . As well as develop education and evacuation procedures.
Why are earthquake predictions not that helpful?
For predictions to be useful they need to be highly accurate both spatial and temporally to enable evacuation of certain areas they are not meaning the usefulness of them is arguable.
How can volcanic eruptions be predicted?
- monitoring equipment on volcanos can measure changes as the magma chambers fill
- tilt meters can record tithe volcanos ‘bulging’ as the mahatma rises
- seismometers can record minor earthquakes including magma movement
- gas spectrometers analyse gas emissions. (Carbon dioxide and sulphur dioxide)
How useful are volcanic predictions?
Volcanic eruptions are fairly predictable as data is both spatially and temporally accurate. The minimal death rolls from recent volcanic eruption can be mainly attributed to vastly improved prediction.
How can Tsunamis be predicted?
Tsunamis can be partially predicted
- earthquake induced ones cannot be predicted
- seismometers can tell an earthquake occurrence and locate it and ocean monitoring equipment can detect tsunamis in the open sea.
- this can be relayed to coastal areas which can be evacuated.
What is the hazard management cycle?
The hazard management cycle illustrates the different stages of managing hazards it attempt to reduce the scale of a disaster. It creates a cycle with one hazard event informing the preparation of the next.
What are the stages of the hazard management cycle?
- The Hazard
- Response (immediate help to save lives through search and rescue and shelter)
- Recovery (rebuilding infrastructure and services)
- Mitigation (acting it reduce the scale of the next disaster though land use zoning and hazard buildings)
- Preparedness ((community education, warning systems and evacuation drills)
What are the physical factors the can affect a response?
- geographical accessibility
- type of hazard (scale, magnitude)
- topography of region (mountainous)
- climate (e.g, monsoon rains)
What are the human factors that can affect response?
- population density
- degree of community preparedness
- technology and resource abundance
- economic wealth and life, of infrastructure
- level of governance
- ability of services (health, repose teams)
What does the recovery stage of the hazard management cycle depend on?
- the magnitude (bigger means longer recovery)
- development level (poorer nations tend to be more severely effected)
- governance (aid money distribution)
- external hero (international aid)
What does the hazard management cycle depict?
It shows how the choice of response depends on a complex and interlinked range of physical and human factors. As there are limited resources and time to make decisions the relative importance of each factors has to be considered.
What is the parks model?
The parks model is a disaster response curve that provides an illustration of the impacts of a disaster and the resilience. The time taken form the hazard striking and when a counties return to its normal operations can be used to compare different events.
What is the lay out of the Parks model?
Each stage on the X axis shows different stages of time where
- pre-disaster
- relief
- rehabilitation
- reconstruction
And the y axis has
- improvements
- normality
- deterioration
What can the Parks model be used for?
The model can be used to help plan and understand risk and resilience, as well as to be better prepared for future event through modification and mitigation.
What are the stages of the Parks model?
Pre - disaster > normal life before disaster strike. People/ government preparing though education and preparing supply
Relief > hazard event has occurred and immediate relief if the priority
Rehabilitation > charity’s/governments try to return to normal by providing food water and shelter
Reconstruction > long time rehabilitation moves unit the reconstruction period (infrastructure, crops and property’
What are the theoretical frameworks used to understand prediction, impacts and management of tectonic hazards?
- predication and forecasting
- hazard management cycle
- Parks model
What is the Swiss cheese model?
The Swiss cheese model suggests that hazard management can be reduced by
- reducing the number of holes in each layer (number of systemic weakness)
- reducing the size of the holes (gaps in the system or scale of the system weaknesses)
What are the three ways of modifying a disaster impacts?
- Modifying the event
- Modify the vulnerability
- Modify the loss
What is modifying the event?
This happens before the hazard strikes. This is done by mitigating the impacts of the hazard by reducing its areal extent and/or effective magnitude. It’s works but relays on technology and planning systems which are costly so not only available.
What is included in modifying the event?
- land-use zoning
- Aseismic buildings (Earthquake)
- tsunami defences (Tsunamis)
- lava diversion (volcanic eruption)
What is land use zoning and how does it ‘modify the event’?
Land use zone is areas were buildings are prohibited as they are classed at high risk from tectonic hazards such as on
- low lying coastlines
- close to volcanos
- areas of high intensity shaking or high risk form liquefaction
What are the positives and negative of land use zoning?
+ low cost
+ remove people from high risk areas
- prevent economic development of high valued land (coastal tourism)
- requires strict and enforced planning laws so good governance is needed
What is aseismic building and how does it ‘modify the event’?
These are buildings that contain re enforcements making them resistant to most earthquakes. It includes
- cross bracing
- counter weights
- deep foundations
- reinforced cement concrete roof
- hollow concrete bricks designed to cause minimal damage
What are Tsunami defences and how does it ‘modify the event’?
Tsunami sea walls (mangroves or man made) and breakwaters that try and prevent the waves travelling inland or dissipate some of the wave energy.
What are the advantages or disadvantages of tsunami defences?
+ reduced damages as less wave energy
+ provides a sense of security for the community
- can be overtopped (community then might be underprepared)
- very high cost
- can be ugly and restrict coastal tourism
What is lava diversion and how does it ‘modify the event’?
These are channels, barriers or water coolers that are used to divert the lava away from areas of high vulnerability or cool it before it gets there.
E.g. 1973 eruption Island of Heimaey, Iceland. The community sprayed sea water on the lava flow preventing it hitting the fishing ports (economic centre of the island)
What are the advantages and disadvantages of lava diversion?
+ diverts lava out of harms ways
+ relatively low cost
- only works for basaltic lava
- lava flows aren’t the main killers/destroyers of volcanos
What is modifying the vulnerability of a tectonic hazard?
This happens before a hazard strikes. It means increasing the resilience of the community to increase their capacity to cope.
What are the different approaches to ‘modifying the vulnerability’?
-prediction, forecasting and warnings
- improvements in community preparedness (evacuation and survival kits)
- working/educating people to change behaviours to reduce disaster risk
What is predictions and how does it ‘modify the vulnerability’?
Predictions are used to warn ommunities to a tectonic hazard giving them a chance of evacuate or prepare for the impacts. It includes
- Hi tech monitoring
- prediction
- education and community preparedness
- adaptation
How does Japan ‘modify the vulnerability’?
After the 1995 Kobe earthquake NIED deployed 1000 strong motion accelerometers throughout the country. During an earthquake the primary and secondary wave velocity’s are measured at each site and logged. Data is then sent to the local government, where it is used to plan Lao land emergency management and repose.
What are the advantage and disadvantages to Hi-tech Scientific Monitoring for prediction?
+ in most cases it is accurate and correct
+ the warnings and evacuation save lives
- costly (most developing worlds can afford
- may not be accurate especially for earthquakes (2009 L’Aquila)
- dosas not prevent property damage
What is community preparedness and education and how does it ‘modify the vulnerability’?
This includes education in schools, earthquake kits (with key resources) and evacuation planning.
What are the advantages and disadvantages of community preparedness and education?
+ lost cost as often implemented by NGOs
+ can save lives through small actions
- does not prevent property damage
- harder to implement in rural areas
What is adaptation and how does it ‘modify the vulnerability’?
This includes moving out of harms way and relocating to a safe area.
What are the advantages and disadvantages of adaptation?
+ saves both lives and property’s
- high population density prevent it
- disrupts people traditional homes and traditions
What is ‘modifying the loss’?
It’s occurs after a hazard and aims to reduce the short and mong term losses through aid recovery and reconstruction. It includes
- short snd long term aid
- insurance
- community actions
What is short term emergency aid and how does it ‘modify the loss’?
This is immediate search and rescue efforts done by NGOs and the community. As well as the provision of food, water and shelter.
What are the advantages and disadvantages of short term aid?
+ reduces death toll by saving lives and keeping people alive until long term aid arrives
- high cost
- difficult to distribute in remote areas
- emergency services and limited snd poorly equipped in developing countries
What is long term aid and how does it ‘modify the loss’?
This is aid in the form of reconstruction plans to rebuild an area and possibly improve resilience.
What are the advantages and disadvantages of long term aid?
+ reconstruction can ‘build in’ resilience through land use planning (Build Back Better was used in the Philippine after Typhoon Haiyan
- very high cost
- needs as quickly forgotten by the media after initial disaster
What are the advantages and disadvantages of long term aid?
+ reconstruction can ‘build in’ resilience through land use planning (Build Back Better was used in the Philippine after Typhoon Haiyan
- very high cost
- needs as quickly forgotten by the media after initial disaster
What is insurance and how does it ‘modify the loss’?
This is compensation given to the people affected by the hazard to replace what they have lost and help regain a sense of normality.
E.g. In the developed world 25%-30% of economic losses from tectonic hazards are insured
What are the advantages and disadvantages of insurance?
+ allows people to recover economically by paying for reconstruction
- does not save lives of buildings
- few people in the developing world have insurance
