study guide 5

• Reasons why we are MORE at risk from tectonic hazards than ever before..

  • Population growth
  • Urbanisation – higher pop density in cities so more vulnerable to EQs
  • More people living in vulnerable locations e.g. marginal land such as steep slopes.
  • Climate change
  • Melting glaciers = destabilised volcanoes underneath = more prone to eruptions
• Reasons why we are LESS at risk from tectonic hazards than ever before..

  • Technology has improved so easier to mitigate vulnerability.
  • Satellites & remote sensing can be used to monitor volcanoes & fault lines.
  • Easier to communicate warning about an impending disaster via media & mobiles.
  • Research has led to better aseismic technology.
• Hazard = A natural event such as an earthquake, tsunami or volcano which has the potential to affect people & property.
• Disaster = The hazard which has caused significant loss and damage to people and infrastructure.
• The disaster risk equation can be used to help understand the components that influence the degree of risk from a tectonic disaster: (Risk = H X V/C)
• The disaster risk equation shows that the degree of risk faced by a community or population arises due to its vulnerability, and from the impact (and severity) of the hazard. The capacity to cope or ‘resilience’ depends upon having the necessary resources, strategies and good governance in place to be able to ‘spring’ back when a destabilising event has affected them.
• • Risk - this is the likelihood that humans will be seriously affected by a hazardous event.
  • Vulnerability - this is how susceptible a population is to the damage caused by a hazard.
  • Capacity to cope - the ability of people, organizations using available resources, to manage risk or disasters. The capacity to cope requires continuing awareness, resources and good management at all times.
  • Resilience – this is the ability to ‘spring back’ from the impacts of a hazard.
• Physical factors might influence a population’s degree of vulnerability to tectonic hazards

  o Magnitude

  o Frequency

  o Plate boundary.

  o Hazards generated.
• Political factors might influence a population’s degree of vulnerability to tectonic hazards

  o   Good governance

  o   Government preparedness and response

  o   Investment into hazard mitigation

  o   Government spending on public services e.g. health care,

  o   The international relations the government has with other countries.
• Socio-economic factors might influence a population’s degree of vulnerability to tectonic hazards

  o   Level of development

  o    Level of education.

  o   Population structure e.g. youthful vs. ageing population

  o   Extent of wealth inequalities in a community

  o   % who are insured
• • World population growth and urbanisation means that more people are at risk from natural hazards.
  • Concern is increasing because 2/3 of world’s population will be urban by 2050 so making them more vulnerable.
• - The World Risk Index considers a number of factors which affect the level of risk to disasters:

  o   Natural hazard frequency & probability

  o   Public infrastructure & housing condition

  o   Education, healthcare & sanitation

  o   Governance and disaster preparedness & warning
• In recent years there has been a lot of news in the media about a series of tectonic events in different parts of the world. Overall more disasters have been reported since 1900s. This does not necessarily imply that disasters are more common! Large increase in hydrological (flood) & meteorological (weather) events). Only slight increase in geophysical events
• Why an increase in reporting of hydrological events i.e. flooding?

  - Sea level rise due to climate change e.g. more hurricanes; more high intensity rainstorm events

  - More people are living in vulnerable locations e.g. on the floodplain.

  - Urbanisation has increased impermeable surfaces on the floodplain.

  - Floods have greater impact, so media are reporting them more.
• Why might it appear that there has been more geophysical events even if there actually hasn’t?

  • Plate movement is very slow.
  • Confined to plate boundary location so may affect less people compared to other hazards.
  • More disasters are reported which occur in remote locations due to better technology.
  • Improvements in social media & internet has led to greater reporting of events.
  • More vulnerable people rather than disasters becoming more common.
• A 2017 study researched a link between melting glaciers and ice caps and an increase in volcanic activity and found that growing ice coverage coincided with a decrease in eruptions. The same was true in reverse: when the ice retreated, the number of eruptions increased.
• As the world’s ice sheets shrink and glaciers melt, it has been suggested the retreat could encourage a new era of volcanic activity.

  The reason for this is -> as ice retreats it leads to isostatic recovery of land (land masses rise back up from their depressed position). This unloading of pressure allows faults to move leading to earthquakes and volcanic eruptions.
• There is some evidence to suggest that as sea levels rise, in some parts of the world, magma sources can be compressed and this, rather like toothpaste being squeezed from a tube, leads to increased volcanic eruptions on adjacent land (subduction zones)
• • Recorded geophysical hazards have slightly increased over the last 50 years.
  • Deaths from tectonic hazards have generally decreased, but exceptional events like the Tohoku earthquake in 2011 have caused spikes.
  • The total number of people affected by geophysical disasters has not significantly increased, although there have been occasional spikes due to exceptional events.
  • Economic costs associated with tectonic hazards have increased over time, attributed to extensive infrastructural development.
• • Earthquakes pose the largest risk in comparison to volcanoes.

  -   Volcanoes cause more localized hazards and are more predictable as to the location of the hazard and when they might erupt.

  -   10 most serious EQs since 2000 = 676,000 deaths

  -   10 most serious volcanic eruptions since 2000 = 659 deaths
• • The costliest disasters are in ACs and EDCs due to the high levels of GDP resulting in sophisticated infrastructure and high-value economies.
  • The highest number of deaths are in LIDCs and EDCs because of higher vulnerability from poverty and lower GDP, resulting in fewer resources for governments to handle hazards effectively.
  • The highest insured losses are in ACs and EDCs because the population is wealthier, enabling more individuals to afford insurance coverage.

   
• Why are the top 5 tectonic disasters not any volcanic eruptions:

  • Volcanoes are typically located in areas of lower population density.
  • Hazards from volcanic eruptions, such as lava flows and pyroclastic flows, affect a smaller area compared to earthquakes.
  • Earthquakes primarily cause building collapse and widespread ground shaking, resulting in higher costs and more loss of life.
  • Predicting volcanic eruptions is comparatively easier than predicting earthquakes = better mitigation of vulnerability
• Not an agreed definition of a disaster/disaster classification = Reporting disaster impacts is controversia:

  • Primary deaths vs secondary deaths are counted.
  • Local or regional events in remote places are often under-recorded.
  • Declaration of deaths/casualties may be subject to political bias.
  • Statistics on major disasters are difficult to collect - remote rural areas.
  • Interpreting historical data to produce trends is difficult. Much depends on the intervals selected and whether the means of data collection have remained constant. Trends can be upset by a cluster of mega-disasters.
• The Park’s model of a disaster response curve is an attempt to model the impact of a disaster from pre to post disaster.

  • Stage 1: Occurs prior to the event and shows that quality of life is at its normal equilibrium level.
  • Stage 2: The hazard event occurs.
  • Stage 3: The hazard event has happened, and immediate relief is priority with search and rescue and medical attention underway. Quality of life drops at this stage and stays low for several hours up to several days depending on the severity of the hazard and the level of development of the region/country.
• Park model of disaster:

  • Stage 4: This is where groups (such as the government) tries to return the state of things back to normal by providing food, water and shelter to those without basic needs. It can take a variable amount of time, from hours and days to weeks and months to reach this stage, but quality of life improves at this time.
  • Stage 5: Refers to the reconstruction and recovery. Quality of life returns to normal and in some cases can be higher than it was originally.
• What factors determine the rate at which quality of life deteriorates?

  -       Speed of onset of event, magnitude & location of epicentre

  -       Hazards created.

  -       Quality & quantity of monitoring, preparation and relief
• What factors determine the rate at which quality of life improves?

  -       How much damage done.

  -       Aftershocks and weather

  -       Speed and onset of aid.

  -       Coordination of agencies involved in aid.

  -       Amount of money and insurance available for rebuilding.
• Future strategies can reduce the risk tectonic events & disasters

  • Record the hazards created - use this information to reduce their vulnerability.
  • Improving understanding of ‘precursors’ to tectonic events = predict a specific time and location that an earthquake will occur. 
  • Most geo-scientists do not believe that we will be able to accurately predict in future
  • Appropriate aseismic building design.
  • Alleviate poverty.

   
• - The Sendai Framework was adopted by UN members in 2015 and provides a comprehensive guidance for Disaster Risk Reduction.

  o   Disaster risk reduction (DRR) is a systematic approach to identifying, assessing and reducing the risks of disaster. It aims to reduce socio-economic vulnerabilities to disaster as well as dealing with the environmental and other hazards that trigger them.
• A key strategy is to “Build Back Better” in order to reduce vulnerability and economic losses from a disaster. In turn, this increases resilience so that development is sustainable.

  • It sets out targets including a substantial reduction in mortality, in the numbers of people affected by disasters, economic losses and damage to critical infrastructure.
• --> Sustainable Development Goals which are the latest UN initiative to improve the lives of people, especially in EDCs and LIDCs.

  • SDG 4: Quality Education Help vulnerable communities to be more prepared for a tectonic event by educating them on the risks & how to best protect themselves if a tectonic event happened.
  • SDG 1: No poverty – Eradicating poverty by creating job security will lead to better food security, better building quality etc = reduced vulnerability. This can be achieved through education and by bottom up schemes aimed at providing aid and assistance to the poorest.