TECTONICS: Management of tectonic hazards and disasters (EQ3) Flashcards
How have the number of recorded disasters changed since 1960? (have they increased/decreased)
They have increased significantly since 1960
What has caused the number of recorded disasters to change since 1960? what impact does this have?
Increased population:
- more people likely to be impacted by any hazard event
- Increased population density in urban & coastal areas increases the vulnerable population
The number of tectonic disasters have fluctuated since the 1960s:
- does the slight increase mean there have been more earthquakes or higher magnitude earthquakes?
- instead what 2 things has this resulted in?
No!
- greater urbanisation= higher population densities & increased building density
- Population growth= more people living in earthquake-prone regions
What has caused the number of deaths from all hazards to decrease since the 1960s? (6 things)
- Improved building construction
- Increased monitoring
- Greater preparation and planning
- Education - earthquake drills
- Improved warning systems
- Increased development
What factors cause the number of deaths from tectonic hazards to fluctuate? (3 factors)
1.Magnitude
2. Level of development
3. Location
Examples of slow onset natural events
Drought & Famine
Examples of rapid onset events
Earthquakes
Give an examples of factors that made disasters worse in two of your case studies on tectonic events?
- Radioactivity at Fukushima following the Tohoku 2011 tsunami
- Relief and aid not evenly distributed, poor infrastructure and services, secondary impacts like disease in Haiti 2010
Pros and cons of disaster statistics
+
More accurate now due to technological advances
+
Modern disaster databases are valuable for identifying patterns and aiding preparedness
What are the positives of Disaster statistics?
- more accurate now
- due to technological advances
- Modern disaster databases are valuable for identifying patterns and aiding preparedness
What are the negatives of disaster statistics?
- data inequality can vary between regions
- due to differences in resources and infrastructure
- developing countries may have unreported data
- due to limited monitoring capabilities
- Historical data has gaps
- especially for events prior to the digital age
- makes long-term trends harder to assess
- Declaration of deaths may be influenced by political bias
Has there been a change in deaths due to tectonic hazards since 1960?
There has been no real change overall in deaths
e.g.
2012 - 2014= less than 1,000 worldwide deaths
2004 - 2010= over 200,000 deaths - mega disasters skey the data
Are volcanic disasters or earthquakes more frequent?
Earthquakes are more frequent
Are economic losses due to earthquakes rising?
Yes - averaging $20-$40bn per year
More people who are more affluent= more property to lose (mainly in developed countries)
What are Mega-Disasters and what are the characteristics?
Disasters that happen on a large scale
- Have social, economic & environmental impacts
- Communities and governments require immediate support
- cCn impact multiple countries
- Are infrequent but server
- Cannot be fully managed
Name the 3 Mega-Disasters (Case Studies)
- 2004 Indian Ocean Tsunami
- 2011 Japanese Tsunami (Tohoku)
- EY10 eruption, Iceland
What happened in the 2004 Indian Ocean Tsunami
- 14 countries surrounding the Indian Ocean affected
- Economic losses and deaths in especially Indonesia, Sri Lanka and Somalia
- Wa made one of largest disasters ever in terms of regional extent
What happened in the 2011 Japanese Tsunami (Tohoku)
- Only Japan directly affected but economic impacts had global consequences
Impacts:
- Disruption to ports, factories & power supplies so…
Global car-production supply chain= Slowed
Electronic production= Slowed
(Japan is one of the centres of excellence for technology)
- In addition= had a nuclear meltdown disaster at Fukushima - caused a radioactive leaking of Fukushima power plant - was a catalyst in Germany abandoning its nuclear energy programme
What happened in the EY10 eruption?
- over 20 European countries affected by total or partial closure of their airspace
- Ash cloud from eruption disrupted air travel - dangers of jet engines ingesting ash
- Over 100,000 cancelled flights costing over £1 billion in loses
What’s a multiple-hazard zone?
When two or more hazards occur at the same time or in rapid succession (one after another).
- combination of tectonic hazards and hydro-meteorological hazards
Tectonic hazards: earthquakes, volcanic eruptions, tsunamis, landslides
hydro-meteorological hazards: flood, drought, storms, tropical cyclones
What makes the Philippines a Multiple-hazard zone? 4 things
- Tectonically active - earthquakes and volcanoes occur
- Geologically young - so has unstable mountain zones prone to tectonic shifting
- On major tropical storm tracks - which move through the area
- May suffer from global climate changes -such as El Nino and La Nina oscillations
What does the accuracy of prediction and forecasting of tectonic hazards depend on?
The type and location of the hazard
Can earthquakes be predicted? If not what can be done?
No but patterns can be identified (Risk forecast)
What type of areas can be identified (risk forecasting)?
Areas at high risk:
- areas likely to suffer severe ground shaking and liquefaction
- areas experiencing ‘seismic gaps’: areas that have not experienced an earthquake for some time and are ‘overdue’ can point to areas of high risk
Can volcanoes be predicted?
Yes
What are signs of an eruption?
- Magma rising which can be detected by heat sensors and satellites
- Changes in surface level as rising magma causes bulges
- Increased emissions of sulphur dioxide and other gases
- Increased seismic activity caused by magma movement detected by seismometers
What do scientists use prediction and forecasting to help with?
planning and preparation for hazards
What is the difference between prediction and forecasting?
Prediction= Knowing when (temporal scale) and where (spatial scale) a hazard will occur
Forecasting= gives a percentage chance of a hazard occurring over a set period of time
Can tsunamis be predicted?
They can be partly predicted however earthquake-induced tsunamis CANNOT
How can tsunamis be predicted?
- Seismometres can tell an earthquake has occured and locate it
- Then ocean monitoring equipment can detect tsunami in the open sea
Why was predicting the Asian 2004 tsunami difficult? (what happened in Indonesia and India) and what was the result of this?
Indonesia: the sensor system had been struck by lightning so didn’t work
India: the warning went to the wrong official
Result= errors in the system increased the number of deaths
What happened when trying to predict the the 2011 Japanese tsunami?
The height of the tsunami was underestimated so the warnings were not accurate
What kind of impacts can tectonic hazards have?
Global impacts
What does having a globalised world mean in terms of who tectonic hazards affect?
More likely that tectonic disasters have major spatial influences on the whole world or world regions
Global impacts of the EY10, Iceland earthquake:
- how much ash erupted in one week & to what altitude?
- what were the global impacts?
- 10 million m3 of ash in one week up to an altitude of about 9km
- over 20 European countries affected by total or partial closure of their airspace
- Ash cloud from eruption disrupted air travel - dangers of jet engines ingesting ash
- Over 100,000 cancelled flights costing over £1 billion in losses
Global impacts of the Tohoku, Japan Tsunami:
- what places did it affect?
- what did it destroy?
- what was the impact of many buildings being destroyed in Japan?
- In Japan, what was there a decline in?
- what was carried throughout the northern pacific? where did it reach?
- How many reactors shut down at Fukushima?
- what level was the nuclear accident at?
- what happened after that?
- places around the Pacific Ocean
- destroyed docks and boats
- wave was 2m high
- Due to the amount of buildings destroyed the chemicals from the debris were released into the atmosphere affecting global warming
- Decline in Japan’s contribution to world industry (e.g. vehicle manufacturing & high tech products)
- Debris & radioactive seawater reached the coast of North America
- 3 reactors shut down
- Level 7 accident
- A 15m tsunami wave flooded the reactor buildings to a depth of 5m, shutting off the emergency electrical supplies.
What are multiple hazard zones?
Places where a number of physical hazards combine to create an increased level of risk for the country and its population.
Example of a multiple hazard zone?
The Philippines
Multiple hazard zone:
- what is the Philippines and where is it located?
- what ocean is it located next to?
- what is the capital city called?
- what’s its estimated population?
- what % of population is urban?
- what % of population and what % of the land area is vulnerable to hazard events?
- what happened in 2019 and 2020?
- An island nation located in Southeast Asia
- Western pacific ocean
- Manila
- population= 102 million
- 50% population urban
- 74% population vulnerable, 60% land area vulnerable
- Country experienced:
4 typhoons
eruption of the Taal volcano
number of earthquakes
Tectonic activity in the Philippines:
- where is the country located in terms of tectonic activity?
- what is it on the western edge of?
- what are the common types of plate boundaries & what do they lead to?
- At the boundaries of a number of major and minor plate boundaries
- The Pacific Ring of Fire
- mainly convergent boundaries leading to both volcanoes and earthquakes
Volcanoes & earthquakes:
- what’s there a number of around the archipelago?
- what have they led to?
- how many non active/active volcanoes are on the islands?
- Approx how many people live within 30km of the Taal volcano
- subduction zones
- led to significant volcano activity
- 37 volcanoes & 18 active volcanoes
- 2.81 million
Tsunamis:
- what makes the Philippines vulnerable to tsunamis?
- what can tsunamis result from?
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- Their location in the Western Pacific
- can result from both volcanic eruptions and earthquakes
Typhoons:
- How many degrees from the equator is the Philippines located?
- what zone does the country lie in?
- when can typhoons occur?
- how many typhoons are the island affected by per year?
Landslides:
- what makes landslides common in the Philippines?
- what can trigger landslides?
Typhoons:
- between 5-20 degrees north of the equator
- The tropical cyclone zones
- at any time of the year
- between 15-20 typhoons per year
Landslides:
- the mountainous landscape
- Earthquake, volcanic eruptions & typhoons
Vulnerability:
- what has increased urbanisation led to?
- what is the population mostly and why?
- what does this increase?
- what has increased population also led to and why?
- how does this factor cause landslides?
- what type of country is the Philippines?
- what does it lack?
- what is the GDP per capita compared to the USA?
- led to high population densities in cities such as Manila
- mostly coastal as island areas are mountainous
- increases the vulnerability to storm surges, typhoons and tsunami
- deforestation in the upland areas due to clearance for agriculture and settlements
- Deforestation= less interception & more surface runoff
- A developing country
- lacks money for planning and preparation
- GDP per capita= US$3,460 (Philippines)
- GDP per capita= US$70, 248 (USA)
