Tectonic Processes & Hazards - EQ3 - 1.7A&B Flashcards
Define meteorlogical hazards
- weather related events
- e.g tropical storms
Define meteorlogical hazards
- water related events
- e.g floods
Define meteorlogical hazards
- tectonic related events
- e.g earthquakes
Define meteorlogical hazards
- events related to climate change
- e.g drought etc
Define meteorlogical hazards
- events related to the biosphere
- e.g disease etc
Why does it seem that natural disasters are increasing
-population
- Increased population - the world population has grown from 3 billion to over 8 billion since 1960
- This means more people are likely to be impacted by any hazard event
- Increased population density in urban and coastal areas increases the vulnerable population
Why does it seem that natural disasters are increasing
-urbanisation
- large portion of the earth’s surface is now concrete - impermeable and prone to floodings
Why does it seem that natural disasters are increasing
-tech
- Increased monitoring and reporting means more hazard events are recorded
- better communication technology means more events can be reported
The slight increase in a number of earthquake disasters does not…
- mean there have been more earthquakes or higher magnitude earthquakes
Why has the number of deaths from all hazards decreased since 1960
- Improved building construction, design and materials
- Increased monitoring
- Greater preparation and planning - hazard mapping, land use zoning, evacuation planning
- Education - earthquake drills
- Improved warning systems
- Increased development
The number of deaths from tectonic hazards fluctuates depending on a range of factors including…
Magnitude
Level of development
Location
What has the trend of eonomic costs from disasters been
Why has the cost from economic disasters continued to rise since the 1960s
- as more people are affected the cost increases
- More people, who are more affluent, have more property to lose
- Infrastructure is more sophisticated and expensive to replace, for example, electric grids
- This is increasingly true in emerging countries as well as developed ones
Define megadisaster
Megadisasters are high-magnitude, high impact, infrequent disasters that affect multiple countries (directly or indirectly), so their impacts are regional or even global
What is the economic impact of diasasters affected by
- The economic cost in US$ tends to be higher in developed (HIC) countries
- The impact on the GDP tends to be much greater in developing and emerging countries (LIC)
Give a percentage of GDP evaluation of the cost of earthquakes for HIC vs LIC
- Gorkha earthquake, Nepal (2015) - 10 billion & 33%
- Tohoku earthquake and tsunami, Japan (2011) - 360 billion & 4%
Give different reasons why it might be difficult for disaster data to be accurate & reliable
- When a disaster strikes, the immediate focus is on organising the rescue and aid efforts - not collecting data.
- The definition of hazard events and their classification into types can be complicated.
- There are also a number of different agencies who track and record disaster data and this can produce different and conflicting data.
- There are even differences in the definitions of some of the key term such as disaster’ and
‘damage’. - It’s difficult to gather data from remote areas.
- Sometimes politics can get in the way of reliable data.
In a …… ……. world, it is perhaps even more likely that tectonic disasters would have ………… .
- globalised
- interlinked
- major spatial influences, possibly throughout the whole world
What are examples of Meg-Disasters
- Eyjafjallajokull eruption, Iceland (2010)
- Tohoku earthquake and tsunami, Japan (2011)
- Asian Tsunami (2004)
Only …% of human fatalities from natural hazards were the result of earthquakes. Volcanic erruptions were only responsible for ….%
2.2%
0.1%
What were the majority of fatalties due to in terms of pace of events
- majority of fatalities were due to slow onset natural events such as drought & famine, rtaher than rapid onset events such as earthquakes
- the duration of a event is therefore important;
- vulnerability increases the longer a natural event lasts
what is the trend of Hydro-met hazards
- such as floods, storms, cyclones and drought,
- appear to have become more common over time, perhaps because of global warming and human environmental management issues such as deforestation
what is the trend of tectonic disasters
- i.the events, have not increased or decreased over time
- the number of events is broadly the same decade over decade
difference between tectonic disasters and hazrads and what this means for trends?
- Tectonic hazards and tectonic disasters are not the same,
- so even though the number of hazard events remains stable, the number of disasters has risen
what is the trend of the number of earthquake events
- There has been no change in the number of earthquake disasters since 1980,
- which varies between 15 and 40 each year
what is the trend of earthquake deaths
- Earthquake deaths are very variable: there were fewer than 1000 deaths worldwide in 2012 and 2014,
- yet more than 200,000 in 2010 and 2004
- Overall, there are fewer earthquake deaths than there were 30-40 years ago,
- but the impact of single megadisasters skews the data.
Whta is the trend for earthquake economic losses
- The trend for earthquake economic losses is upwards, averaging about $20-40 billion per year but, once again, this is affected by very few large events.
Describe the trend of frequency of volcanic erruptions
Volcanic disasters are much less frequent than earthquake ones and deaths from eruptions are now rare
Give a statistic showing that really harmful to people volcanic erruptions are becoming rarer
- The last time an eruption killed more than 1000 people was in Cameron in 1986 (Lake Nyos)
- only seven eruptions since 1980 have killed more than 100 people
Describe how volcanic hazards are getting more widepsread impactful
- However, numbers affected can be very large because of the mass evacuation of people around an erupting volcano,
- e.g. 350,000 affected (evacuated) with the eruption of Mt Merapi in Indonesia in 2010, but only 300 deaths.
Give evidence to support that very large diasasters can be concentrated in a small are but have a big impact
- Three of these - Kashmir 2005, Sichuan 2008 and Nepal 2015 - are in the same tectonic location: the Himalaya colllision zone
- These three disasters account for 40% of all earthquake deaths between 2005 and 2015
How did the ash spread from the Eyjafjallajokull volcano
- 110 million m^3 of ash in one week to an altitude of 9km
- prevailing westerly winds in the mid-latitude zone & a stable polar front jet stream during the eruption directed the ash across main flight paths and over airports so flights over Europe & to North America were disrupted
What was the impact to Kenyans of Eyjafjallajokull
- Kenya lost US$1.3 million a day due to cancelled flights for vegetables and flowers
- 20% of the Kenyan economy relies on exports of vegetables and flowers
- workers became temporarily unemployed
What was the impact on flights of Eyjafjallajokull
- Airlines lost up to £130 million a day due to cancelled flights
- Over 100,000 flights were cancelled
- 10 million travellers were affected
What was the widespread impact of Eyjafjallajokull on Icelandic peoples
- 500 farmers evacuated from the area immediately around the volcano
- Contamination of water sources with fluoride
Impact of Tohuku earthquake and tsunami on Japan’s trade
- US$360 billion in economic losses
- Decrease in industrial production which impacted not only Japan but the many countries which it trades with
- Lead to a stock market crash and negative impact on companies like Sony
What was the impact of Fukishima reactors with Tohuku
- Shutdown of nuclear reactors meant increasing oil imports and loss of electricity for 4.4 million homes and businesses
- Radioactive emissions into atmosphere, land, pacific ocean & groundwater
- Germany decided to phase out its nuclear energy by 2022 closing 17 reactors
- European nations such as Italy Switzerland & Spain confirmed anti-nuclear energy stances after this incidence
What was the extent of damage from the Boxing Day Tsnumai
- Affected 18 countries in south-east Asia and Africa
- Lead to over 225,000 deaths in 12 countries
- Indonesia 170,000 deaths
- Sri Lanka over 35,000 deaths
- But also 46 other countries had fatalities due to tourism such as Sweden - 543 deaths
Economic damage of the boxing day tsunami
- Economic damage of US$10 billion
- Most of Sri Lanka’s fishing boats were destroyed
- Tourism was impacted as people were reluctant to visit the areas
How many people were dispalced in Sri Lanka due to building damage from the Boxing Day Tsunami
17 million people were displaced
90,000 buildings were destroyed in Sri Lanka
environmental impact of boxing day tsunami?
Severe damage to mangroves and coral reefs
