Tectonic Processes & Hazards - EQ3 - 1.7A&B Flashcards
(40 cards)
Define meteorlogical hazards
- weather related events
- e.g tropical storms
Define hydrological hazards
- water related events
- e.g floods
Define geophysical hazards
- tectonic related events
- e.g earthquakes
Define climatological hazards
- events related to climate change
- e.g drought etc
Define biological 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
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 events
- 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