Tectonic Processes & Hazards - EQ3 - 1.7A&B Flashcards
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
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