Lecture 2: Volcanic hazards Flashcards
Why do so many people live in volcanic zones?- Agriculture
Mineral rich rock that erodes rapidly to form fertile soil
Naples- surrounding land is solid limestone->poor soil
Why do so many people live in volcanic zones?- Geothermal energy
Geothermal heat- warms > 70% of iceland homes
Geysers geothermal field in California produces enough electricity to meet the power demands of san francisco
Minerals: Over many of thousand of years, heated groundwater concentrates valuable minerals e.g. copper tin gold, silver- mined throughout the world
Why do so many people live in volcanic zones?- Products
Construction materials
Abrasive and cleaning agents
Raw materials for many chemical and industrial uses
Fatalities
since 1600 ad
- 278,000 fatalities from 533 fatalities
- 40% of fatalities from V are caused by secondary effects rather than eruption
Economic impact
Estimated- $10,000,000,000 in property damage during the 20th century
eg - 1980 Mount St helens- $900 million
Indirect impacts eg Eyjafjallajokull - $1.7 billion to aviation industry
Social impact
Evacuation prior to eruption causes stress to evacuees
Disruption of commuities e.g. Kilauea Hawaii- 1,700 school children relocated
Health Impacts
Volcanic gas and ash- increase in incidence of respiratory illness, suffocation and skin abrasion
Post eruption impacts- famine epidemics
Injuries- fire, roof collapse, burns
Mental health- stress, financial, concern, depression
factors influencing degree of hazard include:
Distance: from volcano eruption products travel
Velocity: of eruption products
Temperature of eruption products
Length of warning precursory activity
Frequency of occurrence
factors influencing degree of social effect include:
nature and degree of hazard
Extent of resultant death injury
Reactions of community leaders to hazards and aftermath
Assistance from overseas local government
Individual perception of risk
Volcanoes occur at
Divergent plate boundaries
Convergent
Intra-plate
