volcanic hazards Flashcards
How is vulcanicity measured
Using the VEI scale, the more powerful the more explosive
Nuées Ardentes/pyroclastic flows
Clouds of hot ash and gas that collapses at high speed can reach up to 500mph
Lave flows
Can flow slow or fast depending on viscosity
(Silica makes lava viscous)
Mudflows or Lahars
Melting of ice at high latitudes mixing with soil
Gases/acid rain
Volcano releases gases such as sulphur dioxide into atmosphere and therefor mixes with clouds and precipitation becomes acidic
Tephra
Pieces of rock emitted by the volcano
What is the spatial distribution of volcanoes
Along any constructive or destructive plate margin or hotspots
What is the name of the area of high volcanic activity
Ring of fire
How is the magnitude calculated of volcanoes
VEI scale
What does the VEI scale consider
How long it lasts
Amount of tephra e.t.c
High magnitude is explosive
Low magnitude is effusive
What are the classification of volcanoes regarding frequency
Dormant
Active
Extinct
Frequency ranges each volcano
How can volcanoes be predicted
Seismic activity
Gas releases
Elevation
Increasing ground temperatures
Migration of animals
Primary effects of volcanic eruptions
-damage to ecosystems
-business and industry destruction
-people killed or injured
-govt buildings destroyed
Secondary effects of volcanoes
-water acidified by acid rain and ghg
-jobs and tourism profit loss
-mudlfows or floods
-traum/homelessness
-conflicts concerning govt response
Can earthquakes be prevented
No
The only kind of prevention could be the risk to people to stop people living near them
