volcanic impacts Flashcards
what are the primary impacts associated with volcanoes
tephra
pyroclastic flows
lava
volcanic gases
what are secondary impacts of volcanoes?
lahars flooding tsunamis acid rain climate change
what is tephra?
solid material that can be from volcanic bombs or ash
ejected into the atmosphere
what are pyroclastic flows?
high velocity, very hot, mixture of gas and tephra
flows down the sides at fast speeds
pompeii
how fast can pyroclastic flows move?
700 km h
what are the types of lava flows?
basaltic
andestic
what kind gases come form the volcano?
co2
monoxide
sulphur dioxide
what lake is associated with gas release?
lake nyos 1986 released co2 into atmosphere
lake on top of volcano
1700 people died
what are lahars?
melted snow/ice which mix with volcanic ash to create a mud flow down river valleys at speed
(Philippines very susceptible to this)
how many people died in the tsunami in Krakatoa and when?
3600
1883
how is acid rain formed?
when carbon dioxide mixes with water to create a weak carbon acid
when do disasters come hazardous/
when they impact people
which lava is viscous?
andesitic
which lava is less violent?
basaltic
how is magnitude of a volcano measured?
voclanic explosivity index (VEI)
logarithmic scale from 0-8
