earthquakes Flashcards
natural hazard
a natural event(earthquake, volcano) that threatens people or has the potential to cause damage, destruction and death
natural disaster
when a natural hazard interacts with a vunerable population
convection currents
heat from core melts rocks in lower mantle
molten rock rises at the crust, some magma escapes at volcanoes
most magma forced sideways, dragging the plates
magma cools and sinks
ridge push
new crust rises when heated and creates a ridge
it pushes older crust away from the ridge
slab pull
old crust is cooler and thicker than the hot mantle, so it sinks to the mantle pulling the plate downwards
oceanic crust and continental crust key differences
oceanic:
made of basalt rock
average thickness, 7km
denser 2.9g/cm3
can be subducted
younger
continental:
mainly made of granite rock
average thickness, 30-50km
less dense 2.7g/cm3
not often subducted
older
composite volcanoes formed
when oceanic plate subducted in the mantle and magma rises up through the crust
what is destructive plate
oceanic and continental collide
denser oceanic crust subducts beneath less dense continental crust
what is constructive plate
plates move apart allowing new magma to rise and form new land
what is conservative plate
plates slide past eachother
they can lock together for years, building energy
eventually, the energy releases
hazards formed in destructive plates
earthquakes
tsunamis
composite volcanoes
hazards formed in constructive plates
earthquakes
tsunami
shield volcanoes
hazards formed in conservative plates
earthquakes
landforms in destructive plates
fold mountains
deep ocean trenches
landforms at constructive plates
mid ocean ridge
underwater volcanoes
landforms at conservative plates
faults
destructive plate example
nazca > south american
constructive plate example
north american < > eurasion
nazca < > pacific
conservative plate example
san andreas fault
primary effect
effects that happen immediately after or during the shaking of the earthquake
secondary effect
a long term effect that occurs as a result of the primary effect
social impact
impact on society
economic impact
impact on money
NGO
non governmental organisation
someone who is not tied to polotics or government e.g. oxfam
international aid
assisstance from another country
immediate response
solve primary effects such as deaths and injuries
long term responses
important for secondary responses
responses that go on for months and years after a disaster
appropriate technology
technology that is suited to the needs, skills, resources, wealth and knowledge of the people who live in a local area for the environment in which they live
seismic gap
an area on a known earthquake fault where earthquake activity has not happened for a while
deaths in nepal
9000
injuries nepal
20 000
schools destroyed nepal
7000
deaths christchurch
181
schools destroyed christchurch
9
christchurch economic damage
$3.5 billion
nepal economic damage
$5 billion
chemical toilets sent CC
27 000
examples of immediate responses
rescue teams
tents, 500 000
road blocks
emergency aid
evacuation
secondary responses examples
rebuilt schools - hospitals
field hospitals
seeds provided
