1 natural and tectonic hazards Flashcards
what is a natural hazard
A natural hazard is a large scale natural event that provides a major risk to human life
what is the theory of plate tectonics
convections currents pull the earths plates away from each otherm causing land to move overtime
what are the three types of boundaries and what occurs at each one
Destructive-Oceanic plate slides underneath the continental plate
Constructive-Plates move away from each other
conservative-Plates slide against each otherm creating tension either going in opposite directions or the same directions at different speeds
what causes an earthquake
tension building as plates get stuck when they move past each other, it is when the ground snaps and this tension is released that causes an earthquake
what causes a volcano
pressure building up and magma moving through the cracks
what are the two types of natural hazards
meterlogical- weather related
geological-tectonically related
primary effect of an earthquake and a volcano
eq- buildings collapsing, crushes
volcanoes- pyrocolastic flows, ash clouds, lava
secondary effects of volcanoes and earthquakes
eq- long term economic damage and homeloss
volcanoes-the same as above
how is an earhtwuake measured and how does the scale used work
richter scale which measures shakingm every new level goes up by 10x
two factors that effect hazard risk
vulnerability and ability to cope
at which marhins do volcanoes occur
destrucive and construcitve
what is an epicentre and a focus
Define an epicentre- the point above the ground where the earthquake originated
Define the focus- the point underneath the ground where the earthquake originated
four hazard management strategies
predict
plan
monitor
protect
why might someone choose to live by an area of high risk (three reasons)
- fertile land
- job
- family
whatare the two types of crust and which one is thicker
oceanic-thicker (30-50km)
continetal (10km)
