natural hazards Flashcards
where do earthquakes occur?
at tectonic plate boundaries.
what happened in Haiti
an earthquake
why was Haiti vulnerable?
it is a vey poor country
it lies on a conservative plate boundary
they only have one airport with one runway
houses are poorly built with hardly any foundations
what are the layers of the earth
crust
mantle
core
what is the earth’s crust broken down into?
tectonic plates
what is a hazard
a danger or risk
what is a natural hazard
a natural event that affects the physical environment and people
what is a disatser
a sudden event that causes loss of life or great damage
what happens at a destructive plate boundary?
the plates push together and the denser plate is forced under the other plate (subduction). the plate sinks into the mantle and melts to form magma. the pressure of the magma builds up and escapes through weaknesses in the earth’s crust. it rises as a volcano which is often very violent.
what happens at a constructive plate boundary?
the tectonic plates move apart from each other making a gap in the earth’s crust. magma fills the gap and creates volcanoes.
what happens at a conservative plate boundary?
plates move past each other and there is friction creating an earthquake. the magnitude (size) of the earthquake relates to the frequency of movement.
where do hurricanes form?
tropical areas near the equator
what do hurricanes need to form?
tropical waters
high humidity, light winds
warm sea surface temperatures
where is the calmest part of the hurricane
the eye
what causes the hurricane to spin?
light winds around the tropical storm.
the earth spinning (Coriolis force)
