Tectonic Hazards
Case Studies
Key terms and definitions
HOTS question: Can we completely protect ourselves from natural hazards?
Collision plate margin
Tectonic plate margin where two plates are coming together which force the land up
creating fold mountains
Conservative plate margin
Tectonic plate margin where two tectonic plates slide past each other
Constructive plate margin
Tectonic plate margin where rising magma adds new material to plates that are moving
apart
Destructive plate margin
Tectonic plate margin where two plates are coming together and one plate is forced under
Earthquake
A sudden or violent movement within the Earth’s crust often followed by aftershocks
Hazard risk
The probability or chance that a natural hazard may take place
High income country (HIC)
A country with a GNI of $12,746 or above
Low income country (LIC)
A country with a GNI of $1,045 or below
Natural hazard
A natural event that threatens people or has the potential to cause damage and destruction
Newly emerging economies
(NEEs)
A country which has begun to experience higher rates of economic development
Tectonic plate
A segment of the Earth’s crust which can float across the semi-molten rock below
Volcano
An opening in the Earth’s crust from which lava, ash and gases erupt
Haiti earthquake
Christchurch earthquake
Eyja volcanic eruption
Boxing day tsunami
Haiti is an LIC. The 7.0
magnitude
earthquake
killed 220,000 people and
caused $8 billion in damage.
Haiti relied on international
support in the aftermath.
New Zealand is a HIC. The
6.3 magnitude earthquake
killed 181 people and
caused $20 billion damage.
Buildings were quickly
repaired and replaced.
Eyja began to erupt on the
20th March. There were no
fatalities
however
the
eruption cost $3 billion from
the
disruption
of
international flights.
The tsunami was caused by
a
magnitude
9.2
earthquake.
It
caused
300,00 deaths in 15
countries and destroyed
countless communities.
Tsunamis are large waves that are caused by
events underwater, often earthquakes. In
open water the waves are not very tall and
can travel up to 500mph, but once they reach
shallow water the wave slows down but
increases in height.
Billions of people choose to live
near tectonic hazards. To protect
them scientists regularly monitor
and try to predict when natural
events will take place.
Governments can protect and plan
for events to try to minimize the
damage caused.
Earthquakes occur when tectonic
plates move and potential energy is
released in seismic waves.
Earthquakes are measured using the
Richter scale with 10 being the most
powerful.
Volcanoes are very dangerous and can kill
people, however living near them can bring
great benefits such as providing geothermal
energy, creating fertile soil and being a
tourist destination.
Natural events are physical events such as
earthquakes or flooding. They only become
natural hazards when they threaten humans or
human activities. Not all natural events become
natural hazards. Humans have increased the risk
from natural hazards through urbanisation,
climate change and poverty.
Over millions of years the Earth’s
landscape has changed drastically.
Tectonic plates are constantly moving
because of convection currents in the
Earth’s mantle. Where the plates meet, we
experience most of the tectonic hazards.
Plate margins are the places where
two plates meet. Plates can either be
moving apart, together or alongside
each other. Depending on the
direction of movement different
hazards are caused.
Shield volcanoes are formed by less sticky magma and
have gently sloping sides and less violent eruptions
whereas composite volcanoes are formed by sticky
magma, have steep sides and violent eruptions.