Hazards Summary Booklet
A hazard is the threat of substantial considered a risk worth taking = the
loss of life, substantial impact upon threat is accepted as a part of
life or damage to property that can everyday life.
be caused by an event. These events
can be caused by human action A disaster can have more impact on
(explosions, nuclear incidents) or are LDEs which are much more reliant
mainly natural (earthquakes, storms, on aid, during and post the event as
volcanoes, wildfires). Although they try to repair the damage
natural events can be the physically, socially and economically.
consequence of human actions. Whereas HDEs =have the wealth to
redevelop and support those
A disaster occurs as a result of a effected.
hazard e.g. living on/near the fault
line is a hazard, whereas an Age, social status and religious
earthquake on the fault has beliefs can be determining factors
enormous impacts and is a disaster. when it comes to leaving
The potential impacts of natural behind in an evacuation all that has
hazards are dependent on several been worked for in a lifetime.
factors: location of hazard relative to
populations, magnitude and extent Fatalism: doing nothing can be seen
of hazard, population density etc. as a defeatist attitude to take but it
There are three main types of is an acceptance that hazards are
hazards: natural events that we can do little
Geophysical- driven by the to control and losses have to be
earths own internal energy accepted. E.g. while fires can be
e.g. plate tectonics, volcanoes, hazardous to human activity, they
seismic activity. are also a natural regenerative
Atmospheric- driven by process within forest ecosystems
processes at work in the which should be allowed to take its
atmosphere e.g. tropical course.
storms/ drought.
Hydrological- driven by Prediction: methods of predicting
water bodies e.g. floods, hazardous events become more
storm surges, tsunamis. sophisticated as technology
increases. Remote sensing and
Perception of Hazards: how we seismic monitoring give clues to
perceive a hazard is determined by activity which may lead to a disaster
the effect it may have on our lives. which needs to be acted on.
This increases if people have a Advances in communications mean
direct experience with a particular that information can be shared and
hazard and how long term the analysed quickly + warnings can be
impact of this experience has been. communicated promptly and reach a
The advantages of living with the greater number of those at risk.
threat of hazards sometimes
outweigh the risk , making use of The hazardous management
fertile soils on flood plains in the cycle:
vicinity of a volcano can be
, - Preparedness: education and lives and coordinating medical
raising public awareness can assistance.
adjust behaviour to minimise - Recovery: restoring the
the likely impact of the affected area to something
hazard. + knowing what to do approaching normality.
in the immediate aftermath - Mitigation: actions aimed at
can speed up recovery reducing the severity of an
processes. In areas of high event and lessening its
risk,m the level of impacts. E.g. building design
preparedness will be greater that can withstands
than in areas where such earthquakes, barriers.
events are rare. Support after a disaster and
- Response: the speed of insurance can reduce the
response will depend on the long-term impacts. However,
effectiveness of the insurance is particularly
emergency plan that has been difficult for LDEs to afford,
put in place. Immediate where often its needed the
responses focus on saving most.
EARTHS STRUCTURE AND INTERNAL ENERGY SOURCES:
within this zone, the mainly silicate
The crust: there are two parts of the rocks are in a thick, liquid state,
crust, oceanic (silica and which becomes denser withd depth.
magnesium) and continental (silica The rocks in the upper mantle are
and aluminion). Oceanic crust is solif and sit on top of the
denser than continental crust. asthenosphere, a layer of softerm
almost plastic like rock. The
The lithosphere: the crust and the asthenosphere can move very slowly,
upper mantle together are known as carrying the lithosphere on top.
the lithosphere. This is the zone that Densiyies within the manyle
tectonic plates are formed. increase as you go down to the
lower mantle.
The core: the centre and hottest part
of the earth- temperatures can reach
5000°. Its mostly made of iron and
nickel and is four times as dense as
the crust. The outer core is semi-
liquid and is mainly iron, the inner
core is solid and made up of an iron-
nickel alloy. The core’s internal heat
is the major cause of the Earth’s
tectonic activity. The phenomonal
heat at thecore generates
convection currents within th
The mantle: this is the widest
section of the earth (2900km thick).
Due to the great heat and pressure
The earth’s surface is made up of seven major and several minor tectonic
plates. Continental plates are permenant and may extent far beyong the
margins of current land masses. They wont sink into the astehnosphere because
, of their relatively low density. In contrast, denser oceanic plates are continually
being formed at mid-ocean ridges and destriyed at deep ocean trenches- hence
their relatively young age
Conventional explanations suggest that tectonic movement is solely driven by
slow-moving convection currents. But there are other theories that could
contribute. Gravitational sliding: the lithosphere thickens with distance away
from the mid-ocean ridge. This is because u cools with distance and the
boundary between the solid lithosphere and plastic asthenosphere becomes
deeper. Gravity acting on the weight of the lithosphere near the ridge ‘pushes’
the older part of the plate in front (ridge push) . furthermore, following
subduction, the lithosphere sinks into the mantle under its own weight, helping
to ‘pull’ the rest of the plate with it (slab pull)
Plate Margins
CONSTRUCTIVE (DIVERGENT) PLATE MARGINS:
When two plates separate, they form a constructive margin. There are two
types: In oceanic areas, seafloor spreading occurs on either side of mid-ocean
ridges (e.g. mid-Atlantic ridge). In continental areas, stretching and collapsing
of the crust creates rift valleys (e.g. the Great African Rift Valley). At
constructive margins, there is some of the youngest rocks on earth’s surface as
it’s here new crust is formed when the gap is filled with magma rising from the
asthenosphere. As it cools it turns into basaltic rock.
Mid-ocean ridges: forms chains of from the asthenosphere, which cools
submarine mountain ridges. Regular and solidifies to form new crust.
breaks called transform faults cut Volcanic eruptions along the ridges
across the ridges, similar to the way can build submarine volcanoes, and
our discs break up our spines. These overtime may grow above sea level,
faults occur at right angles to the creating volcanic islands.
plate boundary, separating sections
of the ridge. They may widen at
different rates, leading to frictional
stresses building up, with shallow-
focus earthquakes releasing the
tension. The middle of mid-ocean
ridges can be marked by deep rift
valleys. Over centuries, the rift
valleys are widened by magma rising
A hazard is the threat of substantial considered a risk worth taking = the
loss of life, substantial impact upon threat is accepted as a part of
life or damage to property that can everyday life.
be caused by an event. These events
can be caused by human action A disaster can have more impact on
(explosions, nuclear incidents) or are LDEs which are much more reliant
mainly natural (earthquakes, storms, on aid, during and post the event as
volcanoes, wildfires). Although they try to repair the damage
natural events can be the physically, socially and economically.
consequence of human actions. Whereas HDEs =have the wealth to
redevelop and support those
A disaster occurs as a result of a effected.
hazard e.g. living on/near the fault
line is a hazard, whereas an Age, social status and religious
earthquake on the fault has beliefs can be determining factors
enormous impacts and is a disaster. when it comes to leaving
The potential impacts of natural behind in an evacuation all that has
hazards are dependent on several been worked for in a lifetime.
factors: location of hazard relative to
populations, magnitude and extent Fatalism: doing nothing can be seen
of hazard, population density etc. as a defeatist attitude to take but it
There are three main types of is an acceptance that hazards are
hazards: natural events that we can do little
Geophysical- driven by the to control and losses have to be
earths own internal energy accepted. E.g. while fires can be
e.g. plate tectonics, volcanoes, hazardous to human activity, they
seismic activity. are also a natural regenerative
Atmospheric- driven by process within forest ecosystems
processes at work in the which should be allowed to take its
atmosphere e.g. tropical course.
storms/ drought.
Hydrological- driven by Prediction: methods of predicting
water bodies e.g. floods, hazardous events become more
storm surges, tsunamis. sophisticated as technology
increases. Remote sensing and
Perception of Hazards: how we seismic monitoring give clues to
perceive a hazard is determined by activity which may lead to a disaster
the effect it may have on our lives. which needs to be acted on.
This increases if people have a Advances in communications mean
direct experience with a particular that information can be shared and
hazard and how long term the analysed quickly + warnings can be
impact of this experience has been. communicated promptly and reach a
The advantages of living with the greater number of those at risk.
threat of hazards sometimes
outweigh the risk , making use of The hazardous management
fertile soils on flood plains in the cycle:
vicinity of a volcano can be
, - Preparedness: education and lives and coordinating medical
raising public awareness can assistance.
adjust behaviour to minimise - Recovery: restoring the
the likely impact of the affected area to something
hazard. + knowing what to do approaching normality.
in the immediate aftermath - Mitigation: actions aimed at
can speed up recovery reducing the severity of an
processes. In areas of high event and lessening its
risk,m the level of impacts. E.g. building design
preparedness will be greater that can withstands
than in areas where such earthquakes, barriers.
events are rare. Support after a disaster and
- Response: the speed of insurance can reduce the
response will depend on the long-term impacts. However,
effectiveness of the insurance is particularly
emergency plan that has been difficult for LDEs to afford,
put in place. Immediate where often its needed the
responses focus on saving most.
EARTHS STRUCTURE AND INTERNAL ENERGY SOURCES:
within this zone, the mainly silicate
The crust: there are two parts of the rocks are in a thick, liquid state,
crust, oceanic (silica and which becomes denser withd depth.
magnesium) and continental (silica The rocks in the upper mantle are
and aluminion). Oceanic crust is solif and sit on top of the
denser than continental crust. asthenosphere, a layer of softerm
almost plastic like rock. The
The lithosphere: the crust and the asthenosphere can move very slowly,
upper mantle together are known as carrying the lithosphere on top.
the lithosphere. This is the zone that Densiyies within the manyle
tectonic plates are formed. increase as you go down to the
lower mantle.
The core: the centre and hottest part
of the earth- temperatures can reach
5000°. Its mostly made of iron and
nickel and is four times as dense as
the crust. The outer core is semi-
liquid and is mainly iron, the inner
core is solid and made up of an iron-
nickel alloy. The core’s internal heat
is the major cause of the Earth’s
tectonic activity. The phenomonal
heat at thecore generates
convection currents within th
The mantle: this is the widest
section of the earth (2900km thick).
Due to the great heat and pressure
The earth’s surface is made up of seven major and several minor tectonic
plates. Continental plates are permenant and may extent far beyong the
margins of current land masses. They wont sink into the astehnosphere because
, of their relatively low density. In contrast, denser oceanic plates are continually
being formed at mid-ocean ridges and destriyed at deep ocean trenches- hence
their relatively young age
Conventional explanations suggest that tectonic movement is solely driven by
slow-moving convection currents. But there are other theories that could
contribute. Gravitational sliding: the lithosphere thickens with distance away
from the mid-ocean ridge. This is because u cools with distance and the
boundary between the solid lithosphere and plastic asthenosphere becomes
deeper. Gravity acting on the weight of the lithosphere near the ridge ‘pushes’
the older part of the plate in front (ridge push) . furthermore, following
subduction, the lithosphere sinks into the mantle under its own weight, helping
to ‘pull’ the rest of the plate with it (slab pull)
Plate Margins
CONSTRUCTIVE (DIVERGENT) PLATE MARGINS:
When two plates separate, they form a constructive margin. There are two
types: In oceanic areas, seafloor spreading occurs on either side of mid-ocean
ridges (e.g. mid-Atlantic ridge). In continental areas, stretching and collapsing
of the crust creates rift valleys (e.g. the Great African Rift Valley). At
constructive margins, there is some of the youngest rocks on earth’s surface as
it’s here new crust is formed when the gap is filled with magma rising from the
asthenosphere. As it cools it turns into basaltic rock.
Mid-ocean ridges: forms chains of from the asthenosphere, which cools
submarine mountain ridges. Regular and solidifies to form new crust.
breaks called transform faults cut Volcanic eruptions along the ridges
across the ridges, similar to the way can build submarine volcanoes, and
our discs break up our spines. These overtime may grow above sea level,
faults occur at right angles to the creating volcanic islands.
plate boundary, separating sections
of the ridge. They may widen at
different rates, leading to frictional
stresses building up, with shallow-
focus earthquakes releasing the
tension. The middle of mid-ocean
ridges can be marked by deep rift
valleys. Over centuries, the rift
valleys are widened by magma rising
