hazardous earth Flashcards
Asthenosphere
The semi-molten layer at the top of the
mantle which flows due to convection
currents, moving the solid lithosphere
above.
Atmospheric circulation
The general movements of air around
the Earth due to pressure and
temperature.
Climate change
A distinct change in global or regional
patterns of climate, such as changes in
temperature or precipitation patterns.
Conservative plate boundary
A plate boundary where two plates are
moving alongside each other.
Continental crust
The thicker, less dense crust that makes
up the continents.
Convection current
The movement of a fluid caused by a
difference in temperature or density.
Convergent plate boundary
A plate boundary where two plates are
moving towards each other.
Coriolis Effect
The effect of the Earth’s rotation on wind
movements.
Cyclone
A tropical cyclone that hits Oceania or
Madagascar.
Divergent plate boundary
A plate boundary where two plates are
moving away from each other.
Eccentricity
The changing of the orbit of the Earth
around the Sun from a circular shape to
an ellipse.
Eye
An area of a tropical cyclone with
extremely low pressure and calm
conditions.
Eyewall
An area of a tropical cyclone with the
most intense, powerful winds and
torrential rain.
Ferrel Cell
At around 60° either side of the equator,
moist air rises, and travels to lower
latitudes at around 30° where it sinks,
along with air travelling from the equator.
Fossil fuels
Fuels made up of the remains of organic
material, such as oil, coal and gas.
Geological hazard
A hazard caused by processes on the
land.
Greenhouse Gases
Gases in the Earth’s atmosphere that
trap energy in the Earth’s system and
contribute to the greenhouse effect
(carbon dioxide, methane, water vapour
and nitrous oxides).
Hadley Cell
At the equator, hot moist air rises, moves
to higher latitudes (30°) and sinks.
Hazard risk
The probability that a natural hazard will
negatively affect a population.
Hotspot
An area where unusually hot magma
breaks through the middle of a plate and
travels up to the surface, creating a
volcano.
Hurricane
A tropical cyclone that hits the USA,
Latin America or the Caribbean.
Ice core
A cylinder of ice extracted from an ice
sheet or glacier, which is used to analyse
past environmental conditions.
Immediate responses
Actions taken as soon as the hazard
happens and in its immediate aftermath
(hours, days, and potentially a week or
so after the event).
Inner core
A solid ball of iron/nickel at the Earth’s
centre. Radioactive decay within the
inner core provides Earth’s internal
energy.
Inter-Tropical Convergence Zone (ITCZ)
An area surrounding the equator where
global winds converge, causing an area
of low pressure with rainy conditions.
Lithosphere
Solid rock that lies on top of the
asthenosphere. The top of the
lithosphere is the crust, which is broken
up into tectonic plates.
Long-term responses
Actions taken after the immediate
responses when the effects of the
hazard have been minimised (weeks,
months, and years after the event).
Magma
Molten rock found beneath the Earth’s
surface.
Mantle
The area underneath the crust which
contains magma.
Milankovitch Cycles
The cyclical variations in the Earth’s orbit
around the Sun
Natural hazard
A naturally occurring event that is a
threat to a population.
Obliquity (or axial tilt)
The tilt of the Earth’s axis, which
changes from 21.5° and 24.5°.
Ocean currents
The predictable, continuous circulation of
ocean water which transfers heat around
the globe.
Oceanic crust
The thinner, denser crust that makes up
the ocean floor.
Outer core
A molten layer of iron and nickel that
surrounds the inner core and transfers
energy by convection currents.
Plate boundary
The point at which two plates meet.
Polar Cell
At 60° north or south of the equator,
moist air rises, and travels to the poles
(90°), where it sinks.
Precession
The point at which two plates meet.
Pressure belt
A region of the Earth which is generally
under the same pressure.
Primary effects
The effects that are directly caused by
the hazard itself.
Quaternary Period
The geological time period that started
2.6 million years ago and extends into
the present.
Richter scale
A logarithmic scale used to measure the
magnitude of earthquakes.
Secondary effects
The effects that are a result of the
primary effects.
Storm surge
A rise in sea level caused when a
tropical cyclone pushes a large amount
of sea water onto the shore.
Subduction
A process that occurs at a destructive
plate boundary when a plate is pushed
below another plate, forcing it to sink into
the asthenosphere.
Tectonic hazard
A natural hazard caused by the physical
processes and movements of tectonic
plates.
Tectonic plates
Large slabs of the Earth’s crust that sit
and move on top of the liquid mantle.
The Enhanced Greenhouse Effect
A process where the Earth’s surface is
heated by the greenhouse effect at a
higher rate due to increased greenhouse
gas emissions from human activities.
The Greenhouse Effect
A natural process where greenhouse
gases trap the energy from the Sun
inside the Earth’s atmosphere, warming
the Earth’s surface.
Track
A typical pathway that a tropical cyclone
takes which is driven by global wind
circulation.
Tree rings
A ring in a tree trunk that grows annually,
indicating the conditions in the year it
grew.
Tropical cyclone
A very large, spinning storm with high
winds and torrential rain that forms in the
tropics.
Tsunami
A large wave caused by a large amount
of water being displaced when plates
move.
Typhoon
A tropical cyclone that hits India, Japan
or the Philippines.
