A hazard which operates on a global/ worldwide scale, eg sea level rise, volcanic ash cloud
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Chronic Hazard
A chronic hazard is when a context hazard increases the threat of an environmental hazard, eg sea level rise increases the risk of flooding.
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Hydrometerological Hazard
A hazard formed by hydrological and atmospheric processes, eg floods, storms or droughts.
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Geophysical Hazard
A hazard formed by tectonic/ geological processes, eg earthquakes, tsunamis, volcanoes.
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Hazard Risk Equation
Risk= Magnitude of Hazard (H) x Level of Vulnerability (V) / Capacity to Cope (C) --- (HxV)/C
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The Greenhouse Effect
The natural process by which the Earth's Infrared radiation is re-reflected and temporarily stored by a layer of greenhouse gases. Without this the Earth's atmosphere would be 33C cooler.
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Global Warming
The effect of a thickening layer of greenhouse gases. Infrared radiation is prevented from escaping back into space. This process is also called the Enhanced Greenhouse Effect.
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Negative Feedback
When a change to a system changes something else, eg rising temperatures melt glaciers, which dilutes ocean currents, weakening the warming powers of the North Atlantic Drift, decreasing temperatures.
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Positive Feedback
A vicious cycle, eg rising temperatures melt glaciers, leading to more solar radiation being absorbed by land and sea as snow and ice have greater albedo (reflective power). This leads to rising temperatures, melting the ice more.
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Coriolis Effect
The rotation of the Earth causing things to move to the right in the northern hemisphere, and to the left in the southern hemisphere. Responsible for the rotation of hurricanes.
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Constructive Plate Margins
Where new land is created by magma filling the gap created when two plates move apart. It is usually under the sea. Volcanoes can be created. Eg the Mid-Atlantic ridge, Iceland.
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Destructive Plate Margins
When two plates (continental and oceanic) move together. The oceanic plate is more dense so sinks under the continental plate. Land is lost. Magma can bubble up through gaps in the plates and erupt as a volcano. Eg the Nazca and South American plates
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Collision/ crumple zones
Plates of similar densities fold into each other. This can create mountains, eg the Himalayas was made from the African and Eurasian plates folding together.
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Conservative Plate Margins
Two plates don't collide, but instead slide past each other along a fault line. Eg the San Andreas Fault in California.
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El Nino
These occur every 3-8 years and last up to 22 months. Trade winds weaken and flow east. Warm water flows east to S America, creating low air pressure (=more rain/ lower temps). Air descends around Australia, (=high air pressure/ dry weather/ drought)
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ITCZ
Inter-tropical convergence zone; a zone of low atmospheric pressure near the equator.
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Other cards in this set
Card 2
Front
A chronic hazard is when a context hazard increases the threat of an environmental hazard, eg sea level rise increases the risk of flooding.
Back
Chronic Hazard
Card 3
Front
A hazard formed by hydrological and atmospheric processes, eg floods, storms or droughts.
Back
Card 4
Front
A hazard formed by tectonic/ geological processes, eg earthquakes, tsunamis, volcanoes.
Back
Card 5
Front
Risk= Magnitude of Hazard (H) x Level of Vulnerability (V) / Capacity to Cope (C) --- (HxV)/C
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