Global Hazard Patterns

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  • Created by: em42
  • Created on: 26-04-15 08:24
1. How can you research local hazard risks and the links to climate change?
Using a local reference library, research local records including newspaper archives and present-day hazard events. Climatological data on changing climates may only be available at a regional/national level. Also, key indicators e.g. the 1st
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1. How can you research local hazard risks and the links to climate change? [continued]
sightings of various insects could measure the response to climate change.All of these results seem to indicate warmer winters & earlier springs.
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2. Describe the distribution of earthquakes around the world.
The amin earthquake zones are clustered along plate boundaries, the most powerful earthquakes are associated with destructive/conservative boundaries. When they are of high magnitude & occur in a densely populated/urban area, they can develop into
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2. Describe the distribution of earthquakes around the world. [continued]
major disasters. They cause primary hazards from ground movement & shaking, and also cause secondary hazards such as landslides, avalanches & even tsunamis.
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3. Describe the type of volcano you would find at a constructive plate boundary. {usually shield but can be composite/stratovolcanoes}
Most are on the sea floor & aren't hazardous to people except where they emerge above sea level to form islands (e.g. Iceland). East Africa has a line of 14 active volcanoes, some can produce dangerous eruptions e.g. Mt Nyriagongo (stratovolcano).
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4. Describe the type of volcano you would find at a destructive plate boundary.
Around 80% of the world's volcanoes occur along destructive plate boundaries. Oceanic plates are subducted beneath continental & explosive (composite) vlocanoes such as Mt St Helens are formed. The Pacific 'ring of fire' has many volcanoes like this.
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5. Describe a volcanic hotspot.
They are loclaised areas of the Earth's crust which have an unusually high heat flow & where magma rises to the surface as a plume, e.g. Hawai. As a plate moves over a hotspot, a chain of volcanoes is created.
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6. what are the different hazards which can come from a volcanic eruption?
Apart from lava flows, the most catastrophic impacts are pyroclastic flows, ash falls, tsunamis & mudflows.
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7. The natural hazards of slides encompass what?
THey encompass a variety of mass movements, such as rock slides, debris flows, snow avalanches as well as rainfall-/earthquake-induces slides.
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8. What are the main causes of landslides?
Most landslides occur in mountainous areas, often after abnormally heavy rain and/or seismic activity. Human factors such as deforestation of hillsides in SE.Asia & building on slopes in Hong Kong have led to widespread slides following rain.
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9. Where are snow avalanches mainly concentrated?
In high mountainous areas e.g. the Rockies, Alps or the Himalyas. They tend to occur on slopes steeper than 35°.
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10. on average, how many deaths are caused by avalnches in Europe & N.America?
40 deaths per year in Europe & 100 deaths per year in N.America.
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11. Why have trends in deaths due to avalanches slowed?
Effective management has slowed the trend in deaths, but, recent research has suggested that global warming may be increasing avalanche occurence.
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12. Descirbe the distribution of drought.
Over 1/3 of the world's land surface has some level of drought exposure. This includes 70% of the world's people & agricultural value, so drought has an effect on global food security.
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13. How do variations in the movement of the inter-tropical convergence zone (ITCZ) cause drought?
As the ITCZ moves north & south through Africa, it brings a band of seasonal rain. In some years, high-pressure zones expand & block the rain-bearing winds. In Somalia, where farmers depend for food on rain-fed agriculture, famine may result.
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14. How does El Niño cause drought?
El Niño can bring major changes to rainfall patterns. It can bring drought conditions to Indonesia & Australia as it did in 2006.
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15. How do changes in mid-latitude depression tracks cause drought?
In temperate regions, depressions bring large amounts of rainfall. But, if blocking anticylcones form & persist, depressions are forced to track further north, leading to very dry conditions. Droughts in the UK & France in 2006 as well as the US
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15. How do changes in mid-latitude depression tracks cause drought? [continued]
midwest in the 1930s were all related to this cause.
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16. Describe the distribution of flooding.
It is a frequent hazard & is evident in 33% of the world's area, this is inhabited by more than 80% of its population.
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17. Where are regional-scale, high-magnitude floods frequent?
In India/Bangladesh & China.
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18. What is the most common cause of flooding?
Excessive rainfall related to atmospheric processes, including monsoon rainfall & cyclones. In temperate climates, a series of depressions can bring prolonged heavy rainfall.
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19. What is the cause of flash flooding?
Intense rainfall sometimes associated with thunderstorms. These sudden floods can have a devastating effect.
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20. What are two other causes of flooding?
El Niño can bring devastating floods such as those in Mozambique in 1997 & 2006. Also, rapid snowmelt can add water to an already swollen river system e.g. Himalyan melt causing floods in Bangladesh.
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21. How do floods affect developing countries?
Deaths may be caused by drowning & disease, destruction of food crops, infrastructure & loss of homes.
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22. How do floods affect developed countries?
They disrupt transport & infrastructure, damage livelihoods & create high insurance costs.
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23. What does the natural hazard of storms include?
Tropical cyclones (hurricanes in the Atlantic), mid-latitude storms & tornadoes.
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24. What are tropical cyclones?
They are violent storms between 200 & 700 km in diameter which occur in latitudes 5-20° north & south of the equator. They tend to move westwards once generated.
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25. Where do tropical cyclones/hurricanes only occur?
Over warm ocean (+ 26°C) of at least 70 m depth & at least 5°N/5°S of the equator in order that the Coriolis effect (very weak at the equator) can bring about rotation of air.
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26. In what ways can storms cause damage?
Heavy rain can lead to floods & mudslides, High wind velocity & very low central pressure can lead to storm surges & coastal flooding. These can be devastating in low-lying mega-delta regions (e.g. Hurrricane Katrina).
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27. Where are disaster hotspots likely?
Where plate boundaries intersect with major storm belts in areas of high human concentration in low/medium developed countries.
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Card 2

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1. How can you research local hazard risks and the links to climate change? [continued]

Back

sightings of various insects could measure the response to climate change.All of these results seem to indicate warmer winters & earlier springs.

Card 3

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2. Describe the distribution of earthquakes around the world.

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Preview of the front of card 3

Card 4

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2. Describe the distribution of earthquakes around the world. [continued]

Back

Preview of the front of card 4

Card 5

Front

3. Describe the type of volcano you would find at a constructive plate boundary. {usually shield but can be composite/stratovolcanoes}

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