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Hazard Causes and Global Patterns:

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Presentation on theme: "Hazard Causes and Global Patterns:"— Presentation transcript:

1 Hazard Causes and Global Patterns:
Today we will: Know why different hazards happen in different locations Understand the causes and patterns of global hazards Be able to explain using diagrams causes of different hazards and areas prone to these

2 Recap of Last Lesson: Four hazards which have affected the East Midlands in the past: Floods (1947 – 3000 homes flooded, 2007 Summer) Tornado (1984 Gotham) Gales and Storms (2008, 1987) Snow (2003, 1985, 1987) Where in Nottingham is most a risk from Flooding (and Climate Change)?

3 Basic Causes of Hazards
TASK: Drought: Page 7 and 8 Floods: age 8 and 9 Earthquakes: Page 9 and 10 Volcanoes: Page 10 and 11 Landslides and Avalanches: Page 11 In groups, use the green textbook to summarise the following 3 key points about the hazard you have been given Definition of hazard Basic causes of the hazard Basic global pattern of the hazard.

4 Basic Causes of Hazards
Earthquakes The most powerful earthquakes occur at conservative or destructive boundaries

5 Add these terms to your Glossary Sheet
Asthenosphere:- A semi-molten zone of rock underlying the earths crust Lithosphere:- The crust of the earth, around 80-90KM thick

6 Earthquake Distribution
TASK: Add to your map

7 Volcanoes Volcanoes are found at constructive and destructive boundaries as well as hotspots. Hotspot:- A localised area of the Earth’s crust with an unusually high temperature.

8 Volcanoes Constructive plates:- Most magma that reaches the surface wells up at Oceanic ridges such as the mid-Atlantic. Mostly on sea floor and do not represent major hazard- except where they emerge above sea level e.g Iceland

9 Volcanoes Destructive plates:- 80% of worlds active volcanoes occur here. Examples include Soufriere Hills in Montserrat and Mt St Helens. Explosive volcanoes Ring of fire famous area of world around Pacific Ocean

10 Active Volcanoes TASK: Add to your map in a different colour

11 Landslides 7th biggest killer with over 1,400 deaths a year ranks above volcanoes and drought Mountainous areas prone to Landslides after period of heavy rain or seismic activity. Humans also play a part in deforestation and building on hillslopes

12 Landslide and Avalanche Risk TASK: Add to your map in a different colour

13 Drought 1/3 of world’s land surface has some drought exposure-includes 70% of world’s people and agricultural value, having an effect on global food. Droughts can lead to failure of crops and loss of livestock, wildfires, duststorms and famine.

14 Drought Risk TASK: Add to your map in a different colour

15 Flooding 33% of world’s surface suffers from floods. The most common cause of floods is excessive rainfall related to atmospheric pressure e.g. monsoons and cyclones. Intense rainfall sometimes leads to flash floods which can have a devastating effect El Nino can bring devastating floods as in Mozambique in 2006 Rapid snowmelt can add water to already swollen rivers

16 Flood Risk TASK: Add to your map in a different colour

17 Storms Key Terms: Hurricanes are strong tropical wind storms in Atlantic In the West Pacific they are Typhoons In the Indian Ocean they are Cyclones Cyclones and hurricanes are violent storms between 200 and 700KM in diameter. Cyclones and hurricanes will only occur over warm ocean (over 26ºC) They form between 20º and a minimum of 5º degrees North or South of the equator. This is needed for the Coriolis effect to spin the air effectively. Once generated they tend to move westwards. (E.G. from West of Africa towards Florida etc.)

18 Tropical Storms TASK: Add to your map in a different colour

19 Multiple Hazard Hotspots
How could we describe the map we have created? Where in the world are the multiple hazard hotspots?

20 Global patterns of hazards
From the World Banks analysis they discovered that more than ½ the worlds population live in an area that could be affected by at least one hazard. But some places live in danger of more than one – Multiple Hazard Zones. Taiwan is one of the riskiest with 73% of the population exposed to 3 or more hazards Bangladesh, Nepal, Malawi and Honduras have 90% of their population exposed to at least 2 hazards. Hydro-meteorological hot spots Southern, Eastern and South East Asia, in addition to Central America and eastern parts of South America. Central Africa is largely affected by droughts Geophysical hot spots: The Himalayan region, Japan and parts of the Middle East and Southern Europe exposed to multiple hazards

21 California- USA Some of hazards California suffers from include:
Earthquakes River floods Coastal Flooding Drought Wildfire Landslides/mudslides Fog and smog

22 Philippines – SE Asia Some of hazards Philippines suffers from include: Earthquakes Floods Coastal Flooding Drought Tsunami Landslides/mudslides Typhoons

23 TASK: Produce Factsheets on the Multiple Hazard Case Studies of the Philippines and California Coast
Include: A list of the hazards which affect the area and a map showing distribution. The causes of the regions hazards (including names of plates etc.) The impacts of the regions hazards (Social, Environmental and Economic) The interaction of hazards in these areas (such as earthquakes causing tsunami or landslides etc.) Use Pages in the green textbook and in the black textbook plus the geofactsheets to help.

24 Consider the following information and suggest reasons WHY:
The less developed and developing nations of the world are at the greatest risk from natural disasters. It is estimated that 95% of all deaths caused by natural hazards actually occur outside of the developed world. Total financial losses due to natural disasters, when considered as a % of GDP, are 20 times greater in the less developed world than developed world.

25 Independent Study (Homework)
Input hazards into your hazard log table (you have been ed this). Use and to find the information plus library and news. Complete your COMPULSORY case study factsheets of the Philippines and the California Coast by the first lesson back after half term. Use the Geofactsheet (72 on the VLE) your textbook (Pages 38 and 39) and the websites you will be ed. FIELD TRIP 1st PAYMENT DUE BY NEXT FRIDAY 24th OCTOBER.


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