Name the 3 different types of plate boundary. What happens at each of them?

1. LO:consider the actions that governments can take to reduce the harmful effects of natural disasters • Name the 3 different types of plate boundary. • What happens at each of them?

2. Geohazards that might affect us

3. WHAT IS A GEOHAZARD?

4. Geohazards that might affect us today are: • landslide • flood • the effects of a volcanic eruption • earthquake • tsunami What Earth processes can affect us?

5. Landslides are triggered where: • slopes are steep • rocks are weak or fractured • erosion undermines a slope • water builds up in the ground • earthquakes strike • human activities are poorly planned Landslide

6. Collapse • But, even on flat ground: • Foundations on weak rock can subside. • Old mine workings can collapse. • Soluble rocks below ground can dissolve.

7. Flood • Floods occur: • in low-lying areas • after a storm upstream • after many wet days upstream • if snow melts quickly • when rivers overflow • on stormy coasts at high tide • if dams burst

8. There are thick mud and silt deposits. • Sewers overflow. • Large objects are swept away:bridges, houses, embankments, cars. • There is electrical danger. It’s not just the amount of water in a flood: Flood mayhem

9. a volcanic winter – from ash and sulfur dioxide in the atmosphere • drought over great regions • widespread crop failure in summer, bitter cold in winter • the whole Earth cooled • fantastic sunsets There are no active volcanoes in the UK, but a major eruption elsewhere may cause: Eruption afar

10. Catastrophic effects include: • blast: 30km+ – everything is destroyed • glowing cloud– a red-hot current of ash– travelling with speeds of 100km/h+ • lahar– waterlogged volcanic ash flooding down valleys • tsunami– a great wave in coastal areas • lava flow– rarely kills because you can get out of the way Eruption on your doorstep

11. Earthquakes in the UK • They are not big enough to make surface waves, so little damage occurs. • We can feel seismic waves. • Recent UK earthquakes:www.quakes.bgs.ac.uk/recent_events/recent_events.html • Earthquakes are plotted from eyewitness accounts. • If you feel an earthquake, send in your evidence:www.quakes.bgs.ac.uk/questionnaire/EqQuestIntroB.html

12. In a catastrophic earthquake: • The ground rises and falls in waves. • There is total destruction of non-flexible structures. • People are killed by falling buildings – outside is safest. • There is risk from falling glass and fire storms. • There may be a tsunami – a huge wave in coastal areas. • Many die afterwards from disease. • The most recent big earthquake: earthquake.usgs.gov/eqcenter/recenteqsww/index.php?old=world.html Earthquake

13. can form waves over 40m high • can reach speeds of 1000km/h • can travel 10000 km across oceans, killing thousands in coastal areas • can trick you, because water first draws back from the coast – and then thunders back in These huge waves produced by volcanic eruptions, earthquakes, or submarine landslides: Tsunami

14. Major eruptions and earthquakes affect only the active zones of the Earth. • They don’t happen in the UK. • But – could a geohazard happen here? • What might its effects be? Worry? – Us?

15. http://www.brainpop.com/science/earthsystem/naturaldisasters/http://www.brainpop.com/science/earthsystem/naturaldisasters/ • http://www.brainpop.com/science/earthsystem/earthquakes/ • http://www.brainpop.com/science/earthsystem/tsunami/

16. Imagine you are in an earthquake... • Using the worksheet as a guide, write down the effects of the earthquake on you and your family.

17. How can the government prepare their countries for a disaster such as these? Discuss the methods that we would have to use to protect ourselves.

18. Bingo Volcano Earthquake Conservative Convergent Divergent Tectonic Pangea Wegener Fossils Igneous Metamorphic Pressure Heat Sedimentary Sediment Erosion Weathering Magma