Zusammenfassung der Ressource
Restless Earth
- Case studies
- Earthquake in Kobe, Japan 1995
- Magnitude 7.2
- 5000 dead, 26000 injured
- Disrupted transport/communication
- £100 billion in damages
- Caused homelessness and unemployment
- Eruption at Mt. Nyiragongo, Congo 2002
- 1000km wide river of fast-flowing basalt lava
- 100 died, 400 000 evacuated
- 12 500 homes destroyed
- Tectonic plates
- Plate boundaries
- Destructive
- Two plates collide and one flows beneath the other (subduction)
- Causes earthquakes and volcanoes
- Form composite volcanoes
- Constructive
- Convection currents pull the crust apart, forming a volcanic ridge
- Form shield volcanoes
- Conservative
- Two plates slide past eachother
- Creates fault lines
- Causes earthquakes
- Collision
- Two continental plates collide, causing them to buckle
- Causes earthquakes
- Convection currents
- 1. Core heats molten rock in mantle
- 2. Heated rock rises to Earth's surface
- 3. Current moves tectonic plates
- 4. Molten rock cools and flows downwards
- Crust
- Continental crust
- Less dense, granite rocks
- Oceanic crust
- Denser basaltic rocks
- Hazards
- Volcanoes
- Shield volcanoes
- Formed on constructive plate
boundaries
- Eruptions of thin runny
lava flow a long distance
before solidifying
- Gently sloping sides and a wide base
- Contain basaltic magma
- Very hot, but with low silica
and gas content
- Frequent, but not violent, eruptions
- Composite volcanoes
- Formed on destructive plate boundaries
- Eruptions of viscous and sticky lava/ash
which don't flow very far
- Steep sloping sides and a narrow base
- Thick layers of lava/ash
- Contain andesitic magma
- Less hot than basaltic magma, but with
higher silica and gas content
- Erupt infrequently but violently
- Causes pyroclastic flows
- Fast moving current containing a mixture
of ash, gases and rock
- Earthquakes
- Can be large amounts of death or injury
- Expensive property damage
- Remote areas cannot easily get help
- Managing hazards
- Earthquake-resistant design
- Very strong framework
- Rubber/steel foundations which move slightly
- Shock absorbers
- Deeper
foundations
- Strengthened walls
- Predicting earthquakes and eruptions
- Difficulties - we don't know...
- When/where they could happen
- How big of an impact they will have
- How many people live there/will be affected
- What can help us predict them?
- Strange animal and bird activity/migration
- Increases in gas emissions or soil temperature
- Volcano swelling
- Small earthquakes getting more frequent
- Water getting warmer
- Relief
- Volunteers/emergency services
- Clear debris + help injured
- Clean water prevents
spread of disease
- Food and medical help
- Radio communication
- Evacuation plan