Restless Earth Flashcards
Features of a shield volcano
Gentle slopes with a wide base Layers of lava Frequent eruptions of runny lava Less violent eruptions An example is Mauna Loa in Hawaii
Convection current
Movement of magma under the crust. It is this movement which causes plates to move creating earthquakes and volcanoes.
What is a Tsunami?
A special type of wave where the entire depth of the sea or ocean is set in motion by an event, often an earthquake, which displaces water above it.
Features of a composite volcano
Steep sided cone shape with a narrow base Alternate layers of lava and ash Eruptions can be very explosive Found at Destructive plate margins An example is Mount St Helens in the USA
Primary effects of an earthquake.
Buildings sway, are damaged or in extreme cases fall down.
Gas mains rupture, water pipes fracture, roads and railway lines are damaged.
People can be injured or killed.
Secondary effects of an earthquake.
Fires can spread as electricity lines are damaged.
Disease spreads as local water supplies are contaminated.
Homeless people need temporary housing.
Food and water may need to be brought in to affected areas.
Primary effects of a tsunami
Wave washes on to land.
People killed or injured.
Buildings are washed away and destroyed.
Roads and railways are blocked by debris from the wave.
Secondary effects of a tsunami.
Disease spreads as dirty water contaminates clean water supplies.
Rotting bodies of the dead can be found on the streets and in collapsed buildings.
Power lines take time to be replaced.
In winter people may freeze as their is no shelter
Features of an earthquake proof building.
Interlocking steel frame. Cross bracing. Fire resistant materials. Foundations in the bedrock. Rubber shock absorbers. Open space outside to evacuate to. Computer controlled weights on the roof to reduce movement.
What case studies (volcano, earthquake or tsunami) have you studied for the Restless Earth unit?
Fold mountains in the Andes - farming, HEP, mining and tourism.
Mount St Helens , USA - Volcanic eruption MEDC
Yellowstone national park - super volcano
Kobe, Japan - earthquake MEDC
Sichuan, China - earthquake developing country
Indian Ocean - Tsunami LEDC
Sendai, Japan - Tsunami MEDC
Crust
The outer layer of the earth
Plate margin
Plate margin
Collision
The meeting of two plates of continental crust. They are both the same type so they meet ‘head on’ and buckle
Ocean Trenches
Deep sections of the ocean, usually where an oceanic plate is sinking below a continental plate
Terraces
Steps cut into hill sides to create areas of flat land
Hydroelectric Power
The use of flowing water to turn turbines to generate electricity
Aid
Money, food, training, and technology given by richer countries to poorer ones, either to help with an emergency or to encourage long term development
Immediate response
How people react as the disaster happens and in the immediate aftermath
Vent
The opening—usually central and single—in a volcano, from which magma is emitted
Supervolcano
A mega colossal volcano that erupts at least 1000km³ of material
Fissures
Extended openings along a line of weakness that allow magma to escape
Geyser
A geothermal feature in which water erupts into the air under pressure
Earthquake
A sudden and brief period of ground shaking
Richter Scale
A logarithmic scale used for measuring earthquakes based on scientific recordings of the amount of movement
Shock waves
Seismic waves generated by an earthquake that pass through the earth’s crust
Debt
Money owed to others, to a bank, or to a global organisation such as the World Bank
Prediction
Attempts to forecast an event—where and when it will happen—based on current knowledge
Preparation
Organising activities and drills so that people know what to do in an earthquake
Plate
A section of the earth’s crust
Mantle
The dense mostly solid layer between the outer core and the crust
Subduction
The sinking of oceanic crust at a destructive margin
Fold Mountains
Large Mountain ranges where rock layers have been crumpled as they have been forced together
Subsistence
Farming to provide food and other resources for the farmers own family
Irrigation
Artificial watering of land
Natural Hazard
An occurrence over which people have little control, which poses a threat to people’s lives and possessions. This is different to a natural event as volcanoes can erupt in unpopulated areas without being a hazard.
Secondary effects
The after effect of the eruption on a longer timescale
Earthquake
A sudden and often violent shift in the rocks forming the earths crust, which is felt at the surface
Long-term responses
Later reactions that occur in the weeks, months and years after the event
Lahar
These secondary effects of eruptions are mudflows resulting from ash mixing with melting ice or water
Caldera
The depression of the supervolano marking the collapsed magma chamber
Geothermal
Water that is heated beneath the ground, which comes to the surface in a variety of ways
Hot spot
A section of the earths crust where plumes of magma rise, weakening the crust. These are away from plate boundaries
Focus
The point in the earth’s crust where the earthquake originates
Epicentre
The point at the earth’s surface directly above the focus the focus
Mercalli scale
A means of measuring earthquakes be describing and comparing the damage done, on a scale of 1-12
The three P’s
The collective term for prediction, protection and preparation
Protection
Constructing buildings so that they are safe to live in and will not collapse.
Tsunami
A special type of wave where the entire depth of the sea or ocean is set in motion by an event, often an earthquake, which displaces the water above it and creates a huge wave
