Why do the causes and impacts of tectonic activity vary in different countries? Flashcards
To know what the structure of the earth is like.
What makes the Earth’s tectonic plates move?
•Convection currents
Where does the heat come to make the convection currents?
- The inner core.
- (1) heat from when the planet formed which has not yet been lost;
- (2) frictional heating, caused by denser/heavier core material sinking to the center of the planet;
- (3) heat from the decay of radioactive elements in the core
To know the three types of plate boundary.
What is a hot spot?
- A really hot part of the mantle.
- A magma plume (bulge).
- It doesn’t move.
- It melts the plate above it.
- It creates a volcano.
- As the plate moves slowly over the hot spot new volcanoes are formed.
- The volcanoes form in a line.
What is an example of a hot spot?
- In the middle of the Pacific plate.
- It has created the group of islands that are called Hawaii.
What is an earthquake?
- The shaking and vibration of the Earth’s crust
- Due to movement of the Earth’s plates (plate tectonics).
- Earthquakes can happen along any type of plate boundary.
What causes an earthquake?
- The plates moving.
- The release of built-up pressure inside the Earth’s crust.
What is the focus of an earthquake?
•It is the specific point where the pressure is released in the crust.
What is the epicentre?
- The point above the focus on the earth’s surface.
- Where there is the most damage.
What is a tsunami?
- A large wave
- Created by an under water earthquake.
- The plates suddenly move and move the water above them.
- This creates a large set of waves that travel over 200mph towards the coast.
How did an earthquake impact a developing country?
How did an earthquake impact a developed country?
How can you prepare for an earthquake?
- Build life save buildings
- Shock-absorbers in the foundations.
- Steel frames to hold the building up.
Shutters to stop smashed glass from falling
- Strap bookcases and furniture to the walls so they don’t fall and crush people.
- Have an emergency kits- fresh water, torches, heater, first aid kit, food.
- Know where to shut off gas and electricity- to stop fires from starting.
What is a composite volcano?
- A volcano on a destructive plate boundary.
- It has tall sides.
- It is made of layers of ash and lava from previous eruptions.
What type of eruption does it do?
- Very explosive and violent.
- Pyroclastic flows, lava bombs.
- Sticky (viscous) lava that doesn’t travel very far before cooling and solidifying.
What is a shield volcano?
- A volcano on a constructive plate boundary.
- It has shallow sides.
- It is made of layers of ash and lava from previous eruptions.
It has runny lava that travels further before it cools and becomes hard rock.
What type of eruption does it do?
- Very gentle.
- Lots of runny lava.
How did a volcanic eruption impact a developing country?
What can you do before a volcano erupts?
- Monitor the gases using an aeroplane-
- to see if there are any changes in gases.
- It could give you information if it is going to erupt.
- Put seismometers on the volcano- to monitor ground movement and shaking
- More movement- it could be about to erupt.
- Put tilt meters to see if the slopes change shape.
- If the volcano changes shape it could be filling up with magma and could erupt.
- Measure the temperature of water in boreholes-
- If the water is getting hotter- it might be about to erupt.
What can you do to protect yourself from the volcano?
- Move away- evacuate if it is more active.
- Have evacuation routes to escape.
- Build concrete shelters that could stop volcanic bombs and ash falling on you.
- Dig channels to divert/move the lava/mud flows away from you.
- Get aircraft to spread cold water on the lava flows so they harden and become rock- so they don’t reach homes and buildings.
