geography — global hazards (tectonic)

What are the 4 layers of the earth? Are they solid or liquid?

What are the 4 layers of the earth? Are they solid or liquid?

• Crust, solid

• Mantle, semi-molten

• Outer core, liquid

• Inner core, solid

How hot is the inner core? (°C)

5,500

How thick is the crust?

0-60km

continental crust

crust found underneath large land masses

oceanic crust

crust found underneath the oceans. (ocean floor)

focus

Underneath the crust where the earthquake is made

shallow-focus EQs are between…

0-70km

intermediate EQs are between…

70-300km

deep-focus EQs are deeper than…

70km

The more shallow the earthquake, the more _________ it can produce at the surface.

damage

Hotspots

places where the magma rises up through the crust

Volcanoes form on areas where two tectonic plates are moving away from one another, at _______ and ________ plate margins.

constructive and destructive

constructive plates

tectonic plates moving away

destructive plates

• tectonic plates move towards one another.

• The oceanic crust is forced to sink, the continental crust rises above

Conservative plates

tectonic plates move past each other

Convection currents

Hot currents that make plates move

How are earthquakes formed?

By the sudden release of energy in the crust due to tectonic plate movements.

Seismic waves

Shock waves from earthquakes

earthquakes are found at ____ __ plate boundaries.

all 4

Richter scale measures the….

the strength of earthquakes

seismometer detects…

seismic waves from earthquakes

give 4 impacts of an earthquake

• buildings collapsing

• loss of electricity, water supply

• landslides

• loss of jobs/ businesses

give 3 short-term responses of an earthquake

• Search and rescue teams

• Public Safety Communications, through media and social platforms (advising on safety measures and potential aftershocks)

• Temporary Shelters

give 3 long-term responses of an earthquake

• Governments invest in rebuilding and improving infrastructure

• Educating the public about earthquakes, safety drills and emergency plans

• Mental health services to help people with loss/ trauma

Volcanoes are formed on the margins ___________ and __________

Constructive and destructice

State 3 facts about composite volcanoes

• found at destructive margins

• most violent eruptions

• lava is thick and heavy

State 3 facts about shield volcanoes

• found at constructive margins

• Not as violent eruptions

• Lava is thin and runny.

State 2 advantages of volcanoes

• tourist attractions

• ash acts as a natural fertiliser for the soil

State 3 disadvantages of volcanoes

• Destroyed homes, making people homeless

• Economic activity can suffer

• Natural habitats are disrupted