Tectonic activity

Question 1

Composite Volcano

Answer 1

• layers of ash and lava
• found at destructive or compressional boundaries
• Erupt pyroclastic flow
• Explosive eruptions
• Andesitic Magma
• High with steep sides
• High pressure
• Thick, sticky lava

Question 2

Shield Volcanoes

Answer 2

• found at constructive or tensions boundaries
• Basaltic magma
• Low pressure
• Thin runny lava
• Frequent but gentle eruptions
• Low with gently sloping sides

Question 3

Earthquake Preparation for developed countries

Answer 3

• earthquake drills
• earthquake proof infrastructure
• X bracing in buildings
• Underground building shock absorbers
• Damper in roof acts reducing building sway
• Cross bracing stops floor collapsing
• steel frame used because it is flexible
• double glazing to stop broken glass showering down

Question 4

Conservative plate boundary

Answer 4

• plates slide past each other in opposite or same direction but at different speeds
• Friction is over come and one plate slips past in a sudden movement
• e.g. San Andreas Fault in California
• North american + Pacific plate

Question 5

Primary impacts of volcanoes

Answer 5

• Deaths
• Volcanic ash released into atmosphere
• Loss of homes

Question 6

List Earths Layered Structure

Answer 6

• Inner Core
• Outer Core
• Mantle (asthenosphere)
• Crust

Question 7

Crust

Answer 7

• made of igneous, metamorphic + sedimentary rocks
• Oceanic + Continental
• Temp ranges from 200C to 400C

Question 8

Continental crust

Answer 8

• 30km to 50km thick
• Made of granite
• Less dense
• Older
• Can’t be renewed and destroyed

Question 9

Secondary impacts of earthquakes

Answer 9

• Diseases from poor sanitation
• Loss in economy
• Loss of jobs
• Tsunamis
• Rebuilding cost

Question 10

Oceanic crust

Answer 10

• 6-8km thick
• Made of basalt, diabase and gabbro
• Denser
• Can sink
• Can be renewed and destroyed

Question 11

How the core’s internal heat source generated through convection?

Answer 11

Radioactive decay heats up in the inner core and rises magma up to the mantle. the magma then cools causing it to go in opposite directions and fall creating a convection current. The convection current then causes the outer core to also push apart causing movement of tectonic plates.

Question 12

Primary impacts of earthquakes

Answer 12

• Deaths
• Loss of homes
• Building damage
• Loss of water

Question 13

Volcano Preparation

Answer 13

• Exclusion zone around the volcano
• Ready + able to evacuate residents
• Emergency kit

Question 14

Earthquake Preparation for developing countries

Answer 14

• Emergency kits
• Hollow concrete bricks used to minimise damage if they fall.
• Steel corner pillars to provide strength and flexibility
• Cross braces or wood frame
• lightweight thatched roof
• simple steel rod foundations
• Wall made of mud and straw packed between wooden slats

Question 15

Properties of the inner core

Answer 15

• Solid
• Radius(thickness) of 1,220km
• Made of iron-nickel
• Boundary is approximately 5400C

Question 16

Convergent plate boundary(continental collision)

Answer 16

• Caused if two continental crusts push towards each other
• Creates mountains or earthquakes
• Nepal earthquake 2015

Question 17

Upper Mantle

Answer 17

Inner asthenosphere:
-Lubricating layer underneath lithosphere 
-Made of plastic flowing rocks
-200km thick
-Highly viscous
Lithosphere:
-Made of rigid rock
-50 to 120km thick

Question 18

Properties of the outer core

Answer 18

• Liquid layer
• Radius(thickness) of 3483km
• Made of iron-nickel
• Temp ranges from 2,700C to 7,730C near boundary

Question 19

Divergent plate boundary

Answer 19

• Moving away from each other
• As tectonic plates tear apart earthquakes are caused by friction
• earthquakes are small
• when plates move apart hot and runny magma rises through gaps

Question 20

Pyroclastic Flow

Answer 20

• hot steam, ash, rock and dust.
• roll down sides of a volcano at high speeds
• temps over 400C

Question 21

Convergent plate boundary (subduction zone)

Answer 21

• oceanic and continental crust
• towards each other but Oceanic crust sub-ducts because more dense
• As oceanic plate sinks it melts and creates magma
• Creates volcanoes or earthquakes

Question 22

Earthquake Hazards

Answer 22

• Buildings can be damaged by shaking
• Flow of electricity through cities can be cut
• Causes tsunamis
• Lose of economy
• Infrastructure damage
• Disease
• Looting

Question 23

Properties of the mantle

Answer 23

• Mainly solid
• Silicate rocky shell
• Radius(thickness) of 2,886km
• Made if iron-nickel

Question 24

Seismic waves

Answer 24

The longer seismic waves have to reach the surface the weaker the earthquake becomes

Question 25

Secondary impacts of volcanoes

Answer 25

• Tourism attraction
• nutrients for soil
• deaths from mud flows(lahars)