1.1A Tectonic Hazards

Question 1

(4)

Label the structure of the Earth’s atmosphere.

Answer 1

Inner core, Outer core, Mantle, Crust.

Question 2

(2)

Which crust is thicker? Oceanic or Continental?

Answer 2

Continental (30-50km)

Question 3

(2)

Which crust is denser? Oceanic or Continental?

Answer 3

Oceanic (5-10km)

Question 4

(6)

How do volcanoes form at destructive margins?

Answer 4

• The plates move TOWARDS each other(1)
• The Oceanic Plate SUBDUCTS into the Continental Plate(1)
• Gas rich magma is formed in the MAGMA PLUME(1)
• At HIGH PRESSURE, magma erupts through FISSURE(1)
• Forms COMPOSITE volcanoes (TALL and STEEP) (1)
• HIGH VISCOSITY of magma(1)

Question 5

(4)

How do earthquakes form at destructive margins?

Answer 5

• As the Oceanic plate SUBDUCTS into to Continental plate…(1)
• Tension BUILDS UP(1)
• Due to FRICTION(1)
• Causing the Oceanic Plate to get STUCK into the Continental Plate whilst causing INTENSE VIBRATIONS(1)

Question 6

(6)

How do volcanoes form at constructive margins?

Answer 6

• The plates move AWAY from each other(1)
• as magma RISES from the MANTLE(1).
• It fills the FISSURE and COOLS(1).
• It erupts at LOW PRESSURE(1).
• Forming SHIELD (WIDE and SHALLOW) volcanoes(1).
• At LOW VISCOSITY.(1)

Question 7

(3)

How do earthquakes form at constructive margins?

Answer 7

• TENSION builds along cracks in plates(1)
• as they move AWAY from each other(1).
• This causes shockwaves to be released(1).

Question 8

(4)

How do earthquakes form at conservative margins?

Answer 8

• The two plates move SIDEWAYS past each other(1)
• at DIFFERENT VELOCITIES(1).
• This causes shockwaves to be emitted(1)
• through the INTENSE FRICTION being created(1).

Question 9

(3)

Why do people live in areas at risk from tectonic hazards?

Answer 9

• May not have a choice to leave
• Minerals from volcanic ash –> volcanic soil = fertile –> attracts farmers.
• Confidence of government support.

Question 10

(2)

How does monitoring reduce the effects of tectonic hazards?

Answer 10

• Earthquakes: Seismometers: detects earth movements –> able to give a warning.
• Volcanoes: Using satellites to tell the changes in volcanic activity.

Question 11

(2)

How does prediction reduce the effects of tectonic hazards?

Answer 11

• Earthquakes: Using a forecast.
• Volcanoes: Using satellites.

Question 12

(3)

How does planning reduce the effects of tectonic hazards?

Answer 12

• Evacuation routes planned by govs.
• Educate people so they know what to do in hazard.
• Provide emergency supplies.

Question 13

(2)

How does protection reduce the effects of tectonic hazards?

Answer 13

• Earthquakes: Seismic base isolation: Magnetic piece of large rubber that absorbs the energy so that buildings are LESS LIKELY to collapse.
• Volcanoes: Trenches/Barriers: Divert the lava away from settlements.