TECTONICS

Question 1

What are the characteristics of the continental crust?

Answer 1

30–60 km thick, solid granite

Question 2

What makes up the lithosphere?

Answer 2

The crust and the uppermost part of the mantle

Question 3

What is the asthenosphere?

Answer 3

The top 100 km of the mantle; it is viscous

Question 4

What is the composition and thickness of the mantle?

Answer 4

2900–3000 km thick, low viscosity, composed of peridotite

Question 5

What is the outer core made of and how thick is it?

Answer 5

Liquid iron and nickel, 2300 km thick

Question 6

What is the inner core made of and how thick is it?

Answer 6

Solid iron and nickel, 1200 km thick

Question 7

What drives convection currents in the mantle?

Answer 7

Heat from the core causing liquid rock to rise, move sideways, cool, and sink

Question 8

Describe the ridge push mechanism.

Answer 8

Magma rises at mid-ocean ridges, forming a slope; cooled lithosphere slides down due to gravity

Question 9

What is slab pull?

Answer 9

At subduction zones, the denser plate sinks and pulls the rest of the plate with it

Question 10

Name the types of plate boundaries.

Answer 10

Destructive (converging), constructive (diverging), and transform

Question 11

What is a hotspot?

Answer 11

A plume of magma pushing through the asthenosphere away from plate boundaries (e.g., Hawaii)

Question 12

What are the characteristics of shield volcanoes?

Answer 12

Gentle upper slopes, low-viscosity basaltic lava, steady eruptions, little pyroclastic material

Question 13

What defines a composite/stratovolcano?

Answer 13

Steep top slopes, explosive felsic lava, inter-layering of lava and pyroclastic materials

Question 14

What is an acid dome volcano?

Answer 14

Steep-sided, formed by viscous rhyolitic lava cooling quickly

Question 15

What is a caldera?

Answer 15

A large volcanic depression formed after an explosive eruption and magma chamber collapse

Question 16

Name 4 primary volcanic hazards.

Answer 16

Pyroclastic flows, lava, ash & tephra, toxic gases

Question 17

Name 4 secondary volcanic hazards.

Answer 17

Lahars, volcanic landslides, jokulhlaups, tsunamis

Question 18

What type of volcano and plate boundary was involved in the E15 eruption?

Answer 18

Stratovolcano, divergent boundary (Mid-Atlantic Ridge)

Question 19

What were the short-term local economic impacts of E15?

Answer 19

20 farms destroyed, road closures, contaminated water

Question 20

What were the international impacts of E15?

Answer 20

£130 million/day airline losses, halted flights, stranded travelers

Question 21

What were some responses to E15?

Answer 21

IMO warnings, evacuations, flight cancellations, improved future preparedness

Question 22

What are P-waves?

Answer 22

Primary waves, fastest seismic waves, travel through solids and liquids

Question 23

What are S-waves?

Answer 23

Secondary waves, slower than P-waves, only travel through solids

Question 24

What are surface waves?

Answer 24

Seismic waves that travel along Earth’s surface causing most damage

Question 25

What does the Richter scale measure?

Answer 25

Seismic wave amplitude (1–9, tenfold increase per level)

Question 26

What does the Moment Magnitude Scale measure?

Answer 26

Energy released, considers geology (1–9, more reliable)

Question 27

What is the Mercalli Scale?

Answer 27

Qualitative scale (1–12) based on observed damage and effects

Question 28

Name 3 primary earthquake hazards.

Answer 28

Ground shaking, building collapse, underground pipe damage

Question 29

Name 3 secondary earthquake hazards.

Answer 29

Liquefaction, aftershocks, tsunamis

Question 30

What were the social impacts of the Haiti earthquake?

Answer 30

230,000 dead, 1.5 million homeless, cholera outbreak, prison escape

Question 31

What were the economic impacts of the Haiti earthquake?

Answer 31

$8 billion short-term damage, $11.5 billion long-term, job losses

Question 32

How did the international community respond to Haiti?

Answer 32

£100m raised, UN/USA aid, difficulty due to damaged infrastructure

Question 33

What factors are used to categorize tectonic hazards?

Answer 33

Magnitude, speed of onset, duration, frequency, areal extent, predictability

Question 34

What is the risk equation?

Answer 34

Risk = Hazard x Vulnerability / Resilience

Question 35

What does the PAR model show?

Answer 35

How vulnerability and socio-economic factors affect impact of hazards

Question 36

How are hazards predicted?

Answer 36

Monitoring seismic activity, gas emissions, ground deformation, etc.

Question 37

How can people prepare for earthquakes?

Answer 37

Drills, education, hazard maps, EQ-proof buildings

Question 38

What are mitigation strategies for tsunamis?

Answer 38

Coastal defences, early warning systems, buildings on stilts

Question 39

How can loss from hazards be modified?

Answer 39

Relief efforts, insurance, government and NGO aid