Tectonic Hazards

Question 1

What are the main layers of the Earth?

Answer 1

Inner core, outer core, mantle, lithosphere, crust

The inner core is solid and dense, the outer core is semi-molten, the mantle is semi-molten and solid, the lithosphere includes the crust and upper mantle.

Question 2

What is the composition and thickness of the oceanic crust?

Answer 2

Thinner (5-10km), heavier, denser, composed mainly of basalt

The oceanic crust is continually created and destroyed due to plate movement.

Question 3

What are the characteristics of the continental crust?

Answer 3

Thicker (25-100km), older, less dense, composed mainly of granite

The continental crust is less dense than the oceanic crust.

Question 4

What generates convection currents in the mantle?

Answer 4

Heat from the Earth’s core

This heat is generated by radioactive decay.

Question 5

What is slab pull theory?

Answer 5

Plate movement is caused by the weight of denser oceanic plates subducting

This theory suggests slab pull complements convection currents.

Question 6

What are mantle plumes?

Answer 6

Upwellings of superheated rock in the mantle

Mantle plumes can lead to hot spots and divergent plate boundaries.

Question 7

What are the three main types of plate boundaries?

Answer 7

• Divergent
• Convergent
• Conservative

These boundaries are associated with volcanic eruptions and earthquakes.

Question 8

What occurs at a divergent plate boundary?

Answer 8

Plates are moving apart

An example is the Mid Atlantic Ridge.

Question 9

What happens at a convergent plate boundary?

Answer 9

Plates are moving together; denser oceanic plate subducts under continental plate

An example is the Nazca plate converging with the South American plate.

Question 10

What is a collision zone?

Answer 10

Where two continental plates collide, forming fold mountains

An example is the collision of the Eurasian and Indo-Australian plates forming the Himalayas.

Question 11

What characterizes a conservative boundary?

Answer 11

Plates move past each other in opposite directions or at different speeds

An example is the San Andreas Fault.

Question 12

What is a hot spot?

Answer 12

A location where a tectonic plate passes over a plume of magma

This can lead to the formation of volcanic islands, such as Hawaii.

Question 13

What is the Volcanic Explosivity Index (VEI)?

Answer 13

A scale used to measure the magnitude of a volcanic eruption

The highest recorded VEI was 8 during the Tambora eruption in 1815.

Question 14

What is the difference between composite and shield volcanoes?

Answer 14

Composite: steep-sided, sticky lava, more explosive; Shield: gently sloping, runny lava, less explosive

Composite volcanoes form on convergent boundaries, while shield volcanoes form on divergent boundaries or hot spots.

Question 15

What are the three types of volcanic activity?

Answer 15

• Active
• Dormant
• Extinct

Active volcanoes have erupted recently, dormant volcanoes have erupted in the last 2000 years, and extinct volcanoes show no evidence of recent eruptions.

Question 16

What is the focus of an earthquake?

Answer 16

The point where the earthquake starts below the Earth’s surface

The epicenter is directly above the focus on the Earth’s surface.

Question 17

What scale measures the magnitude of earthquakes?

Answer 17

Moment Magnitude Scale

This scale replaced the Richter scale.

Question 18

What are primary hazards of earthquakes?

Answer 18

• Ground shaking
• Surface rupture

Primary hazards are direct results of the earthquake.

Question 19

What are secondary hazards of volcanic eruptions?

Answer 19

• Pyroclastic flow
• Lahars
• Ash fallout

Secondary hazards occur as a result of primary effects.

Question 20

How can a tsunami be caused?

Answer 20

By earthquakes, landslides, or underwater volcanic eruptions

Tsunamis occur when there is a significant displacement of water.

Question 21

What is liquefaction?

Answer 21

A secondary hazard where saturated soil loses strength and behaves like a liquid

This can occur during an earthquake.

Question 22

What are the main causes of tsunamis?

Answer 22

Tsunamis can be caused by:
* Earthquakes
* Landslides
* Underwater volcanic eruptions
* Large meteor strikes

Each cause displaces water, generating large waves.

Question 23

What immediate impacts can result from earthquakes and volcanic eruptions?

Answer 23

Immediate impacts include:
* Loss of life and injury
* Collapse or destruction of buildings
* Damage to transport networks
* Loss of jobs and businesses
* Loss of crops
* Damage to power and water supplies
* Damage to the environment
* Closure of airports

These impacts can lead to long-term consequences for affected communities.

Question 24

List the primary effects of volcanic eruptions.

Answer 24

Primary effects include:
* Lava flow
* Deaths and injuries
* Ash fall
* Pyroclastic flow
* Lahars (mudflows)
* Destruction of transport routes
* Damage to water, gas, and electricity supplies

These effects can vary based on factors such as magnitude and location.

Question 25

What are secondary effects of volcanic eruptions?

Answer 25

Secondary effects include: * Flooding * Tsunamis from landslides * Fires due to broken utilities * Lack of clean water leading to disease * Increases in food prices ## Footnote Secondary effects often arise from the primary impacts and can exacerbate the situation.

Question 26

True or False: The impact of tectonic hazards is the same in developed and developing countries.

Answer 26

False ## Footnote Developing countries often face greater impacts due to lack of monitoring, preparation, and resources.

Question 27

What factors influence the impact of tectonic hazards?

Answer 27

Factors include: * Magnitude of the event * Location of the epicenter * Population density * Preparation and planning * Monitoring and warning ## Footnote These factors can determine the severity of the impact on communities.

Question 28

What was the magnitude of the 2015 Nepal earthquake?

Answer 28

7.8 ## Footnote The earthquake struck on April 25, 2015, and had significant impacts on the region.

Question 29

Fill in the blank: The Cumbre Vieja volcano on La Palma began to erupt on _______.

Answer 29

September 19, 2021 ## Footnote This eruption lasted for almost three months and had a VEI of 2 to 3.

Question 30

What are some primary impacts of the La Palma eruption?

Answer 30

Primary impacts include: * Destruction of nearly 1,500 houses * Damage to over 1,500 other buildings * Water supply cut off for almost 3,000 people * Destruction of 400 hectares of banana farms * 1 death ## Footnote These impacts highlight the destructive nature of volcanic eruptions.

Question 31

What was one of the main consequences of the 2016 earthquake in Italy?

Answer 31

Severe damage to buildings ## Footnote 80% of buildings in Amatrice old town were affected, leading to significant casualties.

Question 32

What is a major challenge for managing earthquakes in Nepal?

Answer 32

Prediction of earthquakes is not possible ## Footnote Nepal relies on monitoring seismic activity but cannot predict when earthquakes will occur.

Question 33

List some management strategies for volcanic eruptions.

Answer 33

Management strategies include: * Prediction * Preparation * Planning * Short-term relief ## Footnote Strategies vary based on whether the country is developed or developing.

Question 34

What improvements were made in Nepal after the 2015 earthquake?

Answer 34

Improvements included: * Creation of a government task force for future earthquake planning * Disaster Management Act passed * Improved building codes and awareness * Training courses for stonemasons * Increased education on earthquake drills ## Footnote These changes aim to better prepare for future seismic events.

Question 35

How quickly did rescue workers arrive after the earthquake?

Answer 35

Within an hour of the earthquake ## Footnote This highlights the prompt response of rescue teams in disaster situations.

Question 36

What was set up to assist with medical needs after the earthquake?

Answer 36

A temporary hospital was set up ## Footnote This was part of the immediate response to provide medical care.

Question 37

How did locals maintain effective communication during the crisis?

Answer 37

By removing wi-fi passwords ## Footnote This action facilitated communication among residents and rescue teams.

Question 38

What types of aid were sent by NGOs?

Answer 38

Food, water, and medical supplies ## Footnote NGOs play a crucial role in disaster relief efforts.

Question 39

How many helicopters were used in the rescue operations?

Answer 39

Twelve helicopters were used in the rescue ## Footnote Air support is often critical in reaching affected areas.

Question 40

What does the national plan Casa Italia aim to improve?

Answer 40

Earthquake resistance ## Footnote This plan was initiated after the 2016 earthquake to enhance safety.

Question 41

Who was appointed to oversee reconstruction and planning after the earthquake?

Answer 41

A Special Commissioner ## Footnote This role is vital for coordinated recovery efforts.

Question 42

What structural improvement was made to buildings after the earthquake?

Answer 42

Retro-fitting of buildings to improve earthquake resistance ## Footnote This is a preventative measure against future earthquakes.

Question 43

What key factors should be assessed when comparing earthquake management in different countries?

Answer 43

Planning, preparation, monitoring, and short term relief ## Footnote Understanding these factors can show how different approaches affect disaster outcomes.

Question 44

True or False: Effective communication in crisis situations can be enhanced by removing restrictions like wi-fi passwords.

Answer 44

True ## Footnote This approach allows for better coordination among affected individuals.

Question 45

Fill in the blank: The _______ was established to improve earthquake resistance after the 2016 earthquake.

Answer 45

National plan Casa Italia ## Footnote This plan represents a significant policy shift in disaster preparedness.