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Questions and Answers
Which of the following is NOT a type of volcanic hazard mentioned in the text?
Which of the following is NOT a type of volcanic hazard mentioned in the text?
- Earthquake (correct)
- Ballistic Projectiles
- Lava Flows
- Pyroclastic Flow
High silica magma results in low viscosity lava flows, moving at high speeds.
High silica magma results in low viscosity lava flows, moving at high speeds.
False (B)
What is the main difference between a pyroclastic flow and a pyroclastic surge?
What is the main difference between a pyroclastic flow and a pyroclastic surge?
A pyroclastic surge is a diluted form of a pyroclastic flow with greater mobility, posing a higher risk to communities.
The speed of a lava flow is influenced by the ______ of the slope and the ______ of the magma.
The speed of a lava flow is influenced by the ______ of the slope and the ______ of the magma.
Which volcanic gas is the most abundant?
Which volcanic gas is the most abundant?
Match the following volcanic features with their descriptions:
Match the following volcanic features with their descriptions:
Volcanic gases are only released during an eruption.
Volcanic gases are only released during an eruption.
Describe one way in which volcanic activity can be monitored to predict potential eruptions.
Describe one way in which volcanic activity can be monitored to predict potential eruptions.
Which of the following is NOT a sign of an impending volcanic eruption?
Which of the following is NOT a sign of an impending volcanic eruption?
Camiguin is ranked as the province with the highest risk for volcano-related damage.
Camiguin is ranked as the province with the highest risk for volcano-related damage.
Name one of the two provinces ranked second for volcano-related risk.
Name one of the two provinces ranked second for volcano-related risk.
The increased _____ emission is an indicator that magma is close to the surface.
The increased _____ emission is an indicator that magma is close to the surface.
Match each province with its risk level for volcano-related damage:
Match each province with its risk level for volcano-related damage:
What is one natural sign that a tsunami may be approaching?
What is one natural sign that a tsunami may be approaching?
Earthquakes can only cause landslides due to their force and speed.
Earthquakes can only cause landslides due to their force and speed.
List one of the three parts that comprise a landslide.
List one of the three parts that comprise a landslide.
Unusual sea level changes can signify a ______ is approaching.
Unusual sea level changes can signify a ______ is approaching.
Match the terms related to landslides and their descriptions:
Match the terms related to landslides and their descriptions:
Which of the following is NOT a trigger for landslides?
Which of the following is NOT a trigger for landslides?
Landslides can only occur in mountainous regions.
Landslides can only occur in mountainous regions.
What force is always the primary factor enabling landslides to occur?
What force is always the primary factor enabling landslides to occur?
Which of the following describes lahar?
Which of the following describes lahar?
Ashfalls consist of volcanic particles that are all larger than 2 mm in diameter.
Ashfalls consist of volcanic particles that are all larger than 2 mm in diameter.
What is a significant health hazard associated with ashfall?
What is a significant health hazard associated with ashfall?
The explosive materials released from a volcano, including volcanic particles and hot gases, are classified as _________.
The explosive materials released from a volcano, including volcanic particles and hot gases, are classified as _________.
What type of current is a pyroclastic flow classified as?
What type of current is a pyroclastic flow classified as?
What is tephra?
What is tephra?
Match the volcanic hazards with their characteristics:
Match the volcanic hazards with their characteristics:
The area where tectonic plates collide, leading to the formation of volcanoes, is known as a __________.
The area where tectonic plates collide, leading to the formation of volcanoes, is known as a __________.
What occurs during ground rupture?
What occurs during ground rupture?
Liquefaction leads to the ground becoming solid and stable.
Liquefaction leads to the ground becoming solid and stable.
What can cause earthquake-induced ground subsidence?
What can cause earthquake-induced ground subsidence?
Ground shaking can lead to ______, causing grains of soil to mix with water.
Ground shaking can lead to ______, causing grains of soil to mix with water.
Match the following earthquake hazards with their definitions:
Match the following earthquake hazards with their definitions:
Which of the following is a consequence of liquefaction?
Which of the following is a consequence of liquefaction?
Earthquake-induced landslides only occur in mountainous regions.
Earthquake-induced landslides only occur in mountainous regions.
What is the typical effect of ground shaking on structures in liquefaction-prone areas?
What is the typical effect of ground shaking on structures in liquefaction-prone areas?
What primarily causes land subsidence during an earthquake?
What primarily causes land subsidence during an earthquake?
Tsunami waves generated by seismic activity are also known as harbor waves.
Tsunami waves generated by seismic activity are also known as harbor waves.
What is the term for the gradual sinking of land, which can lead to sinkholes?
What is the term for the gradual sinking of land, which can lead to sinkholes?
The displacement of the _____ triggers the formation of tsunami waves.
The displacement of the _____ triggers the formation of tsunami waves.
Match the stages of a seismic-related tsunami with their descriptions:
Match the stages of a seismic-related tsunami with their descriptions:
What happens to ocean water during the amplification stage of a tsunami?
What happens to ocean water during the amplification stage of a tsunami?
Earthquake-induced ground subsidence can lead to an increase in flooding susceptibility in an area.
Earthquake-induced ground subsidence can lead to an increase in flooding susceptibility in an area.
The term ____________ originates from the Japanese words
The term ____________ originates from the Japanese words
What is the main cause of tsunami waves generated by seismic activity?
What is the main cause of tsunami waves generated by seismic activity?
The term 'tsunami' translates to 'harbor wave' in Japanese.
The term 'tsunami' translates to 'harbor wave' in Japanese.
What is the term for the gradual setting or sinking of land that may lead to sinkholes?
What is the term for the gradual setting or sinking of land that may lead to sinkholes?
The _______ of the seafloor is the initiation stage of a tsunami.
The _______ of the seafloor is the initiation stage of a tsunami.
Which of the following describes what happens during the amplification stage of a tsunami?
Which of the following describes what happens during the amplification stage of a tsunami?
Ground shaking during an earthquake can lead to liquefaction, causing soil to become unstable.
Ground shaking during an earthquake can lead to liquefaction, causing soil to become unstable.
Tsunamis generated by seismic movement are also referred to as __________ tsunamis.
Tsunamis generated by seismic movement are also referred to as __________ tsunamis.
Flashcards
Liquefaction
Liquefaction
A phenomenon where loose soil becomes compacted due to ground shaking, causing the ground to sink.
Thrust fault
Thrust fault
A type of fault where the land on one side of the fault moves upward and over the land on the other side.
Subsidence
Subsidence
A gradual lowering of the ground level, often caused by the removal of underground water or oil.
Tsunami
Tsunami
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Initiation
Initiation
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Splitting
Splitting
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Amplification
Amplification
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Runup
Runup
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Earthquake
Earthquake
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Landslide
Landslide
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Fault
Fault
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Gravity
Gravity
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Weathering
Weathering
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Unstable slope
Unstable slope
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Overloading
Overloading
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What is Ground Rupture?
What is Ground Rupture?
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What is Liquefaction?
What is Liquefaction?
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What is Earthquake-Induced Ground Subsidence?
What is Earthquake-Induced Ground Subsidence?
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What are some signs of Liquefaction?
What are some signs of Liquefaction?
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How does Liquefaction affect structures?
How does Liquefaction affect structures?
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How does Liquefaction impact roads?
How does Liquefaction impact roads?
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What dangers are associated with tsunamis?
What dangers are associated with tsunamis?
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What dangers are associated with earthquakes and landslides?
What dangers are associated with earthquakes and landslides?
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Increased Seismic Activity
Increased Seismic Activity
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Increased Steam and Gas Release
Increased Steam and Gas Release
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Increased Fumarolic Activity
Increased Fumarolic Activity
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Increased Heat Emission
Increased Heat Emission
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Which province has the highest volcano risk?
Which province has the highest volcano risk?
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Pyroclastic Surge
Pyroclastic Surge
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Pyroclastic Flow
Pyroclastic Flow
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Ballistic Projectiles
Ballistic Projectiles
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Volcanic Gases
Volcanic Gases
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Lava Flows
Lava Flows
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Low Viscosity Lava Flow
Low Viscosity Lava Flow
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High Viscosity Lava Flow
High Viscosity Lava Flow
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Signs of Impending Volcanic Eruption
Signs of Impending Volcanic Eruption
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What is a Lahar?
What is a Lahar?
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What is Ashfall?
What is Ashfall?
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What are Pyroclastic Flows?
What are Pyroclastic Flows?
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What is a Subduction Zone?
What is a Subduction Zone?
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What is a Lava flow?
What is a Lava flow?
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What is Tephra?
What is Tephra?
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What is a Volcanic Eruption?
What is a Volcanic Eruption?
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What are Volcanic Gases?
What are Volcanic Gases?
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Study Notes
Earthquake Hazards
- Earthquake hazards include ground shaking, ground rupture, liquefaction, tsunamis, earthquake-induced ground subsidence, and earthquake-induced landslide.
Ground Rupture
- Ground ruptures, also known as fissures, are tension cracks where the ground surface breaks due to ground movement.
- They are commonly found near or along fault lines.
- Structures built on fault lines are prone to breakage, and significant ruptures can cause damage to transportation, power, and communication lines, as well as water lines underneath.
Liquefaction
- Liquefaction is a phenomenon where saturated sediment "liquefies" and behaves like water, flowing.
- On a normal day, water-saturated ground underneath does not cause destruction.
- However, ground shaking can disturb underlying materials.
- Grains loosen and mix with water.
- The flowing water causes structures to collapse.
- Common signs of liquefaction include ground water leaking and ground undulation causing uneven land formations
Earthquake-Induced Ground Subsidence
- Land subsidence results from human activity, such as over-pumping groundwater, and also, from earthquakes.
- Earthquake-induced ground subsidence is the sinking of the ground, either gradually or suddenly.
- Sinking land areas become catch basins for rainwater, which increases flooding risk.
- Subsidence can cause the development of sinkholes in adjacent areas.
Tsunamis
- Tsunamis, of seismic origin, are formed when there's a movement beneath the ocean. This is described as a displacement, initiating the tsunami.
- Tsunamis are a wave or series of waves in a wave train caused by the sudden, vertical displacement of a column of water.
- They can be triggered by seismic activity, explosive volcanism, or underwater landslides.
- The term tsunami comes from Japanese words "tsu" (harbor) and "nami" (wave), also called "harbor wave."
- Stages of a seismic tsunami include 1. Initiation, 2. Splitting, 3. Amplification, and 4. Runup - During Initiation, the displacement of the seafloor is followed by the displacement of ocean water. - Splitting divides tsunamis into two waves, one heading towards the deep ocean, and the second toward the shoreline. - During Amplification, the waves' height increases and their wavelength decreases, making the shore water recede, exposing parts of the beach. - Runup refers to the tsunami's approach to the shore, accumulating in force. The receding of parts of the wave adds to the height of succeeding leading waves.
- Natural signs of an impending tsunami include ground shaking near a body of water, unusual sea levels, and the sound of rumbling waves.
Earthquake-Induced Landslide
- Earthquakes trigger landslides by combining their effects with the force of gravity.
- Gravity enables landslides to occur when combined with the triggering of earthquakes.
- Landslides are defined as a mass movement of rock, soil, and debris down a slope due to gravity.
- Landslides can occur due to ground vibrations caused by tectonic or volcanic earthquakes.
- Other triggers for landslides include natural triggers (plant and animal movement), rainfall, weathering of rocks, and human activities (excessive mining, massive urbanization in unstable areas).
- Factors that increase landslide potential in a region are steep slopes, unstable landmass from the weakening of slope material, weathering of rocks affecting slope condition over time, and the overloading of slopes by human activity.
- Landslides are divided into 3 parts: Source, Path, and Deposit.
Volcano Hazards
- Volcano hazards include Lahar, Ashfall, Pyroclastic Flow, Ballistic Projectiles, Volcanic Gas, and Lava Flow.
Lahar
- Lahars are wet cement-like mixtures of volcanic material and water, originating from Indonesia.
- Lahars carry fresh volcanic materials (pyroclastic flows and ashfalls).
- Lahars are dangerous due to their thickness and toxic chemicals, making survival impossible.
Ashfall
- Ashfall events consist of fragmented volcanic particles less than 2mm in diameter.
- Ashfall follows a volcanic eruption, creating an ash column that settles, blanketing affected areas.
- Ashfall events can have respiratory health hazards, damage skin, and contaminate water sources.
Pyroclastic Flow
- Pyroclastic flows are the results of volcanic explosions.
- They are dense currents of volcanic particles (pyroclastic, hot gases, and ashes) rushing down from the volcano's mouth after an explosion.
- Pyroclastic flows are classified by density and viscosity into flow (slower movement attached to the ground) and surges (more mobile currents, with higher risk to communities).
Ballistic Projectiles
- Ballistic projectiles, or large blocks/bombs, are volcanic materials (not flows).
- They are ejected from a volcanic vent at high velocity; their impact is within 2-5km away from the volcano.
- They can travel further if the volcano is more explosive.
Volcanic Gases
- Before eruptions, gases build pressure inside magma and may be released.
- Various volcanic gases (water vapor, carbon dioxide, sulfur dioxide, hydrogen sulfide, and halogens) are released.
Lava Flows
- Lava flows, in a bright red-orange appearance, are from released magma inside volcanoes.
- Lava flow speed depends on silica content:
- Low silica magma = low viscosity = high lava flow speeds
- High silica magma = high viscosity = low lava flow speeds.
- Lava flow impacts, with its high temperature, are capable of forest fires, burning vegetation, residential houses, and infrastructure.
Signs of Impending Volcanic Eruptions
- The Frequency of earthquakes increases.
- The release of steam or gases from vents near the volcano increases (seen as a cloud afar).
- Fumarolic activity increases, showing an increase in carbon dioxide concentration in the air.
- The heat from magma close to the volcano's surface dramatically raises temperatures in the region.
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Description
This quiz explores various earthquake hazards such as ground shaking, ground rupture, liquefaction, and their impacts. You will learn about how these hazards affect structures and the environment. Test your knowledge on the causes and consequences of these seismic phenomena.
