Geologic Processes and Hazards Quiz

Earthquake Hazards

• Water waves generated by earthquakes, volcanic eruptions, or landslides are called tsunamis.
• Ground shaking refers to the disruptive vibrations caused by seismic waves passing through the ground.
• Ground rupture is the deformation on the surface where a fault intersects with the earth.
• Liquefaction occurs when loose, water-logged sediments lose strength due to strong ground shaking.
• Earthquake-induced landslides often occur with intense shaking, leading to the downhill movement of debris.

Philippine Institute of Volcanology and Seismology (PHIVOLCS)

• PHIVOLCS is a service agency under the Department of Science and Technology (DOST) focused on disaster mitigation from volcanic eruptions and earthquakes.

Types of Earthquakes

• Earthquakes are classified into tectonic and volcanic types, with tectonic earthquakes resulting from sudden movements along faults and plate boundaries.

Measuring Earthquake Strength

• Earthquake strength is measured using two metrics: magnitude and intensity.
• Magnitude indicates the energy released and is calculated using a seismograph, represented by Arabic numbers (e.g., 4.8, 9.0).

Effects of Geologic Layers on Ground Shaking

• Seismic waves have varying effects based on the geological materials they traverse, with solid bedrock resulting in high frequency and low amplitude shaking, and weaker materials causing higher amplitude and lower frequency vibrations.

Overview of Earthquake Hazards

• Earthquake hazards can lead to loss of life, injuries, property damage, economic disruptions, and environmental harm.
• Common hazards include ground shaking, ground rupture, liquefaction, landslides, and tsunamis.

Hazard Maps

• Hazard Maps visualize potential hazards in specific areas, identifying risks associated with earthquakes, liquefaction, and landslides.
• Ground shaking hazard maps display levels of shaking probability, while ground rupture hazard maps highlight fault lines.

Landslide Triggers

• Gravity is the primary driver of landslides, acting on sloped areas that lack stability.
• Landslide causes fall into two categories: natural and human-induced factors, with many instances arising from a combination of both.

Volcanic Activity as a Landslide Trigger

• Volcanoes, characterized by weak geological structures, are prone to collapse, leading to rockslides, landslides, and debris avalanches.

Test your understanding of various geological hazards associated with earthquakes, volcanic eruptions, and landslides. The quiz includes identifying prone areas using hazard maps and discussing human activities that may trigger these hazards. Enhance your knowledge on how natural processes influence our environment.