Earthquake Hazards: Primary and Secondary

Active learning works for this topic because students must physically and visually experience how shaking, saturation, and displacement translate into hazard types. Handling materials and analyzing real cases lets them build accurate mental models that static explanations cannot convey.

• Year 12
• Geography
• 4 activities
• 35 min–50 min

Learning Objectives

1. Differentiate between primary earthquake hazards, such as ground shaking and building collapse, and secondary hazards, including tsunamis, landslides, and liquefaction, by analyzing their causes and immediate effects.
2. Explain the specific conditions, including loose, saturated soil and cyclic loading, required for liquefaction to occur and evaluate its destructive potential on infrastructure.
3. Analyze the formation of tsunamis from submarine earthquakes, describing the role of vertical seafloor displacement and predicting their wave behavior and impact zones.
4. Compare the spatial and temporal characteristics of primary and secondary earthquake hazards, assessing which pose a greater risk in different geological settings.

Case Study Analysis

⏱ 35 min·Small Groups

Model Building: Liquefaction Shake

Provide trays with dry sand, wet sand, and saturated sand layers. Students shake trays at set frequencies using a simple shaker device, observe settling and flow, then measure surface displacement. Groups record variables like water content and shaking intensity, drawing links to real soil conditions.

Prepare & details

Differentiate between primary and secondary earthquake hazards.

Facilitation Tip: During Model Building: Liquefaction Shake, ask groups to predict which soil samples will liquefy before the shake, then compare predictions to observations to surface misconceptions immediately.

Setup: Groups at tables with case materials

Materials: Case study packet (3-5 pages), Analysis framework worksheet, Presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Jigsaw

⏱ 50 min·Small Groups

Jigsaw: Hazard Impacts

Assign groups one earthquake case, like Christchurch 2011 or Sumatra 2004, focusing on primary or secondary hazards. Each expert group analyzes data on impacts and mitigation, then jigsaws to teach peers. Conclude with class timeline comparing hazard sequences.

Prepare & details

Explain the conditions necessary for liquefaction to occur and its destructive potential.

Facilitation Tip: When running the Case Study Jigsaw, assign each expert group a different hazard type so every student must teach their findings to peers, building accountability.

Setup: Flexible seating for regrouping

Materials: Expert group reading packets, Note-taking template, Summary graphic organizer

• Understand
• Analyze
• Evaluate
• Relationship Skills
• Self-Management

Case Study Analysis

⏱ 40 min·Pairs

Simulation Pairs: Tsunami Waves

Pairs use shallow water trays to model seabed uplift by pushing the bottom suddenly, timing wave travel and height changes with depth. Add barriers as coastlines, measure run-up, and graph results. Discuss parallels to real monitoring systems.

Prepare & details

Analyze the formation and impact of tsunamis generated by submarine earthquakes.

Facilitation Tip: For Simulation Pairs: Tsunami Waves, have pairs alternate roles of operator and recorder so both students process the wave formation and timing data.

Setup: Groups at tables with case materials

Materials: Case study packet (3-5 pages), Analysis framework worksheet, Presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Case Study Analysis

⏱ 45 min·Small Groups

Mapping Carousel: Hazard Zones

Stations feature maps of a tectonic region; students identify primary and secondary risk zones, annotating triggers and mitigation. Rotate every 10 minutes, adding peer notes. Whole class synthesizes a composite risk profile.

Prepare & details

Differentiate between primary and secondary earthquake hazards.

Facilitation Tip: During Mapping Carousel: Hazard Zones, rotate students through stations every three minutes so they actively compare causes, effects, and data across locations.

Setup: Groups at tables with case materials

Materials: Case study packet (3-5 pages), Analysis framework worksheet, Presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Teaching This Topic

Teach this topic by moving from concrete to abstract: start with hands-on modeling to establish mechanisms, then use case studies to add human and geographic context. Avoid overloading students with lecture; instead, use guided inquiry where students articulate patterns before receiving formal terms. Research shows that tactile experiences combined with collaborative explanation deepen retention and transfer of hazard concepts.

What to Expect

Successful learning looks like students reliably distinguishing primary from secondary hazards, explaining mechanisms like liquefaction or tsunami generation, and using evidence from models and case studies to support their reasoning. They should also transfer this understanding to new earthquake scenarios.

Watch Out for These Misconceptions

Common Misconception

During Case Study Jigsaw: Hazard Impacts, watch for students assuming secondary hazards are always less destructive because they appear later in news reports. Redirect by having groups compare total affected areas and economic losses from both hazard types in their assigned cases.

What to Teach Instead

During Case Study Jigsaw: Hazard Impacts, redirect by having groups compare total affected areas and economic losses from both hazard types in their assigned cases.

Common Misconception

During Model Building: Liquefaction Shake, watch for students believing liquefaction only occurs near coasts or during massive quakes. Redirect by having groups test multiple soil types with the same moderate shake to see liquefaction in inland sands.

What to Teach Instead

During Model Building: Liquefaction Shake, have groups test multiple soil types with the same moderate shake to see liquefaction in inland sands, then record their observations on a class chart.

Common Misconception

During Simulation Pairs: Tsunami Waves, watch for students assuming all submarine quakes produce tsunamis. Redirect by having each pair test both vertical and horizontal fault movements and measure wave height differences.

What to Teach Instead

During Simulation Pairs: Tsunami Waves, have each pair test both vertical and horizontal fault movements and measure wave height differences, then share results with the class.

Assessment Ideas

Exit Ticket

After Model Building: Liquefaction Shake, give students a scenario describing a moderate earthquake in an inland city with saturated sandy soil. Ask them to identify the hazard type and explain the mechanism using evidence from their tray experiment.

Discussion Prompt

During Simulation Pairs: Tsunami Waves, pose the question: ‘What specific seafloor movement pattern produces the largest tsunami?’ Have pairs discuss their findings and then share with the class, using key vocabulary such as vertical displacement and wave amplitude.

Quick Check

After Mapping Carousel: Hazard Zones, present students with images showing different earthquake impacts. Ask them to label each as primary or secondary and write one sentence explaining their choice, using a sentence frame provided on the handout.

Extensions & Scaffolding

• Challenge early finishers to design a one-minute public service announcement explaining how to recognize liquefaction risk before building on unstable ground.
• For students who struggle, provide a graphic organizer with labeled diagrams of primary and secondary hazards to fill in during the jigsaw discussion.
• Give extra time for students to research and present an additional case study that combines multiple hazards, such as an earthquake-triggered landslide causing a dam breach and downstream flooding.

Key Vocabulary

Liquefaction	A phenomenon where saturated soil or sediment temporarily loses strength and acts like a liquid due to increased pore water pressure, often caused by seismic shaking.
Tsunami	A series of large ocean waves generated by a sudden displacement of a large volume of water, typically caused by underwater earthquakes, volcanic eruptions, or landslides.
Ground Shaking	The violent movement of the Earth's surface caused by seismic waves radiating from an earthquake's focus, leading to direct structural damage.
Landslide	The rapid downhill movement of rock, debris, or earth, often triggered by seismic activity on unstable slopes.
Pore Water Pressure	The pressure of groundwater held within the pores of soil or rock, which can increase during seismic shaking and lead to liquefaction.