# Earthquake Hazards: The next big one?

#### Summary

In this activity, students explore of the concept of probability and the distribution of earthquake sizes, and then work to understand how earthquake hazards are described by probabilities. Students then work in small groups to collect and analyze data from a simple physical earthquake model and use online data to investigate and compare the earthquake hazards in California and Missouri. The activity concludes with a reflection where they students are asked to consider how, in the role of a city planner or emergency manager, they would use what they have learned to mitigate the earthquake hazard in California and Missouri.

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## Context

#### Audience

This lab is designed to be used in an intro level geoscience course for either majors or non-majors.

#### Skills and concepts that students must have mastered

Prior to this activity, students should have been introduced to earthquake basics, including the concepts of magnitude and intensity. They should also have the ability to plot on a log plot.

#### How the activity is situated in the course

This lab is designed to accompany a lecture on earthquakes, magnitude, and intensity and seismic hazard and risk

## Goals

#### Content/concepts goals for this activity

Students will be able to:
- Compare and contrast the probability of an earthquake occurring in different regions and relate that probability to the seismic hazard of the regions.
- Explain in a written essay how a region can have a high seismic hazard but have a low seismic risk.
- Describe at least three factors that affect the intensity of an earthquake at a given location.

#### Higher order thinking skills goals for this activity

In addition to analyzing data, working with models is a key part of this activity and students are asked to reflect on how the earthquake model is like and unlike the real earth.

#### Other skills goals for this activity

Students are asked to related what they have learned to real-world hazard mitigation.

## Description and Teaching Materials

Activity flow:
1. Students first review basic probability and investigate the earthquake machine model.
2. Then arrange the students in groups of 3 and provide them with the materials and instructions to setup their EQ machine.
4. Provide an opportunity for students to freely investigate the model. Challenge them to consider the following... "How this might this model represent the earthquake process?" Discuss student ideas. Help students see the mapping between the model (analog) and Earth materials (target), and discuss how the model is like and unlike fault rupture on Earth.
5. Assign students to complete Part II of the lab, calculating earthquake probabilities with the earthquake machine. Review and discuss student responses.
6. Assign students to complete Part III of the Lab, investigating seismic hazard, and Part IV, relating earthquake probabilities to ground shaking hazard. Review and discuss student responses.

Materials List

- Student worksheets (color copies of figures are helpful)

- Computer with internet access for each group

- Calculator or computer for simple calculations

- One Earthquake Machine setup for every 3 students

- Earthquake Machine slide set – Hazards_EQ_machine.ppt

This IRIS (Incorporated Research Institutions for Seismology) activity is part of a collection of activities based on questions that identify promising research directions on the frontiers of seismology as outlined in the Seismological Grand Challenges in Understanding Earth's Dynamic System. The collection has been developed to engage students in the analysis of real data and to bring examples of frontier research topics into the undergraduate classroom. Further information about the activity including links to related resources is available on the IRIS website at http://www.iris.edu/hq/inclass/lesson/earthquake_hazards_next_big_one

Instructor's guide for hazards activity (Microsoft Word 2007 (.docx) 419kB Jun14 17)

Student handout for hazards activity (Microsoft Word 2007 (.docx) 1.8MB Jun14 17)

Student worksheet KEY Seismic Hazards (Microsoft Word 2007 (.docx) 1.8MB Jun14 17)

Seismic Hazards earthquake machine slides (PowerPoint 2007 (.pptx) 9.9MB Jun14 17)

## Assessment

An activity key is provided which can be used to assess whether students have met the goals of the activity.

## References and Resources

Earthquake Machine: Demonstration of the 1-Block Model (introduction to model)
http://www.iris.edu/hq/inclass/video/66

Earthquake Machine Animations (illustrating model behavior)
http://www.iris.edu/hq/inclass/animation/68
http://www.iris.edu/hq/inclass/animation/129
http://www.iris.edu/hq/inclass/animation/131

Understanding Intensity: http://www.iris.edu/hq/inclass/animation/517
Moment Magnitude: http://www.iris.edu/hq/inclass/animation/205

USGS Earthquake Hazards 101 https://earthquake.usgs.gov/hazards/learn/basics.php

Earthquake rates in the US
https://earthquake.usgs.gov/earthquakes/browse/stats.php

Grand Challenge #2 - How does the Near-Surface Environment Affect Natural Hazards and Resources?
http://www.iris.edu/hq/files/programs/education_and_outreach/CCLI/Hazards/NearSurface_Affect_Hazards.pdf