Threat of Flank Collapse at Kilauea Volcano, Hawaii: Case Example

Barbara Tewksbury, Hamilton College

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Summary

Students evaluate fault and earthquake data plus focal mechanism solutions, and develop a picture of on-going deformation of the south flank of Kilauea Volcano that might one day transition to catastrophic flank collapse.

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Context

Audience

Structural geology course for geo majors.

Skills and concepts that students must have mastered

Faults and faulting, focal mechanism solutions.

How the activity is situated in the course

In some years, I have used this as part of a combined homework assignment and in-class activity. In other years, I have had students read the Silent Earthquakes article when we worked with pore fluid pressure and then gave them the Kilauea case example as a follow-on problem or as part of a take-home exam.

Goals

Content/concepts goals for this activity

The primary goal is for students to apply content and concepts that they have already learned, but they also learn about volcano flank collapse and the usefulness of structural geology concepts for analyzing potential geologic hazards.

Higher order thinking skills goals for this activity

Interpret fault, earthquake, and focal mechanism data; synthesize the movement picture for the south flank of Kilauea and defend with evidence.

Other skills goals for this activity

Description and Teaching Materials

The case example is written with the assumption that students have read Cervelli's article (listed below), which focuses on slow slip events ("silent earthquakes"). The article paints a very clear picture of what volcano flank collapse is, what the catastrophic consequences are, and what the geologic evidence is for multiple flank collapses in the Hawaiian volcanic chain in the geologic past. The preparatory homework assignment is a simple set of questions to make sure that students read the article carefully. If students have not read this article, the instructor would need to provide a bit of background in class before students tackled the case example.

The beginning of the case example itself presents students with data on "normal" earthquakes occurring between 1971 and 1999. Students then combine information on surface faults, locations of earthquake hypocenters, and composite focal mechanism solutions to synthesize a movement picture for the south flank and defend their analyses with evidence.

Preparatory homework assignment for Kilauea flank collapse case example (Microsoft Word 2007 (.docx) 20kB May9 12)
Assignment for Kilauea flank collapse case example (Microsoft Word 2007 (.docx) 879kB May9 12)

Teaching Notes and Tips

Assessment

Students individually submit written analyses with argument and evidence.

References and Resources

Cervelli, Peter, 2004, The threat of silent earthquakes: Scientific American, March 2004, p. 86-91.

Poland, Michael, Miklius Asta, Wilson, David, Okubo, Paul, Montgomery-Brown, Emily, Segall, Paul, Brooks, Benjamin, Foster, James, Wolfe, Cecily, Syracuse, Ellen, and Thurber, Clifford, 2010, Slow slip events at Kilauea Volcano: EOS, v. 91, no. 13, 30 March 2010, p. 118-119.

Gillard, Dominique, Wyss, Max, Okubo, Paul, 1996, Type of faulting and orientation of stress and strain as a function of space and time in Kilauea's south flank, Hawaii: JGR, v. 101, no, B7, p. 16,025-16,042.