Cause of the Mogul, Nevada, Earthquake Swarm, Spring 2008
Initial Publication Date: November 21, 2008
Summary
Students examine data from fault- and magma- related earthquakes and determine distinguishing characteristics. They then apply these criteria to determine the cause of the Mogul earthquake sequence (that most of the students experienced) last spring.
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Context
Audience
Introductory course for non-majors; satisfies the college's core requirement for science.
Skills and concepts that students must have mastered
None; the exercise stands alone.
How the activity is situated in the course
This is one of four homework assignments in which students analyze and interpret real data. The students have several weeks to work on each.
Goals
Content/concepts goals for this activity
The Mogul earthquake swarm generated a lot of attention locally. This was in part because its origin was not immediately clear, so no one could predict how long it would continue or how big the earthquakes might get. In this exercise, students learn to distinguish between fault-generated and magma-generated seismicity.
Higher order thinking skills goals for this activity
One theme throughout this course is distinguishing data from interpretations. Another is application of the scientific method, as demonstrated by collecting and interpreting real data, and writing up the results in the standard format for a scientific report. Students do this in four lab projects and four homework exercises; this is one of the latter.
Other skills goals for this activity
Writing a scientific report
Description of the activity/assignment
Students examine seismicity related to:
(1) a typical fault-generated earthquake sequence, the February, 2008 Wells earthquake, and
(2) a typical volcanic-generated earthquake sequence at Mt. St. Helens.
For each of these, students describe the distribution of earthquakes on the ground surface and at depth in the earth, and look for characteristics that are unique to each kind of earthquake. They also look for distinctive patterns in the size or depth of the earthquakes with time, again to establish criteria for determining the cause of seismicity.
Students then look at seismic records from the "Mogul earthquake swarm" in Spring 2008, and determine whether it looks like it was generated by faulting or by volcanic activity. They conclude with the reason(s) the Mogul earthquake swarm was unusual.
(1) a typical fault-generated earthquake sequence, the February, 2008 Wells earthquake, and
(2) a typical volcanic-generated earthquake sequence at Mt. St. Helens.
For each of these, students describe the distribution of earthquakes on the ground surface and at depth in the earth, and look for characteristics that are unique to each kind of earthquake. They also look for distinctive patterns in the size or depth of the earthquakes with time, again to establish criteria for determining the cause of seismicity.
Students then look at seismic records from the "Mogul earthquake swarm" in Spring 2008, and determine whether it looks like it was generated by faulting or by volcanic activity. They conclude with the reason(s) the Mogul earthquake swarm was unusual.
Determining whether students have met the goals
Student reports are graded using a rubric based on the specific questions in the homework handout. The report outline is the same for all lab reports and homework write-ups in the course.
More information about assessment tools and techniques.Teaching materials and tips
- Student Handout (Microsoft Word 2007 (.docx) PRIVATE FILE 138kB Nov21 08)
The students also get figures with this text (below).
Other Materials
Mogul earthquake map (click to enlarge)
Mogul depth vs time (click to enlarge)
Mogul magnitude vs time (click to enlarge)
Wells earthquake map (click to enlarge)
Wells earthquake cross section (click to enlarge)
Supporting references/URLs
M 6.0 Wells earthquake data from the Nevada Seismological Laboratory
3D animation of this event (AVI file, 4.7 MB)
Mogul-Somersett Earthquake Sequence; West Reno, Nevada from the Nevada Seismological Laboratory
Animation of 2008 Mogul sequence (AVI file, 23 MB)
USGS data from Mt. St. Helens