Initial Publication Date: December 14, 2015
Colin Amos: Using Imaging Active Tectonics in Active Tectonics Seminar at Western Washington University
Colin Amos
Provenance: Colin Amos, Western Washington University
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About this Course
This seminar course explores the history, effects, and mechanics of earthquake deformation from a geologic and geophysical perspective. Topics covered include ground surface deformation associated with the earthquake cycle, as well as detection and measurement of geologic strain using geodesy and paleoseismology.
7
undergraduate,
6
graduate students
Two 2-hour sessions
per week
Regional, public MS-granting
institution.
GEOL 451/551. The overall goal of the course is to explore the history, effects, and mechanics of earthquake deformation from a geologic and geophysical perspective. Topics covered include ground surface deformation associated with the earthquake cycle, as well as detection and measurement of geologic strain using geodesy and paleoseismology. The class is also taught with a regional focus on the Pacific Northwest. During spring quarter of 2015, our readings and discussions centered on Cascadia and the Olympic Mountains in particular.
Course Outcomes / How outcomes will be assessed (SWBAT):
1. Understand how earthquake cycle deformation manifests as geologic strain.
a. Students will describe surface deformation associated with the interseismic, coseismic, and postseismic periods of an earthquake.
b. Students will demonstrate a basic knowledge of earthquake magnitude.
2. Gain experience using field and laboratory techniques for identifying and quantifying earthquake deformation.
a. Students will be able to predict and evaluate the societal impacts (risk) of fault motion (e.g. lifelines crossing faults, building codes, infrastructure damage) based on an understanding of the fault type and specific characteristics of a fault (orientation, area of potential slip, fault displacement vector). They are able to articulate the relationship between risk and hazard.
b. Students will be able to recognize and categorize active faults using LiDAR, InSAR, or other imagery and recommend geodetic data set(s) for a given scenario considering the strengths/weaknesses/capabilities to find characteristic features for different fault types.
c. Students will be able to synthesize the longer-term behavior of faults (i.e. from the landscape) and the short-term behavior of individual earthquakes to determine recurrence intervals, potential magnitudes of future earthquakes, and hence forecast seismic hazards.
d. Students will understand local active tectonic sources in the Pacific Northwest and will describe how the local framework of active faults fits in to the overall, regional neotectonics of the Pacific Northwest.
3. Gain basic experience with framing research questions and proposals
a. Students will design, propose, and present a plan for pursuing outstanding research questions in active tectonics.
Hands-on classroom activities to support topical seminar
I used the Imaging Active Tectonics module as the basis for in-class activities and take-home assignments that complemented a traditional seminar class based on readings from the primary literature and term research projects. The modules provided experience analyzing and manipulating geodetic data in support of readings centered on incorporating geodesy and earthquake-cycle deformation toward an understanding of long-term mountain building. Classroom time typically uses student-centered activities to discuss scientific papers—I shifted some of this time toward implementing and discussing the GETSI modules.
Students were engaged throughout the course, in particular during classroom sessions where we worked on module activities in a department computer lab. A particular success came from an in-class compilation of small, lateral geomorphic offset data from student groups analyzing sections of the Carrizo Plain LiDAR data along the San Andreas fault. Students were able to create a high-quality data set in under an hour that reproduced published findings and also sparked a number of interesting new questions and debates about interpreting data of this sort. Additionally, the interactive, online InSAR modeling tool (through 3point Science) really gave the students a good feel for how models complement geodetic observations for understanding earthquake deformation. This hands-on component was an extremely valuable exercise for demystifying this process for the students.
My Experience Teaching with GETSI Materials
Unit 1: I did not use Google Earth since I did not have access to computer lab for this class meeting. Students used existing files (and infrastructure data sets) for the assignment, rather than researching an additional site.
Unit 2: I did the histogram compilation of Carrizo offsets as a class rather than as part of the homework. Students were not able to get all the kmz files to resolve, so they had to skip the reverse faulting component of the class assignment.
Units 3–5: No modifications.
Relationship of GETSI Materials to my Course
The module was implemented throughout the 10-week quarter, with the units mostly front-loaded and wrapped up with the summative assessment completed by week 6 or so. Please see the attached syllabus.
Below, I summarize some of the basic structure of how each unit was incorporated into my classes.
Unit 1: If an earthquake happens in the desert . . .
- Students participated in a gallery walk focused on three of the six examples/scenarios. Color handouts were printed and clipped to the large boards for the gallery walks.
- Students were divided into groups and asked to list primary and secondary hazards for each example, and then link those hazards to individual infrastructure components. Students were then asked to rank these hazards.
- Students completed a write-up/scenario report for the other examples using the provided kmz files.
Unit 2: Fault type identification
- The class met in the department computer lab so that students could browse and navigate Google Earth files.
- Students worked in groups on sections of the Carrizo data set during class, where they were to identify and measure small geomorphic offsets.
- I compiled student measurements to create histogram of offsets to try and mimic the findings of the Zielke paper.
- Students worked individually to make LiDAR measurements from the remaining examples outside of class.
Unit 3: How to see an earthquake from space
- One half of a class period focused on an introduction to InSAR (using the provided PowerPoint) followed by a discussion of the provided questions using a think-pair-share.
- The class moved to the computer lab to view/explore the Dinar interferograms using Google Earth.
- Students worked in groups on analyzing the Dinar data to complete a cross section (on paper) of range change across the rupture.
Unit 4: Phenomenology of earthquakes
- Students met in the computer lab to work individually on the Dinar InSAR data and to practice using the 3point Science tool to model the event and view residuals.
- The class viewed histograms of the rupture parameters to discuss uncertainty associated with these estimates.
- Students worked in groups to analyze a different event to complete the assignment outside of class.
Unit 5: Given as an out of class assignment as the summative assessment at the end of the quarter.
Assessments
The primary assessment for the module component of the class was the last unit (Unit 5), which forms the summative assessment for the module. This module was confusing in that it seemed to ask them to create a scenario report for a hypothetical earthquake in an area that recently experienced a damaging earthquake rupture. As such, some of the student assignments read more like a basic report on the El Mayor Cucapah event rather than a synthesis or exploration of the provided data. The kmz of LiDAR for this area was also quite small and of insufficient resolution for many of the students to make meaningful measurements from the LiDAR.
Outcomes
I hoped that the students would get more hands-on experience with geodetic data (which they did), although some of this overlapped with assignments in my other classes and was somewhat of a repeat for several of the graduate students. As described in my answers in the faculty reflection, the InSAR modules were fantastic. The units on seismic hazard were harder to get off the ground and were often too vague for the students—particularly Units 1 and 5.