Unit 5: How do earthquakes affect society?
Unit 5 Learning Outcomes
This unit is intended to provide the summative assessment for the entire module. Students should demonstrate a mastery of the learning goals for the entire module. These include the following:
- Students will be able to predict and evaluate the societal impacts (risk) of fault motion (e.g. damage to buildings and infrastructure) based on an understanding of the fault type and specific characteristics of a fault (orientation, area of potential slip, fault displacement vector).
- 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.
- 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.
Unit 5 Teaching Objectives
Unit 5 is intended to be a synthesis of the different techniques and concepts covered in the module, as applied to a real-world scenario, emphasizing potential societal impacts. Support students as they progress through the Unit 5 workflow and, where necessary, help them in recalling and applying previously learned material. Novel angles for the exercise could involve the audience for the report: you work for an insurance company, you are trying to build a oil or gas pipeline, you are drawing up legislation defining national standards for critical fault-crossing infrastructure such as water pipes/aqueducts.
Context for Use
Description and Teaching Materials
This activity is motivated by the imminent risk of many population centers to earthquake-related disasters primarily stemming from the impact of an earthquake on critical infrastructure components necessary to support such a concentration of people—such as water, electrical, and gas lines; roads, bridges, and buildings; and food and medical supplies. There is a long-standing tradition in the sciences to produce a final report that documents all the critical steps of a particular scientific inquiry that includes the identification of a problem, the selection of the most appropriate resources from which to collect relevant data, the analysis of the data, and the drawing of conclusions and implications from the data. The final step is to make suggestions as to how this information can be used to mitigate the societal impact of an earthquake. Data are provided for two potential case study sites for the final report -- El Major Cucapah Earthquake (Mexico 2010) and South Napa Earthquake (California 2014). The data file below has LiDAR data for both sites and InSAR data is on Visible Earthquakes. Alternatively, the instructor or students can choose another site/s to analyze instead of the two provided.
Students will prepare a report with citation to previous exercises (comparing and contrasting to reflect on learning); standard scientific citations of published scientific articles and appropriate websites (e.g. US Geological Survey) also will be part of the assessment. Students will integrate a number of different aspects from subdisciplines within the geosciences such as geomorphology, surficial processes, seismology (including the earthquake cycle and the mechanics of energy propagation in the form of various seismic waves), and quantitative analysis and error analysis, along with various remote sensing technology, geodetic data sets, and spatial and temporal context. A rubric for scoring the various sections of the report is given below.
This problem is inherently interdisciplinary, as it requires consideration of both geoscience data and societal needs. Students must use systems thinking to investigate interactions between the geosphere and the anthroposphere, in particular the positive feedback between the earthquake cycle, faulting and the associated energy release, and the risk to infrastructure critical for societal well-being.
This activity is designed to start during a class or laboratory period. Students will be introduced to the assignment, receive an overall explanation of how to work through the assignment using the flow path outlined above, and be provided with guidelines for writing their report. Students will then begin to work during the remainder of the laboratory period and continue to work on the project as an out-of-class assignment. It is expected that students will need 1–2 weeks outside of class to complete this assignment; the final due date should be determined by the instructor based on the instructional setting.
Unit 5 Data Files (Zip Archive 81.6MB Dec5 15)
Teaching Notes and Tips
This final exercise is intended to take longer than the previous units, which could be finished within a normal laboratory period and homework/write-up time (consistent with the course being one for advanced majors). Unit 5 will require the students to work longer outside of laboratory meeting time and could be scheduled such that a second laboratory session could be used as a time when the faculty member would be available for consultation and guidance to catch misconceptions and also minimize time spent pursuing dead ends. This exercise will serve as a useful reinforcement of the technical skills already acquired in working on Units 1–4 and may add some additional technical skills.
Students will be able to use the experience as a means of preparing for a final exam question on a related topic.
Specific comments about the unit and its materials are:
- Students should be steered towards areas that have the same data available to them as in Units 1–4. Potential study sites, for which the data is provided here, are El Mayor-Cucapah earthquake and South Napa; these are located in regions with populations and infrastructure at risk.
- Students will need to make decisions as to the most appropriate data to collect from the various resources available and to also determine whether additional information is necessary such as maps that show infrastructure or, lacking such specific information, suggest what infrastructure would be expected to exist.
- Students will use what they have learned about 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.
- Students will need to create data tables, summary charts, appropriate graph, and simple diagrams and also show examples of their calculations.
- Students will present their findings in a summative report and in their response to an open-ended essay question on the final exam.
Example Unit 5 Assessment Rubric (Microsoft Word 2007 (.docx) 119kB Dec1 15)
References and Resources
- El Mayor Cucapah, Mexico 2010
- Earthquake Engineering Research Institute El Mayor -Cucapah Earthquake Report
- Oskin, M.E., Arrowsmith, J.R., Corona, A.H., Elliott, A.J., Fletcher, J.M., Fielding, E.J., Gold, P.O., Garcia, J.J.G., Hudnet, K.W., Liu-Zeng, J., and Teran, O.J., 2012, Near-Field Deformation from the El Mayor–Cucapah Earthquake Revealed by Differential LIDAR. Science, 335, 6069, 702-705.
- Wei, S., Fielding, E., Leprince, S., Sladen, A., Avouac, J.P., Helmberger, D., Hauksson, E., Chu, R., Simons, M., Hudnut, K., Herring, T., and Briggs, R., Superficial simplicity of the 2010 El Mayor–Cucapah earthquake of Baja California in Mexico. Nature Geoscience, 4, 9, 615-619.
- South Napa, CA 2014
- South Napa, USA Earthquake Clearinghouse
- F. Guangcaia, L. Zhiweia, S. Xinjianb, X, Binga, and D. Yanan, 2015, Source parameters of the 2014 Mw 6.1 South Napa earthquake estimated from the Sentinel 1A, COSMO-SkyMed and GPS data. Tectonophysics, 655, 139–146.
- DS Dreger, MH Huang, A Rodgers, T Taira, and K Wooddell, 2015, Kinematic Finite‐Source Model for the 24 August 2014 South Napa, California, Earthquake from Joint Inversion of Seismic, GPS, and InSAR Data. Seismological research Letters, 86, 2A, 327-334.