Looking into Earth with GIS (College Level)
This material is replicated on a number of sites as part of the SERC Pedagogic Service Project
This exercise is an adaptation of an existing chapter of the Earth Exploration Toolbook. The exercise described ideas that can be used to introduce this exercise in a college-level introductory geoscience course.
The following description is from the EET chapter...
Users work with data from a seismic wave model in a freely available GIS (geographic information system) program, ArcVoyager SE. Using a GIS, they examine maps and produce graphs to explore variations in seismic wave velocities at depths of 28 and 100 km below Earth's surface. By examining and analyzing GIS-ready data, users visualize density changes and earthquake distributions near a spreading center and two subduction zones. Finally, users infer the location (depth) of the upper mantle under ocean basins and under continents from their analyses.
- Download geospatial data for GIS analyses
- Map, graph, and analyze geospatial information
- Interpret the results of GIS analyses to understand the relationship between earthquake locations, plate boundaries, and seismic waves
Context for Use
This exercise can be used as a lab exercise, a take-home assignment, or a classroom exercise to stimulate discussion about the theory of plate tectonics. By plotting recent earthquake data on a map of the world the students see the relationship between quakes and plate boundaries.
The exercise introduces mapping and spatial context to data sets. Students can also consider properties of the quake data (e.g. magnitude, depth) to consider additional aspects of the plate boundaries.
The EET chapter is aimed at middle and high school levels, but the techniques and concepts of the exercise are certainly appropriate for introductory geoscience courses. The instructions are comprehensive and adequate for students to follow on their own outside of the classroom (e.g. a homework or project assignment). The exercise presents an interesting opportunity to have the students explore the data before discussing the tectonic interpretation.
Teaching Notes and Tips
The "Teaching Notes" page of the EET chapter has excellent ideas on how to implement this exercise within the context discussions about the interior of the Earth. It also describes the topics that should be covered before the students are introduced to this exercise.
The step-by-step instructions for the exercise mean that college level students should be able to complete the exercise outside of class, provided they have access to install software on a computer (lab/classroom/personal). ArcVoyager SE is available for free from ESRI and available for Macintosh or Windows as a download or on CD (by request). Note that ArcVoyager SE resembles the ArcView 3.x in its behavior and functionality. More information about ArcVoyager SE is available on the "About the Tool and Data" page of the EET chapter.
References and Resources
ArcVoyager SE - free GIS software from ESRI
The "Going Further" and "Teaching Notes" pages of the EET chapter discuss additional possibilities with the ArcVoyager SE tool using other data sets (e.g. earthquake activity, stream flow conditions, global land and sea surface temperatures).