Profiling Earth's Surface using GeoMapApp

(1) To recognize large-scale surface features on Earth as plate boundaries, continents, ocean basins, mountain ranges, etc.
(2) To relate these features to volcanoes and earthquakes.
(3) To understand that variations in surface elevation reflect variations in crustal and lithospheric thickness.

This exercise is appropriate for an introductory physical geology class or as a review in a structural geology or introductory geophysics class. It is designed as homework following lectures related to plate tectonics and Earth's interior structure. Alternatively, it could be used as an in-class or in-lab exercise provided students have access to computers connected to the internet and printers. Although the exercise should take approximately an hour for students to complete, it is likely to take longer as students experiment with GeoMapApp. GeoMapApp is easy to use, but it has a lot of interesting features that students can explore.

The Assignment Handout is a ready-to-use exercise for students. Identical WORD and PDF versions are provided. The handout is given to students. Students take the handout to a computer connected to the internet and a printer to complete the exercise. Students must download GeoMapApp, a freely available mapping program that works on both Mac and PC platforms.
The B to B' elevation profile that students should produce using GeoMapApp is provided as a PDF file.
Assignment Handout as PDF (Acrobat (PDF) 689kB Apr3 07)
Assignment Handout as WORD file (Microsoft Word 107kB Apr3 07)
Elevation Cross Section ( 54kB Apr3 07)
Schematic Answer Key ( 136kB Aug2 07)

--Suggest to students that they attempt to download GeoMapApp well before the assignment is due. It should download without any trouble, but, as with any program, there can be glitches.
--One strategy is for the instructor to demonstrate GeoMapApp in class. Students may start the exercise in class, thereby decreasing the fear-factor associated with learning new software.
--The assignment contains little background information on plate tectonics, so the instructor must supply the appropriate context for students. At an introductory level, this might involve a number of lectures before students attempt the homework. At an upper level, this might simply be a brief review of plate tectonic concepts. Encourage students to use their textbooks and lecture notes while completing the activity.
--Students must have a basic understanding of the following concepts to complete this exercise:

• topographic maps, profiles, and geologic cross sections
• plate boundaries (spreading centers, transform faults, subduction zones, continental collisions, and continental rifts)
• active and passive margins
• earthquake locations and depths
• volcano locations
• shallow Earth structure (crust, mantle, Moho, lithosphere, and asthenosphere)
  

--The assignment asks for sketches to the Moho and lithosphere/asthenosphere boundary. Make sure students understand whether or not you want a scaled drawing or simply a sketch of relative changes in thickness.
--Note that a schematic answer key is available on this website. Savvy students may find this solution online, so instructors may consider choosing a different location for the profile, which can be done easily simply by replacing the first figure in the assignment.
--To explore tectonic settings in greater detail, an instructor could divide the cross section into smaller segments. This would allow students to investigate regions such as active and passive margins, hotspot volcanoes, trenches, mid-ocean ridges, continental rifts, etc. This strategy, however, will take more time and require additional printing resources.
--GeoMapApp has many interesting features. This exercise is meant, in large part, to introduce students to the software. There may be additional assignments where students will find it useful.

Students turn in a cross section to be graded. It would also be useful to review this in class to ensure students understood the most important concepts. The assignment, as presented, asks for a drawing and does not ask for additional written explanations. One could easily add some questions requiring students to comment on specific tectonic features.