Venus, Earth's structural sister: Investigations using radar imagery
University of Minnesota Duluth Author Profile
Used this activity? Share your experiences and modifications
Students conduct fieldwork on Venus without leaving the lab. Concepts include basic mapping principles, remote data set interpretation, structure morphology and interaction, rheology, temporal relations, and large-scale planet processes. Perhaps most importantly students learn that a geologic map is an interpretation.
This exercise can be used in undergraduate structural geology course, or in an advanced structural geology course (advance undergraduate and/or graduate level); the exercise can be easily expanded to accommodate more or less concerns/lessons.
Skills and concepts that students must have mastered
I have used this exercise in a grade school setting, junior-high school/senior high school science groups, girl scout/boy scout groups, structural geology setting, and I used it in a graduate level course Fall 2004. The activity provides an opportunity for students to learn new concepts as well as apply known concepts. All this by way of saying, there is no single background required. Students apply the skills and concepts they know and learn new skills and concepts along the way.
How the activity is situated in the course
I have used this project as a lecture-exercise ('lectursize') in which I direct student mapping and inquiry as an introductory lecture for structure-a 'to-do-what' sort of introduction to structural analysis. I have also used this exercise as a late-term lab project in undergraduate structural geology serving as a culminating 'field' exercise in which students apply various aspects of what they have learned over the course of the semester to address an integrative tectonic problem. I will also use the exercise this fall semester as an early-term project in advanced structure, in which context I hope that it will allow me a means to evaluate the levels of understanding/analysis of a wide range of student coming together with different backgrounds, as they complete the exercise. I will learn about the level of each student, structural background as well as investigative skills, but I hope that each of the students will also learn through the exercise so that it provides a service to me as the instructor at the same time providing a valuable learning experience for the students; in this context it serves as a framework the exercise should also pose concepts for the course work ahead.
Content/concepts goals for this activity
Remote-sensing data interpretation; structural element identification; pattern recognition; temporal relations and constraints; bulk strain patterns.
Higher order thinking skills goals for this activity
Students learn concepts of field mapping and interpretation-but in a setting in which they are not distracted by outside elements; they learn that geologic maps are interpretations; they learn data synthesis and how to make predictive models (hypotheses), and how to test models/hypotheses with further data collection. They also learn that the real world is not quite as neat and tidy as they might think based on lectures and textbooks. Students experience thinking through time and space, as well as the importance of history/sequence in deformation.
Other skills goals for this activity
Write up or oral presentation (instructor's choice) aspects can be incorporated; exercise can be run as group or individual activity. Students can present written flow charts that illustrate branching analysis and required assumptions. The sequence cartoons are particularly useful to get students to think about process and how various factors interact and change through the evolution of a feature or a surface.
Description of the activity/assignment
Students construct a geologic map of a region of Venus' surface using NASA Magellan synthetic aperture radar(SAR) data (provided) and/or synthetic stereo data (provided, and constructed using Magellan SAR and altimetry data)- 3D anaglyph viewed through red-blue glasses. Mapping can be done digitally using Adobe Illustrator (or a similar graphic program) or using hard copy images and overhead transparencies for mapping. Students construct a complete geologic map, determine a geologic history for the area, and propose hypotheses for the evolution of a large quasi-circular geomorphic/geologic feature that occurs within the map area. Students also propose tests of their hypotheses (whether such tests can be accomplished through further mapping, future missions, experiments, theoretical arguments, calculations, etc.). Students must clearly identify assumptions they make in their hypotheses/models. Individual, or small group, write-ups and completed geologic maps summarize student analysis. This activity connects structural geology to other fields, and provides the students with an opportunity to experience geologic investigation in which there is no single right answer, but there are "wrong" or unlikely hypotheses. This exercise helps students think outside the box with little fear given that they are dealing with - literally - an extraterrestrial world in which very little is known - and yet, we assume that chemistry and physics, as we know them, likely operated on Earth's sister planet. Students are given a short introductory presentation about the environmental conditions of Venus (which could have been different in the past), and an introduction to radar data before they begin.
Determining whether students have met the goals
Evaluation is based on the nature of the geologic map (a full range of styles is allowed and encouraged; it is extremely useful for students to see how different individuals or groups mapped the same region), and the quality of the arguments (consistency!) of the developed history and range of proposed and evaluated hypotheses. Again, there a lot of latitude in this exercise for the instructor to chose goals dependent on the particular level of the students based on course level, or time of the semester/program. If write up or oral presentations are included, these are evaluated on both content and mechanics.More information about assessment tools and techniques.
Teaching materials and tips
Useful websites for Instructors: