High Precision Positioning in Field Courses: Applying GNSS to geologic questions

Wednesday 4:30pm-5:45pm TSU - Humphries: 118
Poster Session Part of Wednesday

Authors

Benjamin Crosby, Idaho State University
Ian Lauer, Idaho State University
GPS/GNSS enabled consumer grade positioning devices are now super accessible to both geologic field research and education. These devices geotag images, digital field book entries or measurements but the positions are not sufficiently precise enough to quantify subtle changes in the earth. Thus, most students approach GNSS as an aid to mapping or collecting rather being the primary data source itself.

In order to introduce students to more precise applications, we develop and test a three-unit teaching module within the GETSI – SERC curriculum framework that uses high precision positioning as a primary source of geologic data. Units focus on three core topics: GNSS Fundamentals, Kinematic GNSS and Static GNSS Methods. Module goals enable students to (a) design and conduct a GNSS survey to answer a geologic question, (b) justify why their GNSS technique is appropriate to their question and (c) to articulate how answering their question benefits society. Skill building is via quantitative and qualitative analysis, concept sketches, and both field and office based data acquisition and interrogation. Exercises are site-independent and include example datasets for those unable to travel.

In the summers of 2017 and 2018, we tested the module with ~20 undergraduate students over two days at the ISU field geology camp. We explored the use of static GNSS data for active tectonics and visited a station in person. The summative assessment focused on kinematic GNSS, using RTK rovers to reoccupy leveling monuments spanning the active Lost River fault that ruptured in 1983. The data confirmed that RTK is an appropriate tool and that interseismic deformation continues, demanding consideration in the design of any infrastructure that spans the fault. The exercise integrated well with existing camp curriculum, giving a modern context to geologic structures students had already mapped.