DESIGNING A VIRTUAL CHIRP (COMPRESSED HIGH-INTENSITY RADIATED PULSES) INTERPRETATION EXERCISE FOR AN APPLIED GEOPHYSICS COURSE

The move to distance learning during the COVID-19 pandemic has radically changed how we think about and conduct field experiential learning. In our applied geophysics class, we had planned to have students collect, process, and interpret lacustrine CHIRP sonar data collected during the semester. Once we moved to virtual learning, we completely re-designed the exercise to allow students to work in virtual groups to complete the project, without access to specialized software.

For the virtual project, each team was given CHIRP data (~30-50 lines) from one of six lakes in Maine to analyze and interpret. Each line was provided as a 2D pdf file and all of the lines were included in a 3D pdf file that the students could view but not modify. The students first picked horizons on the 2D lines in PowerPoint. Then they used these to map the distribution each facies in their lake using Google Earth. They were also given LiDAR data to help interpret glacial features that carried from the surface into the basal layer in each lake. We had meetings both separately with each group and in class for updates at each step of the data analysis and interpretation process. Once the students completed their facies distribution maps they wrote an abstract where they presented an interpretation of the depositional history of their lake and a comparison to the other lakes in the area. Each group then presented their results in a virtual poster session and the groups consolidated their results into three abstracts submitted for presentation at a regional meeting.

The remote learning environment also presented some challenges. Success in this project required open communication and for the instructors and students to be flexible. For example, because the students were not on campus, they only had access to programs that were on their individual machines. We were initially going to have the students use a seismic interpretation program, but 1) not all of the students had computing resources that could run the program and 2) the dual steep-learning curve of a new program and new interpretation skills would make success difficult. These challenges required us to rethink methodology and outcomes. Ultimately, though the students didn’t make as much progress as anticipated, they were able to use their available tools and acquired skills to successfully complete the project.