Student-built acoustic sensors for hands-on learning in the earth sciences

Friday 1:30pm-1:50pm Bruininks 131B

Teaching Demonstration Part of Friday Teaching Demos

Leaders

Sasha Seroy, University of Washington-Seattle Campus

Claire McKinley, Bellevue Community College

Robert Levine, University of Washington-Seattle Campus

Demonstration

We will demonstrate:
- An overview of microcontroller-based acoustic sensor.
- A table-top activity using a simple student-built acoustic sensor demonstrating the application of acoustic sensors for detecting seafloor features, and the role of sampling resolution in detecting, resolving, and mapping features.
- A follow-up activity where students use the same acoustic sensor to calculate the speed of sound in air.
- An overview of activity extensions and related modules using the same low-cost sensor package within the earth and environmental sciences.

Abstract

This activity introduces students to the concept and function of acoustics within the geosciences using inexpensive and commercially available sensor building materials. Several adaptations of this activity introduce students to a variety of applications of acoustics in geoscience from understanding pressure waves and controls on the speed of sound to mapping bathymetric features. In the basic table-top form of the activity, students build a simple acoustic sensor and use it to map features in a bathymetry box. In the field applications, students apply the same concepts to map bathymetric features off a dock or geologic features from above. Learning outcomes include an understanding of acoustic principles, experience building and using sensors, various applications of acoustics in geosciences and a consideration of sampling resolution and tradeoffs.

Context

The activity has been used in multiple contexts and in several undergraduate Oceanography and Geology courses. With minimal modifications, this activity is appropriate for introductory through advanced undergraduate-level courses across a variety of disciplines, as well as for high school earth science, technology, or physics students.

We have used it in Geological Oceanography (CM) as a way to investigate pressure waves and their echo sounding applications for bathymetry. We have used it in a 100-level environmental monitoring course (SS) to introduce how acoustic techniques are used to study environmental processes. We have also used a field adaptation of the activity in a 300-level ocean sensors course to map bathymetry off a nearby dock (RL).

Why It Works

- Introduces students to simple sensor building, electronics, and coding.
- Encourages applied thinking about sampling resolution, sensor accuracy and precision, and data analysis/interpretation.
- Is an accessible parallel to real-world methods in earth sciences (e.g., seismic and bathymetric surveys, seismic wave analysis).
-In addition, the activity has several expansions from a classroom activity to field applications that are applicable to geology, oceanography, math, physics, and biology courses.