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A miniature research vessel: A small-scale ocean-exploration demonstration of geophysical methods

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Abstract

Through programs such as the Student Chapter Excellence Program and Student Chapter Outreach Grant, the Society of Exploration Geophysicists strives to provide worldwide educational opportunities and experiences that result in impactful and meaningful experiences. SEG understands that inspiring the next generation of exploration geoscientists is vital for continued success and innovation within the field. These future scientists will face global-scale challenges as they take over current research, develop new energy solutions, explore the world's resources, and work to mitigate the effects of adverse environmental impacts. A student's introduction to the geosciences can vary across the globe. Interesting and impactful experiences are critical for attracting and engaging future geoscientists, and SEG is proud to have Student Chapter partners working to promote geoscience education.

In Hawaii, students typically learn only basic geology, with some highlights about the hot-spot volcanoes they live on. From a young age, with the vast Pacific Ocean at their feet, many of our youth are inspired to wonder about additional oceanic processes that remain hidden to their eyes, but they are often left in the dark about the massive marine mountain ranges and deep-sea trenches. The University of Hawaii Geophysical Society (UHGS), an SEG Student Chapter, seeks to further motivate students to pursue the geosciences by demonstrating a miniature, real-time sonar-mapping cruise. As an added bonus, UHGS students gain valuable experience in explaining their research to the public as they assume the roles of mentors and teachers.

One major constraint on many outreach endeavors is making the product “visual” enough that a wide range of students can understand the basic principles. UHGS designed a physical model that actively demonstrates how scientists employ geophysical methods to map the seafloor. The students presented this pilot project to the public at the University of Hawaii at Mānoa School of Ocean and Earth Science and Technology's (SOEST) Biennial Open House weekend in October 2013. An estimated 7600 people attended the two-day event, including children and teachers from O'ahu schools, home-school students, community groups, parents, children, and science enthusiasts. The UHGS exhibit featured real-time bathymetry mapping of a cardboard model of a seamount using the toy-sized research vessel R/V UHGS to demonstrate geophysics in action. The well-attended exhibit captured the attention of the audience, inspired countless questions, and fostered in-depth discussions between the students and the UHGS exhibitors.

This preliminary model was fairly crude, which limited student interaction. The toy-sized R/V used a 40-Hz single-channel transducer, controlled by an Arduino microcontroller, with echo returns processed and transmitted to a laptop running MATLAB. These returns updated a 3D model seafloor surface plot in real time on a large monitor so students could watch a digital image of the seamount develop. Required ancillary electronics consisted of readily available components installed on a breadboard. The survey grid was strung with cable on a wooden frame over a cardboard volcano with a framework that allowed us to translate the R/V using a system of pulleys, mimicking the design of real bathymetry surveys. Photoelectric sensors on one of the pulleys determined cable displacement, allowing the ship location to be determined from the preprogrammed survey geometry.

This seafloor-mapping model conveyed to the community how geoscientists employ sonar to explore the marine geology surrounding our islands, demonstrating the practical use of wave physics and simple geometric calculations. In addition, by changing the R/V model and decor of the demo, this exhibit could easily be adapted to show how some mammals use echolocation to navigate or to find prey.

Harrison Togia explains basic sonar methods to students. In the foreground, a 3D model of the mapped volcano is shown on the monitor.

In the next version of the project, with a more sensitive sensor at higher frequency, students will be able to map objects in finer detail at a wider range of angles. Coupled with an improved motor-driven system to translate the R/V along the ship track and track position, the resulting digital map will show a more accurate representation of the objects scanned. With the new setup, it will be possible to construct a wide variety of seafloor objects and allow students to place a new seafloor configuration for every scan, adding a vital hands-on component to the exhibit. An improved software graphical user interface will also allow the students to start and stop the survey (this was impossible before because the cables were cranked manually), send the ship to a specific location on the grid with a single click, and manipulate the 3D seafloor scan. UHGS will make a thoroughly documented redesign publicly available to allow any interested party or SEG Student Chapter to reproduce the exhibit and use the software developed to create a demonstration for their own outreach event.

The UHGS proposal to produce this version 2.0 of its system was accepted recently by the SEG Foundation Student Chapter Outreach Grant. This grant supports student research done in collaboration with an SEG Student Chapter faculty advisor if the project promotes geosciences to the public. This individual award is one of nine projects funded in part by the $11,000 given so generously by the SEG Foundation. With this funding from the SEG Foundation, UHGS can improve the exhibit in several ways to greatly enhance future outreach experiences and introduce the geosciences in a fun and engaging way.

UHGS thanks SOEST for contributions to the preliminary design and implementation of the exhibit. UHGS is also grateful for the support of the SEG Foundation through the Student Chapter Outreach Grant and gives thanks for all the SEG Student Chapter support for making this outreach demonstration possible.

SEG supports 320 Student Chapters worldwide through funding opportunities that include travel grants and chapter development support. For more information about SEG Student Chapters, please visit www.seg.org/students or contact SEG University and Student Programs at .

Ship captain Sarah Maher (left) and first mate Jonathan Sleeper drive the ship over a cardboard volcano.

— Brian Boston and Samuel Howell, University of Hawaii Geophysical Society

— Gregory Moore, faculty advisor of the University of Hawaii Geophysical Society