Field Observations of Wave-Induced Pressure: Distributed Fiber-Optic Sensing and Pressure Sensors

Characterizing the hydrodynamic forces responsible for the initiation of the movement of sediment is fundamental for improved understanding of how and when sediment is moved around in coastal areas. Forcing from wave-induced pressure gradients in both the horizontal and vertical directions have been shown to influence the movement of sediment. Few field experiments have provided detailed observations of these pressure gradients and it is challenging to collect spatially distributed measurements of these near-bed processes in energetic nearshore environments. Here, novel field observational methods were utilized to collect measurements of wave-induced pressure gradients at Rockaway Beach, Oregon in fall 2025. This field work was done in collaboration with the Coastal Boundary Dynamics Research Group from Oregon State University (OSU). The instruments deployed included Pressure Sticks from the University of New Hampshire (UNH) and a Distributed Acoustic Sensing (DAS) system from OSU. Pressure Sticks are vertical arrays of pressure sensors that measure the hydrodynamic quantities of the field site and the wave-induced pressure forces on and within the sediment. The DAS is a type of fiber-optic sensing technology that can measure the strain/pressure within the sediment from the waves. These DAS pressure measurements can be taken continuously at many locations across the beach, while the Pressure Sticks can only record pressure at one location on the beach. Preliminary results from this field experiment will be presented.

BIO

 Melissa Marry received her Ph.D. in ocean engineering at the University of New Hampshire (UNH) in August 2025. She is currently a postdoctoral research associate at UNH with Dr. Tracy Mandel. Melissa also holds a dual bachelor’s degree in physics and mathematics from SUNY Oneonta. Her research interests include sediment transport, nearshore processes, and coastal resiliency.