“Mobility of Instrumented Unexploded Ordnance in the Nearshore Environment” by Dr. Jack Puleo
This project supports SERDP’s efforts to understand mobility, exposure, and burial characteristics of underwater unexploded ordnance (UXO). UXO are present on the seafloor along the coast from past military activity (over 400 formerly used defense sites) and may constitute a potential risk for the public. Knowledge of the physics responsible for UXO mobility/burial and quantification of mobility/burial processes is needed to improve predictive and probabilistic models and efficient use of limited resources for UXO site characterization and clearing. This research developed instrumented surrogates spanning a range of calibers and matching the physical characteristics of the real UXO. The surrogates were then tested in small-scale and large-scale laboratory facilities and in the field to quantify the mobility and burial characteristics as a function of the hydrodynamic forcing. The presentation described the instrumented surrogates, measurement campaigns, results related to the surrogate mobility and burial identified from internal and external sensors, and relationships of mobility and burial to the prevailing conditions.
While current studies are addressing the mobility and detection of UXO in sandy coastal areas, a significant data gap has been identified regarding UXO in shallow muddy environments. With a significant proportion of military sites linked to muddy environments, this study is worked to address this data gap. Using a shallow estuarine site in the Delaware Bay, this study aims to (1) monitor the mobility and behavior of sensor-integrated surrogate munitions in cohesive sediments using a high-accuracy acoustic positioning system, (2) compare surrogate munition response to hydrodynamic forcing through instrumented bottom frame time-lapse hydrodynamic data and sonar imagery, and (3) check site changes and testing an autonomous underwater vehicle-borne magnetometer through repetitive site surveying. Surrogate UXO, modified with acoustic tracking devices and inertial motion units (IMU) were deployed at an estuarine site with cohesive sediment. The surrogates were monitored for changes in mobility and burial using the VEMCO positioning system (VPS), an off-the-shelf acoustic positioning system capable of tracking the position of multiple acoustic tags with accuracies down to 10 cm. Concurrently, time-series acoustic imagery and hydrodynamic sensors were deployed to characterize UXO response to varied hydrodynamic conditions and compared to site-wide surrogate behavior. A series of repetitive surveys were conducted using a magnetometer specifically designed for UXO detection on an autonomous underwater vehicle (AUV) to monitor and compare to acoustic tracking results. Field data from this study will help inform parameters for UXO mobility and behavior in storms and muddy environments for integration into the existing expert system modeling of UXO burial and mobility.
Dr. Jack Puleo is a Professor and Associate Chair in the Department of Civil and Environmental Engineering at the University of Delaware. He is also the director of the Center for Applied Coastal Research. Jack’s areas of research include quantifying small-scale hydrodynamic and sediment transport processes in the nearshore environment including under extreme conditions and the mobility, exposure and/or burial of underwater unexploded ordnance (UXO). Jack has served as a Principal Investigator on numerous grants related to sediment transport since 2004 and on SERDP-funded UXO studies since 2015. He received the SERDP project of the year award in 2018. He has authored or co-authored more than 75 peer-reviewed research papers on nearshore processes. He received bachelor’s degrees in oceanography mathematics from Humboldt State University in 1996, a master’s degree in oceanography from Oregon State University in 1998, and a doctoral degree in coastal engineering from the University of Florida in 2004.
Dr. Arthur Trembanis is an associate professor at the University of Delaware, director of the Coastal Sediments Hydrodynamics and Engineering Laboratory, co-founder of the Robotics Discovery Laboratory and founding Director of the UD Maker Gym Initiative. He has over 18 years of experience working with autonomous underwater vehicles (AUVs) and other oceanographic field robotic systems. His work entails collaborative exploration of the oceans integrating geological, physical, biological, and chemical oceanography from estuaries to the outer edge of the continental shelf. Ongoing topics of interest include beach erosion, sand ripple dynamics, scour processes associated with shipwrecks, artificial reefs, and unexploded ordnance. In recent years, his research group has helped discover lost shipwrecks including the SS W.R. Grace, the whaleback Choctaw and Ohio in Lake Huron, and ancient shipwrecks and WWII aircraft in the Aegean. His research involves extensive field-work in remote locations around the world including New Zealand, Australia, the Caribbean, Canada, Italy, Turkey, and Greece. Art received his undergraduate degree from Duke University, was a Fulbright fellow at Sydney University, received his doctoral degree from the College of William and Mary, and was a post-doctoral at the Woods Hole Oceanographic Institution and the USGS.
Dr. Carter DuVal has over 8 years of experience working with remote sensing technologies, hydrographic surveys, seabed morphodynamics, shipwreck and artificial reef monitoring, and research in unexploded ordnance burial, mobility and detection. As part of the Hawaii Undersea Military Munitions Assessment, Carter worked with acoustic and optical data to detect and identify UXO disposed off Oahu, Hawaii. He co-authored the Bureau of Ocean Energy Management report on “Munitions and Explosives of Concern Survey Methodology and In-field Testing for Wind Energy Areas on the Atlantic Outer Continental Shelf.” This study included data collection and processing of multiple acoustic, magnetic and optical datasets to optimize survey methods for the detection of UXO. Carter is currently the co-principal investigator for a SERDP study evaluating munitions mobility, with a focus on storm driven dynamics on UXO scour, burial and mobility. Carter received his bachelor’s degree in archaeology from St. Mary’s College of California, and master’s degree in marine studies and doctoral degree in oceanography from University of Delaware.