Presented May 7, 2015 – Webinar Slides
Concepts and Forces Important in Burial, Initiation of Motion, and Continued Motion of Underwater Munitions by Dr. Carl Friedrichs
Better understanding and predictive ability regarding the re-exposure and migration of underwater munitions will enhance the ability of the Department of Defense (DoD) to productively detect and thus characterize and remediate environmental and safety hazards. The scientific and engineering communities will also benefit from a better and more unified understanding of fundamental controls on the interaction of sediment with munitions-sized objects, including a wide range of natural and man-made objects. Completed work associated with this project has involved reviewing the geologic, engineering, and DoD literature for relevant data sets involving sediments and objects ranging from sands and bullets to meter-long seabed mines and boulders, including environments from laboratory flumes, to rivers, to the continental shelf. A balance of forces approach following the hydraulic and coastal engineering literature was then used to derive parameterized models to fit the uncovered data sets. Both initiation of motion and burial of munitions-sized objects were found to be well represented by forms of the Shields Parameter, which scales the tendency of drag forces to move objects or sediment relative to the tendency of their weight to keep them still. Ongoing work is focused on formulations for continued motion of underwater munitions occurring at higher Shields Parameter values.
In Situ Measurements of Munitions Mobility by Dr. Joseph Calantoni
This study aims to provide detailed time series measurements of the in situ boundary layer processes responsible for munitions mobility including transport, burial, and excavation. Field experiments were performed to characterize the environment in which munitions are found while simultaneously recording the location of munitions relative to the seafloor at high spatial and temporal frequency. Unlike previous investigations that have provided before and after snapshots of munitions mobility, the instrumentation used in this work is capable of providing high spatial and temporal resolution measurements for the relevant boundary layer processes (e.g., wave height and direction, current profiles, suspended sediment concentrations, and sediment erosion and deposition) while simultaneously monitoring the mobility of surrogate munitions. The project team sought to provide answers to fundamental questions about the fate of munitions that have significant implications on site remediation and management efforts conducted by the Department of Defense. In addition, in situ measurements are necessary to provide a baseline data set for verification and validation of process-based models for prediction of munitions mobility. Results from field experiments performed in April and May 2013 in the Northern Gulf of Mexico and January through March 2015 on the outer banks of North Carolina was presented and discussed. Preliminary modeling of data for observed munitions burial during storm events was also presented.
Dr. Carl T. Friedrichs is Chair of the Physical Sciences Department at the Virginia Institute of Marine Science (VIMS) and a Professor at VIMS/the School of Marine Science at the College of William and Mary, located in Gloucester Point, Virginia. At VIMS, Carl studies coastal and estuarine processes, teaches graduate courses in physical oceanography and marine geology, and directs the VIMS Coastal Hydrodynamics & Sediment Dynamics Laboratory (www.vims.edu/~cfried). He received a BA in Geology at Amherst College in 1986 and a PhD in Oceanography at the Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program in 1993. Carl has authored 80 peer-reviewed publications on topics related to coastal oceanography and has been the principal investigator on federally funded research grants totaling >$8 million. He is a recipient of the Commonwealth of Virginia Outstanding Faculty Award and the White House Presidential Early Career Award for Scientists and Engineers. His long-term research goals are to better understand the fundamental aspects of coastal and estuarine physics which control sediment and other material fluxes at time-and length-scales important to geology, biogeochemistry, and environmental engineering.
Dr. Joseph Calantoni is the head of the Sediment Dynamics Section in the Marine Geosciences Division of the Naval Research Laboratory (NRL) at Stennis Space Center (SSC), Mississippi. The Sediment Dynamics Section performs basic and applied research leading to advanced technology development and demonstration and validation efforts focused around the physical, mechanical, and acoustical properties of seafloor, estuarine, and riverine sediments through a combination of high performance computing simulations and numerical modeling, detailed laboratory measurements, and field experiments. Dr. Calantoni received an undergraduate degree from the Pennsylvania State University and master’s and doctoral degrees from North Carolina State University all in physics. He was granted a National Research Council Research Associateship Award and began working as a postdoctoral fellow at NRL immediately after defending his dissertation in late 2002. In 2004, he accepted a position as a full-time NRL research physicist.
Dr. Calantoni is internationally recognized for his novel approach to sediment transport modeling and simulation where the motions and interactions of every grain of sand are directly computed. In August of 2009, he initiated and continues to direct a K-12 education outreach program to promote science, technology, engineering, and mathematics (STEM) in the communities geographically local to SSC. Educational partnership agreements (EPAs) have been signed with 12 local school districts, six private schools, and two community organizations across eastern Louisiana and the Mississippi Gulf Coast. The goal of the education outreach program is to encourage a new generation of scientists and engineers to apply their talents in DoD laboratories.