Hydrographic & Geophysical Surveys to Support Shore to Shelf Cable Burial
Geodynamics was contracted by L3 MariPro, Inc. to provide hydrographic and geophysical surveys and analysis as part of the design, fabrication and installation of the Undersea Warfare Training Range (USWTR) in the Atlantic Ocean. Located offshore of Jacksonville, FL, the USWTR tracking range will consist of several strings of listening nodes on the seabed. To mitigate the risk of interaction with fishing gear, range cabling will be buried as much as possible while avoiding hardbottom substrate and areas identified as Essential Fish Habitat or of potential archaeological significance.
Geodynamics designed and implemented hydrographic and geophysical surveys of the proposed trunk cable route using a Kongsberg EM2040 multibeam, an Edgetech 2000 combined sidescan and sub-bottom sonar towfish, and a SeaSPY 2 marine magnetometer with precise positioning provided through iXBlue USBL transceiver and an Applanix POS-MV 320 inertial motion unit. Data was acquired aboard the UNOLS vessel R/V Savannah to describe general seabed morphology and bathymetry along the proposed route and identify any seabed features that may have an impact on the laying and plough burial of the trunk cable. Geodynamics also provided identification and precise positioning of all natural and manmade obstructions in the vicinity of the proposed cable route and node sites. Deliverables included daily “at sea” reports and preliminary data, and final data deliverables were provided in a directory-designed geodatabase for all processed data files and ancillary data acquired during the field operation.
In a follow-on effort, Geodynamics designed and led an ROV survey to assess and measure the extent of cable burial following construction. Aboard the M/V Shelia Bordelon, an inspection-class ROV collected high-definition video of selected portions of the trunk cable. In addition to standard survey deliverables reporting, Geodynamics also integrated this Full Motion Video (FMV) into a GIS database to support data-driven documentation and analysis of the acquired ROV inspection data.