HVDC Submarine Power Cable Project

CSR GeoSurveys Ltd. completed a comprehensive desktop study, hydrographic survey, marine geophysical investigation, and a geotechnical exploration program for a high-voltage direct current (HVDC) submarine cable project in The Great Lakes. The proposed cable route extended approximately 104 km along the lakebed of Lake Erie between Nanticoke, Ontario and Springfield, Pennsylvania. 

Desktop Route Assessment

CSR completed a preliminary desktop routing assessment to evaluate potential submarine cable corridors across Lake Erie. The study included the review and interpretation of available bathymetric, geological, and environmental datasets to identify optimal routing solutions and potential engineering constraints. 

The cable route assessment considered:

• Lakebed bathymetry and geomorphology
• Regional and surficial geology
• Potential geohazards and seabed constraints
• Ice scour susceptibility
• Existing obstructions and infrastructure
• Commercial navigation and marine activity

The desktop study provided the basis for planning the subsequent marine surveys and geotechnical investigation programs.

Hydrographic & Marine Geophysical Surveys

CSR conducted high-resolution hydrographic and marine geophysical surveys along the preliminary cable route corridor using:

• Chirp sub-bottom data (Klein 3310 Chirp)
• Boomer reflection sub-bottom data (Surface Tow/CSP-P 350J)
• Sidescan sonar data (Klein 3000)
• Marine magnetometer data (Marine Magnetics SeaSpy)
• Multibeam echosounder data (Odom MB1)
• Dual frequency single beam echosounder (Odom CV3)
• Nearshore video transects

These surveys provided detailed information on:

• Lakebed bathymetry
• Surficial sediment distribution
• Subsurface geological conditions
• Geological hazards, including shallow gas and ice scours
• Shipwreck and obstruction locations
• Existing subsea infrastructure and pipeline crossings

The survey data supported route optimization, engineering design, installation planning, and permitting requirements for the proposed submarine cable system. 

Geotechnical Investigation Program

Following the completion of the hydrographic and geophysical surveys, CSR carried out a comprehensive geotechnical exploration and sampling program consisting of:

• 62 vibracore samples (5 m core length)
• 36 in situ thermal resistivity test locations
• 8 boreholes completed at landfall sites using a jack-up barge and track mounted auger drill
• 10 nearshore grab samples

Field investigations included sample collection, onboard testing and logging, and laboratory analysis to characterize subsurface conditions and support cable burial and thermal performance assessments.