Geophysical surveys play a vital role in the early stages of development and infrastructure projects. They serve as critical investigation tools prior to the commencement of major engineering, marine construction, or energy exploration works.

Core Survey Technologies

1. Side Scan Sonar

Side scan sonar—also known as side-imaging or side-looking sonar—is typically towed behind a survey vessel. It captures high-resolution, near-photographic images of the seabed across hundreds of meters on each side, enabling rapid and accurate mapping of large underwater areas.

Applications:

• Seabed characterization

• Debris detection

• Wreck and pipeline location

• Port and harbor planning

2. Seismic Surveys

Seismic methods are the most widely used geophysical tools in geological and engineering surveys. They provide detailed imaging of subsurface layers by analyzing how seismic waves reflect and refract through the ground.

Applications:

• Oil & gas exploration

• Mineral surveys

• Fault mapping

• Foundation and subsurface modeling

3. Magnetometer Surveys

Magnetometers detect variations in the Earth’s magnetic field, identifying buried ferrous objects of all sizes. These surveys are essential in marine and archaeological investigations.

Detectable Objects:

• Anchors, chains, and pipelines

• Ballast stones, shipwreck debris

• Munitions, engines, aircraft parts

4. Remote Operated Vehicles (ROVs)

ROVs are tethered, mobile underwater robots used for detailed visual inspection and sensor-based surveys.

• Class I: Observation only

• Class II: Observation with payload (e.g., sonar, cameras)

Applications:

• Pipeline and cable surveys

• Jacket and subsea structure inspections

• Hull inspections of vessels

Additional Geophysical Methods

Survey Applications by Industry

Geophysical services are tailored for a wide range of engineering and marine applications, including:

• Land Reclamation & Coastal Engineering:
  Sand/Cap Rock surveys for beach replenishment

• Port & Harbor Development:
  Feasibility studies for ports, power plants, desalination facilities

• Dredging Support:
  Pre- and post-dredging/channel access surveys

• Marine Infrastructure:
  Seabed and pre-engineering surveys for pipelines, bridges, and jetties

• Offshore Energy:
  Pre-lay, pre-construction, and anchor clearance surveys

• Salvage & Debris Recovery:
  Surveys to locate lost subsea assets such as anchors, cutter heads, chains, pipelines, and shipwrecks