Sub-bottom profiler

Sub-bottom profilers work by transmitting sound energy in the form of short pulses towards the seabed. This sound energy is reflected from the seabed to determine the physical properties of the seafloor.
Sub-bottom profilerSub-bottom profiler

What is sub-bottom profiling

In recent years, sub-bottom profilers have been used to measure high-resolution small-scale sedimentary structures and processes. Marine geological profiling through sub-bottom profiling has allowed scientists to detect and map differences between the various sedimentary layers beneath a body of water.

The technology has been widely adopted because of its ability to collect data rapidly and non-intrusively, even though there is a trade-off between resolution and signal penetration with sub-bottom profiling systems.

How sub-bottom profilers work

Sub-bottom profiling systems are used to determine the physical properties of the seabed and to visualize geological formations a few meters below the seafloor.

These devices are usually comprised of a single-channel source that sends sound pulses into the shallow sub-seafloor sediment. The sound pulses bounce off the seafloor and subsequent buried sediment layers in relation to their acoustic impedance (hardness) differences.

Acoustic impedance is tied to the density of the material and the rate at which sound travels through this material. Therefore, the reflected energy intensity depends on the different densities of the sediments—the denser (harder) the sediments, the stronger the reflected signal.

The reflected signal then travels back through the water to the receiver, and the received signals are then amplified, processed and displayed in an acquisition system.

Sub-bottom profilers are used extensively in offshore, coastal and port engineering and geotechnical site surveys, renewable energy surveys, dredging studies, mineral exploration and habitat mapping projects.

2 types of Sub bottom profiling. Credit: Wessex Archaeology
Scanning result. Credit: Stockholm University

About the images
RWMT work with nation states, government agencies and institutions on sensitive and often classified operations. Also, the tools we use are constantly being evaluated and changes depending on the nature of the operation. Because of this, we have sometimes chosen to show example images of the tools we use, rather than images from actual projects.

Used for

Scanning the sediment layers beneath the seafloor

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