Bathymetric map showing undersea mountains.

Geophysical Survey and Mapping

Australia has the third largest ocean territory in the world, but only 25% of Australia’s Exclusive Economic Zone (EEZ) has been mapped with multibeam. Much of our deep ocean remains unexplored and unknown.

A bathymetric map of the seafloor

A bathymetric map of the seafloor

Investigator is equipped with advanced geoscience equipment.

Many of the acoustic systems are housed in a steel housing called a gondola, which is suspended below the ship’s hull to minimise acoustic interference. Further acoustic instrumentation are housed in drop-keels, which ensure the sensors can be deployed below the bubble sweepdown zone. The gondola houses two multibeam echosounders, a sub-bottom profiler, and a multibeam water column bioacoustic echosounder, while a multifrequency bioacoustic echosounder suite is located in the drop-keels.

Creating maps of the sea floor helps us understand ecosystems, discover canyons, mountains and ancient river systems, and other geological features. Geoscience research will also help provide a greater understanding of the changing dynamics of the ocean floor such as the movement of tectonic plates, which can trigger tsunamis. Being able to image the watercolumn allows us to understand where marine animals congregate and investigate methane plumes from the seafloor.

Capability

Full ocean depth multibeam system

The Kongsberg EM122 is a deep water multibeam echosounder, capable of working to full ocean depth.  It has a 1 x 1 degree array at 12 kHz, and is capable of surveying to 5.5 times water depth or up to 30 km. It is best suited for survey on the continental slope and abyssal plain.

Shallow water multibeam scientific echo sounder system

The Kongsberg EM710 is a high resolution multibeam echosounder with a flexible configuration for acquiring bathymetry and back scatter data down to 2,000 m. It has a 0.5 x 1 degree array with transmit frequencies between 70 and 100 kHz, and is capable of surveying to 5.5 times water depth. It is best suited to survey on the continental shelf and upper slope.

Multibeam scientific and fisheries echo sounder system

The Kongsberg/Simrad ME70 is a fish biomass sonar system, which spreads a signal in a fan shape to 120 degrees, collecting data to 500 m depth and up to 3,000 m wide. This system can be used to develop biomass estimates in 3D.

Multi-frequency scientific split-beam echo sounders

The EK60 system with transducers working at 12 kHz, 18kHz, 38kHz, 70kHz, 120kHz, 200kHz and 333kHz. This system is used to target many different fish species for biomass estimation.

Sub-bottom profiler integrated with 12kHz multibeam

The Kongsberg SBP120 is a sub bottom profiler used to investigate composition below the sea floor, up to 100 m depth depending on sediment type. It has its own 2 – 12 kHz transducer but utilises the EM122 receive array. The SBP120 has a 3 x 3 degree array and operates in a narrow-beam configuration, with 1 – 11 beams. It can be operated with both the EM710 and the EM122.

Micro g Lacoste marine gravity meter

Marine stabilised gravity meter, designed to measure small variations in regional gravity, corrected for the vessel’s motion.

 

Updated: 15 July 2015