Great Barrier Reef map in 3D

James Cook University

An example of the map (Cooktown) Image: Deepreef explorer

A researcher at James Cook University in Cairns has produced a map that would have made a world of difference to the University’s namesake.

Dr Robin Beaman’s three-dimensional bathymetry (or depth) model of the Great Barrier Reef and the Coral Sea could have kept James Cook and the HMS Endeavour out of trouble as they sailed along Australia’s east coast.

The 3D depth model covers an area of three million square kilometres, including the entire Queensland coast, Great Barrier Reef, and the Coral Sea almost to New Caledonia.

The depth model can represent seabed features down to 100 metres in size, revealing the seafloor in unprecedented detail for such a large area.

“At that scale, we’re able to show the true shapes of the coral reefs, including the older and deeper Pleistocene bases upon which modern reefs have grown,” Dr Beaman said.

“Users can see vast underwater dune fields, the extensive algal reefs on the northern Great Barrier Reef shelf, ancient river channels preserved in the seabed, and a nearly unbroken line of fossil barrier reefs extending more than 900 kilometres along the shelf edge.”

Creating the 3D depth model has been an enormous undertaking over three years, using data collected from a wide range of sources, including multibeam and singlebeam echo sounders, airborne laser bathymetry and satellite imagery.

Dr Beaman liaised with multiple Government agencies and other researchers who have collected bathymetry data in the region over the years.

Much of the source depth data were provided by the Australian Hydrographic Service using Royal Australian Navy survey data, collected primarily for navigational safety.

Project partner Geoscience Australia also provided vital source depth data.

In addition, Dr Beaman participated in three Coral Sea mapping surveys using Australia’s Marine National Facility, the RV Southern Surveyor, our largest blue-water research ship.

After gathering and processing around 900 million individual depth points, Dr Beaman collaborated with the U.S. Scripps Institution of Oceanography to develop a method to convert the data points into a gridded surface, which can then be viewed as a 3D map.

On screen, the results of Dr Beaman’s meticulous work could easily be mistaken for a new computer game.

“It certainly gives you a sense of how dramatic the undersea landscape is and how little we really know about it,” he said.

“With 3D visualisation software, users can experience a thrilling sense of discovery as they glide over the seafloor. It’s like diving on a grand scale, looking at landscape features rather than individual corals.”

“As you cruise along the continental slope you can see dozens of submarine canyons that plunge over two kilometres deep. Further offshore in the Coral Sea the model is detailed enough to reveal the results of vast underwater landslides.”

As a keen diver and a marine geologist Dr Beaman has always been aware that most visitors to the reef only skim the surface of the underwater landscape.

“Coral reefs comprise only five to seven per cent of the geographical area of the Great Barrier Reef World Heritage Area, and even the most experienced of divers will usually only dive down around 40 metres,” he said.

“Previously we’ve had little understanding of what exists below 200 metres, so it’s very exciting to be able to map from the coastline all the way down to the abyss, over five kilometres deep.”

Future uses for the 3D depth model are myriad.

“Dr Beaman’s model is an important piece of research in its own right, but it will also form a solid foundation upon which many other activities aimed at improving our understanding of the Great Barrier Reef can be built,” said Dr David Souter, Research Director at the Reef and Rainforest Research Centre.

“It will allow oceanographers to accurately map currents and biologists to target important sites on the seafloor for studying deep-sea marine life.”

Oceanographers at the Australian Institute of Marine Science (AIMS) are already using the grid to simulate current flow within a whole-of-reef hydrodynamic model that will be used to study the effects of water quality changes on the Great Barrier Reef.

Importantly, the 3D model can also be an educational resource, with outputs being publicly available at www.deepreef.org/bathymetry.

The model can also be explored interactively on the e-Atlas (www.e-atlas.org.au) a new online knowledge sharing initiative funded through the Australian Government’s Marine and Tropical Sciences Research Facility, and coordinated by AIMS and the Reef and Rainforest Research Centre.

Dr Beaman’s research was supported by a $150,000 Queensland Government Smart Futures Fellowship and a matching grant from the Reef and Rainforest Research Centre.

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Category: Great Barrier Reef
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