State boundary area of the Australia continental shelf (including Lord Howe Island) [for NESP D3]

The state boundary area of the Australia continental shelf (including Lord Howe Island). The coastline is at Lowest Astronomical Tide (LAT) and the shelf break is defined by the 200 m isobath taken from Geoscience Australia's GA 2009 bathymetric dataset.

Petrological and Geophysical Characterization of Exhumed Subcontinental Mantle from the Australian-Antarctic Ocean-Continent Transition Zone

The final lithospheric breakup of the Australian-Antarctic rift system remains controversial due to sparse geological constraints on the nature of the basement along the ocean-continent transition zones. We present new interpretations of multichannel seismic reflection transects, as well as new petrological data of dredged mantle rocks along the East Antarctic margin (Seamount B, offshore Terre Adélie). By combining both datasets, we show that a 50–100 km wide domain of cold (900°C), fertile subcontinental mantle was exhumed along the non-volcanic Antarctic margin. The dredged peridotites preserve characteristics similar to mantle xenoliths found in syn- to post-rift volcanism at the eastern end of the Australian margin (Victoria and Tasmania), indicating the sampling of a common fertile subcontinental mantle during rifting between Australia and Antarctica. Seamount B represents the initial stages of exhumation of cold subcontinental lithosphere along an ocean-continent transition during rifting. This thick mantle domain was likely affected by syn-rift melt impregnation at high-pressure (8 kbar), leading to the formation of plagioclase-pyroxenites. Overall, the combination of continental rifted blocks, a 50-100 km wide domain of volcanic-poor subcontinental mantle and (ultra)-slow spreading implies that ocean-continent transition zones along the Australian-Antarctic margins represent a recent analogue to ocean continent transition zones from the Jurassic Western Tethys. Additionally, evidence of syn-rift melt stagnation at high pressure suggests that magmatism along the Australian-Antarctic rifted margins was sufficient to form magnetic anomalies that can be used as isochrons despite their formation in lithosphere other than mature, steady-state ocean crust.

Marine Futures Project - Abrolhos Islands - reef habitat

The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including the Abrolhos Islands, a group of 122 limestone outcrops surrounded by fringing reed ca. 60km west from the city of Geraldton. The Abrolhos research location is the most northerly of the Marine Futures sampling sites, selected due to the unique mixture of tropical coral reef habitats, and temperate reef and seagrass communities.The hydroacoustics data were processed to construct full coverage maps of bathymetry and textural information.

Marine Futures Project - Southwest Capes - reef habitat

The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including the Capes region of southwest Western Australia. The area is one of the most diverse temperate marine environments in Australia. Warm, tropical waters of the Leeuwin Current mingle with the cool waters of the Capes Current, resulting in high finfish diversity, including tropical and temperate species, as well as internationally significant seagrass diversity with meadows occurring at depths greater than 40 metres. The region's geomorphology is complex with an array of intertidal and subtidal reef environments. Many marine plants and animals are endemic to the southern coast of Australia due to its long geographical isolation, with seagrass, algae and estuarine habitats functioning as spawning, nursery and feeding grounds for a wide range of invertebrates and fish. Significant numbers of marine mammals also frequent the area, including the blue whale, the largest of all marine creatures.

Marine Futures Project - Jurien Bay - reef habitat

The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including Jurien Bay. The Jurien Bay marine environment is highly diverse, and is home to a wide variety of species, including sea lions and sea birds on the many offshore islands. Limestone reef and seagrass habitats in the area support a diverse fish and invertebrate fauna, and a local crayfishing industry is based around the Western Rock Lobster (Panulirus cygnus).

Marine Futures Project - Point Ann - reef habitat

The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including Point Ann, a site which lies within the Fitzgerald Biosphere, a UNESCO designated International Biosphere Reserve and one of the largest and biologically significant National Parks in Australia (DEC) on West Australia’s south coast, approximately 180km east of Albany.

WA Marine Futures Project - reef habitat

The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. This project record provides linkage to each of metadata records describing data collected from the 9 study areas: Jurien Bay, Rottnest, Abrolhos Islands, Point Ann, Middle Island, Mount Gardner, Broke Inlet, and Geographe Bay. To access the source datasets from each study site in their original (unaggregated) form, see child records linked to this parent record.

Marine Futures Project - Rottnest Island - reef habitat

The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including Rottnest Island, a popular family holiday destination just 20 km off the Perth coast. One of the main drawcards of the island is the diverse marine life inhabiting the surounding waters, which Western Australian locals and tourists can experience by snorkelling, diving, boating and fishing. The marine environment around Rottnest includes seagrass meadows, kelp-covered reef tops, coral patches, and sponge gardens in deeper water. As a result of the warm, southward flowing Leeuwin Current, the island represents the southern limit of the distributions of many tropical corals and fish. The marine life around Rottnest therefore represents a unique mix of tropical and temperate species and habitats.

Marine Futures Project - Broke Inlet - reef habitat

The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including Broke Inlet, a relatively remote area 400km south of Perth, between the towns of Augusta and Albany. The nearest major town, Manjimup, is situated 100km north and the small coastal settlement Windy Harbour approximately 30km west of Broke Inlet. The Inlet is entirely surrounded by the D’Entrecasteaux National Park, which is accessible via a sealed road and attracts limited ‘through-traffic’ to the area. The marine environment off Broke is one fairly untouched by major tourism pressures and thus this location was selected due to its relative inaccessibility.

Marine Futures Project - Middle Island - reef habitat

The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including Middle Island, the project's easternmost site located within the Recherche Archipelago. The Recherche Archipelago provides habitats for a diverse range of both terrestrial and marine species, and can be accessed either by vessel from the town of Esperance, or by four wheel drive along the coastal roads adjoining the Cape Arid National Park.

EARTH SCIENCE | OCEANS | BATHYMETRY/SEAFLOOR TOPOGRAPHY | CONTINENTAL MARGINS