Multibeam sonar swath-mapping has revealed small submarine volcanic cones on the northeastern Lord Howe Rise (LHR), a submerged ribbon continent. Two such cones, aligned NNW and 120 km apart, were dredged at 23-24Degrees S. Water depth is about 1150 m nearby: the southern cone rises to 750 m and the northern to 900 m. Volcanic rocks dredged from the cones are predominantly highly altered hyaloclastites with minor basalt. The clasts are mostly intensely altered vesicular brownish glass with lesser basalt, in zeolitic, clayey, micritic or ferruginous cement. Lavas and hyaloclastites contain altered phenocrysts of olivine and plagioclase, and fresh clinopyroxene. The latter have compositions between acmite and Ti-augite, and match well clinopyroxene phenocrysts in undersaturated intraplate basanitic mafic lavas. Interbedded micrites in the volcaniclastics represent calcareous ooze that was deposited with (or later than) the volcanic pile. Foraminifera indicate that the oldest micrite is late Early Miocene (~16 Ma), and that the original ooze was deposited in cool water. Late Miocene to Pliocene micrites, presumed to be later infillings, all contain warm water forms. This evidence strongly suggests that both cones formed in pelagic depths in the Early Miocene. Ferromanganese crusts from the two cones are up to 7 cm thick and similar physically, but different chemically. The average growth rate is 3 mm/m.y.. Copper, nickel and cobalt content are relatively high in the north, but copper does not exceed 0.08 wt %, nickel 0.65% and cobalt 0.25%. The Mn:Fe ratio is high in the south (average 13.7) suggesting strong hydrothermal influence. Such small volcanic cones related to intraplate hotspot-type magmatism may occur in extensive fields like those off southern Tasmania. On Lord Howe Rise, the known small volcanic cones coincide with broad gravity highs in areas of shallow continental basement. The highs probably represent Neogene plume-related magmatism. The thick continental crust may dissipate and spread the magma widely, whereas plumes may penetrate thin oceanic crust more readily and build larger edifices. The correspondence of the ages derived from micropalaeontology and from extrapolating from nearby dated hotspot traces support such a genesis. Accordingly, gravity highs in the right setting may help predict fields of small volcanic seamounts.

Australian estuaries and coastal waterways were classified into six subclasses according to the wave-, tide- and river-energies that shape them, and also according to their overall geomorphology. The geomorphic classification confirmed the energy classification. Within this framework: - 17% were classified as wave-dominated estuaries; - 11% were classified as tide-dominated estuaries; - 10% were classified as wave-dominated deltas; and - 9% were classified as tide-dominated deltas Therefore, only ~28% of Australian coastal waterways are actually estuaries. The remainder are delta's (19%), strandplains (~5%), or tidal creeks (~35%). A seventh subclass others (13%) includes: Drowned River Valleys, Embayments and Coastal Lakes/Lagoons/Creeks. Strandplains and Tidal Creeks are indicative of very low river-energy, and their joint dominance in the data set (~40%) reflects the fact that Australia is a dry continent, with relatively little river runoff by world standards.

A growing need to manage marine biodiversity sustainably at local, regional and global scales cannot be met by applying the limited existing biological data. Abiotic surrogates of biodiversity are thus increasingly valuable in filling the gaps in our knowledge of biodiversity patterns, especially identification of hotspots, habitats needed by endangered or commercially valuable species and systems or processes important to the sustained provision of ecosystem services. This review examines the use of abiotic variables as surrogates for patterns in benthic assemblages with particular regard to how variables are tied to processes affecting biodiversity and how easily those variables can be measured at scales relevant to resource management decisions.

In 2008, the performance of 14 statistical and mathematical methods for spatial interpolation was compared using samples of seabed mud content across the Australian Exclusive Economic Zone (AEEZ), which indicated that machine learning methods are generally among the most accurate methods. In this study, we further test the performance of machine learning methods in combination with ordinary kriging (OK) and inverse distance squared (IDS). We aim to identify the most accurate methods for spatial interpolation of seabed mud content in three regions (i.e., N, NE and SW) in AEEZ using samples extracted from Geoscience Australia's Marine Samples Database (MARS). The performance of 18 methods (machine learning methods and their combinations with OK or IDS) is compared using a simulation experiment. The prediction accuracy changes with the methods, inclusion and exclusion of slope, search window size, model averaging and the study region. The combination of RF and OK (RFOK) and the combination of RF and IDS (RFIDS) are, on average, more accurate than the other methods based on the prediction accuracy and visual examination of prediction maps in all three regions when slope is included and when their searching widow size is 12 and 7, respectively. Averaging the predictions of these two most accurate methods could be an alternative for spatial interpolation. The methods identified in this study reduce the prediction error by up to 19% and their predictions depict the transitional zones between geomorphic features in comparison with the control. This study confirmed the effectiveness of combining machine learning methods with OK or IDS and produced an alternative source of methods for spatial interpolation. Procedures employed in this study for selecting the most accurate prediction methods provide guidance for future studies.

Map showing all of Australia's Maritime Jurisdiction north of approx 25°S . This includes areas around Cocos (Keeling) Islands and areas west of Christmas Island as well as those contiguous to the continent in the north. Included as one of the now 28 constituent maps of the "Australia's Maritime Jurisdiction Map Series" (GeoCat 71789). Depicting Australia's extended continental shelf approved by the Commission on the Limits of the Continental Shelf in April 2008, treaties and various maritime zones. Background bathymetry image is derived from a combination of the 2009 9 arc second bathymetry and topographic grid by Geoscience Australia and a grid by W.H.F. Smith and D.T. Sandwell, 1997. Background land imagery derived from Blue Marble, NASA's Earth Observatory. 3277mm x 1050mm (for 42" plotter) sized .pdf downloadable from the web.

For the first time, the distribution of seafloor geomorphic features has been systematically mapped over much of the Australian margin and adjacent seafloor. Each of 21 feature types was identified using a new, 250 m spatial resolution bathymetry model and supporting literature. The total area mapped was 48.9 million km2 and included the seafloor surrounding the Australian mainland and island territories of Christmas, Cocos (Keeling), Macquarie and Norfolk Islands. Of this total mapped area, the shelf is 41.9 million km2 (21.92%), the slope 44.0 million km2 (44.80%) and the abyssal plain/deep ocean floor 42.8 million km2 (32.20%). The rise covers 97 070 km2 or 1.08% of the mapped area. A total of 6702 individual geomorphic features were mapped. Plateaus have the largest surface area and cover 1.49 million km2 or 16.54%, followed by basins (714 000 km2; 7.98%), and terraces (577 700 km2; 6.44%), with the remaining 14 types each making up 55%. Reefs, which total 4172 individual features (47 900 km2; 0.54%), are the most numerous type of geomorphic feature, principally due to the large number of individual coral reefs of the Great Barrier Reef. The geomorphology of the margin is most complex where marginal plateaus, terraces, trench/troughs and submarine canyons are present. Comparison with global seafloor geomorphology indicates that the Australian margin is relatively under-represented in shelf and rise and over-represented in slope area, a pattern that reflects the mainland being bounded on three sides by rifted continent ocean margins and associated large marginal plateaus. Significantly, marginal plateaus on the Australian margin cover 20% of the total world area of marginal plateaus. The mapped area can be divided into 10 geomorphic regions by quantifying regional differences in diagnostic assemblages of features, and these regions can be used as a starting-point to infer broad-scale seafloor habitat types.

Map showing all of Australia's Maritime Jurisdiction north of approx 25CS . This includes areas around Cocos (Keeling) Islands and areas west of Christmas Island as well as those contiguous to the continent in the north. Map derived from one of the "Australia's Maritime Jurisdiction Map Series" (GeoCat 71985). Depicting Australia's extended continental shelf approved by the Commission on the Limits of the Continental Shelf in April 2008. Background bathymetry image is derived from a combination of the 2009 9 arc second bathymetry and topographic grid by Geoscience Australia and a grid by W.H.F. Smith and D.T. Sandwell, 1997. Background land imagery derived from Blue Marble, NASA's Earth Observatory. Map size 3m x 2m for Australian Customs and Border Protection Service. (for internal use only - not for publication)

This dataset provides the spatially continuous data of seabed gravel (sediment fraction >2000 µm), mud (sediment fraction < 63 µm) and sand content (sediment fraction 63-2000 µm) expressed as a weight percentage ranging from 0 to 100%, presented in 0.0025 decimal degree (dd) resolution raster grids format and ascii text file. The dataset covers the Vlaming sub-basin in the Australian continental EEZ. This dataset supersedes previous predictions of sediment gravel, mud and sand content for the basin with demonstrated improvements in accuracy. Accuracy of predictions varies based on density of underlying data and level of seabed complexity. Artefacts occur in this dataset as a result of insufficient samples in relevant regions. This dataset is intended for use at the basin scale. The dataset may not be appropriate for use at smaller scales in areas where sample density is insufficient to detect local variation in sediment properties. To obtain the most accurate interpretation of sediment distribution in these areas, it is recommended that additional samples be collected and interpolations updated.

Map showing all of Australia's Maritime Jurisdiction north of approx 25°S. Updated in June 2014 from "Australia's Maritime Jurisdiction North of 25°S" (GeoCat 71985) to conform with "Australian Maritime Boundaries 2014" data by Geoscience Australia. This includes areas around Cocos (Keeling) Islands and areas around Christmas Island as well as those contiguous to the continent in the north. Included as one of the now 28 constituent maps of the "Australia's Maritime Jurisdiction Map Series" (GeoCat 71789). Depicting Australia's continental shelf as proclaimed in the "Seas and Submerged Lands (Limits of Continental Shelf) Proclamation 2012" established under the "Seas and Submerged Lands Act 1973". Background bathymetry image is derived from a combination of the 2009 9 arc second bathymetry and topographic grid by Geoscience Australia and a grid by W.H.F. Smith and D.T. Sandwell, 1997. Background land imagery derived from Blue Marble, NASA's Earth Observatory. 3277mm x 1050mm (for 42" plotter) sized .pdf downloadable from the web.

This report details the keystroke methodology used to create the seascape maps for planning areas of the Australian margin.