A large multibeam echo sounder (MBES) dataset (710, 000 km2, inclusive of transit data) was acquired in the SE Indian Ocean to assist the search for Malaysia Airlines Flight 370 (MH370). Here, we present the results of a geomorphic analysis of this new data and compare with the Global Seafloor Geomorphic Features Map (GSFM) that is based on coarser resolution satellite-derived bathymetry data. The analyses show that abyssal plains and basins are significantly more rugged than their representation in the GSFM, with a 20% increase in the extent of hills and mountains. The new model also reveals four times more seamounts than presented in the GSFM, suggesting a greater number of these features than previously estimated for the broader region and indeed globally. This is important considering the potential ecological significance of these high-relief structures. Analyses of the new data also enabled knolls, fans, valleys, canyons, troughs and holes to be identified, doubling the number of discrete features mapped and revealing the true geodiversity of the deep ocean in this area. This high-resolution mapping of the seafloor also provides new insights into the geological evolution of the region, both in terms of structural, tectonic, and sedimentary processes. For example, sub-parallel ridges extend over approximately 20% of the area mapped and their form and alignment provide valuable insight into Southeast Indian Ridge seafloor spreading processes. Rifting is recorded along the Broken Ridge – Diamantina Escarpment, with rift blocks and well-bedded sedimentary bedrock exposures discernible down to 2,400 m water depth. Ocean floor sedimentary processes are represented in sediment mass transport features, especially along and north of Broken Ridge, and pockmarks (the finest-scale features mapped) south of Diamantina Trench. The new MBES data highlight the complexity of the search area and serve to demonstrate how little we know about the 85-90% of the ocean floor that has not been mapped with this technology. The availability of high-resolution and accurate maps of the ocean floor can clearly provide new insights into the Earth’s geological evolution, modern ocean floor processes, and the location of sites that are likely to have relatively high biodiversity. Abstract presented the 2017 American Geophysical Union, Fall Meeting

This dataset contains four-class hardness (i.e., hard-1, hard-soft-2, soft-3 and soft-hard-4) prediction data from seabed mapping surveys on the Van Diemen Rise in the eastern Joseph Bonaparte Gulf of the Timor Sea. This dataset was generated based on hard90 seabed hardness classification scheme using random forest methods based on the point data of seabed hardness classification using video images and multibeam data. Refer to Selecting optimal random forest predictive models: a case study on predicting the spatial distribution of seabed hardness for further information on processing techniques applied [1]. [1] Li, J., Tran, M., Siwabessy, J., 2016. Selecting optimal random forest predictive models: a case study on predicting the spatial distribution of seabed hardness PLOS ONE 11(2) e0149089.

The Rowley Shoals/Offshore Canning and Roebuck basins survey was conducted on the RV Southern Surveyor survey SS06/2006 (GA-2408) between the 29th May and 22 June 2006. The primary aim of the survey was to identify any sites of natural hydrocarbon seepage, that may provide direct evidence for an active petroleum system within the sub‐surface. A secondary objective was to contribute to the understanding of the modern sedimentary and oceanographic processes influencing this part of the shelf, and to assess the nature of the benthic habitats. Underwater video was captured at 12 sites, with a minimum of 10 minutes to 60 minutes at each site, which totalled approximately 5.5 hours of footage. Video was recorded to mini DV tapes and copied to digital format. Descriptions of footage acquired during the underwater video tows are provided in the post-survey report (GA Record 2007/21 - Geocat # 65453). Please note that the underwater video is unclipped, contains descent and ascent through the water column, laser points in the video are reported to be spaced at 25 cm, and start locations of the underwater video camera stations are found in the Post-survey report.

Australia is increasingly recognised as a global hotspot for sponge biodiversity, with sponges playing key roles in habitat provision, water quality, bioerosion, and biodiscovery. Despite the intense focus on marine resource management in northern Australia, there is a large knowledge gap about sponge communities in this region. This study focuses on shelf environments of the Timor Sea, in particular the Van Diemen Rise and Londonderry Rise which are characterised by extensive carbonate terraces, banks and reefs, separated by soft sediment plains and deeply incised valleys. These carbonate terraces and banks are recognised as a Key Ecological Feature (KEF) in the marine region plans for northern Australia (North and Northwest Marine Regions) and are in part incorporated into the Oceanic Shoals Commonwealth Marine Reserve. To support the management of this marine reserve and its associated KEF, we use new datasets to investigate regional patterns in sponge assemblages and their relationships to seabed geomorphology. To do this, we use sponge assemblage data and multibeam-derived variables (depth, backscatter, slope, geomorphic feature) from seven survey areas located on the Van Diemen Rise (four sites) and Londonderry Rise (three sites), spanning approximately 320 km in an east-west direction. The dataset was collected during three collaborative surveys undertaken in 2009, 2010 and 2012 by Geoscience Australia, the Australian Institute of Marine Science and the Museum and Art Gallery of the Northern Territory as part of the Australian Government's Offshore Energy Security Initiative and the National Environmental Research Program Marine Biodiversity Hub. All surveys returned geophysical, biological, geochemical, and sedimentological data. Benthic biota were collected with a benthic sled across a range of geomorphic features (bank, terrace, ridge, plain, valley) identified from high-resolution multibeam sonar. Sponges were then taxonomically identified to 350 species, with the species accumulation curve indicating there may be over 900 sponge species in the region. Sponge assemblages were different between the Van Diemen Rise and Londonderry Rise, as well as between individual banks in the same area, indicating that different suites of species occurred at regional (east-west) and local (between banks) scales. Relationships between sponges and other multibeam-derived variables are more complex and warrant further research. The current study will help: i) facilitate integrated marine management by providing a baseline species inventory; ii) support the listing of carbonate banks of the Timor Sea shelf as a Key Ecological Feature, and; iii) inform future monitoring of marine protected area performance, particularly for areas of complex seabed geomorphology.

The collection consists of seabed samples collected by Geoscience Australia and other organizations since the 1950s. Samples consist of various shallow cores types, rocks derived from dredging, and sea bed sediments collected by grab and dredge methods. A large proportion of samples are refrigerated.

This dataset contains species identifications of crinoids collected during survey SOL4934 (R.V. Solander, 27 August - 24 September, 2009). Animals were collected from the Joseph Bonaparte Gulf with a benthic sled. Specimens were lodged at Museum of Victoria on the 19 April 2010. Species-level identifications were undertaken by Kate Naughton at the Museum of Victoria and were delivered to Geoscience Australia in December 2010. See GA Record 2010/09 for further details on survey methods and specimen acquisition. Data is presented here exactly as delivered by the taxonomist, and Geoscience Australia is unable to verify the accuracy of the taxonomic identifications.

Multibeam sonar data incorporates a wide range of metrics of physical seabed properties that can be utilised to generate substrate maps for marine habitat mapping. In particular, statistical descriptors of seabed form and texture can be derived to maximise the information provided by multibeam data. This study investigates the full potential of multibeam data for mapping seabed properties for an area of geomorphically complex seabed on the continental shelf offshore from Point Cloates, Western Australia. In 2008, as part of a collaborative survey within the Commonwealth Environmental Research Facilities (CERF) Marine Biodiversity Hub, Geoscience Australia acquired high resolution multibeam data and sediment samples across a 280 km2 area of the shelf, using a Kongsberg EM 3002 (300 kHz) system. Using this data, a two stage analysis was developed to: (i) separate 'hard seabed (e.g., reefs, ridges and mounds) from 'soft' sediments, and; (ii) predict textural properties for seabed sediments, including %Gravel, %Sand, %Mud, mean grain size and sorting. For a mapping tool, we chose the Random Forest Decision Tree technique. This entailed using ten combinations of input datasets as explanatory variables, including morphometric variables derived from bathymetry, and angular response curves and related statistics derived from backscatter mosaics. The training dataset was derived by combining sediment data from grab samples with locations of hard substrate inferred from bathymetry data. The predictive mapping of 'hard' and 'soft' seabed types resulted in predictions with very strong confidence levels, especially when bathymetry information was combined with backscatter data (i.e., cross-validated Area Under Curve = 0.99). The five sediment properties were predicted with moderate to good cross-validation accuracies (Figure 1). The highest accuracies were achieved for %Mud and Sorting, (R2s equal 0.73 and 0.68, respectively).

This is a compilation of Seabed and Habitat Mapping Publications 2008 - 2010: GA Record 2008_20.pdf Vlaming Sub-Basin and Mentelle Basin: Environmental Summary GA Record 2008_23.pdf A Review of Spatial Interpolation Methods for Environmental Scientists GA Record 2009_02.pdf Carnarvon Shelf Survey Post-Survey Report GA Record 2009_09.pdf Ceduna Sub-basin: Environmental Summary GA Record 2009_10.pdf Mapping and characterising soft sediment habitats, and evaluating physical variables as surrogates of biodiversity in Jervis Bay, NSW GA Record 2009_12.pdf Temporal and fine-scale variation in the biogeochemistry of Jervis Bay GA Record 2009_13.pdf Review of Ten Key Ecological Features (KEFs) in the Northwest Marine Region GA Record 2009_22.pdf Seabed Environments and Subsurface Geology of the Capel and Faust basins and Gifford Guyot,Eastern Australia GA Record 2009_26.pdf Deep Sea Lebensspuren: Biological Features on the Seafloor of the Eastern and Western Australian Margin GA Record 2009_38.pdf Frontier basins of the west Australian continental margin: post-survey report of marine reconnaissance and geological sampling survey GA2476 GA Record 2009_42.pdf A Review of Surrogates for Marine Benthic Biodiversity GA Record 2009_43.pdf Southeast Tasmania Temperate Reef Survey Post-Survey Report GA Record 2010_09.pdf Seabed Environments of the Eastern Joseph Bonaparte Gulf, Northern Australia

Keppel Bay is a large shallow coastal embayment adjacent to the mouth of the Fitzroy River, located on the central coast of Queensland. The geomorphology and distribution of sediment in Keppel Bay is complex due to the influence of Late Quaternary sea-level change, relict topography, a geologically diverse catchment, macrotidal hydrodynamic processes and flood events. Seabed morphology, sub-bottom profiles and sediment cores reveal the former path of the Fitzroy River across Keppel Bay and the continental shelf. The palaeo-Fitzroy River flowed west across the shelf to the north of Northwest Reef, a position on the shelf that is now under approximately 60 m of water. With the rise in sea level during the early Holocene, the mouth of the Fitzroy River retreated across the continental shelf and by the middle Holocene it was landwards of its present location, near Rockhampton. During the last few thousand years under a relatively stable sea level, much of the shallow inner region of Keppel Bay has been infilled and the coast has prograded several kilometres. Palaeochannels in the inner section of Keppel Bay have mostly been infilled with sediment, which mainly comprises muddy sand from the Fitzroy River. In the outer bay and on the shelf further west many relict channels have not been infilled with marine sediment indicating that the area is relatively starved of sediment. Sediments in outer Keppel Bay are dominantly relict fluvial deposits that are well sorted with only a minor mud component. Subaqueous dunes in the outer southeastern section of Keppel Bay and Centre Bank indicate that tidal currents and currents associated with the predominant southeasterly winds, appear to be transporting marine biogenic sediments and relict coarse terrigenous sediments into Keppel Bay.

Geoscience Australia (GA) conducted a marine survey (GA0345/GA0346/TAN1411) of the north-eastern Browse Basin (Caswell Sub-basin) between 9 October and 9 November 2014 to acquire seabed and shallow geological information to support an assessment of the CO2 storage potential of the basin. The survey, undertaken as part of the Department of Industry and Science's National CO2 Infrastructure Plan (NCIP), aimed to identify and characterise indicators of natural hydrocarbon or fluid seepage that may indicate compromised seal integrity in the region. The survey was conducted in three legs aboard the New Zealand research vessel RV Tangaroa, and included scientists and technical staff from GA, the NZ National Institute of Water and Atmospheric Research Ltd. (NIWA) and Fugro Survey Pty Ltd. Shipboard data (survey ID GA0345) collected included multibeam sonar bathymetry and backscatter over 12 areas (A1, A2, A3, A4, A6b, A7, A8, B1, C1, C2b, F1, M1) totalling 455 km2 in water depths ranging from 90 - 430 m, and 611 km of sub-bottom profile lines. Seabed samples were collected from 48 stations and included 99 Smith-McIntyre grabs and 41 piston cores. An Autonomous Underwater Vehicle (AUV) (survey ID GA0346) collected higher-resolution multibeam sonar bathymetry and backscatter data, totalling 7.7 km2, along with 71 line km of side scan sonar, underwater camera and sub-bottom profile data. Twenty two Remotely Operated Vehicle (ROV) missions collected 31 hours of underwater video, 657 still images, eight grabs and one core. This catalogue entry refers to chlorophyll a, b, c and phaeophytin a conentrations in the upper 2 cm of seabed sediments.