<div>The Abbot Point to Hydrographers Passage bathymetry survey was acquired for the Australian Hydrographic Office (AHO) onboard the RV Escape during the period 6 Oct 2020 – 16 Mar 2021. This was a contracted survey conducted for the Australian Hydrographic Office by iXblue Pty Ltd as part of the Hydroscheme Industry Partnership Program. The survey area encompases a section of Two-Way Route from Abbot Point through Hydrographers Passage QLD. Bathymetry data was acquired using a Kongsberg EM 2040, and processed using QPS QINSy. The dataset was then exported as a 30m resolution, 32 bit floating point GeoTIFF grid of the survey area.</div><div>This dataset is not to be used for navigational purposes.</div>

<p>This resource contains multibeam backscatter data for Bynoe Harbour collected by Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS) and the Northern Territory Government (Department of Environment and Natural Resources) during the period between 3 and 27 May 2016 on the RV Solander (survey SOL6187/GA0351). This project was made possible through offset funds provided by INPEX-led Ichthys LNG Project to Northern Territory Government Department of Environment and Natural Resources, and co-investment from Geoscience Australia and Australian Institute of Marine Science. The intent of this four year (2014-2018) program is to improve knowledge of the marine environments in the Darwin and Bynoe Harbour regions by collating and collecting baseline data that enable the creation of thematic habitat maps that underpin marine resource management decisions. <p>The specific objectives of the survey were to: <p>1. Obtain high resolution geophysical (bathymetry) data for Bynoe Harbour; <p>2. Characterise substrates (acoustic backscatter properties, grainsize, sediment chemistry) for Bynoe Harbour; and <p>3. Collect tidal data for the survey area. Data acquired during the survey included: multibeam sonar bathymetry and acoustic backscatter; physical samples of seabed sediments, underwater photography and video of grab sample locations and oceanographic information including tidal data and sound velocity profiles. <p>This dataset comprises multibeam backscatter data. A detailed account of the survey is provided in: Siwabessy, P.J.W., Smit, N., Atkinson, I., Dando, N., Harries, S., Howard, F.J.F., Li, J., Nicholas W.A., Picard, K., Radke, L.C., Tran, M., Williams, D. and Whiteway, T. 2016. Bynoe Harbour Marine Survey 2016: GA4452/SOL6432 – Post-survey report. Record 2017/04. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/Record.2017.004.

<div>The Kangaroo Island (South-East)&nbsp;bathymetry survey was acquired for the Australian Hydrographic Office (AHO) during the period 1 Dec 2022 – 31 May 2023. This was a contracted survey conducted for the Australian Hydrographic Office by Precision Hydrographic Services as part of the Hydroscheme Industry Partnership Program. The survey area encompasses an area in Kangaroo Island (South-East)&nbsp;. Bathymetry data was acquired using Kongsberg EM2040-07, Kongsberg EM2040-P and Kongsberg EM2040-P SV MKII, and processed using QIMERA processing software. The dataset was then exported as a 30m resolution, 32 bit floating point GeoTIFF grid of the survey area.</div><div>This dataset is not to be used for navigational purposes.</div>

<div>The Lord Mayor Shoal to Pitt Shoals&nbsp;bathymetry survey was acquired for the Australian Hydrographic Office (AHO) during the period 1 Oct 2023 – 30 Nov 2023. This was a contracted survey conducted for the Australian Hydrographic Office as part of the Hydroscheme Industry Partnership Program. The survey area encompasses an area in Lord Mayor Shoal to Pitt Shoals. Bathymetry data was acquired using a Kongsberg EM2040 MKII, and processed using CARIS HIPS and SIPS processing software. The dataset was then exported as a 30m resolution, 32 bit floating point GeoTIFF grid of the survey area.</div><div>This dataset is not to be used for navigational purposes.</div>

<div>The Howard Channel&nbsp;bathymetry survey was acquired for the Australian Hydrographic Office (AHO) during the period 9 Aug 2023 – 13 Sep 2023. This was a contracted survey conducted for the Australian Hydrographic Office by EGS Australia as part of the Hydroscheme Industry Partnership Program. The survey area encompasses an area in Howard Channel. Bathymetry data was acquired using a Kongsberg EM2040C, and processed using CARIS HIPS and SIPS, and QIMERA processing software. The dataset was then exported as a 30m resolution, 32 bit floating point GeoTIFF grid of the survey area.</div><div>This dataset is not to be used for navigational purposes.</div>

<div>The Torres Strait Reference Surfaces bathymetry survey was acquired for the Australian Hydrographic Office (AHO) on 12 Dec 2021. This surface was created from a contracted national reference survey between Goods Island and Goods Island cardinal mark, and Tuesday Island and the Herald Patches QLD, collected for the purpose of calibrating multibeam echosounders.&nbsp;It was conducted for the Australian Hydrographic Office as part of the Hydroscheme Industry Partnership Program, acquired using Kongsberg EM2040D, and processed using QPS Qimera. Seperate grids in 0.5m resolution are provided for the two surveyed sites within this survey area in MSL, LAT and Ellipsoid vertical datum. The dataset was then exported as a 0.5m resolution, 32 bit floating point GeoTIFF grid of the survey area.</div><div>This dataset is not to be used for navigational purposes.</div>

<div>The Zeehan and Franklin Marine Parks, West Coast Tasmania&nbsp;Bathymetry Acquisition was acquired by CSIRO onboard the TV Bluefin between 22 Feb 2022 and 21 Mar 2022, using a Kongsberg EM2040C. This was a contracted survey conducted for the Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, to conduct a multibeam survey encompasing the Zeehan and Franklin Marine Parks for Parks Australia. Bathymetry data was processed using QPS Qimera and Caris Hips & Sips processing software. The dataset was then exported as a 2m resolution, 32 bit floating point GeoTIFF grid of the survey area. A detailed report on the survey is provided in: Hydrographic Survey of Zeehan and Franklin Marine Parks, West Coast Tasmania (https://figshare.utas.edu.au/articles/report/Hydrographic_Survey_of_Zeehan_and_Franklin_Marine_Parks_West_Coast_Tasmania/23171318).</div><div>This dataset is not to be used for navigational purposes.</div>

<div>The Rottnest Reference Surface was created from a bathymetry survey acquired for the Australian Hydrographic Office (AHO) on 11 December 2022. This surface was created from a contracted national reference survey adjacent to Rottnest Island, WA, collected for the purpose of calibrating multibeam echosounders. It was conducted for the Australian Hydrographic Office as part of the Hydroscheme Industry Partnership Program, using a Kongsberg EM2040P and processed using Caris HIPS & SIPS. Separate grids in 0.5m and 2m resolution are provided for the two surveyed sites within this survey area in MSL, LAT and Ellipsoid vertical datums. The datasets were exported as 0.5m and 2m resolution, 32-bit floating point GeoTIFF grids.</div><br><div>This dataset is not to be used for navigational purposes.</div>

This is a subset of Geoscience Australia's Marine Connectivity Database (<a href="https://pid.geoscience.gov.au/dataset/ga/82692">here</a>), covering the North-west marine planning region for initial releases taking place in the interval January-March 2010. The subset is intended for use in development and testing as part of the GovHack 2016 competition.

A new methodology is proposed to estimate storm demand and dune recession by clustered and non-clustered events, to determine if the morphological response to storm clusters results in greater beach erosion than that from individual storms that have the same average recurrence interval (ARI) or return period. The method is tested using a numerical morphodynamic model that combines both cross-shore and longshore beach profile evolution processes, forced by a 2D wave transformation model, and is applied as an example within a 20 km long coastal cell at an erosion hotspot at Old Bar, NSW mid-north coast, Australia. Wave and water level data hindcast in previous modelling (Davies et al., 2017) were used to provide two thousand different synthetic wave and tide records of 100 years duration for input to a nested nearshore 2D SWAN model that provides wave conditions at the 12 m depth contour. An open-source shoreline evolution model was used with these wave conditions to model cross-shore and longshore beach profile evolution, and was calibrated and verified against long-term dune recession observations. After a 50 year model spin up, 50 years of storm demand (change in sub-aerial beach volume) and dune toe position were simulated and ranked to form natural estimators for the 50, 25, 16, 12.5 and 10 year return period of individual events, together with confidence limits. The storm demand analysis was then repeated to find the return period of clustered and non-clustered morphological events. Morphological clusters are defined here by considering the response of the beach, rather than the forcing, with a sensitivity analysis of the influence of different recovery thresholds between storms also investigated. The new analysis approach provides storm demand versus return period curves for the combined population of clustered and non-clustered events, as well as a curve for the total population of individual events. In this approach, non-clustered events can be interpreted as the response to isolated storms. For clustered and non-clustered morphological events the expected storm demand for a 50-year return period is approximately 25% greater than that for individual events. Alternatively, for clustered and non-clustered events the magnitude of the storm demand that occurs at a return period of 17 years is the same as that which occurs at a return period of 50 years for individual events. However, further analysis shows that for a 50-year return period, the expected storm demand for the population of non-clustered events is similar to that of the clustered events, although the size of the population of the latter is much greater. Hence, isolated storms can generate the same storm demand as storm clusters, but there is a much higher probability that a given storm demand is generated by a morphologically clustered event. Appeared online in Coastal Engineering Volume 168, September 2021.