The Australian Submarine Canyons service identifies the location of 753 submarine canyons surrounding mainland Australia and its external territories, with associated metrics.

The Australian Submarine Canyons service identifies the location of 753 submarine canyons surrounding mainland Australia and its external territories, with associated metrics.

The high frequency (10 min) and resolution (~2km) of Himawari-8 data provides an enormous opportunity for the monitoring and investigation of highly dynamic oceanographic phenomena. This presentation aims to demonstrate the value of himawari-8 SST data for studies of the Bonney Coast upwelling, East Australian Current (EAC) and Madden-Julian Oscillation (MJO) diurnal SST (dSST) variations. During the 2016–17 summer, we identified three distinct upwelling events along the Bonney Coast. Each event surpassed its predecessor in area of influence, minimum temperature and duration. The EAC’s mapped between July 2015 and Sept 2017 showed clear seasonal and intra-seasonal variations. During summer, the EAC and its extension frequently encroached into the coastal areas of northern NSW and eastern Tasmania. A composite analysis based on MJO phases during the summer seasons of 2015–16 and 2016–17 showed that the dSST typically peaked during phases 2 and 3 off the northwest shelf, prior to the onset of the active phases of MJO (phase 4). The analysis indicated that dSST is negatively correlated with the surface wind speed but positively correlated with short-wave latent heat flux. In future, these monitoring and analytical capabilities can be effectively implemented in Geoscience Australia’s Digital Earth Australia platform. Abstract submitted/presented to 2019 Australian Marine science Association AMSA Conference (https://www.amsa.asn.au/2019-fremantle)

This data represents the average time between events when the Shields parameter (Shields, 1936) exceeds 0.25 based on a Peaks-Over-Thresholds (POT) analysis. The Shields parameter (non-dimensional bed shear stress) value of 0.25 is assumed to be the threshold for creating disturbed patches. This value is several times larger than that required to initiate traction bedload transport (~0.05) and falls in the middle of the ripple and dune bedform stability field. It represents conditions when the seabed is highly mobile and where patches of disturbed habitat are likely to be created. The unit for the dataset is day. Shields, A. 1936. Application of similarity principles and turbulence research to bed-load movement. Mitteilunger der Preussischen Versuchsanstalt f'ur Wasserbau und Schiffbau 26: 5-24

The Australian Submarine Canyons service identifies the location of 753 submarine canyons surrounding mainland Australia and its external territories, with associated metrics.

<div>The development of Australia’s offshore renewable energy (ORE) industry can learn and benefit from decades of international experience and research. However, local knowledge of our unique receiving environment and the organisms that depend on it is critical for ensuring development minimises impacts on marine ecosystems. Long-term monitoring and adaptive management strategies that consistently evaluate and address environmental impacts of offshore wind farms will be necessary throughout the operational lifespan of ORE. This collaborative National Environmental Science Program project established an inventory of environmental and cultural data and best practice monitoring standards to support regulatory decision-making for ORE development for current proposed and declared areas: Hunter, Gippsland and Bass Strait, Illawarra, Southern Ocean and south-west Western Australia. We provide detail on 1) potential impacts of installation, operation, and decommissioning; 2) best practice standards for monitoring; 3) cultural and environmental values of Indigenous communities with links to development areas; 4) seabed geomorphology and habitat characterisation; potential interactions with oceanography and 5) the seasonality and distribution of interacting species. The inventory, which is available to the Government, proponents, and researchers, will improve the effectiveness of future research for the sustainable development of ORE in Australia. Presented at the 2024 AMSA-NZMSS Conference Hobart Tas

This data represents the integrated Shields (Shields, 1936) parameter exceeding 0.25 divided by the integrated total Shields parameter. The Shields parameter (non-dimensional bed shear stress) value of 0.25 is assumed to be the threshold for creating disturbed patches. This value is several times larger than that required to initiate traction bedload transport (~0.05) and falls in the middle of the ripple and dune bedform stability field. It represents conditions when the seabed is highly mobile and where patches of disturbed habitat are likely to be created. Shields, A. 1936. Application of similarity principles and turbulence research to bed-load movement. Mitteilunger der Preussischen Versuchsanstalt f¨ur Wasserbau und Schiffbau 26: 5-24

<b>This service with existing dataset is migrated to a new server and the existing links will expire by the end of this year (31-Dec-2024). The replacement service is located at https://services.ga.gov.au/gis/rest/services/DEM_SRTM_1Second_over_Bathymetry_Topography_2024/MapServer </b> The Australian Bathymetry and Topography web service includes the topography of Australia and the bathymetry of the adjoining Australian Exclusive Economic Zone. The area selected does not include data from Australia's marine jurisdiction offshore from the Territory of Heard and McDonald Islands and the Australian Antarctic Territory. The 2009 bathymetry data were compiled by Geoscience Australia from multibeam and single beam data, and along with the topography (onshore) data, was derived from multiple sources. As per the 2005 grid, the 0.0025 dd resolution is only supported where direct bathymetric observations are sufficiently dense (e.g. where swath bathymetry data or digitised chart data exist) (Webster and Petkovic, 2005). In areas where no sounding data are available (in waters off the Australian shelf), the grid is based on the 2 arc minute ETOPO (Smith and Sandwell, 1997) and 1 arc minute ETOPO (Amante and Eakins, 2008) satellite derived bathymetry. The topographic data (onshore data) is based on the revised Australian 0.0025dd topography grid (Geoscience Australia, 2008), the 0.0025dd New Zealand topography grid (Geographx, 2008) and the 90m SRTM DEM (Jarvis et al, 2008).

Dense water formed in the Mertz Polynya supplies the lower limb of the global overturning circulation and ventilates the abyssal Indian and Pacific Oceans. In February 2010, an 80 km section of the Mertz Glacier Tongue calved, altering the regional distribution of ice, and the polynya activity. After calving, the absolute salinity and density of dense shelf water decreased abruptly, and surface waters freshened by up to 1 g kg-1. Break-out and melt of thick multi-year sea ice, likely rich in iron, provided a favourable light and nutrient setting for a bloom of large diatoms, doubling carbon uptake relative to pre-calving conditions. These observations highlight the sensitivity of bottom water formation, biogeochemical cycles and biological productivity to changes in the Antarctic icescape.

This data represents a dimensionless ecological disturbance index, as the ratio of ecological succession and disturbance recurrence interval times the fraction of the area disturbed in any event. Small values of the ecological disturbance index represent decreasing proportions of time when disturbed/recovering habitats are present.