Seafloor Mapping Survey of South-east Tasmania and Macquarie Ridge

AUSTREA-2 Cruise Report details a 25-day seabed swath-mapping and geophysical survey conducted in January/February 2000 by the Australian Geological Survey Organisation (AGSO). The survey mapped approximately 140,000 km² of seabed over 10,200 km off south-east Tasmania and south of Macquarie Island. Data collection supported Australia's Continental Shelf definition under UNCLOS and marine zone planning.

Use Cases

• Analyze swath bathymetry and backscatter data to model seabed topography and identify features like slope canyons and seamounts.
• Use 6-channel GI-gun seismic and 3.5 kHz sub-bottom profiling data to investigate sub-surface geological structures and sediment layers.
• Correlate gravity and magnetic profile data with bathymetry to study the tectonic fabric of seafloor spreading regions.
• Integrate oceanographic data like seawater temperature, current, and salinity depth profiles with geophysical data for habitat or climate studies.
• Map the foot-of-slope position from bathymetric data to support legal Continental Shelf definition under the United Nations Convention on the Law of the Sea.

Strengths

• Mapped approximately 140,000 km² of seabed, providing broad spatial coverage.
• Collected multiple geophysical and oceanographic data types (bathymetry, seismic, sub-bottom, gravity, magnetic, temperature, salinity) for integrated analysis.
• Survey conducted over 25 days with generally excellent data quality due to favourable weather conditions.

Limitations

• Primary data formats are PDF and HTML reports, not raw, machine-readable data files.
• Dataset is from a single survey in early 2000, offering a historical snapshot but no temporal series.
• Specific row counts, sample sizes, and data precision metrics for individual measurements are not provided.

Provenance

Source

Australian Geological Survey Organisation (AGSO), now Geoscience Australia, via the Australian Ocean Data Network.

Collection Method

Ship-based survey using the N/O L'Atalante vessel, employing Simrad EM12D swath systems, GI-gun seismic, sub-bottom profilers, and oceanographic sensors.

Time Range

January to February 2000.

Freshness

Survey conducted in 2000; metadata last updated in 2026.

Geography

Waters off south and south-east Tasmania and south of Macquarie Island (Southern Macquarie Ridge Complex).