The South China Sea (SCS) is the most important source of water vapor for the East Asian monsoon (EAM). Late Cenozoic (~34–30 Ma) opening of the SCS likely contributed significantly to the establishment of a strong, modern-like EAM at ~25 Ma per climate sensitivity studies. However, the importance of SCS tectonics in contributing to the evolution of the EAM has been neglected due to the temporal mismatch between both events (5–9 million years). Here, we investigate the bathymetric, sedimentary and oceanographic evolution of the SCS basin by combining Sr-Nd isotopic analyses of rift- to drift sediments from recent ocean drilling expeditions, high-resolution paleobathymetry reconstructions and ocean circulation simulations of this crucial time period. We show that the transition from fluvial, to shallow- and deep-marine environment in the SCS and its opening to the Pacific Ocean occurred well after the onset of seafloor spreading. We highlight a rapid (<1 myr), “flooding” event of Pacific bottom waters entering the young SCS through the narrow Luzon Strait between 25.5–24.5 Ma, coinciding with the strengthening EAM pattern. This shift is underscored by isotopic analysis of detrital fractions which suggest a change in provenance from local sources to inland China deserts and Loess signal shortly before ~25.5 Ma, likely transported as eolian dust by intensifying winter monsoon winds. Tectonic-driven rapid Pacific flooding likely increased the east-west humidity gradient between land and sea and contributed to the establishment of a modern-like, strong EAM at 25 Ma.

Time Series video to support Project C3 of the Marine Biodiversity Hub NESP programme. The video illustrates coastal change at the Murray Mouth and Lower Lakes, SA using 104 Landsat observations from within the Australian Geoscience Data Cube (AGDC) from 1988-2013.

Land features were derived by aggregating and dissolving the boundaries of the 1 degree S57 file (lndare_a layer) series for the Australian continent (+ Lord Howe Island). This represents land the area defined at Lowest Astronomical Tide (LAT) by the Australian Hydrographic Office. The Great Australian Bight was missing from this series, and was replaced by Geoscience Australia's 1:100k coastline. This data has been made available through the data collation process conducted by the NESP Marine Biodiversity Hub Project D3 (Reefs on the Australian Continental Shelf).

This resource includes bathymetry data for South-west Corner Marine Park collected by Geoscience Australia during the periods 9 – 12 March 2020 and 27 January – 16 February 2021 on the charter vessel Santosha. The survey was undertaken as a collaborative project with the University of Western Australia, the University of Tasmania and the Australian Centre for Field Robotics (University of Sydney), and funded through the National Environmental Science Program Marine Biodiversity Hub, with co-investment by all partners and the Director of National Parks. The purpose of the project was to build baseline information for benthic habitats on the continental shelf in the marine park that will support ongoing environmental monitoring within the South-West Marine Park Network as part of the 10-year management plan (2018-2028). Data acquisition for the project included multibeam bathymetry and backscatter for an area covering 330 km^2 (excluding transit) offshore from Cape Naturaliste to Cape Leeuwin coast, with underwater imagery of benthic communities and demersal fish collected by the University of Western Australia on separate field deployments. This bathymetry dataset contains a 5 m resolution 32-bit geotiff file of the survey area produced from the processed Kongsberg EM2040C multibeam sonar system using CARIS HIPS and SIPS software. For further information see: Giraldo-Ospina, A. et al., 2021. South-west Corner Marine Park Post Survey Report. Report to the National Environmental Science Program, Marine Biodiversity Hub.

Relevant spatial datasets for mapping pressures were identified and collated. Pressures were categorised as resource extraction and use, pollution, habitat modification, climate, and ‘other’. Pressures included Commonwealth trawl fisheries effort, aquaculture infrastructure, location of oil and gas infrastructure, historical shipping and pollution data, location of historical seismic operations, cyclone intensity, spoil dumping, sewage outfalls, location of ports, and tourism operations. Two main pressure maps were derived i) an additive pressure hotspots map, which gives higher weight to areas with multiple pressures of high risk; and, ii) a multiplicative hotspot pressure map, which gives lower weighting to areas with multiple low risk pressures. Areas of high risk were identified, and thus possibly high benefit for management versus low risk or low associated benefit for mitigation. The information generated needs to be considered alongside robust species distribution data and interaction matrices for effective decision-making.

Point data collected from video drops identifying benthic habitats such as seagrass, macroalgae and reef, collected during field work in 2007 to 2011. Used to support the Benthic Habitat Mapping project undertaken by DENR to map the nearshore benthic habitats of South Australia

Voyage IN2019_V04 contributed an additional 29,000 kms2 of seafloor survey data to the Coral Sea knowledge base. From this new bathymetric data individual seamounts have been extracted and have been classified to the Geoscience Australia Geomorphology Classification Scheme. This dataset contains two layers representing the classification layers- 1) Surface (Plain, Slope, Escarpment) and 2) fine scale Geomorphology of the seamount for the Cassowary Seamount. Ongoing research with this survey data will provide new insights into the detailed geomorphic shape and spatial relationships between adjacent seabed features. This information will be released in future publications to show the potential of how the scale of such seafloor data can be used for predictive habitat modelling when analysed with the biological data overlays.