Authors: Beaman, R.J.
Year: 2023
Publication: Recently discovered drowned reefs on the Queensland Plateau, Coral Sea Marine Park, Australia, AMSA 2023 Conference, 04 July 2023. Australian Marine Sciences Association (AMSA), Gold Coast Australia.
Abstract
In 2020/21, the Schmidt Ocean Institute’s RV Falkor and CSIRO’s Marine National Facility RV Investigator conducted multibeam mapping on the Queensland Plateau, within the Coral Sea Marine Park.
Through surveys around the steeper flanks of the 30 shallow reefs and banks, or transits between these reefs, 20 drowned reefs were discovered. Their heights range from ~100-600 m above the surrounding seafloor.
Their morphology tends to be cone-shaped with summits rising to a point. Their conical shape is due to coral growth progressively becoming more restricted in surface area within the photic zone as the plateau subsided over long geological time, until at last they became drowned.
These drowned reefs fall into two types: (1) pinnacles lying close to the edges of shallow reefs and emplaced on their steep flanks. Several of these are shallow enough to be a danger to surface navigation; and (2) isolated drowned reefs scattered across the deeper plateau surface.
None of these deeper drowned reefs pose a danger to surface navigation but are possibly a hazard to sub-surface navigation by submersibles.
Likely, there are more drowned reefs yet to be discovered on the Queensland Plateau, with implications for defence, shipping and fishing, management and marine habitats.