Tsunamigenic submarine landslides and deep-marine canyons of Australia’s Tasman Sea margin

Voyage Number

IN2022_V05

Voyage Dates

28 May, 2022 to 03 Jul, 2022

Voyage Location

Hobart to Brisbane

Chief Scientist

A/Prof Thomas Hubble

Institution

University of Sydney

View the full voyage

Voyage summary

RV Investigator will undertake a research voyage to the Tasman Sea to investigate submarine landslides and the deep marine canyons along Australia's east coast.

The research will help identify the risks that locally generated tsunamis from submarine landslides can pose to communities along the coast and inform strategies to mitigate those risks. Research shows that submarine landslides have occurred along the east coast of Australia for about 15 million years and are expected to occur in the future with continued potential to generate tsunamis. 

The primary voyage objective is to investigate the marine geology and sample deep water features along Australia's east coast which have not previously been mapped in high detail. Some of the previous mapping for this research was completed during a voyage of RV Southern Surveyor in 2013. A secondary objective is to identify, map, and sample continental-shelf-edge features that may influence the movement of materials from the shelf.

There are two other projects on the voyage:

• Argo float deployments (Mr Craig Hanstein, CSIRO): Deployment of two standard Argo floats.
• Resurvey of MV Limerick (Dr Matt Carter, Major Projects Foundation): Updated bathymetric survey of the wreck of MV Limerick.

The science team on this voyage will have 32 participants representing 3 institutions (CSIRO, University of Sydney and University of Newcastle). There are 21 ship crew on this voyage.

COVID-19 Protocols

To safeguard the health and well-being of participants, strict COVID-19 protocols apply to all activities on this voyage. This includes 3-phase PCR testing of all participants for COVID-19 prior to departure and a 7-day quarantine on shore prior to boarding the vessel.

Voyage outcomes

The data acquired on this voyage improves our understanding of how the submarine landslide scars, and how canyons, located offshore from the south-eastern Australian coastline, formed and why they are in the places where they occur. Researchers mapped 44,250 square kilometres of the continental shelf, slope and abyssal plain off eastern Australia during the voyage, and collected sixteen dredge samples, ten kasten cores and six piston cores of sediments.

Preliminary analysis of the data and samples, to identify the characteristics of the deposits and the distances of sediment transport involved, suggest that submarine landslides more likely occurred as a series of progressive, incremental events and at lower speeds than suggested by earlier work. These findings give us a better understanding of the processes controlling the formation and geographical distribution of submarine landslides on the eastern Australian continental margin. In particular, researchers have identified that the sediment layer geometry and the structure of the geological basement are likely controlling factors on where submarine landslides have occurred.

These findings will be of interest to the international community of scientists who study submarine landslides as well as the government authorities who manage and coordinate disaster responses for coastal New South Wales and Queensland.