Launching the CTD

Supplementary Research voyage details

This page details currently available opportunities for Supplementary applications on Research and Transit voyages in the 2019-20 voyage schedule.

Below are brief descriptions of the Research voyages relevant to this call for Supplementary applications, which will enable applicants to assess the suitability of their proposal.

 

IN2019_V04 - Dr Joanne Whittaker (Cairns to Brisbane)

One of the world’s most extensive intraplate volcanic regions is located in Eastern Australia, including the world’s longest continental hotspot trail and two parallel trails offshore (Tasmantid and Lord Howe Seamount chains). Hotspot trails are thought to arise from deep mantle plumes, whose episodic eruptions have caused environmental crises affecting the world’s atmosphere (release of gas and aerosols), biosphere (mass extinctions) and hydrosphere (altering ocean circulation and chemistry). These trails have also proved a powerful tool in constraining the past motions of tectonic plates, and how plate motions change in response to geodynamic reorganisations.

We will use this offshore region as a natural laboratory to test competing hypotheses for how deep mantle plumes have influenced the evolution of the Australian plate. Using a combination of geophysical characterisation and geological sampling, we will determine the spatial and temporal extent of mantle plume activity in the Tasman and Coral Seas to test the following hypotheses:

  1. The Louisiade Plateau is the birthplace of Eastern Australian intraplate volcanism and predominantly composed of volcanic material.
  2. This volcanism formed within a short (1-2 Ma) timeframe shortly before the oldest Tasmantid seamounts.
  3. The initiation of plume activity predates a major plate-mantle reorganisation affecting the southwest Pacific, and plume products provide a detailed record of Australian plate motion before, during, and after this reorganisation.
  4. Fragments of rifted continental crust underlie the volcanic carapace.

Identifying the sites of mantle plume eruptions allows us to make connections between the surface and deep Earth with global scientific significance for understanding our planet’s geodynamic and climatic history and biotic evolution. The results from this project will help inform government and industry on the effect of magmatism on distal continental margins and basins, and help constrain the extent of Australian continental crust into the Coral Sea.

Map of proposed voyage track

 Whittaker voyage track

IN2019_V05 – Dr Bernadette Sloyan (Brisbane to Brisbane)

The East Australian Current (EAC) is the complex and highly energetic western boundary current of the South Pacific Ocean.  This voyage will retrieve and redeploy an array of full-depth current meter and property (temperature, salinity and pressure) moorings from the continental slope to the abyssal ocean off Brisbane (27oS).   At this location the EAC, north of the high eddy variability, is approaching its maximum strength and its flow is relatively uniform and coherent. The aim of this observing system is to capture the mean and time-varying flow of the EAC.

Mass, heat and salt transports within boundary currents are of leading importance in basin-scale ocean budgets, yet direct observations of these transports have not been sustained to the extent required to fully complement observations within the ocean interior. In large part, this is due to the particular challenges of maintaining observing networks within energetic regimes, and capturing the significantly shorter time and space scales of variability there. 

The long-term monitoring of boundary currents, at key locations, will provide a comprehensive reference data set that will: measure mass, heat and salt transport; improve our understanding of the relationship of boundary currents and the basin-scale gyre forcing and; determine the impact of the boundary current variability on the coastal circulation and marine ecosystem. The observations will also be used to assess the simulation of boundary currents in various climate and ocean models. The continued monitoring of boundary currents is central to our understanding of how climate signals are communicated through the ocean.

Map of proposed voyage track

Sloyan voyage track

IN2020_V01 – Prof Mike Coffin (Fremantle to Fremantle)

The complex evolution of the Indian Ocean, which began forming more than 150 million years ago, has featured isolation of numerous continental fragments by jumps of seafloor spreading ridges, formation of multiple oceanic plateaus by hotspot/mantle plume magmatism, and many changes in tectonic plate configurations. Between ~120 and ~95 million years ago magmatic processes formed the massive, then-contiguous Kerguelen Plateau and Broken Ridge, which incorporated some continental fragments. Initiation of seafloor spreading along the Southeast Indian Ridge ~45 million years ago separated the enormous original feature into the Kerguelen Plateau and Broken Ridge. Extending southeast from the Central Kerguelen Plateau, William’s Ridge is a prominent 500-km-long spur that probably nearly completely separated from the Kerguelen Plateau during the initial stages of rifting.

Through acquisition, analysis, and interpretation of new geophysical data and geological samples from William’s Ridge, as well as the portion of Broken Ridge that once abutted William’s Ridge, we aim to determine the origin and evolution of William’s Ridge. The data will reveal the nature of the crust (continental, hotspot-related, oceanic, or hybrid), and the tectonic evolution of the region in relation to voluminous magmatism associated with hotspot/mantle plume activity and changing tectonic plate configurations. These results will, in turn, help elucidate the underlying geodynamic processes responsible for hotspots/mantle plumes and changes in plate configuration, and the formation of microcontinents.

Additionally, testing current hypotheses for formation of William’s Ridge through partial separation from the Kerguelen Plateau in Cretaceous time due to a complex breakup history provides the required framework for successful formulation of a renewed submission to the United Nations Commission on the Limits of the Continental Shelf (CLCS) for inclusion of William’s Ridge into Australia’s Extended Continental Shelf (ECS). Success of the submission will result in Australia gaining the significant territory of William’s Ridge and surrounding areas.

Map of proposed voyage track 

Coffin voyage track

IN2020_V02 – Prof Tom Trull (Hobart to Hobart)

This proposal requests voyages in March-May 2018, 2019, and 2020 to service automated moorings that form the Southern Ocean Time Series (SOTS) facility of the Integrated Marine Observing System, located in the Subantarctic Zone southwest of Tasmania near 47ºS, 141ºE.

Obtaining sustained observations at SOTS is motivated by recognition that the Southern Ocean has a predominant role in the movement of heat and carbon into the ocean interior – thereby moderating Earth’s average surface climate, it’s variability, and rate of change.  SOTS measures these processes under extreme conditions, where they are most intense and have been least studied.  The atmosphere-ocean exchanges occur on many timescales, related to diel insolation cycles, weather events in the atmosphere, the evolution of eddies in the ocean, and seasonal and interannual dynamics.  The quantification of these effects requires sustained observations at hourly or higher frequency, and can only be achieved via automation.The two SOTS moorings measure specific aspects of the atmosphere-ocean exchanges:

  1. the FluxPulse mooring combines the previous Southern Ocean Flux Station and Pulse biogeochemistry mooring capabilities into one platform and focuses on heat, water, oxygen and CO2 fluxes across the air- ocean interface, and the physical conditions and biological processes that these transfers.
  2. the SAZ sediment trap mooring focuses on quantifying the transfer of carbon and other nutrients to the ocean interior by sinking particles.

The observations obtained by continuous automated sensors and sample collection the influence of all timescales on these processes to be measured.  This information is essential to the advancement of quantification and eventually prediction of the transfer of heat and CO2 from the atmosphere into the ocean which moderate climate, but drive changes in ocean ecosystems via warming, stratification, and ocean acidification.

Map of proposed voyage track 

Trull voyage track

IN2019_T02 - Transit voyage (Brisbane to Darwin)

IN2019_T03 - Transit voyage (Darwin to Fremantle)

 


Updated: 26 March 2018