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Project details
| Title: | Tritium/Helium Measurements |
| Id: | 2523 |
| Investigator(s): | Stephanie Downes
University of Tasmania - Institute of Marine and Antarctic Studies [details] |
| Description: | The scientific objective of this work is to obtain Tritium/Helium measurements in the Antarctic Circumpolar Current. Helium is an inert gas naturally released at hydrothermal vents, and (as a passive tracer) is commonly used to trace deep ocean circulation. Recently, hydrothermal vents and plumes have been identified along the Australian-Antarctic Ridge and Pacific-Antarctic Ridge using observations of temperature, helium and other tracers. Only one voyage to date has been undertaken with ocean surface to floor data south of the Pacific Antarctic Ridge along 170oW (67oS to the Equator; 1996). However, helium data was not collected during this voyage. The new helium dataset acquired on this voyage, will be used to fulfil the following main objectives are: •Provide new evidence of hydrothermal activity along the western end of the Pacific Ridge, including a possible description of plume dispersion along the ocean’s strongest current, Antarctic Circumpolar Current. •Assess interconnectivity of hydrothermal systems between the Australian-Antarctic Ridge and Pacific Antarctic Ridge. •Provide new descriptions of water mass pathways and exchange within and between the Antarctic Circumpolar Current and the Ross Gyre. |
| Years: | 2016 |
List of surveys that this project was on.
Use [details] link to view survey details (map, reports, metadata etc) including links to download data.
| Survey | Investigator | Description |
|---|---|---|
| IN2016_V03 [details] |
B. Sloyan (CSIRO, O&A) | RV Investigator research voyage in2016_v03. Titled Monitoring Ocean Change and Variability along 170oW from the ice edge to the equator This voyage involves two legs from Hobart to Wellington(NZ) and Wellington(NZ) to Lautoka(Fiji). Voyage objectives of the major project - Monitoring Ocean Change and Variability along 170oW from the ice edge to the equator are: The primary voyage objective is to obtain repeat occupations of the 155 full-depth CTD and Niskin casts along the GO-SHIP P15S section, with chemistry performed on water collected at 36 bottle levels. We will measure temperature, salinity, pressure, oxygen, fluorometry, shear and micro-scale temperature continuously, and the major nutrients, oxygen, salinity, CFC and carbon components discretely via chemical analysis on board. Small amounts of material will be filtered and stored for genomic analyses back on land. CSIRO has completed this line twice before and international groups have completed similar work along lines further east. The work plan and timings are based on these past voyages. Argo float deployments will also be carried out - usually when just leaving a CTD station (SOCCOM floats) or during transit (we may slow the ship speed slightly). These will be over the ship's stern (preferred). Voyage objectives of the supplementary project -Facing the challenges of under-ice for autonomous navigation are: Accurate navigation under both drift and stationary ice is one of the key unanswered questions in polar marine science and engineering. The primary aims of this project are to (1) estimate INS drift and calibration times; and, (2) test the integration of acoustic positioning methods in an INS within a drifting and rotating frame of reference. This project will develop error propagation models at increasing latitudes and test the use of a non-stationary, ship borne acoustic positioning network on a small (<3 m) AUV. Both are critical for robust, accurate and reliable AUV operation under-ice. The primary voyage objective is make measurements of inertial drift during vessel transit and calibration time while the Investigator is on station across as broad a range of latitudes as possible. The way that this will be achieved is that, while the vessel is on station, bench top tests will be conducted for alignment. Then, while moving, tests of inertial drift will be conducted. The student on board will work with the other PIs on board to coordinate timings of these tests but will not disrupt the other work taking place on board. The work plan and timing is based on methodologies established during past voyages. Full details can be found in the in2016_v03 voyage plan. Previous MNF voyages include RV Franklin FR 05/2001 and RV Southern Surveyor SS200901. |