NEPTUNE Canada scientists and engineers are sailing again, aboard the R/V Thompson for 3 weeks. The cruise's dive plan is an ambitious one, with Endeavour being the focal point of repairs and new installations.
R/V Thompson at Esquimalt Graving Dock, 10 September 2011.
A new cable into Main Endeavour vent field (MEF) will be installed (the old cable one stopped working last October and had to be chopped up and retrieved by ROPOS during our July cruise). Once reconnected, our MEF instruments (COVIS, RAS water sampler, short-period seismometer) can be reactivated and new instruments installed. These will include Tempo-mini and benthic and resistivity sensors (BARS), which had its connector cable fried by molten lava.
Tempo-mini, designed and developed by our French collaborators IFREMER, is a unique instrument platform, which integrates a video camera, oxygen sensor, dissolved iron sensor and temperature probes in one compact platform. We're eager to install Tempo-mini, after a series of delays.
Tempo mini, September 2011.
A new cable will connect Endeavour node to the dynamic Mothra hydrothermal vent field, where we hope to deploy a second BARS and a short-period seismometer (SPS).
If the weather gods smile on us, new Regional Circular Moorings (RCMs) will be deployed. The first mooring was successfully installed last year with the assistance of the CCGS John P. Tully; however, due to scheduling conflicts this year's deployment of the RCMs will be attempted by the R/V Thompson alone. This complex and risky procedure will therefore likely be a slower process than previous RCM deployments and is further complicated by being highly dependent on good weather and very calm seas.
Our plans call for replacement of the northeast RCM and installation of two more at the northwest and southwest corners of the mooring "box" we intend to build around Endeavour ridge. Each of these moorings includes three different types of instruments affixed at varying depths along a cable extending upward from the seafloor. The uppermost instrument is an Acoustic Doppler Current Profiler (ADCP) which is able to estimate currents up to 800m above the sea floor. Below this are four instrument pairs positioned at different locations down the mooring line. Each pair includes a Conductivity Temperature and Depth (CTD) sensor and an Acoustic Current Meter (ACM). Working together, these instruments measure deep-sea current velocity in three-dimensions as well temperature and salinity of the water. The top of the mooring line is kept vertical at all times by a large buoy while the base of the RCM is anchored to the sea floor by a 650kg weight.
If all goes well, we also hope to install a short-period seismometer at Endeavour node.
Pacific Geosciences Centre technician Bob Meldrum (left) describes short-period seismometer preparations to NEPTUNE Canada contractor Kim Wallace, 6 September 2011.
A stop at ODP 1027 will be made to install three bottom pressure recorders (BPRs) for the "Tsunami-meter" experiment. While these instruments will not be connected to the network until 2012, they will be recording data autonomously. They will be deployed to new sites, 25km distant from the central node, which will help scientists improve their ability to detect and model tsunamis in the northeast Pacific.
We also hope to diagnose and repair a problem with our piezometer, installed during the July 2011 cruise.
Wally the Crawler made it back just in time from Germany where the team at Jacob's University Bremen and the Max Planck Institute for Marine Microbiology worked feverishly to get him ready for his next adventure in Barkley Canyon. This time, Wally is equipped with a webcam, a sediment micro-profiler, methane sensor, current meter, fluorometer, turbidity sensor and a CTD device.
NEPTUNE Canada instrument manager Reece Hasanen with Wally II, September 2011.
Additionally, Barkley Benthic Pod 3 will be retrieved, refitted with a new Kongsberg sonar and redeployed. Collection bottles on the sediment trap will be swapped out and a new stand-alone video camera system will also be connected to Pod 3.
The new HD camera slated for Barkley Benthic Pod 3.
On such a tight schedule, hopefully there will be time to revisit ODP 889 and install a refurbished Imagenex multibeam sonar (a.k.a. "Kraki"), which will hopefully be used to observe methane bubble plumes. We then need to retrieve the seismometer auxiliary platform, which developed a ground fault and was disconnected earlier this month. We also hope there will be time to download the data from the IODP Circulation Obviation Retrofit Kit (CORK) 1364A to be sure the CORK is healthy and our work last cruise was successful.
DMAS (Data Management and Archive System) has been preparing for the cruise since the end of July! They have tested approximately 60 instruments for the upcoming cruise. Each instrument had to be put through an extensive testing procedure. The testing procedures include:
- Preparing meta-data
- Prepare the correct parameters for the instruments
- Retrieve raw data
- Pair and calibrate the raw data to be readable by people rather than just computers
- Prepare a camera control page for camera users to operate the device
- Prepare a final data product in order to allow a user to search and download data
NEPTUNE Canada quality assurance specialist Daisy Qi meets with DMAS staff during final preparations for the cruise.
DMAS, NEPTUNE Canada scientists and engineers have been working tirelessly to ensure that the cruise has an excellent chance of success. Hopefully, the weather will be on our side as well.