Wednesday, June 26, 2013

Geomorphology Cruise aboard the RV Weatherbird II

This 10-day cruise has the objective of surveying the geomorphology and benthic habitats of the northern rim of DeSoto Canyon and collecting water samples to filter for pelagic foraminifra. Co-Chief Scientist Dr. Stan Locker will be using side-scan sonar instruments to map the acoustic texture of the sea bottom. Co-Chief Ian MacDonald will be using the MILET benthic imaging platform to extend and ground-truth the side scan tracks with photographic sampling of the seafloor and acoustic measurement of the subbottom profiles. 

The science team members come from University of South Florida, Florida State University, and Valdosta State University: 
  1. Stan Locker, USF, Chief Scientist 
  2. Ian MacDonald, FSU, Co-Chief Scientist 
  3. Peter Lazaravich, FSU 
  4. Eric Howarth, FSU 
  5. Mauricio Silva, FSU 
  6. Anne Harvey, FSU 
  7. Samir Daneshgar, FSU 
  8. Dana Fields, FSU 
  9. Courtney Bryller, VSU 
  10. Charnelle Bland, VSU (Intern from Emory University)
  11. Chelsea Kuhs, USFSP 
  12. Leo Meirose, USFSP
In addition to the mapping activity, collecting water samples with the CTD rosette happens at every station. The CTD measures the temperature, salinity and depth of the water and the rosette of sampling bottles collects water at designated depths. 

Charnelle Bland and Courtney Kuhs from Valdosta State University
collect water from the rosette after a profile at the Mooring Site.

Success of the cruise depends on getting all the equipment to work correctly.  As is often the case, the team has to spend many hours coaxing complicated electronic equipment to function underwater. 
George and Chris from the Weatherbird II crew
lower a pole-mounted sonar into position.
Stan Locker is using his side scan sonar in two modes: as a pole mounted sensor for shallow depths and as in a towfish to access the deeper stations.  
Chief Scientist Stan Locker preparing his
sonar system for towfish deployment

The MILET (Modular Instrument Lander and Equipment Toolsled) will collect data from the deepest stations.  Initially, MILET has trouble communicating through the fiber optic cable that transmits its images and measurements back to the surface.  The FSU team spends the better part of two days disassembling and troubleshooting before locating the problem — a faulty cable, which was brand new for the cruise!

Ian MacDonald working on the MILET benthic imaging platform.
With all  the equipment working, the long hours of survey can begin.  The teams trade watches recording the data files and keeping the RV Weatherbird II on track by radioing instructions to the bridge.

Samira Daneshgar and Leo Meirose, with Stan Locker in the background,
are standing watch during a sidescan sonar survey of the mooring site.

Post Author:

Ian MacDonald,
Florida State University

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