Saturday, September 22, 2012

Deep-C Geomorphology/Benthic Studies Cruise - Fall 2012

Ship’s Blog: Weatherbird II (WB1305)
22 September 2012
RV Weatherbird II

We departed the Florida Institute of Oceanography dock at University of South Florida at 08:30.  We are a research team from the Earth, Ocean, and Atmospheric Sciences Dept, The Florida State University (FSU) and from the Department of Biology, Georgia Institute of Technology participating in the DEEP-C project.  Our objectives are to complete photo surveys of the Deep-C project's DeSoto Canyon study sites and to collect water column profiles, water sampling, and sediment sampling at selected sites.    

These are the members of our team:
  • Ian MacDonald, chief scientist
  • Eric Howarth, technician for benthic photographic surveys
  • Peter Lazaravich, technician for navigation
  • Samantha Bosman, technician for geochemistry
  • Samira Daneshgar-Asl, PhD student for physical oceanography
  • Mau Silva, PhD student for benthic biology
  • Arvid Shamtharam, PhD student for benthic biology
  • Nikki Morgan, MS student for benthic biology
  • Chrissy Rakowski, MS student for microbiology
  • Chris Malinowski, MS student for fish ecology
  • Patrick Chanton, MS student for microbiology and geochemistry
In the days ahead, this blog will document our work and give brief descriptions of our most immediate findings.  The Google Earth display of our progress will show our track made good as a heavy line and the planned track with sampling sites has thin lines.  By clicking on a site, you can see the official name of each site (e.g AC-1).  

Arvid Shamtharam, Samantha
Bosman, and Nikki Morgan
examine practice cores
from the multiple corer.
After leaving the dock, we were given a briefing by Capt. Matt White on shipboard safety and conducted a fire drill.  It will take over 30 hours to motor to our main sampling area in DeSoto Canyon. On this first day, we motored to locations in shallow water (Sites 1 & 2) to practice our instrument deployments and make sure all our equipment was in working order.  We practiced deploying and recovering the multiple corer that will be used for sediment collections and went over the procedures for removing the samples from each core.  

We also launched and recovered the CTD-rosette.  This instrument records the water temperature, salinity, and other ocean variables in a profile of values from the surface to the  bottom.  Our site was only 30 m deep, but when we get to DeSoto Canyon, we will be taking profiles at depths of 500 to  2500 m. 
Chrissy Rakowski and the MILET camera system.
The Modular Instrument Lander and Equipment Toolsled (MILET) is a system developed at FSU for studying the ocean bottom with video, high-resolution digital images, and subbottom profiling.  For this  cruise, we will  only be using the video and digital cameras.  MILET was launched in 33 m of water for  a quick  check of the systems.  

Our coring and photographic transects will be collected with equipment deployed over cables that can be up to 2.5 km long.  At those distances, the bottom location can be quite different from the ship position.  So for precise navigation, we use a Ultra Short BaseLine system (USBL).  This device uses a sensitive hydrophone attached to the ship by a long pole that is lowered over the side.  The hydrophone detected pulses from an acoustic pinger mounted on the equipment we are tracking.  Our final operation before getting underway for DeSoto Canyon was to calibrate the USBL hydrophone pole and pinger.

Arvid Shamtharam and Patrick Chapman recover the multiple corer.

A curious remora chases the lights of the
MILET system during a test in 30 m water depth.

Eric Howarth, Peter Lazaravich, and
second engineer George position the hydrophone pole.

Samira Daneshgar-Asl taking notes.
We finished our operations at about 11pm and got underway for DeSoto Canyon.  We expect to  arrive about 11pm on 23 September.  The weather is good and all systems have checked out.  Stay tuned for more.

Post Author:
Dr. Ian MacDonald

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