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Two Toronto Touchdowns

Much to the delight of all involved, two experiments, designed and developed by researchers at the University of Toronto, were deployed at ODP 889 during the waning hours of our installation cruise. They are the Sea Floor Compliance (SFC) and the Controlled-Source Electro-Magnetic (CSEM) experiments (learn more).

Both deployments occurred in a sudden burst of activity. A lucky weather window allowed a last-minute flurry of 4 dives to troubleshoot a connection problem, install a broadband seismometer, lay the CSEM receiver string and finally connect the CSEM and SFC equipment to our network.

Sea Floor Compliance (SFC)

The SFC apparatus includes a differential pressure gauge and a gravimeter, which is sealed within a pressure-resistant metal sphere. The deployment method for this apparatus was unlike that for anything else we put into the water this cruise. It was fitted with a transponder, lifted over the water and dropped to free-fall 1259m from the surface to the seafloor.

Then ROPOS flew down to the seafloor with Mini-ROCLS, a pint-sized cable-laying system used for short cable deployments. After ROPOS located the SFC apparatus (pin-pointed by the ROPOS navigation system), cable was strung out and the apparatus connected to the ODP 889 instrument platform.

(Click the pictures to view slideshow.)

Controlled-Sources Electro-Magnetic (CSEM)

The CSEM deployment was more complicated than the SFC and involved two ROPOS dives and two equipment drops using the ship's winch. The man of the hour during all of this was University of Toronto doctoral candidate Reza Mir, who joined the installation cruise to help coordinate and oversee installation of both experiments.

The CSEM equipment consists of a transmitter, affixed to a small instrument platform, and a string of 5 receivers, spaced 200m apart along a 1km cable. The cable and receivers were spooled onto a drum, which was connected to ROCLS. Both of these payloads were lowered by winch to the seafloor.

(Click the pictures to view slideshow.)

Once the ROCLS spool and the transmitter platform were placed on the seafloor, ROPOS flew down, attached to ROCLS, laid the 1km reciever string and recovered ROCLS to the ship. In the following dive, ROPOS again located the transmitter platform, arranged two heavy dipoles on the seafloor nearby, connected it to the receiver string and connected the ODP 889 instrument platform to the CSEM platform.

(Click the pictures to view slideshow.)

Looking Forward

It remains to be seen how these two unusual experiments will perform, once powered up and running. Needless to say, we're all keeping our fingers crossed they will operate properly and provide valuable data to for researchers investigating the properties and evolution of gas hydrates outcrops.