The first dive was aborted — twice! Shortly after ROPOS entered the water the first time, the pilots noticed pressure drop quickly within the oil-filled tubes that house its electrical wires. This pressure drop was likely caused by air bubbles trapped somewhere in the system. They brought the ROV back to the ship, quickly bled the lines as best they could and re-deployed immediately.
During the second dive, pressure dropped again, but it occurred more gradually throughout the descent. By the time we reached bottom the pressure gauge read zero. It was decided to quickly drop off the new instrument platform (which was connected beneath the vehicle) and recover.
After recovery, ROPOS crew bled the lines again and prepared for a third dive. This time, ROPOS carried an auxiliary instrument platform to be connected to the broadband seismometer. This auxiliary platform holds a back-up battery to power the seismometer in event of a power outage. Additionally, it hosts a Nortek Aquadopp current meter and a differential pressure gauge. These instruments can be used to help seismologists detect and remove current, tides and wave signatures from seismic data.
During the lengthy dive that ensued, we unplugged the old ODP 889 instrument platform, plugged in the new one and installed the new seismometer auxiliary platform.
After recovery, we were happy to learn that NEPTUNE Canada systems successfully powered up and communicated with the junction box, seismometer, current meter and CSEM apparatus. Later tonight, they will do a more extensive test of the CSEM, working virtually with University of Toronto scientist Reza Mir, who is currently attending a conference in New Zealand!