Text: Bénédicte Ferré
One of our operations was to deploy two piezometers in order to monitor the pore pressure within the sediment near the seeps, an operation lead by Thibaut Barreyre at UiB. We used a huge 4-tons rig to deploy this thin 3-m long equipment. The operation requires the ROV to detach the weights from the rig that releases the piezometer onto the sediment, and once the rig is lifted back up from the ship, the ROV installs the datalogger that will keep collecting data for 511 days. The data will then be analyzed and used to unravel the subseafloor permeability, to ultimately constrain how much methane is released from the seabed to the overlying ocean.
And sometimes sciences means improvising, here is how we clean dirty piezometers at a 250m deep site… and it worked!
Rig used to deploy the piezometers.
The ROV releases the weights so the standpipe penetrates the sediment.
The ROV has installed the datalogger on the standpipe.
This is not rocket science, but it does the job.
