First Live Data From the Seafloor

Saturday, July 13, 2013
FIrst Pressure Data off of the Cabled Observatory
Powering up the Junction Box

The medium powered Junction Box (MJ01A) is connected to > 1800 feet of extension cable deployed by ROPOS on the seafloor at the base of Axial Seamount. A pressure sensor inside the node is awaiting deployment for follow-on testing.

Photo credit: NSF-OOI/UW/CSSF

ROPOS Providing Power and Communications

View of the front porch of ROPOS showing a connection from the RSN Interface Box on ROPOS to an extension cable that is 1800 feet in length connected to a Secondary Junction Box (another power and communications outlet on the seafloor). The connector with the orange handle is "wet-mateable", meaning that it can be unplugged and plugged in on the seafloor.  When disconnected, it is placed in a parking position to keep the connectors clean and safe (stand with red handle to the right).


Photo credit: NSF-OOI/UW/CSSF


With the first live streaming of data received from the seafloor, last night was an historic moment for the Regional Scale Nodes OOI-NSF cabled observatory project. It is difficult to convey what an amazing engineering-science accomplishment this event was. But what an exciting several hours for the team both on the ship and onshore! The path to obtaining real-time streaming data included:

1) The robotic vehicle ROPOS at > 8000 ft beneath the ship with power and communications provided by the fiber-optic tether on the vehicle;
2) A testing interface box on the vehicle with a wet-mateable connector that provided communications and power to an extension cable on the seafloor;
3) Connection of a wet-mateable cable on the test box on ROPOS to the 1600 feet of extension cable that had been previously laid on the seafloor and plugged into a secondary junction box that provides power and communication to sensors; and
4) Connection of the secondary junction box to a pressure sensor on the seafloor and a current meter within the node.

It was tense as the commands by the engineers were sent to the junction box, telling it to power up and begin "talking" back to us from >8000 feet below. Cheers and a few happy dances ensued as the first data were received. For ~ 3 hrs hours data streamed live to the ship with the seafloor system powered by ROPOS. Then the command was given to end the test and for ROPOS to surface --- now we are off to install another cable on the summit of Axial Volcano.

Almost immediately after the pressure data were collected onboard the R/V Thompson, University of Washington graduate student Owen Coyle wrote code to convert the streamed data into scientific values, resulting in the pressure-time plot above. Long-term pressure measurements on the seafloor are important because they can be used to monitor tsunami events and can help inform us about the impact of lunar tides on earthquakes within the volcano and on venting of hotspring fluids from the seafloor.