Engineering tests and bubble plume chases

August 15, 2011

ROPOS is launched with the BIA recovery frame attached to the undercarriage. The hinged floats in the foreground are clamped around ROPOS's tether to absorb any shock that travels down the tether from wave motion on the surface. (photo by Allison Fundis)

We have had quite a few sharks and mola mola visit the ship since we have been out at Southern Hydrate Ridge. Credit: Allison Fundis, University of Washington, V11.

Cody Turner, a UW undergraduate student, and Orest Kawka, OOI-RSN project scientist, deploy the CTD at Southern Hydrate Ridge August 14.

Monitoring the CTD data as the CTD is lowered almost 800 m down in the water column August 14. From left to right: Alden Denny (UW graduate student), Lexi Brewer and Cody Turner (UW undergraduate students), and Orest Kawka and Kendra Daly (OOI-RSN project scientists). (photo by Ed McNichol)

The UW Applied Physics Laboratory frame was deployed at Southern Hydrate Ridge for a year to test the weathering of an epoxy coating on the frame.

The UW-Applied Physics Laboratory's secondary node test frame after it was recovered from being deployed at Hydrate since last summer. (photo by Allison Fundis)

Today was a full day beginning with an early morning ROPOS dive for the second round of engineering tests of L3-MariPro’s OOI primary node, an EM302 survey over the future site of one of these nodes at Hydrate Ridge, and then another ROPOS dive to recover the secondary node test frame that was deployed during the ENLIGHTEN’10 expedition last year. This mock frame was deployed to test the various materials that will be used to construct the secondary nodes. Engineers from University of Washington’s Applied Physics Laboratory will assess how the epoxy coating placed on the frame (white portions) and the galvanized legs withstood the year of being left on the seafloor at Southern Hydrate Ridge.

In addition to recovering the secondary node test frame, we also searched out a methane bubble plume that was seen during the afternoon’s EM302 multibeam survey and was coincident with an eH anomaly during a survey last year with the autonomous underwater vehicle (AUV) Sentry. Unfortunately, we were unable to visually locate the source of the plume. We moved on to take five push-core samples for Evan Solomon to investigate the sediment porosity at the site of his instrument deployments.

Tomorrow we will be launching the ROV at 10:00 to obtain detailed imagery of the sites where instruments will be deployed on the OOI cabled observatory.