Revelle: A Mooring Milestone

We hit a huge milestone on Monday: we dropped mooring number 15, the last of our planned long-term moorings, as the sun set over the Tasmanian Landscape. All of the ingredients of the moorings—40 oversized spools of cable, 15 giant orange buoys, 50 thousand pounds of anchors, clusters of spherical glass balls enclosed in oversized yellow “hard hats,” and hundreds of shackles and links—all neatly and deliberately arranged on the deck when we left port on January 9th have disappeared. Tonight the rear deck is clear of gear.

The team’s plan to deploy 15 moorings in 10 days was a lofty one. But our hard-working mooring crew, led by Gunnar Voet (UCSD) and Eric Boget (APL-UW) and including all of the remaining scientists, pulled it off (I even participated by raising and lowering the A-frame—our main hoist to lift the heaviest items off the back deck). We strategically plunged more than 20 miles of line, dotted with 400 instruments, within meters of their targets more than two miles beneath the ship. These are all carefully calculated points on the ocean floor where the signals are anticipated to be the clearest

Everyone is thrilled that phase one is complete! But this doesn’t mean that our work is done. Now we move into a new phase of our operation—executing process experiments with our instrument-laden CTD/LADCP system (see next post!) to elucidate the physics that causes the breaking of these huge undersea waves. First stop—“the bump,” a small hill 1.5 miles below us where we think the shoaling waves are first feeling the influence of the deep submarine slopes of Tasmania, the southernmost state of Australia and the last piece of Gondwanaland to break off of the Australian continent.

Stay tuned.

—Julia Calderone, The Revelle


The Tasman Tidal Dissipation Experiment//Supported by the National Science Foundation