Please select your home edition
Edition
Zhik 2024 December

Eddies found to be deep, powerful modes of ocean transport

by Woods Hole Oceanographic Institution on 4 May 2011
Black smoke rises vigorously at vents when the hot, chemically-altered seawater mixes with the cold, oxygenated bottom water. The hydrothermal alterations to seawater occurring at these relatively isolated locations affect the global ocean chemical budget and sustain thriving and strange communities, including these giant tubeworms, Riftia pachyptila, and gastropod limpets grazing on their tubes Woods Hole Oceanographic Institution (WHOI) http://www.whoi.edu/
Researchers from Woods Hole Oceanographic Institution (WHOI) and their colleagues have discovered that massive, swirling ocean eddies - known to be up to 500 kilometers across at the surface--can reach all the way to the ocean bottom at mid-ocean ridges, some 2,500 meters deep, transporting tiny sea creatures, chemicals, and heat from hydrothermal vents over large distances.

The previously unknown deep-sea phenomenon, reported in the April 28 issue of the journal Science, helps explain how some larvae travel huge distances from one vent area to another, said Diane K. Adams, lead author at WHOI and now at the National Institutes of Health.

'We knew these eddies existed,' said Adams, a biologist. 'But nobody realized they can affect processes on the bottom of the ocean. Previous studies had looked at the upper ocean.'

Using deep-sea moorings, current meters and sediment traps over a six-month period, along with computer models, Adams and her colleagues studied the eddies at the underwater mountain range known as the East Pacific Rise. That site experienced a well-documented eruption in 2006 that led to a discovery reported last year that larvae from as far away as 350 km somehow traveled that distance to settle in the aftermath of the eruption.

The newly discovered depth of the powerful eddies helps explain that phenomenon but also opens up a host of other scientific possibilities in oceans around the world. 'This atmospherically generated mechanism is affecting the deep sea and how larvae, chemical and heat are transported over large distances,' Adams said.

The eddies are generated at the surface by atmospheric events, such as wind jets, which can be strengthened during an El Niño, and 'are known to have a strong influence on surface ocean dynamics and production,' say Adams and Dennis J. McGillicuddy from WHOI, along with colleagues from Florida State University, Lamont Doherty Earth Observatory, and the University of Brest in France. But this 'atmospheric forcing…is typically not considered in studies of the deep sea,' they report.

Moreover, the eddies appear to form seasonally, suggesting repeated interactions with undersea ridges such as the Eastern Pacific Rise. The models 'predict a train of eddies across the ocean,' Adams said. 'There may be two to three eddies per year at this location,' Adams said. Each one, she says, 'could connect the site of the eruption to other sites hundreds of miles away.' Elsewhere, she adds, 'there are numerous places around the globe where they could be interacting with the deep sea.'


In her 2010 report on larvae traveling great distances to settle at the eruption site, WHOI Senior Scientist Lauren S. Mullineaux , along with Adams and others, suggested the larvae traveled along something like an undersea superhighway, ocean-bottom 'jets' travelling up to 10 centimeters a second. But conceding that even those would not be enough to carry the larvae all that distance in such a short time, the researchers speculated that large eddies may be propelling the migrating larvae even faster.

Adams’s current work follows up on that possibility. 'The mechanism we found helps explain what we saw in the first paper,' Adams said.

It is the larger picture, over longer periods of time, however, that Adams and her colleagues find particularly intriguing. 'Transport [of ocean products] could occur wherever…eddies interact with ridges—including the Mid-Atlantic Ridge, the Southwest Indian Ridge, and the East Scotia Ridge—and the surrounding deep ocean,' the researchers say.

And because the eddies appear to form repeatedly, the high-speed, long-distance transport can last for months. 'Although the deep sea and hydrothermal vents in particular are often naively thought of as being isolated from the surface ocean and atmosphere, the interaction of the surface-generated eddies with the deep sea offers a conduit for seasonality and longer-period atmospheric phenomena to influence the ‘seasonless’ deep sea,' Adams and her colleagues write.

'Thus, although hydrothermal sources of heat, chemical and larval fluxes do not exhibit seasonality there is potential for long-distance transport and dispersal to have seasonal to interannual variability.'

The study was funded by the National Science Foundation, WHOI, and the U.S. Department of Defense.

Woods Hole Oceanographic Institution website

X-Yachts X4.3Hyde Sails 2024 - One DesignSea Sure 2025

Related Articles

Cape Horn Hall of Fame nominations close by 30 May
Public nominations open for just a little longer The International Association of Cape Horners (IACH) is calling for nominations for new inductees to the Cape Horn Hall of Fame.
Posted on 22 May
America's Cup: Emirates Team NZ respond
Emirates Team New Zealand has responded to the statements sent overnight (NZT) Emirates Team New Zealand has responded to the statements sent overnight by two Challenger teams calling for more transparency in the negotiations over the Protocol and venue for the 38th Match.
Posted on 22 May
World Foiling Congress 2025 concludes
Event attracted top industry leaders, experts, and stakeholders The second edition of the World Foiling Congress took place this week at Palazzo della Borsa in Genova (Italy), attracting top industry leaders, experts, and stakeholders from across the global Foiling Community.
Posted on 22 May
J/70 UK Grand Slam 2 at Royal Southern Yacht Club
7 races for the North Sails May Regatta Having suffered through some tough conditions in Grand Slam 1, the forecasts were looking hopeful for the second event of the UK J/70 Season. As we got closer to the event it was anyone's guess as to how the racing would pan out.
Posted on 22 May
6mR Worlds return to Seawanhaka Corinthian YC
Oyster Bay and Long Island Sound are renowned as some of the best sailing waters in the world Founded in 1871 and located on Oyster Bay, New York, SCYC is America's oldest yacht club and its association with the Sixes goes right back to the class's foundation in 1907.
Posted on 22 May
Steering the Course kicks off to #AccelerateAction
World Sailing's global women's sailing festival gets under way soon The 2025 edition of Steering the Course, World Sailing's global women's sailing festival, gets under way on 23 May with a week-long focus on #AccelerateAction in support of this year's International Women's Day theme.
Posted on 22 May
Solo McIntyre Mini Globe Race - 18,000 miles to go
Pirates, squalls, and paradise found The McIntyre Mini Globe Race fleet has officially fallen under the spell of the South Pacific—a place where dreams of palm-fringed beaches collide with the reality of torrential rain, viscous squalls, Loud lightening, questionable dinghy landings.
Posted on 22 May
Hyde Sails Flying Fifteen Video Tuning Guide
Ben McGrane explains how to get the most out of your B1 mainsail with B1 or 2H jibs Hyde Sails release new detailed video guide for tuning the Flying 15 for use with the B1 mainsail with B1 or 2H jibs.
Posted on 22 May
NYYC American Magic team statement
Concerns over transparency and cooperation necessary to secure a fair Protocol Over the past seven years, we've competed with pride, purpose, and perseverance in two editions of the America's Cup. It has been an honor to represent the New York Yacht Club and the United States on the global stage.
Posted on 22 May
Athena Racing concerned over 38th AC transparency
Around the recent announcement of a Host City for the Cup in 2027 Athena Racing, representing Royal Yacht Squadron Ltd. as Challenger of Record for the 38th America's Cup, is concerned by the ongoing lack of transparency around the recent announcement of a Host City for the Cup in 2027.
Posted on 22 May