Sub to make deep Caribbean dive

Sub to make deep Caribbean dive

Scientists are set to explore the world's deepest undersea volcanoes, which lie 6km down in the Caribbean.

Delving into uncharted waters to hunt for volcanic vents will be Autosub6000, Britain's new autonomously controlled, robot submarine.

Once found, the life, gas and sediment around the vents - the world's hottest - will be sampled and catalogued.

The research will be carried out by a British team aboard the UK's latest research ship, the James Cook.

"We are heading out on two expeditions, each close to a month long, to map the full length of the Cayman Trough," said team leader, Dr Jon Copley of the National Oceanography Centre in Southampton (NOCS).

Dr Copley explained that the Cayman Trough, which lies between Jamaica and the Cayman Islands, is a product of the Caribbean tectonic plate pulling away from the American plate.

"It is the world's deepest volcanic ridge and totally unexplored," the Southampton-based researcher told BBC News.

Along with Autosub6000, the researchers will also rely on Isis, the UK's deepest-diving, remotely operated vehicle to scan the deep.

Double Sub

First overboard will be Autosub6000, an unmanned undersea vehicle that can go down to 6,000m and carry out a dive without being controlled from the surface.

It will be tasked with finding the volcanic vents on the ocean floor.

The second submarine to take the plunge will be the Isis.

Isis will sample fluids and sediments from around the lip of the vents to test their geochemistry, and also collect animal specimens.

Britain's new robot sub will map the entire length of the Cayman Trough

"We are hoping to find several different types of vents along the ridge," said Dr Copley.

"Some of the vents will be very similar in depth to the vents we already know about, and because the conditions will be alike, we might expect very similar animals," he explained.

The researchers will look to compare the animals around the Cayman vents with those in the Atlantic and Pacific, in the hope of better understanding the processes that affect how deep-sea creatures "get about".

If the organisms in the Cayman Trough look like those from other deep volcanic trenches, it will suggest that ocean currents must play a role in shaping the patterns of deep-sea life by transporting the animals' larvae around.

However, if the Cayman Trough animals are very different from those existing in other parts of the Earth's oceans then isolation will be considered more important.

"The deep ocean is our planet's largest ecosystem. If we are going to use its resources responsibly then we need understand what determines its patterns of life," the Southampton-based researcher said.

New vents

Dr Copley told BBC News that there was also another kind of venting that was driven by a very different geological process in which the Earth's mantle is directly exposed to the water.

The researchers will explore vents looking for deep-sea animals

This type of volcanism has only ever been seen once before, in the mid-Atlantic.

The temperatures around these hydrothermal vents were so hot because they were so deep, Dr Copley said.

"They could be hotter than 500C (930F), and if they are that hot, they will probably have quite different chemistry and life forms - we expect to find new species."

The researchers expect that, at depths greater than 3,000m, one in every two animals they come across will be a species new to science.

WEATHER NOTE

Ocean observations reap climate science rewards

Long-term observations of the oceans around Australia are providing the nation’s climate scientists with significant benchmarks for seasonal forecasts and monitoring future climate change.

15 December 2008

Initiated near the end of a two-year El Niño event in May 1983, the program involves the deployment of simple ‘expendable instruments’ (XBTs) from commercial shipping that measure temperature and currents to a depth of 800m along routes in the Indian, Pacific and Southern Oceans.

“There is so much ocean around Australia influencing our daily weather and longer term climate that it made sense to begin a record from which we could connect ocean change to shifts in rainfall patterns across southern Australia,” says Dr Gary Meyers who, with colleagues at CSIRO, the Bureau of Meteorology (BoM) and the Scripps Institute of Oceanography in the US, established the ocean monitoring system.

“The 1982/83 El Niño came as a big surprise when we saw all kinds of changes around Australia but didn’t understand them. Now these ocean temperature data contribute to the BoM’s routine seasonal climate forecast.”

At 25 years the system stands as one of the longest sustained ocean observing networks in the world, and is a rare long-term record of ocean change in the huge and poorly monitored Southern Hemisphere ocean domain.

Based on the records, CSIRO’s Dr Susan Wijffels and co-authors will publish a landmark paper on the mean currents flowing between Australia and Indonesia in the Journal of Physical Oceanography. These currents form a critical ocean interconnection – the so-called Indonesian Throughflow – in the distribution of heat in the global climate system.

“Today, we have over 60,000 measurements of temperature around Australia that scientists regularly use to assess past long-term trends – test models used to predict future climate or forecast ocean behaviour,” says Dr Meyers, who leads Australia’s Integrated Marine Observing System (IMOS). “More than 50 scientific publications and books have been published using the Australian data.”

MARITIME NOTE

USCG – Marine Safety Performance

The US Coast Guard released its Marine Safety Performance Plan for FY 2009-2014.

The plan addresses the goals of: (1) reducing the risk of marine casualties; (2) facilitating commerce; (3) improving program processes and management; and (4) improving human resource capabilities. The Marine Safety Program pursues these goals through a multi-faceted approach that includes standards development; mariner credentialing; compliance enforcement; investigations and casualty analysis; industry and public outreach; and international engagement.

The Plan is a living document and may be changed in the future to reflect the results of a currently-ongoing independent evaluation of the Marine Safety mission, scheduled for completion in March 2009. Comments on the Plan are also solicited from the regulated community and other stakeholders.

(Source: Holland & Knight)