Atlantic, a vast ocean of a million stories

From The Telegraph

In 1903, from a windswept Cape Cod cliff, a Marconi station sent out the first radio message from one head of state to another as President Roosevelt and Edward VII congratulated one another on this remarkable advance.
That day, as Simon Winchester says: 'all the other present-day miracles of long-distance communication began their fantastic and improbably swift spasm of evolution’ (although he does not mention the fact that Guglielmo Marconi also believed his technology could pick up the voices of long-dead men who had drowned in the Atlantic).
Only 50 years before, America and Europe were irrevocably tethered by the first underwater telegraph cable, laid with great difficulty from Ireland to Newfoundland.
Within a century, the Atlantic would be reduced to a six-hour flight and instantaneous communication via satellites circling miles above.
It is such illuminating scenes that Winchester evokes in his wonderful, encyclopedic book, pinpointing key moments in the narrative of an entire ocean and our relationship to it.

We all have our own Atlantics, especially in this island nation whose very identity is shaped by the sea.
Growing up in the port city of Southampton, I was ever aware of the proximity and importance of the Atlantic, from the foghorns I heard from my bedroom and the crates of bananas unloaded in the docks (complete with Caribbean spiders), to my father’s job, testing those same underwater telephone cables.

The Atlantic’s sense of mystery and adventure is perennial, and Winchester charts it in an enthralling manner: from its Permian formation out of the tectonic shifts of Pangaea, to its first encounter with human beings who ventured out on to the beaches of southern Africa at Cape Agulhas, a place where, symbolically, the compass needle swings from magnetic to true north.
Fittingly, it was only when Homo sapiens moved northwards that the ocean asserted its true importance, and even we took our time.
To the classical world, the inland sea of the Mediterranean was an all-encompassing arena; anything beyond the Pillars of Hercules (Gibraltar) represented the fearful, monster-filled unknown.
It was the Vikings and the Basques who opened up the Atlantic to western influence, a process that would lead ultimately to a modern monster of power, Nato.

Following those routes of exploration and exploitation, Winchester’s highly readable prose roves to the extremes of north and south, east and west.
He moves deftly from 18th-century terraces in St Helena, 'a Georgian sanctuary-in-miniature for passing merchants’, via the terrible triangle of the slave trade – from England to Africa and the West Indies and back again, holds filled successively with iron, human beings and sugar – and then to the coeval commerce in whales, through whose 'profound’ legacy America made its first mark on a global economy.

Yet another trade in the ocean’s denizens was as important: that of cod, whose 'white, motherly, nourishing flesh’ not only prompted the Basques’ first epic journeys to the rich fishing grounds of the Grand Banks but also, in its salted form, provided the personal fuel for those voyages.
Winchester excels in such nice detail.
He describes the first packet ships plying the Atlantic from New York to Liverpool, and how their habit of sailing 'in line’ created the notion of ocean 'liner’. In its mid-Victorian heyday, Manhattan’s East River was lined with 500 ships 'like so many waiting stallions’, their forests of masts pointing to the coming American domination of Atlantic trade.

More violent are accounts of the sea as a battlefield, from the Armada and Trafalgar to Scapa Floe and the Falklands. As the ocean swallowed up its dead, it drew a veil over the horror of thousands of men burned, blown up and drowned. Travelling over an unusually calm Bay of Biscay as I did recently, it was hard to imagine that its innocent waters could contain such tragedies.

For a writer, as much as any 'water-gazer’ (to quote Melville), the sense of an invisible past is a potent stimulus to the imagination. Nowadays our only experience of the ocean is a casual glimpse through clouds from a pressurised cabin.
Winchester brings us down to sea level and makes us realise what we owe to the Atlantic.

He also sees storms ahead: 'A great ocean is not a thing to regard with casual disdain. The consequences are myriad, and they are invariably malign.’
In the 20th century, the cod of the Grand Banks fell victim to greed: eight million tons were taken in the first 15 years of factory fishing, as many as were taken in the entire previous century.
We replaced them with our rubbish, including 29,000 tons of radioactive waste dumped by Britain into the sea in the Seventies.

Top-heavy container ships, lacking their predecessors’ charm, create as much carbon as airliners. In a final, chilling chapter, Winchester describes the effects of climate change which he has witnessed first hand.
He concludes that the Atlantic will abide, 'always just minding its business, always just going on’. Whether we will be there to witness it is another matter.

Links :

• TheGuardian : Atlantic, a vast ocean of a million stories by Simon Winchester – review
  

The robotic otter: underwater robot that swims with flippers and can be controlled with a tablet computer

A video of the robot operating in tethered mode shows its ability to react to these visual tags in real time and transmit video back to the underwater tablet.

From DailyMail

Scientists have developed a remote-controlled robot that can receive and carry out commands while underwater.
AQUA is small and nimble, with flippers rather than propellers, and is designed for intricate data collection from shipwrecks and reefs.
The robot, designed by a team of universities from Canada, can be controlled wirelessly using a waterproof tablet computer.
While underwater, divers can program the tablet to display tags onscreen, similar to barcodes read by smartphones. The robot's on-board camera then scans these two-dimensional tags to receive and carry out commands.

Cutting the cord on underwater robots has been a longstanding challenge for scientists.
Water interferes with radio signals, hindering traditional wireless communication via modem. Tethered communication is cumbersome and can create safety issues for divers.
'Having a robot tethered to a vehicle above water creates a scenario where communication between the diver, robot, and surface operator becomes quite complicated,' says Michael Jenkin, professor at York University’s Faculty of Science & Engineering
'Investigating a shipwreck, for example, is a very delicate operation and the diver and robot need to be able to react quickly to changes in the environment. An error or a lag in communication could be dangerous,' Jenkin says.
Realizing there was no device on the market that fit the bill, Jenkin and his team at York's Centre for Vision Research, including the paper's lead author, MSc student Bart Verzijlenberg, set to work constructing a prototype.
The resulting device, fittingly dubbed AQUATablet, is watertight to a depth of 60 feet. Aluminum housing with a clear acrylic cover protects the tablet computer, which can be controlled by a diver using toggle-switches and on-screen prompts.

'A diver at 60 feet can actually teleoperate AQUA 30-40 feet deeper. Needless to say this is much easier on the diver, physically, and much safer,' Jenkin says.
The tablet also allows divers to command the robot much as if they were using a video game joystick; turn the tablet right and AQUA turns right, too.
In this mode, the robot is connected to the tablet by a slim length of optical cable, circumventing many of the issues of a robot-to-surface tether. The optical cable also allows AQUA to provide video feedback from its camera to the operator.
In wireless mode, the robot acknowledges prompts by flashing its on-board light. Its cameras can be used to build 3-D models of the environment which can then be used to guide the robot to particular tasks.
'This is a huge improvement on [a robot] having to travel to the surface to communicate with its operators,' Jenkin says.
In past, divers have used laminated flashcards to visually communicate with robots while underwater. However, these limit the diver to a pre-set sequence of commands.
'It's impossible to anticipate everything you're going to want the robot to do once you get underwater. We wanted to develop a system where we could create commands on the fly, in response to the environment,' he says.

Links :

• Swimming with robots : human robot communication at depth
• A visually guided swimming robot
  

Watch sea traffic from space : S-AIS

Space based Automatic Identification System (S-AIS)

Automatic Identification System (AIS) is a shipboard broadcast system that transmits a vessel's identification, position and other critical data that can be used to assist in navigation and improve maritime safety.

During its last mission, astronauts from the Space Shuttle Atlantis installed an Automatic Identification System antenna on the outside of the International Space Station that will allow astronauts aboard the ISS to monitor signals from the AIS transmitters mandated to be installed on most large ocean-going craft.

Although these VHF signals can be monitored from the Earth's surface, their horizontal range is generally limited to about 75 km (46 mi), leaving large areas of the ocean unwatched.
However, the signals easily reach the 400 km (250 mi) orbit of the ISS.
The European Space Agency sees this experiment as a test platform for a future AIS-monitoring fleet of satellites that will eventually provide worldwide coverage of sea traffic."

Some other players on the market propose S-AIS solutions : SpaceQuest, ORBCOMM, ExactEarth (COMDEV Int.), NSC Norwegian Space Centre all have space based AIS systems using NTS, or Nanosatellite Tracking Ships

A space based receiving system for signals of the automatic identification system (AIS) will extend the coverage of the existing ground network, which is limited to the coastal zone to open seas.
With newly available satellite-based AIS receivers, the complete global ocean shipping fleet of about 60,000 ships (AIS Class A) can be tracked.
The safe processing and distribution of satellite-based AIS messages to authorized users by a public traffic monitoring centre will contribute to a significantly enhanced maritime safety and security.

Links :

• BBC : Norway launches AISSat ship-tracking spacecraft
• ORBCOMM : Worldwide AIS data from Space
  
• ExactEarth : Satellite detection of AIS-SART-EPIRB sea trials
• ESA : Space Station keeps watch on world’s sea traffic
  

Wild seals work as oceanographers’ lab assistants

Elephant seals with electronic tags glued to their heads transmit information tracking the depth of their dives, allowing oceanographers to better map the seafloor (Image: D. Costa)

From ScienceNews

Seals diving for their dinner near Antarctica have surfaced with an extra morsel: information, gathered by electronic tags on the animals’ heads, about the shape of the seafloor there.

The work has revealed previously unknown undersea channels, through which warm water might flow toward fragile ice shelves. And the seals do it all for a fraction of the cost of traditional seafloor mapping done from ships.

“It gives you a much denser picture of what the water depth is than anything you can conceivably do with ship tracks,” says Laurence Padman, an oceanographer at Earth & Space Research in Corvallis, Ore., and a coauthor of an upcoming paper in Geophysical Research Letters describing the technique.

Seals, walruses, whales and other large marine creatures have moonlighted as oceanographers before. Scientists typically glue sensors to the animals’ bodies that measures factors like temperature and salinity. Researchers have used this information to study water temperatures around Greenland, among other topics.

But the new work is the first to extract information on the shape of the seafloor — known as bathymetry — from the sensors, which also measure pressure and hence depth. “You can actually map the ocean floor,” says team member Daniel Costa, a marine biologist at the University of California, Santa Cruz.

The data came from 57 elephant seals, tagged by Costa’s group over five summers at the U.S. Antarctic Marine Living Resources camp in the South Shetland Islands. As the animals swim, the tags record information every few seconds, then relay it via satellite once the seals surface. About 30 percent of the time seals dive all the way to the bottom to forage for food, says Padman, so by studying enough dives for each animal — some 200,000 dives in total — the researchers can deduce where the seafloor lies.

“It’s a novel and useful technique for gathering bathymetry data,” comments Paul Holland, an ocean modeler at the British Antarctic Survey in Cambridge, England.

Within the seal data Padman’s team discovered several significant troughs cutting across the continental slope off the west side of the Antarctic Peninsula. These features hadn’t been mapped before, says Padman, yet they play an important role in ocean circulation. Warm water can flow through such channels and up under the floating ice shelves that extend off Antarctica, such as the Wilkins ice shelf that partially disintegrated in 2008.

Better information on underwater topography could lead to improved models of how the ocean will respond to climate change, says Padman.

Other researchers might now be inspired to dig through seal data to see what features could be mapped, he adds. Ships can cost tens of thousands of dollars a day to operate in Antarctic waters, whereas there is a wealth of readily available information available on seal tags.

“We want to encourage other people who work with seal data to look into it,” says Padman.
“We just thought it was really cool.”

Links :

• NASA : satellites and sea lions, working together to improve ocean models
• NOAA : chart of overwinter movement patterns of Antarctic fur seals
• TOPP : Antarctic Weddell seal tagging project
  

New deep-sea hot springs discovered in the Atlantic

From ScienceDaily

Scientists from the MARUM Center for Marine Environmental Sciences and the Max Planck Institute for Marine Microbiology in Bremen on board the German research vessel Meteor have discovered a new hydrothermal vent 500 kilometres south-west of the Azores.

The vent with chimneys as high as one meter and fluids with temperatures up to 300 degrees Celsius was found at one thousand metres water depth in the middle of the Atlantic Ocean.
The discovery of the new deep-sea vent is remarkable because the area in which it was found has been intensively studied during previous research cruises.
The MARUM and Max Planck researchers describe their discovery in their video blog.

The Bremen scientists were able to find the hydrothermal vent by using the new, latest-generation multibeam echosounder on board the research vessel Meteor that allows the imaging of the water column above the ocean floor with previously unattained precision.
The scientists saw a plume of gas bubbles in the water column at a site about 5 kilometers away from the known large vent field Menez Gwen that they were working on.
A dive with the remote-controlled submarine MARUM-QUEST revealed the new hydrothermal site with smokers and animals typically found at vents on the Mid-Atlantic Ridge.

Since the discovery of the new vent, the scientists have been intensively searching the water column with the multibeam echosounder.
To their astonishment, they have already found at least five other sites with gas plumes.
Some even lie outside the volcanically active spreading zone in areas where hydrothermal activity was previously not assumed to occur.

"Our results indicate that many more of these small active sites exist along the Mid-Atlantic Ridge than previously assumed," said Dr. Nicole Dubilier, the chief scientist of the expedition. "This could change our understanding of the contribution of hydrothermal activity to the thermal budget of the oceans. Our discovery is also exciting because it could provide the answer to a long standing mystery: we do not know how animals travel between the large hydrothermal vents, which are often separated by hundreds to thousands of kilometres from each other. They may be using these smaller sites as stepping stones for their dispersal."

Research on deep-sea hydrothermal vents in the Atlantic is the objective of the 30 marine scientists from Hamburg, Bremen, Kiel, Portugal, and France who have been on board the German research vessel Meteor since September 6th.
The expedition to the submarine volcano Menez Gwen near the Azores is financed by MARUM, the Center for Marine Environmental Sciences in Bremen.
"One of the questions that the team would like to answer is why the hydrothermal sources in this area emit so much methane -- a very potent greenhouse gas," says chief scientist Nicole Dubilier, who is also a member of the Steering Committee of the Census of Marine Life Vents and Seeps project ChEss (Chemosynthetic Ecosystem Science). "Another important focus of the research is the deep-sea mussels that live at the hydrothermal vents and host symbiotic bacteria in their gills. The mussels obtain their nutrition from these bacteria."

Video blog: "News from the main deck"
An expedition on a research vessel is not only marked by great moments, like this discovery; everyday life on the Meteor is also filled with other exciting activities and events. Work on a research vessel goes on round the clock throughout the entire expedition.
In his video podcast "Neues vom Peildeck / News from the observation deck," available through the Hamburg-based newspaper Abendblatt, and in German and English on YouTube, Dennis Fink, a doctoral student at the Max Planck Institute for Marine Microbiology, reports on the activities of the ship's remote-operated vehicle (ROV) MARUM-QUEST, the various instruments used by the scientists and life on board the ship.
In the two-minute video blogs, Fink and his colleagues show fascinating images direct from the sea floor.

Links :

• Wired : Deep-sea vent discovery sets hydrothermal life’s new depth record
  
• WHOI video : Hydrothermal vents