Thursday, February 5, 2015

The great challenge of mapping the sea

Mappemonde (Lowitz, 1746)

From Here360 by CJ Schuler

The oceans that cover seven tenths of the world’s surface present a unique challenge to map makers.
There are no roads, rivers, cities and towns to chart, and to give a sense of scale and distance.
Such features as there are – winds, currents, tides – are intangible and forever on the move.

For centuries, the sea was shown on maps as a blank space between landmasses, which cartographers decorated with fantastic monsters to make up for the absence of other detail.
What lay beneath the waves was a mystery, and even today, only 20 per cent of the ocean floor has been mapped.


The Carta Marina (1539)
by the Swedish topographer Olaus Magnus
fills the otherwise empty ocean with strange creatures.

Here be monsters

The earliest navigational maps were the stick charts made by the Polynesians, who tied together lengths of bamboo or other wood, marking the locations of islands with shells or knots.
Curved pieces of wood represented the movement of the waves around the islands, and the effect of the waves on their canoes.


The sea charts known as portolans used by European and Arab sailors in the Middle Ages are actually maps of the coasts.
These were shown in great detail, with every port, headland and bay depicted and named.
But the open sea remained a void, criss-crossed with rhumbs – diagonal lines emanating from the 32 points of the compass to enable mariners to chart a course to their destination. Islands were shown, but with no accurate way of measuring longitude, their east-west placing was haphazard.


Portolan chart by Jorge de Aguiar (1492)
(Beinecke Rare Book and Manuscript Library, Yale University).

In the 16th century, navigators began measuring the depths of coastal waters, estuaries and harbours by lowering a weighted line over the side of a boat or, in shallows, using poles.
These soundings were plotted on to sea charts such as Lucas Janszoon Waghenaer’s famous Spieghel der Zeevaerd (The Mariner’s Mirror) of 1584 to prevent sailors from running aground on sandbanks and shallows.


The Thames Estuary, from Lukas Janszoon Waghenaer, Spieghel der Zeevaerd ,1584. Waghenaer’s chart extends from Dover in Kent to Orford Ness in Suffolk, with north at the right.
The numbers indicate depth in fathoms; the sandbanks, mapped in detail, have shifted in the intervening centuries.

By the beginning of the 19th century, the offshore waters of Europe and North America had been thoroughly sounded, but beyond the continental shelf, where it was too deep to drop a plumb line, there was no way of measuring the sea floor; and because there was no danger of ships running aground, there was little incentive to do so.
What happened below the open sea remained as much a mystery as when Magellan dropped a rope from his ship and, finding that it did not reach the bottom, concluded that the depth of the ocean was infinite.

 Thomas Burnet's 1694 map of the world without water ("Den Aardkloot van water ontbloot")

The Scientific and Industrial Revolutions

It was the scientific advances of the 18th and 19th centuries that made it possible to map the oceans more thoroughly, and the burgeoning trade and industry of the period that made it necessary.

The first reliable deep-water sounding was made by the British naval officer James Clark Ross on his Antarctic expedition of 1839-43. Ross pushed the traditional rope method to its limits to plumb the South Atlantic to a depth of 2425 fathoms (4365m).

Before long, though, the development of sounding machines, using reels to spool out a wire and measure its length, made systematic deep-sea soundings more practicable, and gave birth to the science of bathymetry – the mapping of the ocean floor.

Bathymetric map of the Atlantic, from The Physical Geography of the Sea (1855) by M. F. Maury.
(Rumsey collection)

Mapping the ocean floor

Telecommunications – one of the main drivers of oceanographic research today – entered the picture in 1858, when the first submarine telegraph cable was laid from Ireland to Newfoundland.
Charting the seabed was no longer a matter of scientific curiosity alone – it had immediate practical applications.


The route of the 1858 telegraph cable, from Howe’s Adventures and Achievements of Americans.
The vignette below shows the profile of the seabed as plotted by the SS Arctic.

In 1871, the British government sponsored the Challenger expedition to research the salinity and temperature of seawater, ocean currents, and underwater mountain chains.
The expedition travelled nearly 130,000km and sounded far deeper than anyone had done before, reaching 5700m at Challenger Deep in the Marianas Trench.

The resulting data filled 50 volumes of reports, and astounded the public, revealing a hidden world:
“The bottom of the ocean it appears is as varied as the land for there are valleys & mountains, hills & plains all across the Atlantic.”

In January 1874, the USS Tuscarora took soundings for a submarine cable between the United States, Japan, and China, while in 1891 the Albatross, an iron-hulled, twin-screwsteamer that was reputedly the first vessel built specifically for marine research, set out to determine “a practicable route for a telegraphic cable” between San Francisco and Honolulu. 


“Albatross-ii” by Unknown – NH 91740, U.S. Army History Institute, Carlisle Barracks, Pennsylvania. via Wikimedia Commons

Submarine warfare

By the close of the 19th century, almost all of the world’s coastlines, except for parts of the polar regions, had been charted in detail.
Oceanography was an established science, and a far-reaching infrastructure of shipping lines and telegraph cables spanned the globe.

During the First World War, the British Anti-Submarine Detection Investigation Committee (ASDICS) developed a system that transmitted sound waves underwater and used their echoes to locate submerged objects and measure distances.
During the Second World War it acquired the name sonar (SOund, NAvigation and Ranging), by which it is now generally known.
As well as finding subs, the technology offered an easier and more reliable method of charting the ocean floor than the old method of dropping a weighted line overboard.

 1981 world ocean floor map

Based on the work of geophysicists Bruce Heezen and Marie Tharp, this 1968 map of the ocean floor helped bring the concept of plate tectonics to a wide audience.

 Indian Ocean


Tharp began plotting the depths in 1950 from soundings taken by ships in the Atlantic, but, as a woman, wasn't allowed on the ships herself.
In 1978 she was awarded the Society's Hubbard Medal for her pioneering research. 

The satellite age

Navigation on land, at sea and in the air was revolutionised once again by the space race of the 1960s.
The US military developed a Global Positioning System (GPS), launching its first GPS satellite in 1978.


Satellite technology gave rise to the science of marine geodesy.
It is now understood that gravity causes the ocean’s surface to bulge outward and inward, mimicking the topography of the ocean floor.
Using satellites to measure these bulges, it is now possible to construct a model of the ridges and troughs that lie beneath the waves.
Harnessing gravity measurements from two orbiting satellites, the Scripps Institution of Oceanography in California has created a new map of the ocean floor that reveals thousands of previously uncharted mountains rising from the deep.

Links :
 

Wednesday, February 4, 2015

Greenland's ice layers mapped in 3D

Peering into the thousands of frozen layers inside Greenland’s ice sheet is like looking back in time. Each layer provides a record of not only snowfall and melting events, but what the Earth’s climate was like at the dawn of civilization, or during the last ice age, or during an ancient period of warmth similar to the one we are experiencing today.
Using radar data from NASA’s Operation IceBridge, scientists have built the first-ever comprehensive map of the layers deep inside the ice sheet.

From LiveSciences by Becky Oskin

Layer by layer, scientists have filled in a new map of the hidden expanses of Greenland's vast ice sheet, revealing where the island hides its oldest ice.

The 3D map reveals where areas of ice of different ages are located across the frozen island.
The research team built the 3D map of Greenland's ice sheet using data from airborne radar and ice cores.
Radar measurements revealed the ice's thickness, and was also used to find internal layers concealed under the surface.
The ice cores provided precisely dated ages for these different layers at various points around the island.
(The oldest ice found so far in Greenland's ice cores is about 130,000 years old.)
Like playing a giant game of connect the dots, the team drew in the map by linking the ice cores with the internal layers detected by airborne radar.
The researchers have divided the map into Holocene-period ice (the last 11,700 years), ice from the Ice Age (from 11,700 to 115,000 years ago) and ice from the Eemian Period (115,000 to 130,000 years ago.)

The biggest surprise revealed by the new map is that more ice from the Eemian Period ice is in central northern Greenland than scientists knew existed, said lead study author Joe MacGregor, a glaciologist at the University of Texas at Austin Institute for Geophysics.
"Figuring out where this Eemian ice might be has been a challenge," MacGregor told Live Science. "It would be great to get more of it [through drilling], so we can understand what the Eemian was like."

Researchers are particularly interested in hunting for Eemian Period ice because it contains clues to how the ice sheet will respond as the planet warms today.
The Eemian Period was Earth's most recent warm spell, when the planet was as warm as it is becoming now.
During this older warming period, Greenland kept some of its ice.
After the Eemian, the planet's climate entered a long ice age, during which modern humans evolved.
"The climate changes that are occurring today are happening a lot faster than in the Eemian, but if we can understand what the Eemian was like, than we can understand where [today's] climate is going," MacGregor said.

This is the first time anyone has assembled a stratigraphic map, one that shows all of the layers of Greenland's ice sheet, the scientists said.
The results were published January 16 in the Journal of Geophysical Research: Earth Surface.

"It was a challenging problem and a daunting one, because there was a lot of data," MacGregor said.
"It had kind of become like cleaning out your garage after 10 years of ignoring it. You know you might find something very exciting, but you have to go through the pain of cleaning it."

The new map will serve as the keystone for several planned research projects, MacGregor said.
For instance, the structure of the ice layers can be used to study how fast the ice sheet flows and where it's melting.
Digging into the history of the ice will also reveal more about how it formed and help predict the future of the ice sheet as the climate warms, he added.

Tuesday, February 3, 2015

What does it take to live at the bottom of the ocean


From BBC by Jasmin Fox-Skelly

In the deepest depths it is pitch-dark, the water is freezing cold and the pressure is pulverising.
Yet animals somehow survive in this most extreme environment 

James Cameron's Deepsea Challenger

On 26 March 2012, film director James Cameron was hunched in the cramped cabin of a submersible, far out in the Pacific ocean.
His vessel, the Deepsea Challenger, looked a bit like a lime-green cigar.
Over the course of two and a half hours, Cameron piloted the submersible down to a depth of 10,898 m, setting a new world record for a solo descent.
He had reached the deepest part of the ocean, the Mariana Trench.
Cameron was only the third person to look upon the desolate, almost lunar landscape at the bottom of the trench.
Fortunately for the rest of us, he took 3D Hi-Definition cameras with him on the dive.
The films he captured show that remarkable sea life exists all the way to the bottom.
They are being pored over by scientists around the world, in a bid to figure out what it takes to live in the ocean's depths.
Cameron's dive is the latest step in a 200-year journey to the deepest depths of the sea, the last unexplored frontier on Earth.
At the bottom of trenches like the Mariana, the water is freezing cold, there is no light, and the pressure is pulverising.
Yet somehow, life endures, and we are only just beginning to learn how it does so.


Until the late 1800s, little was known about the oceans.
Folklores and myths conjured up images of terrifying sea monsters like the Norwegian kraken, and the science fiction author Jules Verne imagined that the heart of the ocean could contain "huge specimens of life from another age".
But most scientists thought the darkness and cold would make the deep sea uninhabitable.

 Frontispiece to Forbes's Natural History of the European Seas
(Forbes's initials are in the lower right of this cartoon depicting deep sea dredging for marine fauna)

The idea that the deeps were a muddy desert devoid of life had been around for centuries.
The Greek philosopher Socrates, who lived 2400 years ago, apparently said: "Everything is corroded by the brine, and there is no vegetation worth mentioning, and scarcely any degree of perfect formation, but only caverns and sand and measureless mud, and tracts of slime."
In the Victorian era, this idea was championed by a scientist called Edward Forbes.
He dredged the Aegean Sea and found that the deeper he looked, the fewer organisms he discovered.
He concluded that life ceased to exist beyond 550 m.
In a book published in 1859, the year Darwin published On the Origin of Species, Forbes wrote: "As we descend deeper and deeper in this region, its inhabitants become more and more modified, and fewer and fewer, indicating our approach towards an abyss where life is either extinguished, or exhibits but a few sparks to mark its lingering presence."
He was confident, but five years later Forbes' ideas were blown out of the water.


Father-and-son naturalists Michael and Georg Ossian Sars spent years dredging Norway's fjords. Then in 1864 they brought the first living sea lilies to shore, from 10,000 ft (3000m) down.
Sea lilies look like flowers, hence the name, but are actually animals.
Each has a stalk that attaches it to the sea bottom, and many feather-like arms that guide small particles of food into their mouths.

The discovery of the sea lilies sent a wave of excitement through the scientific community.
They were thought to have gone extinct millions of years ago, and looked like remnants of a lost, ancient world.
They also showed that the deeps were inhabited.
Many years later, Georg wrote: "So far was I from observing any sign of diminished intensity in this animal life at increased depths, that it seemed, on the contrary, as if there was just beginning to appear a rich and in many respects peculiar deep sea Fauna, of which only a very incomplete notion had previously existed."
The idea that ancient life forms had endured at the bottom of the sea was too tempting to ignore.

Map showing the voyage of the HMS Challenger

British scientists now took the lead. Britain's Empire wanted to rule the waves, so it needed to know what was beneath them.
Between 1872 and 1876, the British ship HMS Challenger sailed for 127,653 km in a bid to catalogue the life in all the Earth's oceans and seas.
It was a journey into the unknown, just like the Apollo Moon landings in the 20th century.
In total 4,700 new species of marine animals were discovered, including the first records of deep-sea organisms.

The animals discovered were extraordinary.
The chief scientist Sir Charles Wyville Thomson described a hydroid, a stalk-shaped animal with tentacles, found in the north Pacific.
It was "a giant of its order, with a stem upwards of 7 feet high, and a head nearly a foot across the crown of expanded tentacles."
But just as important, the Challenger team studied the landscape of the ocean floor.
Thomson described "gently undulating plains, extending for over a hundred millions of square miles at a depth of 2500 fathoms beneath the surface of the sea, and presenting like the land their local areas of secular elevation or depression, and centres of more active volcanic disturbance."
The expedition also discovered the ocean's deepest point.
South of Japan, there is a crescent-shaped canyon called the Mariana Trench, and at its southern end the sea bed seemingly falls away.
In 1875 Thomson and his team recorded a depth of 4,475 fathoms (8,184 m).
Now we know it goes at least 10,916m down.
This near-bottomless pit is called the Challenger Deep, after the ship.

 In 1960, Lieutenant Don Walsh of the US Navy and Swiss oceanographer Jacques Piccard navigated the Trieste bathyscaphe into the Mariana Trench.
They accomplished a feat so incredible that it forever raised the bar for deep-ocean exploration.

Almost a century later, humans went to the bottom of the Challenger Deep.
On 23 January 1960, oceanographer Jacques Piccard and Lieutenant Don Walsh of the US Navy piloted a submersible called Trieste into the Deep.
The descent took four hours and 47 minutes.
Most of the ship was taken up with floats and water ballast tanks, so Piccard and Walsh found themselves in a 7-ft-wide spherical cabin attached to the underside, with a small Plexiglas window.
They were, to put it mildly, cramped.
Once they reached the bottom, they couldn't take any photographs due to the disturbed silt.
Regardless, the debate about whether life could exist at the bottom was settled.
The Trieste's floodlights illuminated a creature that Piccard thought was a flatfish, but is now thought to have been a sea cucumber.
"Here, in an instant, was the answer," Piccard wrote in a book about his journey.
It now seems the deeps are teeming with life.


In late 2014, Jeffrey Drazen of the University of Hawaiʻi at Mānoa in Honolulu led an expedition to the Mariana Trench.
His team used five remotely-operated vehicles to explore the deepest parts of the trench, as well as along the trench walls.
He was surprised by the amount and diversity of life on the walls of the trench.

The first challenge animals encounter as they move deeper is the complete darkness.
Some deep-sea fishes, like the stout blacksmelt, have giant eyes to capture the faintest glimmers. Others have abandoned vision.


The tripodfish, named for its elongated fins that allow it to perch on the sea floor, relies on touch and vibrations to sense its prey.
Still others emit their own light by a process known as bioluminescence.
These lights can be used as headlights, as in lanternfish, or to attract mates or prey.


The darkness also causes a second problem.
Lack of sunlight means no algae or plants to support the food chain, so food is scarce.
Deep-sea animals must survive on the decaying scraps of dead organisms from the upper layers of the ocean, which sink to the bottom.
A rich supply of this stuff might account for the rich ecosystem Drazen found in the Mariana Trench. "It is possible that the trenches are funnelling detritus food down," he says.
Occasionally the scavengers are treated to a dead whale, which provides an enormous feast.
Hagfish burrow into such carcasses and eat them from the inside out, while boneworms eat the bones themselves.
And there are hunters, too: the ping-pong tree sponge uses sharp spikes to impale its prey.
But it's the physical properties of the deep sea that make it lethal.
It is frigid: in most places, temperatures are between -1 and 4⁰C.
Worse, the pressure is a crushing eight tonnes per square inch, about a thousand times the standard atmospheric pressure at sea level.
It's like being crushed to death in a freezer.

This combination of pressure and cold has strange effects on animals' bodies.
All animal cells are surrounded by fatty membranes, which must stay liquid to transmit nerve signals and shuttle materials in and out of cells.
But under these conditions, they would solidify.
"The extreme cold and high pressures of the ocean trenches would make the fat in your cell membranes solid, just like butter in a refrigerator," says Drazen.
So deep-sea animals must adapt their membranes to keep them liquid.
They do this by having lots of unsaturated fats – the group of chemicals that includes vegetable oil - in their membranes.
These remain liquid at low temperatures and keep the membranes loose.
It's not just cell membranes.
Pressure also has a crippling effect on proteins, the huge molecules that do much of the work in our cells, such as breaking down food for energy.
To function, proteins must be free to change their size and shape, for instance becoming larger.
This is difficult under pressure, says Drazen.
"A simple analogy is blowing up a balloon. It's easy in air, but try doing it at the bottom of a swimming pool."

 Descending 200 meters into the dark of the deep sea reveals some weird and wonderful creatures.

Fishy chemicals

To keep their proteins from conking out, deep-sea animals collect small organic molecules called piezolytes in their cells.
These piezolytes bind tightly to water molecules, which gives the proteins more space and stops water being forced into the proteins' interiors and distorting them.
The deeper an animal lives, the more piezolytes they tend to have in their cells.
One piezolyte, TMAO, gives fish their "fishy" smell.
TMAO increases with depth, so deep-sea fish taste fishier than shallow fish.

But there's a limit to this.
As animals take in more piezolytes, their cells become saltier.
Around 8200m down, Drazen has calculated, the cells would be as salty as the surrounding water. Any more piezolytes and seawater would rush into their cells, bursting them.
In line with this, Drazen's 2014 expedition discovered the world's deepest fish living 8145 m down. The new record-holder is a snailfish with a bulbous head and partly transparent body.
Drazen believes that this is about as deep as any fish can go.
If he's right, there are no fish at the bottom of the Challenger Deep.
But there's plenty more than fish in the sea.
Despite the lethal conditions, James Cameron's dive revealed a plethora of animals at the bottom of the ocean.
For most people, they are utterly unfamiliar.

The submersible's cameras picked up crustaceans called amphipods, which look a lot like shrimp.
But whereas most of the ocean's amphipods are around 3cm long, those in the Challenger Deep were over a foot long.
They are the deepest examples of "gigantism" captured in the deep ocean.
A piezolyte called scyllo-inositol was found in their cells, and may help them survive the pressure.
The animals that appeared most frequently on the tapes were foraminifera: giant single-celled organisms a bit like oversized amoebas.
Foraminifera are little-known, but incredibly common.
They live in the sediment on sea beds throughout the world, including some thoroughly inhospitable places.
Normally, foraminifera build hard shells of calcium carbonate to protect themselves.
Then they can poke out their long, sticky arms and snag food.
However the intense pressures at the bottom of Challenger Deep dissolve minerals, so they can't build their shells.

 During a July 2011 voyage to the Pacific Ocean's Mariana Trench, the deepest region on the planet, Scripps researchers and National Geographic engineers deployed untethered free-falling/ascending landers equipped with digital video and lights to search the largely unexplored region.
The team documented the deepest known existence of xenophyophores, single-celled animals exclusively found in deep-sea environments.
Xenophyophores are noteworthy for their size, with individual cells often exceeding 10 centimeters (4 inches), their extreme abundance on the seafloor and their role as hosts for a variety of organisms.

Amoebas in glass houses

Instead they have adapted by building soft shells from proteins, organic polymers and even sand. Grains of sand are made from silicon dioxide, the main constituent of glass, and can withstand intense pressures.
One group of foraminifera, known as xenophyophores, have taken advantage of this when building their shells.
By gluing sand from ocean sediments, cast-off shells, and microbial skeletons to their own faeces, they can make pressure-proof shells.
There could be 50 or even 100 species of xenophyophores in the Challenger Deep, according to Natalya Gallo of the Scripps Institute of Oceanography in La Jolla, California, who has examined Cameron's footage.
The footage also revealed what looked like a series of sticks buried in the sand.
But scientists soon realised that they were sea cucumbers: worm-like creatures with leathery bodies and clusters of tentacles near their mouths.
The Challenger Deep sea cucumbers had all oriented their bodies in exactly the same direction, something never before seen, possibly to ensure that they picked up as much food as possible from the currents.
But despite all these discoveries, the biggest breakthroughs might come from organisms that were invisible even to Cameron's hi-definition cameras: bacteria.

 A compilation of video footage captured from the University of Aberdeen’s Hadal-Lander in the Mariana Trench from 5000m to 10,545 m deep.
The large fish inhabit the shallower depth (5000 to 6500m) are rat-tails, cusk eels and eel pouts.
At the mid depths (6500 to 8000m) are the supergiant amphipods and the small pink snailfish.
The fragile snailfish at 8145m is now the deepest living fish.
At depth greater than 8500m, only large swarms of small scavenging amphipods are visible.
The footage was taken during the HADES-M cruise on Schmidt Ocean Institute’s Research Vessel ‘Falkor’.

Even before Cameron went down, it was clear that the Mariana Trench was home to plenty of microorganisms.
Douglas Bartlett of the Scripps Institute of Oceanography, who was in charge of the scientific side of Cameron's dive, has found clumps of bacteria attached to rocks in the Sirena Deep, east of Challenger Deep.
His team is now examining them to find out how they survive.

Their analysis of the bacteria's genes shows that they can feed off reduced sulphur and carbon dioxide.
Others may feed on gases like methane and hydrogen, which are belched out of the sea bed when the tectonic plates on either side of the Mariana Trench move against one another.
Such deep-sea environments are one of the main contenders for the birthplace of life on Earth.
As a result, the bacteria of the Mariana Trench could help us understand how life began.
They may also help us figure out where to find life on other worlds.
The conditions in the Challenger Deep are nothing like the familiar surface layers of the ocean, but they are quite comparable to Europa, one of Jupiter's moons.
Europa has an icy exterior under which is thought to lie a hidden, liquid ocean with twice as much water as Earth's.
Europa may be our best bet for finding alien life in our solar system, as there may be active volcanoes on the sea bed where bacteria could survive.
Surely, the argument goes, if they can survive in the Challenger Deep, Europa can't be that much harder.
When James Cameron got back to the surface, he said that "in the space of one day, [he] had gone to another planet and come back".
It was an apt line.
His expedition and others like it will not only tell us about the extremes of life on our own planet, but may help us find life on others.

Links :
  • BBC : Meet the creatures that live beyond the abyss

Monday, February 2, 2015

Scientists trial system to improve safety at sea

 This video illustrates new research from the University of Leicester’s Department of Physics and Astronomy who are trialling a concept using satellite technology already in orbit to take images of sea which could significantly reduce search areas for missing boats and planes.
The animations show the ground tracks of the satellites identified that could take images of the sea as part of this concept as they orbit the Earth.
Each of the satellites carry a camera which can take images of objects on the ocean surface. 


New satellite imaging concept proposed by University of Leicester-led team could significantly reduce search areas for missing boats and planes 
  • Concept uses satellite technology already in orbit to take images of sea
  • Enables ship and plane movement to be pinpointed to much more accuracy
  • Data can be used when vessels are lost at sea to minimise search area and speed up search and rescue time
  • Could have been used to aid search for missing Malaysian flight MH370
A space scientist at the University of Leicester, in collaboration with the New Zealand Defence Technology Agency and DMC International Imaging, has been trialling a concept for using satellite imagery to significantly improve the chances of locating ships and planes, such as the missing Malaysian flight MH370, lost at sea.

A preliminary study published this month in the International Journal of Remote Sensing, identified 54 satellites with 85 sensors, currently only taking images of land, which could be used to take images of the Earth’s oceans and inland waters.

The research team believe regularly updated images of the seas via these satellites could enable the reduction of search areas for missing ships to just a few hundred square miles.
This offers the possibility of dramatically reducing search and rescue times and significantly improving chances of survival for missing ships.


Dr Nigel Bannister from the University’s department of Physics and Astronomy explained: “If you are in the open ocean, and you get into difficulty, particularly in a small vessel, there is a significant chance that you will be lost at sea. There is currently a big problem tracking small vessel maritime traffic and this system could provide a much improved awareness of vessel movements across the globe, using technology that already exists."

“This isn’t a surveillance system that monitors vessel movements across the oceans in real time, like radar tracking of aircraft in the sky; instead we have proposed a system which records images every time a satellite passes over specific points of the sea. If we are alerted to a lost vessel, the images allow us to pinpoint its last observed position. This could be very powerful for constraining search areas and it could reduce the time it takes to locate missing boats and planes, and hopefully their crews and passengers.”


David Neyland, former Assistant Director of the US Navy Office of Naval Research-Global, who funded the research, added: “The University of Leicester brought to this research a unique capability to build a public, open source model, of an International Virtual Constellation of spacecraft from 19 nations – a transparent view of space operations never done before.

“Dr Bannister’s critical knowledge and enthusiasm are a driving force to make space-based maritime domain awareness a reality. The University of Leicester’s research is a watershed event encouraging international satellite owners and operators to collect and share open ocean imagery for the common good of enhancing safety of life at sea. The case of the missing Malaysian flight MH370 demonstrates how easy it is to lose a large object, even with today’s technology.”

The team is now testing the concept, working on the automated detection of vessels within imagery provided from the NigeriaSat 2 and UK-DMC2 satellites by DMC International Imaging, and in cooperation with the New Zealand Defence Technology Agency, with the ultimate goal to develop a practical system based on the concept.
It is hoped that this system will be active as a maritime monitoring system in a few years’ time as it exploits satellites and technologies which already exist. 

Links :
  • International Journal of Remote Sensing : study

Sunday, February 1, 2015

Image of the week : Watch the world’s largest animated GIF photographed from outer space


From Deccan Chronicle

Artist INSA is known for creating mesmerizing animated GIFs using street art and photos.
He was recently recruited by the scotch whisky brand Ballantines to create “the world’s largest animated GIF,” one that was created with gigantic paintings on the ground and photos from a satellite camera.

 Marina da Gloria, Rio do Janeiro with the Marine GeoGarage

INSA and a group of 20 helpers gathered at a location in Rio De Janeiro, Brazil in late 2014.
The team painted giant patterns on the ground, doing one design per day over the course of four days.
Each of the four paintings measured 14,379 square metes, meaning the project required a total of 57,515 square meters of paint.


Here’s a behind-the-scenes video showing how the project was done

INSA and Ballantine's collaborated with the commercial satellite division of Airbus to access a pair of Pleiades satellites which could be tasked with shooting a 100km square image at a resolution of one pixel per 50 cm squared.