Saturday, April 21, 2012

Jaws : about adrenaline

>>> geolocalization with the Marine GeoGarage <<<

Matt Meola and Albee Layer share their experiences paddling into massive Jaws.

Friday, April 20, 2012

Arctic Ocean: history and now

Arctic Ocean Seafloor Features Map: International Bathymetric Chart of the Arctic Ocean (IBCAO) annotated with the names of seafloor features

From Geology

Arctic Ocean: History and Now

The Arctic Ocean has played a minor role in world history.
Ice cover severely hinders navigation; the area is remote; there is almost no infrastructure; winters are dark and very cold; summer days are short and foggy.
These challenges make the Arctic Ocean a hostile and difficult area.

Today, we are at a time when interest in the Arctic Ocean is growing steadily.
A warming climate is thinning and shrinking the polar ice pack to allow increased navigation.
New oil and gas assessments have revealed an enormous energy resource.
And, the Law of the Sea Treaty has motivated nations to clearly define their exclusive economic zone in the Arctic Ocean.

The new interest in the Arctic Ocean is not confined to its surface; it extends to the bottom where information about its structure is needed by geologists, oceanographers, biologists and other people who work there.
The primary physical features of the Arctic Ocean seafloor are labeled on the bathymetry map above and described in the paragraphs below.
Maps below illustrate navigational, physical and mineral resource features.

Arctic Ocean Geography

The Arctic Ocean has a surface area of about 14.056 million square kilometers (5.427 million square miles), making it the smallest of Earth's five oceans. Baffin Bay, Barents Sea, Beaufort Sea, Chukchi Sea, East Siberian Sea, Greenland Sea, Hudson Bay, Hudson Straight, Kara Sea, and Laptev Sea are generally considered to be part of the Arctic Ocean.
It is connected to the Pacific Ocean through the Bering Strait and connected to the Atlantic Ocean through the Labrador Sea and the Greenland Sea.

Lomonosov Ridge

The dominant topographic feature of the Arctic Ocean seafloor is the Lomonosov Ridge.
This feature is thought to be part of the Eurasian continental crust that rifted from the Barents-Kara Sea margin and subsided in early Tertiary time (about 64 to 56 million years ago).
The side of the Ridge facing Eurasia is bounded by half-graben faults and the side facing North America is gently sloping.

The Lomonosov Ridge traverses the Arctic Ocean from the Lincoln Shelf (off Ellesmere Island and Greenland) to the New Siberian Islands off the coast of northern Russia.
It divides the Arctic Ocean into two major basins: the Eurasian Basin on the Eurasian side of the ridge and the Amerasian Basin on the North American Side.
It rises over 3000 meters above the floors of these basins and at its highest point is about 954 meters below sea level. It was discovered by Russian scientists in 1948.

It was the first attempt by the international community to establish a formal agreement on a logical allocation of ocean resources.
In addition to the 200 nautical mile economic zone, each country can extend its claim up to 350 nautical miles for those areas that can be proven to be an extension of that country's continental shelf.

Nations could use the "Law of the Sea" treaty to determine who owns the Arctic Ocean seafloor. Russia has presented a claim to the United Nations that the Lomonosov Ridge is an extension of Eurasia and that entitles Russia to an extended exclusive economic zone.
Canada and Denmark make similar claims to extend their control from the opposite side of the Arctic Ocean.

Amerasian and Eurasian Basins

The Lomonosov Ridge divides the floor of the Arctic Ocean into two major basins.
The Eurasian Basin is on the Eurasian side of the Lomonosov Ridge and the Amerasian Basin is on the North American side of the Lomonosov Ridge.

The Amerasian and Eurasian Basins have been subdivided by ridges.
The Gakkel Ridge, a spreading center responsible for the rifting of the Lomonosov block from the Eurasian continent, divides the Eurasian Basin into the Fram Basin on the Lomonosov side of the ridge and the Nansen Basin on the Eurasian continent side.
The Alpha Ridge divides the Amerasian Basin into the Canada Basin on the North American side of the ridge and the Makarov Basin on the Lomonosov side of the ridge.

Continental Shelves

The Amerasian Basin and the Eurasian Basin are surrounded by extensive continental shelves. These include the Chukchi Shelf and the Beaufort Shelf along North America; the Lincoln Shelf along northern Greenland; the Barents Shelf, Kara Shelf, Laptev Shelf and East Siberian Shelf along Eurasia.

Enormous amounts of natural gas are believed to be beneath the Barents Shelf and the Kara Shelf as parts of the East Barents Petroleum Province and the West Siberian Petroleum Province.
Oil and natural gas are believed to be beneath significant parts of the Chukchi Shelf, Beaufort Shelf and Canada Basin as part of the Arctic Alaska Petroleum Province and the Amerasia Petroleum Province.


Rift Basins

Greenland is flanked by two rift basins: the East Greenland Rift Basin and the West Greenland Rift Basin.
These basins connect the Arctic Ocean with the Atlantic Ocean.
Each of these basins is thought to be underlain by a significant oil and natural gas resource.

Navigation Through the Arctic Ocean

Two potentially important navigation channels pass through the Arctic Ocean.

In this image, Ice-covered areas range in color from white (highest concentration) to light blue (lowest concentration).
Open water is dark blue, and land masses are gray.
The yellow outline shows the median minimum ice extent for 1979–2000 (areas that were at least 15 percent ice-covered in at least half the years between 1979 and 2000).
Image and caption information by NASA's Earth Observatory

The Northwest Passage is a sea route that connects the Pacific Ocean to the Atlantic Ocean across the northern coast of North America and through the Canadian Arctic Archipelago.
The Northern Sea Route is a similar route that connects the Atlantic Ocean to the Pacific Ocean across the northern coast of the Eurasian Continent.

Map showing the geographic extent of the Arctic Ocean (as a darker blue tint).
The Northwest Passage and Northern Sea Route are two important seasonal waterways that connect the Atlantic and Pacific Oceans.
In recent years the polar ice pack has thinned allowing for increased navigation through these routes and raising the possibility of future sovereignty and shipping disputes among countries bordering the Arctic Ocean.
Image by the Central Intelligence Agency.

Both of these routes have been virtually impassable in the past because they are covered by thick, year-round sea ice.
However, they have been relatively ice-free for a few weeks in recent years (see map in right column) and have attracted a small amount of commercial shipping.
Each of these routes cuts thousands of miles off of a trip from the Atlantic to the Pacific.
Both routes face jurisdictional problems and questions over who has a right to use them and under what conditions.

Links :

Thursday, April 19, 2012

Floating laboratory follows plankton around the world in 938 days

From TheGuardian (This article originally appeared in Le Monde)

Tara yacht finishes two-and-a-half-year expedition to track and research marine micro-organisms

Last month a strange yacht with an aluminium hull returned to a warm welcome in the port of Lorient, after a two-and-a-half-year absence.
During that time the Tara, a floating laboratory, had sailed round the world, covering some 115,000km as it crisscrossed the oceans tracking invisible marine micro-organisms.

The ambition of the Tara Oceans project is to build up a database of these complex, yet little-known ecosystems.
For the scientists behind the undertaking, to see the Tara, with its twin orange masts, back in its home port in Brittany, north-west France, is a victory in itself, given how crazy the project seemed at its outset.

"When it started, we did have some doubts, particularly regarding funding," says Eric Karsenti, the expedition's senior scientist and a researcher at the European Molecular Biology Laboratory, headquartered in Heidelberg, Germany.
"When the Tara left Lorient in 2009 we weren't entirely sure we had enough money to complete the expedition."

Some €9m ($11.9m) later – drawing on public and private funds – and despite the voyage being cut short by several months due to a lack of resources, the wager seems to have paid off, straying far from the conventional sea lanes of scientific research.
"The other big challenge we faced was to succeed in getting scientists from very different backgrounds to work together," Karsenti says.

Major scientific missions investigating marine ecosystems usually focus on a single line of research.
A typical instance was the expedition initiated by the US genetician Craig Venter.
From 2003 to 2006 his own yacht, the Sorcerer II, sailed round the world in an attempt to collect as much DNA from marine micro-organisms as possible, scooping up in the process more than 6,000 new genes and identifying about 1,700 protein families.

The Tara Oceans project opted for a far-reaching multidisciplinary approach, with microbiologists, oceanographers, geneticians and engineers from all over the world – 35 nationalities in all – working on the Tara at various times during its odyssey.
At each port of call some of the 15 crew members – comprising scientists, sailors and journalists – were replaced.
"Each crew writes its own story," says the skipper, Loïc Vallette.
"The Tara is a hybrid vessel, organised like a typical oceanographic ship, but crammed into a much smaller space."
It operates on slightly different lines too, requiring researchers to do more than just fulfil their scientific duties.
Everyone does their bit to keep place ship-shape, doing maintenance work and the washing-up, and even taking night watches.
"It has been a fabulous human adventure," Vallette adds.

But the main objective was to gain a greater understanding of plankton.
"To begin with we wanted to mount a proper scientific expedition, and at the same time use it to reach out to the general public," Karsenti explains.
"We soon hit on the idea of plankton, which includes little known, little studied organisms, particularly on a global scale."

Marine micro-organisms account for 98% of the oceans' biomass, but scientists have only studied a tiny part of this population.
Indeed the term plankton covers a huge variety of very diverse organisms, ranging from jellyfish to micro-algae.
Traditionally, species are organised on the basis of their anatomical or genetic similarities.
But plankton is defined by its ecological niche, its way of life in a particular environment, or more precisely the particularity of living suspended in a water column, with no ability to swim against the current.
This definition encompasses a myriad of species: zooplankton (animal) comprising fish larvae, small molluscs or crustaceans; phytoplankton (plant), comprising micro-algae but also countless types of virus and bacteria.
Such huge diversity demands the largest possible scientific reach in order to understand complex plankton ecosystems.
But for many years the scientific community shunned them, slow to realise the essential role plankton plays in our oceans and for the planet as a whole.

Plankton forms the basis of marine food chains.
But it also makes a crucial contribution to regulating the climate and affects the Earth's geochemical cycles.
Awareness of these marine organisms came a bit late.
In recent decades the global plankton concentration has declined.

To sample and analyse plankton efficiently the Tara was fitted out to accommodate a battery of scientific equipment.
Alongside the ship, long pipes trailed downwards, pumping up seawater, which then passed through a succession of filters.
On the stern deck a dozen nets, each with a specific mesh, were deployed at various depths.
Each catch was then transferred to a wet laboratory on deck.
Samples were labelled and, for the most part, dipped into liquid nitrogen to be stored for study on land.
But some samples were examined straightaway in the onboard laboratory, equipped with a whole range of imaging instruments.
To round off the proceedings the Tara's key exhibit, referred to as the "rosette" was lowered into the sea.

This contraption was fitted with sample bottles for trapping water at predetermined depths and an array of sensors measuring the temperature, oxygen and salt content.
Loaded with 350kg of equipment, the rosette was the centre of attention each time the Tara stopped to take samples, an operation which sometimes lasted several days.
"Each field station brings new challenges and the stress is permanent," says Sarah Searson, an oceanographer and one of the few scientists to spend several months onboard."
There are so many things to be taken into account I sometimes felt like I was juggling, staying perfectly concentrated at all times."

Thanks to this operation, tens of thousands of test tubes filled with precious samples were collected from the 153 field stations investigated by the Tara: sufficient to occupy the land-based scientists for years.
"It often felt like a real marathon," Searson said. "
One of the achievements was keeping all the equipment in perfect condition."
The yacht is now being prepared for another expedition in 2013, in the Arctic Ocean, the only part of the sea that Tara Oceans did not sample.

Wednesday, April 18, 2012

Deep Intellect : inside the mind of the octopus

From OrionMag


Athena the octopus at New England Aquarium, Boston

No sci-fi alien is so startlingly strange.



Their findings are challenging our understanding of consciousness itself.

I had always longed to meet an octopus.
The heavy lid covering her tank separated our two worlds.

“She’s looking at you,” Dowd said.

Each arm has more than two hundred of them.

One name for the species is “devil fish.”

Occasionally an octopus takes a dislike to someone.
Later, she quit her volunteer position for college.

With his help, Athena and I pulled gently apart.

I was honored that she appeared comfortable with me.
But what did she know about me that informed her opinion?
When Athena looked into my eyes, what was she thinking?

Octopus Walks on Land at Fitzgerald Marine Reserve


But her study subjects were constantly thwarting her.

The first problem was keeping the octopuses alive.
Or they’d mate, which is equally lethal.

Some octopuses did not like being removed from their tanks.
They would hide.

“You’d chase them under the tank, back and forth, like you were chasing a cat,” Warburton said. “It’s so weird!”

Octopuses in captivity actually escape their watery enclosures with alarming frequency.

One of the joubini was such a problem they named her The Bitch.

Then there was Wendy.

But Warburton learned far more than her experiments revealed.

MEASURING THE MINDS OF OTHER creatures is a perplexing problem.
But size doesn’t always match smarts.
As is well known in electronics, anything can be miniaturized.

Octopuses have the largest brains of any invertebrate.

Another measure of intelligence: you can count neurons.
A human has 100 billion.
But this is where things get weird.


Mimic octopus pretending to be a flatfish

Their intelligence sometimes even involves changing colors and shapes.
Another video shows an octopus materializing from a clump of algae.

The deepest layer passively reflects background light.

But new evidence suggests a breathtaking possibility.

Bats can see with sound.
Like dolphins, they can locate their prey using echoes.


A hunting expedition could take five minutes or three hours.

Then it chose a third.
Then it went to sleep.

The scene has stayed with Mather.

She repeated the action twenty times.

Anderson’s observations were reported in the Journal of Comparative Psychology.

An Octopus Enrichment Handbook has been developed by Cincinnati’s Newport Aquarium, with ideas of how to keep these creatures entertained.

How to obtain fish from the inside of a closed parmesan cheese container
at Florida Oceanographic Coastal Center

Later he lets the octopus lift open the lid.

Next he locks the first cube within a second one.
The new latch slides counterclockwise to catch on a bracket.

All the octopuses Murphy has known learned fast.
But each may use a different strategy.

As part of the New England Aquarium's "Killer Instincts" program, aquarist Bill Murphy interacts with a "friendly" giant Pacific Octopus.

George, a calm octopus, opened the boxes methodically.
Truman, Murphy said, was “an opportunist.”
Truman was too excited to bother with locks.
Truman stayed inside half an hour.

I was eager to see how Athena behaved with him.

A bucket with a handful of fish sat nearby.
Did she rise so eagerly sensing the food?
Or was it the sight of her friend that attracted her?
“She knows me,” Menashi answered softly.


Her arms twisted lazily.
Her grip felt calm, relaxed.



But intelligence is another matter.
Octopus and human intelligence evolved independently.



But octopuses are neither long-lived nor social.

So why is the octopus so intelligent?
What is its mind for?
Mather thinks she has the answer.
Losing the shell freed the octopus for mobility.
Each animal you hunt may demand a different skill set:
Shoot through the sea for a fast chase?
Or crawl out of the water to capture escaping prey?

Losing the protective shell was a trade-off.

Such intelligence is not always evident in the laboratory.
This has a great deal to do with consciousness.”

So what does it feel like to be an octopus?


IN MAY, I VISITED Athena a third time.
I wanted to see if she recognized me.
But how could I tell?
Scott Dowd opened the top of her tank for me.

This time I offered her only one arm.
Her hold on me was remarkably gentle.

“They earn their names,” Murphy had told me.
“She’s curious about what you are.”

Was she less curious now?
Did she remember me?
But perhaps she didn’t need to.

Then I thought I might know what she wanted from me.


She will live on, though, through your conveyance.”
To my surprise, I found myself in tears.

Why such sorrow?
I was eager to meet more of her kind.


The author discussed this article with a panel of animal intelligence experts during an Orion live web event.
There’s a new octopus in Sy Montgomery’s life!
The author of this article has now met Octavia, Athena’s successor at the New England Aquarium, and her experience teaches us even more about these intelligent beings. New on our blog.

Links :

Tuesday, April 17, 2012

Climate control: tiny switches, big effects

From BBC

Computer models reveal how small geographic features like the Bering Strait can have a profound impact on the Earth’s climate.
Modelling the global climate is as difficult and vexing a problem.



US NOAA nautical chart of Bering Strait
>>> geolocalization with the Marine GeoGarage <<<

Strait switch


Imagery Nasa



Flow charts

That sort of leap in today’s world would be catastrophic.


The water density also depends on how salty it is.

Bering factor




Monday, April 16, 2012

Canada CHS update in the Marine GeoGarage

46 charts have been updated (Apr 2, 2012) :


So 790 charts (1677 including sub-charts) are available in the Canada CHS layer. (see coverage)

See also written Notices to Shipping and Navarea warnings : NOTSHIP

What's happening under Gibraltar?

The Strait of Gibraltar, which lies between the southern coast of Spain and the northern coast of Morocco, is the only place where water from the Atlantic Ocean mixes with water from the Mediterranean Sea.
Credit : ESA

From OurAmazingPlanet

The ground beneath Portugal, Spain and northern Morocco shook violently on Nov. 1, 1755, during what came to be known as the Great Lisbon Earthquake.
With an estimated magnitude of 8.5 to 9.0, the temblor nearly destroyed the city of Lisbon and its lavish palaces, libraries and cathedrals.
What wasn't leveled by the quake was mostly demolished in the ensuing tsunami and fires that raged for days.
Altogether, at least 40,000 people were killed.

More than 250 years later, geologists are still piecing together the tectonic story behind that powerful earthquake.
A unique subduction zone beneath Gibraltar, the southernmost tip of the Iberian Peninsula, now seems to be culprit.
Subduction zones are the spots where one of Earth's tectonic plates dives beneath another, often producing some of the world's strongest earthquakes.

"At a global scale, subduction is the only process that produces magnitude-8 or -9 earthquakes," said Marc-Andre Gutscher, a geologist at the University of Brest in France.
"If subduction occurred, and is still occurring here, then it's highly relevant to understanding the region's seismic hazards."

Small but powerful

Gutscher's work, discussed in the March 27 issue of the journal Eos, has shown that sunken ocean lithosphere — a layer that comprises Earth's crust and upper mantle — lies beneath Gibraltar, and that it's still attached to the northern part of the African Plate.
Other teams have found crumpled ocean crust and active mud volcanoes in the Gulf of Cadiz, where water within the buried lithosphere mixes with sediments and boils up to the surface.

Altogether, these lines of evidence make a pretty convincing case for subduction, Gutscher said.

But unlike the textbook examples of huge subduction zones found at the Mariana Trench or under Alaska's Aleutian Islands, this subduction zone is comparatively tiny.
"Its very small size and ultra-slow motion make the Gibraltar subduction zone unique," Gutscher told OurAmazingPlanet.
"It's probably the narrowest subduction zone in the world — about 200 kilometers [120 miles] wide at most — and it's moving at far less than a centimeter per year."

What's happening under Gibraltar is an example of something called rollback subduction: As the sliver of lithosphere sinks into the mantle, the line where it's still "hinged" to the African Plate rolls back further and further, stretching the crust above it.

Seismic danger zone?

If subduction under Gibraltar is a thing of the past, there's little danger of future earthquakes. But that's not true if it is still happening — as Gutscher and many others believe to be the case.

That's because subduction has already created a tiny tectonic block, or microplate, between the African and Eurasian Plates.
Researchers using GPS have shown that this microplate is still moving a few millimeters westward every year, thanks to ongoing rollback subduction.

The boundaries of this microplate lie in southern Spain and northern Morocco.
Like California's San Andreas Fault, they're strike-slip boundaries (but smaller and slower-moving), so they're capable of generating earthquakes every now and then, Gutscher said.
For example, a magnitude-6.3 quake struck the city of Al Hoceima, Morocco, in February 2004, killing nearly 600 people.

But as far as another Great Lisbon Earthquake, residents of this region can breathe easy — at least for another millennium or so.
"Given the very slow motion of the faults in the area, you need many centuries to build up enough slip to generate such a great earthquake," Gutscher explained.
"A magnitude-8.5 or -9 earthquake is probably pretty much out of the question, since the last such tremendous event was only 250 years ago."