World War I submarine found off Dutch coast

From HuffingtonPost and other sources

The Dutch navy says it has discovered the sunken wreck of a German World War I submarine off the island of Terschelling and will designate it a war grave.

-> localization with the Marine GeoGarage

The Defense Ministry says the wreck of the SM U-106 is lying on the seabed 40 meters (130 feet) underwater and 65 kilometers (40 miles) north of Terschelling, an island in the Wadden Sea off the northern Netherlands.

The rusting remains of the submarine, photographed by the Remus ROV (credit : Dutch Navy)

The submarine was first discovered in October 2009 during hydrographical research by HNLMS Snellius, but the find was only announced 16th March after the Dutch Defense Ministry authorities confirmed its identity with German authorities and inform descendants of the crew.

"This type of discovery almost always happens by chance," said Jouke Spoelstra, the expedition leader of the identification project. "Some ten years ago, one of the ships of the Hydrographic Service passed by the exact same location, but then the boat was under a layer of sand. The submarine will be left where it is and will be made an official war grave. A commemoration ceremony could be held at sea, but that will only be done on the investigation of the families."

Following the discovery, the mine hunter HNLMS Maassluis searched the area in December 2009, using a wire-guide underwater camera.
The investigation confirmed that the shipwreck was a submarine.
Two months later, the HNLMS Hellevoetsluis launched the underwater robot Remus to further investigate the wreck.
Divers from the Navy's Diving and Explosive Ordnance Disposal Group were able to recover a cylindrical air tank that was used by WWI submarines to dive and surface.
A copper plate bearing the serial and the submarine numbers on the air tank clearly identified the wreck as SM U-106.

The Dutch navy initially believed the wreck was a Dutch submarine, O-13, that went missing during World War II in June 1940, but divers and remote cameras later confirmed it was the SM U-106.
SM U-106 was built by the Germaniawerft in Kiel, Germany.
The 71-meter (233 ft) and 946 ton (submerged) submarine could achieve a speed of 16.8 knots while on the surface and 9.1 knots under water.
It did have a surface range of about 11,200 miles (18,029 km), and 56 miles (90 km) while submerged.

A brass plaque on an air bottle from a recently discovered First World War German submarine as it is displayed in the North Sea, north of the Dutch island of Terschelling.
Photograph by: Royal Dutch Navy, AFP/Getty Images

The sub sank on 7 October 1917 after hitting a mine on its maiden voyage (the SM U-106 was commissioned on 28 July 1917 under the command of Kapitänleutnant Hans Hufnagel and paticipated in one wartime patrol starting on 2 September 1917), with the loss of all 41 crew.

SM U-106

During its first voyage, the submarine had torpedoed two British ships : during the first Battle of the Atlantic, it was credited with the sinking of HMS Contest, an Acasta-class destroyer, and damaging “City of Lincoln,” a 5,867-ton steamer, in the Western approaches.
Normally the German U-boats would be guided through the mines by a surface ship capable of detecting the explosives, Dutch navy spokesman Lt. Col. Robin Middel told The Associated Press, but on its ill-fated voyage the sub ran into a newly laid British mine.
The sub "was to make a rendezvous with that ship, but the ship never found the submarine and nobody had ever heard anything more from it," Middel said.

Links :

• Ministry of Defense NL : Navy discovers first World War German U-boat
• YouTube : Royal Navy finds submarine from WWI
  

New warning on Arctic sea ice melt

Arctic melt

From BBC

Scientists who predicted a few years ago that Arctic summers could be ice-free by 2013 now say summer sea ice will probably be gone in this decade.

The original prediction, made in 2007, gained Wieslaw Maslowski's team a deal of criticism from some of their peers.
Now they are working with a new computer model - compiled partly in response to those criticisms - that produces a "best guess" date of 2016.
Their work was unveiled at the European Geosciences Union (EGU) annual meeting.
The new model is designed to replicate real-world interactions, or "couplings", between the Arctic ocean, the atmosphere, the sea ice and rivers carrying freshwater into the sea.

Scientists fear huge volumes of meltwater from diminishing ice caps
may divert the Gulf Stream

"In the past... we were just extrapolating into the future assuming that trends might persist as we've seen in recent times," said Dr Maslowski, who works at Naval Postgraduate School in Monterey, California.
"Now we're trying to be more systematic, and we've developed a regional Arctic climate model that's very similar to the global climate models participating in Intergovernmental Panel on Climate Change (IPCC) assessments," he told BBC News.
"We can run a fully coupled model for the past and present and see what our model will predict for the future in terms of the sea ice and the Arctic climate."

And one of the projections it comes out with is that the summer melt could lead to ice-free Arctic seas by 2016 - "plus or minus three years".
It does not make predictions about the Greenland ice cap.

Thin evidence

One of the important ingredients of the new model is data on the thickness of ice floating on the sea.

Satellites are increasingly able to detect this, usually by measuring how far the ice sits above the sea surface - which also indicates how far the ice extends beneath.
Inclusion of this data into the team's modeling was one of the factors causing them to retrench on the 2013 date, which raised eyebrows - and subsequently some criticism - when it emerged at a US science meeting four years ago.
Since the spectacularly pronounced melting of 2007, a greater proportion of the Arctic Ocean has been covered by thin ice that is formed in a single season and is more vulnerable to slight temperature increases than older, thicker ice.

Even taking this into account, the projected date range is earlier than other researchers believe likely.
But one peer - Dr Walt Meier from the US National Snow and Ice Data Center in Boulder, Colorado - said the behavior of sea ice becomes less predictable as it gets thinner.
"[Maslowski's] is quite a good model, one thing it has is really high resolution, it can capture details that are lost in global climate models," he said.
"But 2019 is only eight years away; there's been modeling showing that [likely dates are around] 2040/50, and I'd still lean towards that.
"I'd be very surprised if it's 2013 - I wouldn't be totally surprised if it's 2019."

Crystal method

The drastic melt of 2007 remains the record loss of ice area in the satellite era, although subsequent years have still been below the long-term average.
But some researchers believe 2010's melt was equally as notable as 2007's, given weather conditions that were favorable to the durability of ice.

Although many climate scientists and environmental campaigners are seriously concerned about the fate of the Arctic sea ice, for other parts of society and other arms of government its degradation presents challenges and opportunities.

The Russian and Canadian governments, for example, are looking to the opportunities for mineral exploitation that will arise; while the US military has expressed concern about losing a natural defense around the country's northern border for part of the year.

"I'm not trying to be alarmist and not trying to say 'we know the future because we have a crystal ball'," said Dr Maslowski.
"Basically, we're trying to make policymakers and people who need to know about climate change in the Arctic realize there is a chance that summer sea ice could be gone by the end of the decade.
"For the national interest, the defense interest, I think it's important to realize that 2040 is not a crystal ball prediction."

Links :

• TheGuardian : Arctic Ocean freshwater will cause 'unpredictable changes on climate'
• YouTube : New study: melting Arctic ice almost gone in 10 years
• NASA : AMSR-E Arctic Sea Ice: September 2010 to March 2011
• NSID : Ice extent low at start of melt season; ice age increases over last year
• AWI : Large-scale assessment of the Arctic Ocean: significant increase in freshwater content since 1990s
  

On the sizeable wings of albatrosses

“Albatrosses extract energy from winds to soar, as seen in these diagrammatic views from the side (left) and from overhead (right).

Above a wave, winds blow progressively faster the higher you ascend.
As albatrosses rise at an angle from a relatively windless wave trough, they cross a boundary into an area of brisk winds.
They abruptly gain airspeed, giving them a burst of kinetic energy that allows them to climb to heights of 10 to 15 meters above the ocean.
Then they bank downwind and swoop down into another wave trough, adding airspeed as they cross the boundary in reverse, and begin the cycle again.
After the birds gain height, they can proceed in any of three directions.
They can turn downwind, getting a boost from the tailwind (orange).
They can swoop down into the same wave trough, flying parallel to the waves and perpendicular to the wind (green).
Or, like a sailboat, they can tack to the right or left of the wind and head generally into the wind (yellow).”

From Physorg

An oceanographer may be offering the best explanation yet of one of the great mysteries of flight--how albatrosses fly such vast distances, even around the world, almost without flapping their wings.
The answer, says Philip L. Richardson of the Woods Hole Oceanographic Institution (WHOI), lies in a concept called dynamic soaring, in which the large bird utilizes the power of above-ocean wind shear while tacking like an airborne sailboat.
(see WHOI article)

Albatrosses are consummate fliers, spending the majority of their long lives soaring above the ocean, rarely resting or using their wings.
By the age of 50, an albatross has typically flown at least 1.5 million miles.

“I have a simple model that explains the basic physics of what albatrosses do,” says Richardson, a scientist emeritus at WHOI, who, in addition to his primary career in studying ocean currents, has also piloted gliders.
The key, he says, is the bird’s ability to balance the kinetic energy gained in soaring with the energy lost from drag.

In a paper published in the winter 2011 issue of the journal Progress in Oceanography ("How do albatrosses fly around the world without flapping their wings?"), Richardson says that dynamic soaring using wind shear accounts for “80 to 90 percent of the total energy required for sustained soaring.”
He explains that above ocean waves, winds blow in layers—near the surface, air-sea friction slows lower-level winds while winds blow faster at higher levels.

As an albatross climbs from a wave trough, it is met by progressively faster winds that provide a burst of energy, increasing its speed significantly and carrying it as high as 10 to 15 meters.
Richardson was particularly intrigued by how the birds could be doing this while flying into the wind, something he had observed from a ship in the South Atlantic Ocean.
“It’s been a mystery how they fly this way,” he said.

Drawing on previous theories by Nobel laureate physicist Lord Rayleigh in 1883 and later by British scientist Colin Pennycuick, Richardson devised a model that accounts for the albatross’s dramatic, accelerating climbs and dives and elegant twists and turns, incorporating winds and waves.

It also explained the bird’s ability to seemingly fly upwind.
To travel upwind, a sailor tacks into the wind. Richardson realized that albatrosses do the same thing.
Using his model, he calculated that the bird tacks at about a 30-degree angle, “like a sailboat.”
“They are using wind shear both ways,” he says.
“To climb up and dive down.”
Using the model, he estimates that it takes a minimum wind speed of about 7 knots for an albatross to soar.

The wingspans of wandering albatrosses can reach 12 feet, but they rarely flap their wings.
Instead they take advantage of winds and waves to remain aloft without expending energy.

In further describing this dynamic soaring, Richardson says what he has done is to refine previous models.
While calculating that dynamic soaring accounts for the vast majority of energy for albatross flight, he says the remaining 10 to 20 percent comes from updrafts.
“It’s a simple model that explains what albatrosses do,” he said.
“It helps us understand how nature works.”
Beyond that, Richardson suggests that understanding albatross flight might help increase the speeds of radio-controlled gliders, or some day enable fleets of such gliders to be dispatched to measure oceans, he said.

Sex, drugs and sea slime : the ocean's oddest ceatures and why they matter

From NPR

Never threaten a hagfish. And if you do, watch out.

"When it's threatened or in danger or gets injured, it produces — very quickly — huge amounts of slime," says Ellen Prager, a marine scientist and educator.
"In fact, they found that in just a few minutes, it can fill up seven buckets full of gooey, slimy gunk."

The hagfish isn't the only underwater inhabitant with unusual tactics for survival.
In Sex, Drugs, and Sea Slime: The Oceans' Oddest Creatures and Why They Matter, Prager describes some of the craziest underwater activities that help ocean creatures stay alive, fight predators, find food and reproduce.

Consider the lobster

There are more than 100 species of lobsters in the ocean, but the one Americans are probably most familiar with is the Maine lobster, a wide-clawed nocturnal creature with a propensity for urinating on potential mates.

"The male lobsters use [urine] aggressively, but the female lobsters shoot it as a Love Potion No. 9," says Prager. "She shoots when she comes up to a den that might have a male in it. She actually seduces him with her pee and instead of clobbering her over the head with his claw, he says, 'Come in, come in' and gets all touchy-feely."

But before the female and male lobsters mate, the female sheds her shell.

"For the female lobster's private parts to become available, she has to molt," says Prager.
"And then she becomes acceptable to the male."

Dominant males are routinely seduced into one-off sexual encounters while female lobsters are generally more choosy, says Prager.
Females can store a male's sperm for up to three years, using it to fertilize several batches of eggs.

Coral Reefs: The More, The Merrier

Prager has a unique view of marine life because she used to be the chief scientist at an underwater research lab in the Florida Keys.
The lab, which sits underneath 60 feet of water, allows scientists to spend hours underwater studying the ocean without worrying about decompression.

The warm and relatively shallow water provided a fertile ground for reef-building corals.
The organism, which looks like rock, is considered an animal, plant and mineral.
It also provides food and shelter for other marine life and can develop into some of the biggest biologic structures on the planet, says Prager.
And just how do they build those structures?

Most coral reefs are what scientists refer to as "broadcasters."
That means they release either eggs or sperm into the water, where they float to the surface, mix and become fertilized.

"So if you're a coral and you want to mix your eggs with the sperm of another coral of your species, [you must] release [them] at the same time," says Prager.
"So coral reefs spawn synchronously throughout the world. All those corals release their eggs and sperm at the same time."

Prager says she's witnessed the synchronized release of eggs and sperm while on night dives.
"It looks like an undersea snowstorm," she says.
"The eggs look like little tiny pink balls and they all start floating up. And coral spawn is yummy fish food so worms and other things come to feed on it. It really [makes you think about] how active the ocean is."

Like the hagfish, corals also emit a mucuslike slime — dubbed "coral snot" — when disturbed.
"I will tell you from experience that if you disturb corals through something like drilling, [they] start to exude huge quantities of slime," she says.
"You come up just covered in the stuff."

Ellen Prager has written several books about underwater life, including Adventure on Dolphin Island, Chasing Science at Sea: Racing Hurricanes, Stalking Sharks and Living Undersea with Ocean Experts and Volcano: Iceland's Inferno and Earth's Most Active Volcanoes.
She has worked at the Sea Education Association in Woods Hole, Mass., the University of Miami's Rosenstiel School of Marine and Atmospheric Science, and the National Undersea Research Center in the Bahamas.
Prager has a Ph.D. from Louisiana State University and was chairwoman of the Ocean Research and Resources Advisory Panel for the U.S. government.

Links :

• YouTube : Ellen Prager I / II / III / IV
  

NZ Linz update in the Marine GeoGarage

NZ5322 Auckland Harbour

16 charts have been updated in the Marine GeoGarage (Linz March update published 31 March, 2011) :

• NZ68 : Nugget Point to Centre Island
  
• NZ69 : Stewart Island
  
• NZ232 : Lake Taupo (Taupomoana)
  
• NZ532 : Approaches to Auckland
  
• NZ542 : Motiti Island to Pehitari Point
  
• NZ681 : Approaches to Bluff and Riverton / Aparima
  
• NZ5125 : Bay of Islands
  
• NZ5214 : Marsden Point
  
• NZ5215 : Whangarei Harbour
  
• NZ5221 : Cradock Channel and Mokohinau Islands
  
• NZ5222 : Great Barrier Island (Aotea Island)
  
• NZ5321 : Mahurangi Harbour to Rangitoto Island
  
• NZ5322 : Auckland Harbour East
  
• NZ6825 : Paterson Inlet / Whaka A Te Wera
  
• NZ7624 : Charles Sound to Dagg Sound
  
• NZ7625 : Thompson Sound and Doubtful Sound / Patea
  

Today NZ Linz charts (178 charts / 340 including sub-charts) are displayed in the Marine GeoGarage.

Note : LINZ produces official nautical charts to aid safe navigation in New Zealand waters and certain areas of Antarctica and the South-West Pacific.

Using charts safely involves keeping them up-to-date using Notices to Mariners