Saturday, August 27, 2011

Full map of Antarctic ice flow

source NASA

NASA-funded researchers have created the first complete map of the speed and direction of ice flow in Antarctica.
The map, which shows glaciers flowing thousands of miles from the continent's deep interior to its coast, will be critical for tracking future sea-level increases from climate change.
The team created the map using integrated radar observations from a consortium of international satellites.

"This is like seeing a map of all the oceans' currents for the first time. It's a game changer for glaciology," said Eric Rignot of NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the University of California (UC), Irvine.
Rignot is lead author of a paper about the ice flow published online in Science Express.
"We are seeing amazing flows from the heart of the continent that had never been described before."

Rignot and UC Irvine scientists Jeremie Mouginot and Bernd Scheuchl used billions of data points captured by European, Japanese and Canadian satellites to weed out cloud cover, solar glare and land features masking the glaciers.
With the aid of NASA technology, the team painstakingly pieced together the shape and velocity of glacial formations, including the previously uncharted East Antarctica, which comprises 77 percent of the continent.

Like viewers of a completed jigsaw puzzle, the scientists were surprised when they stood back and took in the full picture.
They discovered a new ridge splitting the 5.4 million-square-mile (14 million-square-kilometer) landmass from east to west.

The team also found unnamed formations moving up to 800 feet (244 meters) annually across immense plains sloping toward the Antarctic Ocean and in a different manner than past models of ice migration.

"The map points out something fundamentally new: that ice moves by slipping along the ground it rests on," said Thomas Wagner, NASA's cryospheric program scientist in Washington.
"That's critical knowledge for predicting future sea level rise. It means that if we lose ice at the coasts from the warming ocean, we open the tap to massive amounts of ice in the interior."

The work was conducted in conjunction with the International Polar Year (IPY) (2007-2008). Collaborators worked under the IPY Space Task Group, which included NASA; the European Space Agency (ESA); Canadian Space Agency (CSA); Japan Aerospace Exploration Agency; the Alaska Satellite Facility in Fairbanks; and MacDonald, Dettwiler and Associates of Richmond, British Columbia, Canada.
The map builds on partial charts of Antarctic ice flow created by NASA, CSA and ESA using different techniques.

"To our knowledge, this is the first time that a tightly knit collaboration of civilian space agencies has worked together to create such a huge dataset of this type," said Yves Crevier of CSA.
"It is a dataset of lasting scientific value in assessing the extent and rate of change in polar regions."

Links :
  • University of California - Irvine : Scientists map huge rivers of Antarctic ice flowing into the seas in climate change 'breakthrough'
  • ESA : Revealed, an ice sheet on the move

Friday, August 26, 2011

NZ Linz update in the Marine GeoGarage

NZ4315 Onehunga wharf

charts have been updated in the Marine GeoGarage (Linz July update published 3 August, 2011) :

  • NZ542 : Motiti Island to Pehitari Point
  • NZ4314 : Manukau Harbour
  • NZ4315 :Approaches to Onehunga : Onehunga Wharf
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

Irene looks to break US hurricane Lull

From almost 230 miles above the Earth, cameras on the International Space Station recorded new video of Hurricane Irene, which is strengthening as it takes aim on the southeast Bahamas, and possibly, the Eastern Seaboard of the United States.
The video was captured at 4:08 p.m. EDT on August 23, 2011, as Irene moved west-northwest.

From LiveSciences

The Outer Banks of North Carolina haven't seen a hurricane hit in several years.
That could change Saturday (Aug. 27).

Hurricane Irene is now barreling through the Bahamas as a Category 3 hurricane with winds of 115 mph (185 kph) and could strengthen further when it swirls up the East Coast.
Coastal North Carolina evacuations have begun.
Leaving is voluntary for residents but mandatory for tourists.

Irene's arrival would snap the three-year lull in U.S. hurricane landfalls.
The last hurricane to hit the United States was Hurricane Ike in September 2008.
That storm socked the coasts of Texas and Louisiana, killing dozens of people.
Many cities in Irene's predicted path haven't seen a major hurricane in decades.

Irene is expected to move through the Bahamas, then up to the Outer Banks, a 200-mile (322 kilometers) string of barrier islands.
Irene is then expected to travel along the coast of the Mid-Atlantic and Northeast states and could bring severe winds and rain as far north as Maine.
The storm would likely weaken in the cooler waters off the northern states, though it could still bring torrential rains and strong storm surge. [Related: Could New York City Handle a Hurricane?]

The Outer Banks jut out into the Atlantic, making it a hurricane bull's eye. Several tropical cyclones (which include tropical storms and hurricanes) have hit them or passed nearby in recorded hurricane history.
Hurricane Floyd made landfall over the Outer Banks in September 1999 as a Category 2 hurricane and killed 35 people in North Carolina.
It was the deadliest storm to hit the U.S. since Hurricane Agnes in 1972.

Hurricane Isabel hit the Outer Banks in 2003 as a Category 2 storm, where it caused hundreds of millions of dollars in damages.

Category 2 hurricanes on the Saffir-Simpson scale of hurricane strength have winds between 96 and 110 mph (154 and 177 kph).
Winds in a Category 3 hurricane like Irene range from 111 to 130 mph (178 to 209 kph).

In New York City, people are keeping a close watch on the storm's track.
New York frequently gets the wind and rain from passing storms, including ones that strike Long Island, but hasn't had a direct hurricane hit since 1985, when Gloria caused hundreds of millions of dollars in damage with its high winds and storm surge.
In 1972 and 1976, hurricanes came close but spared the city.

The New England Hurricane of 1938 hit Long Island as a Category 3 storm.
The hurricane caused flooding and power outages and disrupted subway and ferry service.
In 1944, the Great Atlantic Hurricane hit Long Island, sending 100 mph (161 kph) winds into New York City.

Irene could reach New England as a Category 1 late Sunday.
The last hurricane to make landfall in New England was Hurricane Bob in 1991, which struck near the Connecticut-Rhode Island border as a Category 2 storm.

Should Irene last all the way to Maine, it would be the first hurricane to make landfall there since Gerda in 1969.

Irene is the first hurricane in what has been forecast to be an active season.
The National Oceanic and Atmospheric Administration updated its forecast Aug. 4, predicting 14 to 19 named storms (which include tropical storms and hurricanes), seven to 10 hurricanes, and three to five major hurricanes.
An average Atlantic hurricane season will see 11 named storms, six hurricanes and two major hurricanes.
August, September and October are the peak months of the Atlantic hurricane season.

Links :

Thursday, August 25, 2011

Why species matter

From BBC

How many more fish in the sea?
Plenty, according to research commissioned by the Census for Marine Life, which puts the number of species in the world's oceans at 2.2m, and the total for the whole planet at 8.74m (plus or minus 1.3m).

You can read more about the study, published in the journal PloS Biology, and the novel way that it was calculated here, but the figure is a vast improvement on previous estimates, which range form 3 to 100 million - close to useless when it comes to understanding the complex web of ecological interactions underpinning life on earth.

And the number of species we share the planet with does matter.
As one of the co-author's of the study, Boris Worm from Dalhousie University points out,
"If we didn't know - even by an order of magnitude (1m? 10m? 100m?) - the number of people in a nation, how would we plan for the future?"

At its most basic, if we don't know what we've got, we can't protect it, and we can't even be sure what we're losing.

And we are losing species at an alarming rate.
Again estimates vary wildly, but the distinguished biologist E.O. Wilson put the figure at some 30,000 a year, or three every hour.
It's a rate that compares with previous extinction events - like the one that wiped out the dinosaurs 65m years ago - and has been dubbed the 6th mass extinction event in the history of life on earth.

Listening to the government's former chief scientific adviser, Lord Robert May, on the programme this morning I was reminded of a scene in the science fiction blockbuster The Matrix.

Having subdued our hero the villain of the piece, agent Smith, pauses - as Hollywood bad guys so often do - to deliver a soliloquy: Humans, he declares, are like a virus, multiplying until every natural resource on the planet is consumed.

"We need to know how much we can lose...and we ca't do that properly if we don't even know what's there."
"Human beings are a disease. A cancer of this planet. You are a plague, and we are the cure."
Lord May didn't go quite that far, but he's not above employing the occasional sci fi metaphor to make his point.

Speaking some years ago as president of the Royal Society about the rate at which human activity was driving other species to extinction, he suggested that people were probably ingenious enough to survive in the damaged and depleted world of the movie Blade Runner, but the question was did we really want to live in that world?

"We are astonishingly ignorant," Lord May told the programme, "about how many species are alive on earth today, and even more ignorant about how many we can afford to lose while still maintaining the vital ecosystem services that humanity ultimately depends on."

That may be why so many biologists believe the biodiversity crisis is actually a much more profound threat to our future than global warming.

Links :
  • NationalGeographic : 86 percent of Earth's species still unknown?
  • BBC : Species count put at 8.7 million
  • Wired : The mass extinction of scientists who study species

Wednesday, August 24, 2011

La Solitaire du Figaro : near photo finish in leg 4

Live AIS tracking of the arrival in Dieppe with the Marine GeoGarage
(with positions updated every 7 seconds)

An incredible finish to the 2011 Solitaire du Figaro!
Jeremie Beyou (BPI) won leg four by just 12 seconds, with Paul Meilhat (Macif 2011), Fabien Delehaye (Port de Caen Ouistream) and Erwan Tabarly (Nacarat)
all finishing within 38 seconds of Beyou after 430 miles and 72 hours of intense racing.

From VendeeGlobe

Jérémie Beyou gave us a real masterpiece of sailing today.

Dominating throughout this 2011 Solitaire du Figaro, he was not about to let anyone else take victory in this final leg, which set off from Les Sables d'Olonne three days ago... just as in two of the previous legs between Caen and Dublin and between Dublin and Les Sables d'Olonne.

Simply magical.
It is all the more impressive when we remember that he dominated 99% of the first leg – between Perros-Guirec and Caen via the south of England – before a change in the weather enabled the runner-up Fabien Delahaye to take over.
Third place on the podium goes to Erwan Tabarly after a determined struggle.

Newly discovered Icelandic current could change climate picture

Northern Denmark Strait showing newly discovered deep current,
in relation to known pathway.

From NSF

If you'd like to cool off fast in hot summer weather, take a dip in a newly discovered ocean current called the North Icelandic Jet (NIJ).

You'd need to be far, far below the sea's surface near Iceland, however, to reach it.

Scientists have confirmed the presence of the NIJ, a deep-ocean circulation system off Iceland. It could significantly influence the ocean's response to climate change.

The NIJ contributes to a key component of the Atlantic Meridional Overturning Circulation (AMOC), critically important for regulating Earth's climate.

As part of the planet's reciprocal relationship between ocean circulation and climate, the AMOC transports warm surface water to high latitudes where the water warms the air, then cools, sinks and returns toward the equator as a deep flow.

Crucial to this warm-to-cold oceanographic choreography is the Denmark Strait Overflow Water (DSOW), the largest of the deep, overflow plumes that feed the lower limb of the AMOC and return the dense water south through gaps in the Greenland-Scotland Ridge.

For years it has been thought that the primary source of the Denmark Overflow was a current adjacent to Greenland known as the East Greenland Current.

However, this view was recently called into question by two oceanographers from Iceland who discovered a deep current flowing southward along the continental slope of Iceland.

They named the current the North Icelandic Jet and hypothesized that it formed a significant part of the overflow water.

Now, in a paper published in the August 21st online issue of the journal Nature Geoscience, the team of researchers--including the two Icelanders who discovered the current--has confirmed that the Icelandic Jet is not only a major contributor to the DSOW but "is the primary source of the densest overflow water."

"We present the first comprehensive measurements of the NIJ," said Robert Pickart of the Woods Hole Oceanographic Instititution in Massachusetts, one of the co-authors of the paper.

"Our data demonstrate that the NIJ indeed carries overflow water into Denmark Strait and is distinct from the East Greenland Current. The NIJ constitutes approximately half of the total overflow transport and nearly all of the densest component."

The researchers used a numerical model to hypothesize where and how the NIJ is formed.

"These results implicate water mass transformation and exchange near Iceland as central contributors to the deep limb of the Atlantic Meridional Overturning Circulation, and raise new questions about how global ocean circulation will respond to future climate change," said Eric Itsweire, program director in the U.S. National Science Foundation (NSF)'s Division of Ocean Sciences, which funded the research.

"We've identified a new paradigm," Pickart said, likely a new, overturning loop of warm to cold water.
The results, Pickart says, have "important ramifications" for ocean circulation's impact on climate.

Scientists have been concerned that this overturning loop--some call it a conveyor belt--is slowing down due to a rise in global temperatures.
They suggest that increasing amounts of fresh water from melting ice and other warming-related phenomena are making their way into the northern North Atlantic, where it could freeze and decrease the need for the loop to deliver as much warm water as it does now.
Eventually, this could lead to a colder climate in the northern hemisphere.

While this scenario is far from certain, researchers need to understand the overturning process, Pickart said, to make accurate predictions about the future of climate and circulation interaction.

"If a large fraction of the overflow water comes from the NIJ, then we need to re-think how quickly the warm-to-cold conversion of the AMOC occurs, as well as how this process might be altered under a warming climate," said Pickart.

Pickart and a team of scientists from the U.S., Iceland, Norway, and the Netherlands are scheduled to embark on August 22nd on a cruise aboard the research vessel Knorr.
They will collect new information on the overturning in the Iceland Sea.

"During our upcoming cruise we will deploy an array of year-long moorings across the entire Denmark Strait to quantify the NIJ and distinguish it from the East Greenland Current," Pickart said.
"Then we'll collect shipboard measurements in the Iceland Sea to the north of the mooring line to determine more precisely where and how the NIJ originates."

The cruise will be chronicled at the North Icelandic Jet Cruise website.

Links :
  • WHOI : Newly discovered Icelandic current could change North Atlantic climate picture

Tuesday, August 23, 2011

No to Arctic drilling

From TheNYTimes

About 55,000 gallons of oil have escaped into the North Sea since last week from a leaky pipeline operated by Royal Dutch Shell, about 100 miles off Scotland.

Last year, Americans watched in mounting fury as the oil industry and the federal government struggled for five disastrous months to contain the much larger BP blowout in the Gulf of Mexico.

Now imagine the increased danger and difficulty of trying to cope with a similar debacle off Alaska’s northern coast, where waters are sealed by pack ice for eight months of each year, gales roil fog-shrouded seas with waves up to 20 feet high and the temperature, combined with the wind chill, feels like 10 degrees below zero by late September.

That’s the nightmare the Obama administration is inviting with its preliminary approval of a plan by Shell to drill four exploratory wells beginning next summer in the harsh and remote frontier of the Beaufort Sea, off the North Slope of Alaska.

The green light to drill now awaits Shell’s receiving the necessary permits from various federal agencies, including the Environmental Protection Agency, the Fish and Wildlife Service, the National Marine Fisheries Service and the Bureau of Ocean Energy Management, Regulation and Enforcement.

The administration should put on the brakes.
This is a reckless gamble we cannot afford. We can’t prevent an Arctic blowout any more than we can avert disaster in the Gulf of Mexico or the North Sea.
We don’t have the infrastructure, the knowledge or the experience to cope with one if it occurs.
It’s irresponsible to drill in these waters unless we have those capabilities.

When the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, appointed by President Obama in May 2010, reported our findings and recommendations earlier this year, we specifically cited the need to address these shortcomings before exposing Arctic waters to this kind of risk.

We need comprehensive research on the vibrant yet little understood Arctic ecosystems, which are home to rich fisheries of salmon, cod and char, and habitat for beluga whales, golden eagles and spotted seals.

We need containment and response plans tailored to the demands of marine operations under some of the most unforgiving conditions anywhere on earth.

And we must be realistic about the kind of backup available in a place 1,000 miles from the nearest United States Coast Guard station.

Shell’s latest spill, in the North Sea, reminds us of the peril we court by ignoring these urgent needs.

When BP’s Macondo well blew out last year, killing 11 workers aboard the Deepwater Horizon, Americans believed the damage would be quickly contained.

The Gulf of Mexico, after all, is the epicenter of the global offshore oil industry, home to hundreds of companies that specialize in drilling wells beneath the sea.
There were plenty of ships in the region, from the shrimping fleet to the Coast Guard, available to help the efforts to cap the well and contain the spill.

And yet, in the five months it took to kill the runaway well, 170 million gallons of toxic crude oil poured into the gulf.

The systems that we were promised would avert catastrophe by preventing or containing a blowout all failed one by one.

And cleanup operations couldn’t save the marine life and birds that died, the 650 miles of coastline that was oiled or the deep water habitat now carpeted in crude, despite the efforts of nearly 50,000 workers using nearly 7,000 ships and boats.

Now comes Shell, claiming in its drilling application that its blowout preventers will work.
If not, Shell asserts, it can quickly seal the well. And, should oil escape, the company insists, it will have booms, skimmers and helicopters at the ready.

Upon those thin hopes the newly constituted Bureau of Ocean Energy Management, Regulation and Enforcement recently gave Shell preliminary approval to attempt this high-wire act in the Arctic.

We have yet to embrace the lessons of the BP blowout, the worst oil spill in our history.
While the bureau, formerly known as the Minerals Management Service, has improved drilling rules in helpful ways, Congress has yet to pass legislation to protect our waters, workers and wildlife from the dangers of offshore drilling.

Those dangers are only greater in the harsh and remote Arctic waters.
Before we go to the ends of the earth in pursuit of oil, we need deeper knowledge, better technology to prevent blowouts and to clean up after accidents, and greater expertise to protect Alaska’s Arctic waters, one of our oceans’ last frontiers, from grave and needless risk.

Links :

Monday, August 22, 2011

Abandoned boats become unofficial economic indicator

Photo by Cyrus Buffum/Charleston Waterkeeper:
Two abandoned boats litter the waters of Charleston, behind Folly Beach

From FoxNews

Abandoned vessels may have become an unofficial indicator of the tough economy.

While no exact national figures exist, authorities in most states with a coast or large body of water have reported increasing numbers of boat owners abandoning ship in recent years.

"Certainly the economic downturn did seem to increase the number of boats that were being reported as derelict," said Dan Burger, director of communication for the Ocean and Coastal Resource Management division of the South Carolina Department of Health and Environmental Control (DHEC).

There are a host of reasons why people abandon boats, including those who can't keep up on the loan payments, maintenance, or the high cost of fuel.

DHEC is overseeing the removal of scores of abandoned boats from coastal waterways.

During a recent tour of Charleston's Ashley River, DHEC Coastal Projects Manager Curtis Joyner pointed to a saltwater marsh where his agency had supervised the removal of multiple boats.

"There were seven vessels ... consisting of a metal barge, a shrimp boat and several sail boats," Joyner said. "I think it's one of our really good success stories in restoring the environment."

In addition to being eyesores, abandoned vessels often leak fuel and other hazardous chemicals and usually lack any lights to warn approaching boats at night.

Joyner pointed to an abandoned vessel anchored close to a major channel used by commercial and recreational boaters. Over time, anchor lines wear out and boats break free, eventually sinking or colliding with other watercraft.

"When the vessel breaks loose, then we have to deal with it," said David Rogers, harbormaster at the Charleston City Marina. "Normally they're, of course, abandoned and do not have insurance."

South Carolina is among dozens of state and local governments that have recently increased penalties against owners of abandoned vessels. But with boats frequently changing hands and owners often scratching off serial numbers, tracking them can be difficult.

That sticks taxpayers with removal fees ranging from $3,000 to $20,000, depending on the size of the boat.

The same market conditions affecting boat owners are also affecting the government agencies in charge of removing abandoned vessels. So, increasingly, they're relying on help from the private sector.

"A local car dealer chipped in to help us get a big shrimp boat out recently," said Robbie Freeman, managing partner of the Charleston City Marina. "Just people who care about clean water."

Freeman said he advises financially troubled boaters to seek help from local businesses and government authorities before their vessels take on water.

Links :
  • NYTimes : Boats too costly to keep are littering coastlines

Sunday, August 21, 2011

The Glide

An excerpt from The Glide, a multimedia performance combining ocean and surfing footage by Jon Frank with music performed by Richard Tognetti and the Australian Chamber Orchestra. The music in this section is Elgar's Sospiri set with footage from Waimea Bay.

From TheSurfer'Path

This serene collaborative piece shot by Jon Frank and played by the Australian Chamber Orchestra, which is headed up by Richard Tognetti of Musica Surfica fame, is part of a larger collaboration by Frank, Tognetti and the ACO.

Here’s what Jon Frank has to say about the whole thing:

“The Glide was a fascinating project to work on.
It is a concert which runs for about 1 hour and 20 mins and features music composed by JS Bach, Elgar, Strauss, Shostakovich, a traditional sea shanty and a couple of pieces by RT himself.
It’s all about the ocean and surfing and how it feels to be surrounded by water and space and light.
The concert orchestra perform on what is essentially a dark stage, music lit by small lights on black music stands, in front of a giant projection of the motion and still images.
The concert premiered in Maribor, Slovenia in 2009 and selected excerpts have been performed in New York, Noosa and Margaret River.