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
3 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.
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 :
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
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.
