Blog Archive
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2009
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September
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- Sixty gun salutes fired marking China’s 60th anniv...
- China kicks off National Day extravaganza
- The60th anniversary of the founding of the People'...
- 60th anniversary of China's National Day
- News Today
- Rome: 10 Things to Do in 24 Hours
- Do-It-Yourself Translations Through Facebook Connect
- 1-800-Flowers Gets Analytics Tool for Measuring Fa...
- Mad Men Keeps Viewers Involved Through Interactive...
- YouTube Falls Short In Facebook Popularity Contest...
- Love, pleasure, duty: Why women have sex
- Plan your ideal walking workout
- Parents clueless when it comes to kids' growth charts
- 'Sorry I Haven't Written': A Scientific Explanation
- What You Need To Know About The H1N1 Vaccine
- News Today
- T-ara Celebrates Chuseok
- Rain’s Shanghai Concert Is A Scam
- Wonder Girls’ Diary in America Part 1
- Kris Allen Working With Adele and Duffy's Collabor...
- Rob Thomas' 'Someday' Music Video Debuted
- Radiohead's Thom Yorke Forms New Band With RHCP's ...
- Mitchel Musso's 'Shout It' Music Video Comes Out
- Lady GaGa Reveals Storyline of Her Joint Tour With...
- Mayday Parade Premiere 'The Silence' Music Video
- '90210' 2.05 Preview: Naomi Goes Green
- Preview of 'Melrose Place' 1.05: Canon
- 'Grey's Anatomy' Welcomes Sarah Drew as New Doctor
- A New Trailer of Epic Miniseries 'The Pacific'
- The Sue Storm of 'Fantastic Four' is in talks to j...
- Jessica Alba to Stir Things Up in 'Little Fockers'
- 'Whip It!': On the Set With Jimmy Fallon, Ellen Pa...
- Sylvester Stallone in New 'The Expendables' Photo
- 'Avatar' Sequel Could Explore Pandora Deeper
- Mandy Moore Talks Disney's 'Rapunzel'
- Emmy Rossum Reportedly Dating Counting Crows' Adam...
- Jon Cryer and Wife Lisa Joyner Adopt a Baby Girl
- Christina Milian and The-Dream Planning Another We...
- Private Memorial Service for Patrick Swayze Set fo...
- Scarlett Johansson: 'I Have Terrible Stage Fright'
- Karina Smirnoff Has New Boyfriend
- News Today
- The Obama Assassination Poll — Another Story About...
- New England Patriots Use Facebook As Primary Onlin...
- Taylor Swift’s Facebook Page Still Growing Fast, W...
- Miami: 10 Things to Do in 24 Hours
- Want to Lose Weight? Avoid Skinny Overeaters
- Scientists Announce Trove of Fragile New Species i...
- Miss Switzerland 2009 Linda Faeh
- News Today
- Giant panda twin cub
- T-ara And Supernova To Unleash TTL Listen.2
- What’s long, black and fits nicely in SNSD’s hands?
- Opening Dance Stage at Girl Groups Chuseok Special
- Sugababes' Amelle Reportedly Receives Death Threat...
- Snippet of The Queen Project's Debut Single
- Weezer Will Duet With Lil Wayne on 'Can't Stop Par...
- Lady GaGa Named Billboard's Rising Star
- 50 Cent Rushed to Hospital After Listening to Fat ...
- 'Camp Rock 2' Invites Fans to Join the Filming
- 'One Tree Hill' 7.04 Preview: Believe Me, I'm Lying
- Preview of 'Gossip Girl' 3.04: The Stars Are Coming
- Recap: Jive, Tango and Quickstep on 'Dancing with ...
- 'Wizards of Waverly Place' Receives More Episodes
- 'Heroes' 4.04 Preview: Tracy Is Back
- Oren Peli's 'Paranormal Activity' Expands to 20 Mo...
- Salma Hayek Gets a Vision in New 'The Vampire's As...
- 'New Moon' Unleashes Three Fresh Character Posters
- No 'Valentine's Day' for Joe Jonas
- First Look at Amanda in 'Saw VI'
- Plot Details on Robert Rodriguez's 'Predators'
- 'The Princess and the Frog': Extended Clip and Fea...
- Kim Kardashian and Reggie Bush 'Totally Back Toget...
- Emmy Rossum's Husband Justin Siegel Files for Divorce
- Robert Pattinson Isn't an 'Attention-Seeker'
- Hayden Panettiere Denies Dating Kevin Connolly
- Fred Durst and Wife Divorcing
- Taylor Lautner Feels Uncomfortable With His Muscul...
- News Today
- Iran Says It Test-Fires Longest-Range Missiles
- Five insider strategies for avoiding a hotel billi...
- Chicago: 10 Things to Do in 24 Hours
- Cartoons of the Week, September 26, 2009 - October...
- How Can A Pregnant Woman Get Pregnant Again?
- Why Doctors Are Giving Heroin to Heroin Addicts
- News Today
- Follow Ivy Behind the Scenes
- Lee Hyori’s New Album is going to be off the hook!
- JQT Releases Teaser
- Brown Eyed Girls @ Circle Nightclub Teaser!
- Carrie Underwood's 'Cowboy Casanova' Music Video A...
- Artist of the Week: Mariah Carey
- Video: Jenny Slate Dropped the F-Word on 'Saturday...
- 'Amazing Race' Eliminates Two Pairs Early in Its S...
- Cloudy with a Chance' Sticks to Box Office's Top
- A 'Predators' Role for Danny Trejo
- Tickets for Michael Jackson's 'This Is It' On Sale
- Jaime Pressly Ties the Knot
- Khloe Kardashian and Lamar Odom's Wedding Is On, t...
- Justin Guarini Weds Fiancee Reina Capodici
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September
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Friday, September 25, 2009
Rather Than Melt, Some Glaciers Race to the Sea
The seas are rising, and climate scientists say they'll keep rising as the globe continues to warm, causing all sorts of problems along tens of thousands of miles of coastline around the world. What the scientists can't say for sure, though, is how much sea level will go up, or how fast. That's largely because nobody knows for sure how the vast ice sheets covering Greenland and Antarctica will respond — especially the glaciers that flow down and into the sea.But that's changing, thanks largely to ice-watching satellites peering down from space. One of them has just reported in — and the news isn't encouraging. According to a new report in Nature, glaciers are getting thinner all around the perimeter of Greenland, and in West Antarctica as well. It's not so much that they're melting, says lead author Hamish Pritchard, of the British Antarctic Survey; it's that their seaward motion is accelerating. And, says Pritchard, "that's a much more rapid way of losing ice than through melting alone." Glaciologists already knew that Greenland has started shedding ice. "Back in the early 1990s," says Jay Zwally, a glaciologist with NASA's Goddard Space Flight Center, and the principal scientist for the agency's ICEsat orbiter, "Greenland was losing ice at the margins but gaining in the center. It was in balance." Recently, though, NASA's gravity-mapping satellite, known as GRACE, the Gravity Recovery and Climate Experiment, has shown a net loss of about a Lake Erie's worth of ice every six months or so. Part of it is probably due to melting alone, but scientists also knew as early as 1996 that some glaciers' motion had begun speeding up. One clear reason, says Zwally, was that summer meltwater was percolating down through cracks and lubricating the undersides of the glaciers, letting them slip more quickly down rocky slopes — a phenomenon known as the Zwally effect, since he's the one who first described it. But the new study, says Pritchard, using data from ICEsat, shows that there's more to it than slippery slopes. "We're seeing the same phenomenon in West Antarctica, he says, "where there's very little summer melt."What's happening instead, he and his colleagues believe, has to do with changes at the very mouth of the glaciers. When they reach the sea, many glaciers just keep going, reaching out beyond the shoreline to sit on the seafloor. But if warming temperatures or changes in ocean currents make these so-called ice tongues start to melt, they eventually float off the bottom — and the friction between ice and seafloor disappears. "It takes the brakes off," says Pritchard, "and the glacier accelerates." In Antarctica, where many glaciers flow, not directly into the sea but into giant floating ice shelves, it's the thinning or total collapse of the shelves — something that's been happening with increasing frequency — that takes the brakes off.All of this has been seen before in limited areas; the difference here, says Pritchard, is that "we're saying it's happening in all sorts of areas simultaneously, and intensifying in certain regions." Indeed, the speedup isn't limited to the downstream ends of glaciers. "Once it starts, it propagates inland very rapidly — we see a wave of thinning. So even the high, cold and remote areas far from shore are feeling the effects."What Pritchard won't do, however, is predict how this new information will affect estimates of sea level rise. "We don't do sea level because we don't have enough information. Will this lead to a runaway collapse of the ice sheets, or will it all grind to a halt? The honest answer is, nobody knows."Indeed, as recently as 2007, the Intergovernmental Panel on Climate Change (IPCC) declared in its last major report that its own projections of sea level rise — between 7 in. and about 2 ft. by century's end — didn't take into account changes in ice sheet behavior, because nobody really knew what to expect. Information gathered since then has already revised the conventional wisdom about rising seas upward to about 3 ft., and this week's study will undoubtedly figure into future calculations.There's still plenty to figure out, though — and ice experts, including Zwally, are already writing more papers based on ICEsat, GRACE and other observations. "We still really don't know much about ice sheet dynamics," says Zwally. "But the glaciers are doing the experiments for us."Michael D. Lemonick is the senior science writer at Climate Central.source: time.com