Blogs / 80beats

Three months ago 90 rubber duckies set out on a perilous adventure, sliding down deep holes in a Greenland ice sheet that were expected to carry them eventually out to the ocean. In an experiment designed to shed light on the gradual melting of Greenland’s glaciers due to global warming, the duckies were deposited into moulins (tubular holes) in the Jakobshavn Glacier in mid-September by Alberto Behar, a robotics expert at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. The idea was that the ducks would float along the same channels that melt waters do, and wherever they emerged would reveal the path of the disappearing ice [Scientific American].

But thus far the researchers who have been eagerly awaiting news of the duckies’ arrival in the ocean have been disappointed, and they’re now putting out a loud call for sailors, fishermen, and cruise passengers to keep their eyes peeled for bobbing specks of yellow on the waves. The $2 ducks were chosen for their buoyancy and for their durability in low temperatures. Nasa is offering $100 to the first person who finds a duck. The toys are stamped with an email address and the word “reward” in three languages, including Inuit [Telegraph].

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Hope you’re not bored of stories about water ice on Mars: Now that scientists have found it, they can’t seem to stop finding it. Just a few months after the dear, departed Mars Phoenix Lander made history by touching and analyzing water ice beneath the soil near the Martian north pole, researchers using NASA’s Mars Reconnaissance Orbiter have discovered massive glaciers near the equator. The glaciers, buried under rocky debris, are said to be more than three times the size of Los Angeles, up to half a mile thick and skirt the edges of mountains and cliffs [Telegraph].

The glaciers’ presence means that rovers on future scientific missions won’t have to land at the freezing cold poles to study the planet’s ice. The glaciers could even prove helpful as a source of drinkable water to future astronauts exploring Mars. “This says there may be samples of ice within our reach,” [researcher Jim] Head said. “If we’re thinking ahead to human exploration of Mars, it means we could go to some of these places and actually have water ice there” [Wired News]. Astronauts could also make hydrogen fuel from the ice, researchers say.

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Deep beneath the Antarctic ice sheet, floods of water from buried lakes can hurry glaciers along on their slow slide towards the sea, according to a new study that tracked recent floods beneath the Byrd Glacier. “It’s like putting in a squirt of oil,” says Andy Smith of the British Antarctic Survey, who was not involved in this latest study. “The water lubricates the base of the glacier” [New Scientist]. The findings will help researchers understand the movement of glaciers around the world, a matter of great interest to climate scientists who are investigating how rapidly ice sheets may melt into the ocean due to global warming.

Researchers discovered only recently that inaccessible subglacial lakes in Antarctica periodically shed huge quantities of water. Data collected by a satellite launched in 2003 … revealed a complex network of subglacial plumbing in which water periodically cascades from one hidden reservoir to another [AFP]. The water in the lakes remains liquid, despite being buried beneath a mile of ice in some places, due to warmth from the underlying rock. Now, researchers have shown that these hidden floods affect the thick mountains of ice above.

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Climate scientists have long predicted that global warming will melt polar ice sheets and cause sea levels to rise throughout the century, potentially swamping island nations and flooding low-lying coastal cities. But exactly how much ocean waters will rise has yet to be settled. Now, two studies have come out that at first appear to contradict each other, leading to clashing headlines like “An Inconvenient Truth” Exaggerated Sea Level Rise [Telegraph], and Sea Level Rise May Be Twice More Than Expected [Discovery News].

One study seems to downplay the risk of an extreme sea-level rise, while the other hypes it up. But a closer look reveals that the two studies actually bring researchers nearer to scientific consensus.

In the study published in Science [subscription required], researchers examined the hypothesis of a six-foot sea-level rise by 2100, and calculated how quickly the ice sheets in Greenland and Antarctica would have to melt into the oceans to produce this effect. Their calculations showed that the glaciers would have to essentially gallop towards the sea, which seems an unlikely outcome. In Greenland, the glaciers moving into the island’s calving fjords would have to increase their speed to 28.4 miles per year and sustain that speed until the end of the century [Telegraph]. These researchers believe the most plausible scenario is a sea-level rise of between two and six feet within this century. As their results have been compared to more radical estimates like the 20-foot rise mentioned in the documentary film An Inconvenient Truth, the findings are being greeted with relief.

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The deep furrows carved in the sides of Martian craters were most likely formed by snowmelt in the planet’s recent geological past, according to a new study. The findings indicate that seasonal flows of liquid water may have streamed down the craters’ flanks when Mars was a wetter planet, as recently as a few hundred thousand years ago. Today, the Red Planet is a colder and drier place; although the Mars Phoenix Lander found water ice buried under the dirt near the north pole, no liquid water currently exists on the planet, and any ice exposed to air quickly turns into vapor due to the low atmospheric pressure.

The gullies were first sighted several years ago, but researchers couldn’t immediately determine what had caused them. [S]ome scientists proposed that the features were formed either by dry avalanches or by groundwater pushing up from below the surface and running down the sides of craters [SPACE.com]. But in a new study of crater images taken by the Mars orbiters, researchers found evidence that ice and melting snow were the culprits.

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