时差N小时:南极冰层下洪流加速冰河流入海中

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南极冰层下洪流加速冰河流入海中

Scientists unveiled the first direct evidence thatmassive floods deep below Antarctica's ice cover areaccelerating the flow of glaciers into the sea. Howquickly these huge bodies of ice slide off theAntarctic and Greenland land masses into the oceanhelp determine the speed at which sea levels rise.

科学家首度公布资料，证明南极冰川下的巨大洪流正使冰川加速流向海洋。这些体积庞大的冰川正从南极大陆和格陵兰岛流向海洋，它们漂移的速度直接决定了海平面升高的速度。

The stakes are enormous: an increase measured in tens of centimeters (inches) couldwreak havoc for hundreds of millions of people living in low-lying deltas and island nationsaround the world.

这导致的后果将惊心动魄：即使海平面只上升几十厘米，就足以对世界各地居住在低海拔三角洲和岛国的人民造成毁灭性灾难。

Researchers discovered only recently that inaccessible subglacial lakes in Antarcticaperiodically shed huge quantities of water. They discovered that during the same 14-monthperiod that 1.7 cubic kilometers (0.4 cubic miles) of water cascaded through subglacialwaterways, the 75-kilometer (45-mile) long glacier downstream picked up speed, movingabout 10 percent faster.

研究者近日发现，在南极冰层下隐秘的冰下湖泊会周期性的倾泻大量水流。他们发现在同样的14个月期间，冰层下湖泊溢出了1.7立方千米的水(相当于0.4立方英里)，75公里(相当于45英里)长的伯德冰川的移动速度加快了10%。

"Our findings provide direct evidence that an active lake drainage system can cause largeand rapid changes in glacier dynamics," the researchers concluded.

研究人员由此得出结论：“活跃的湖泊排水系统会导致冰川运动出现大规模、快速的变化，我们的研究结果为此提供了直接证据。”

The study adds to growing scientific concern about the pace at which glaciers are meltinginto the seas. The ice sheet that sits atop Greenland, for example, contains enough water toraise world ocean levels by seven meters (23 feet). Even the gloomiest global warmingpredictions do not include such a scenario.

该研究进一步加剧了科学家对冰川融化速度的担忧。例如，光是格陵兰岛表面覆盖的冰层溶化后就能使海平面上升7米(相当于23英尺)。即使最悲观的全球气候变暖预言也没有报道这样的情形。