時差N小時:南極冰層下洪流加速冰河流入海中

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南極冰層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.

科學(xué)家首度公布資料，證明南極冰川下的巨大洪流正使冰川加速流向海洋。這些體積龐大的冰川正從南極大陸和格陵蘭島流向海洋，它們漂移的速度直接決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.

這導(dǎo)致的后果將驚心動魄：即使海平面只上升幾十厘米，就足以對世界各地居住在低海拔三角洲和島國的人民造成毀滅性災(zāi)難。

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.

研究者近日發(fā)現(xiàn)，在南極冰層下隱秘的冰下湖泊會周期性的傾瀉大量水流。他們發(fā)現(xiàn)在同樣的14個月期間，冰層下湖泊溢出了1.7立方千米的水(相當(dāng)于0.4立方英里)，75公里(相當(dāng)于45英里)長的伯德冰川的移動速度加快了10%。

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

研究人員由此得出結(jié)論：“活躍的湖泊排水系統(tǒng)會導(dǎo)致冰川運(yùn)動出現(xiàn)大規(guī)模、快速的變化，我們的研究結(jié)果為此提供了直接證據(jù)。”

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.

該研究進(jìn)一步加劇了科學(xué)家對冰川融化速度的擔(dān)憂。例如，光是格陵蘭島表面覆蓋的冰層溶化后就能使海平面上升7米(相當(dāng)于23英尺)。即使最悲觀的全球氣候變暖預(yù)言也沒有報道這樣的情形。