美国地球物理联合会（AGU）2021年度会议上研究人员警告称，目前南极洲最大冰川——思韦茨冰川正在逐渐融化，其加速融化趋势可能导致该冰架在未来三年内完全崩塌。思韦茨冰川有时也被称为“末日冰川”，因为它的崩塌可能会引发南极洲冰川崩塌的连锁反应。
Antarctica's 'Doomsday Glacier' could meet its doom within 3 years
Time is melting away for one of Antarctica's biggest glaciers, and its rapid deterioration could end with the ice shelf's complete collapse in just a few years, researchers warned at a virtual press briefing on Monday (Dec. 13) at the annual meeting of the American Geophysical Union (AGU).
12月13日，美国地球物理联合会（AGU）2021年度会议上，研究人员警告称，目前南极洲最大冰川——思韦茨冰川正在逐渐融化，其加速融化趋势可能导致该冰架在未来几年内完全崩塌。
Thwaites glacier in western Antarctica is the widest glacier on Earth, spanning about 80 miles (120 kilometers) and extending to a depth of about 2,600 to 3,900 feet (800 to 1,200 meters) at its grounding line — where the glacier transitions from a land-attached ice mass to a floating ice shelf in the Amundsen Sea. Thwaites is sometimes referred to as the "Doomsday Glacier," as its collapse could trigger a cascade of glacial collapse in Antarctica, and the latest research from the frozen continent suggests that doomsday may be coming for the dwindling glacier even sooner than expected.
位于南极洲西部的思韦茨冰川是地球上最大的冰川之一，横跨大约120公里（80英里），冰川底基延伸深度大约800-1200米，目前该冰川正在从陆地连接冰川转变成阿蒙森海漂浮冰架，思韦茨冰川有时也被称为“末日冰川”，因为它的崩塌可能会引发南极洲冰川崩塌的连锁反应，最新研究表明，这座不断缩小冰川的末日可能会比预期的更早到来。
Warming ocean water is not just melting Thwaites from below; it's also loosening the glacier's grip on the submerged seamount below, making it even more unstable. As the glacier weakens, it then becomes more prone to surface fractures that could spread until the entire ice shelf shatters "like a car window" — and that could happen as soon as three years from now, researchers said at AGU, held in New Orleans and online.
海水变暖不仅使思韦茨冰川底部开始融化，同时该冰川的海底冰山部分也开始松动，使其更加不稳定。研究人员在新奥尔良举行的 AGU 会议上表示，随着冰川逐渐消融，它更容易出现表面裂缝，这种裂缝可能会逐渐蔓延，直到整个冰架像汽车车窗玻璃一样破碎，预计这些悲剧将在三年后发生。
Over the last decade, observations of Thwaites showed that the glacier is changing more dramatically than any other ice and ocean system in Antarctica, thanks to human-induced climate change and increased warming in Earth's atmosphere and oceans. Thwaites has already lost an estimated 1,000 billion tons (900 billion metric tons) of ice since 2000; its annual ice loss has doubled in the past 30 years, and it now loses approximately 50 billion tons (45 billion metric tons) more ice than it receives in snowfall per year, according to The International Thwaites Glacier Collaboration (ITGC).
在过去的十年里，研究人员对思韦茨冰川的观察表明，由于人类活动导致的气候变化以及地球大气和海洋变暖加剧，该冰川的变化比南极洲任何其他冰川和海冰结构更加剧烈。自2000年以来，思韦茨冰川已失去了10000亿吨冰，依据国际思韦茨冰川合作组织（ITGC）的统计数据，过去30年，该冰川每年冰流失量递增一倍，现在每年损失冰比每年降雪量增加冰多500亿吨。
If Thwaites were to break up entirely and release all its water into the ocean, sea levels worldwide would rise by more than 2 feet (65 centimeters), said ITGC lead coordinator Ted Scambos, one of the presenters at AGU and a senior research scientist at the Cooperative Institute for Research in Environmental Sciences (CIRES).
国际思韦茨冰川合作组织调研员，美国地球物理联合会发言人之一，同时也是环境科学研究合作研究所 (CIRES)高级研究员的泰德·斯卡姆波斯称，如果思韦茨冰川完全分解并释放所有海水流入大海，全球海平面将上升65厘米以上。
"And it could lead to even more sea-level rise, up to 10 feet [3 m], if it draws the surrounding glaciers with it," Scambos said in a statement, referring to the weakening effect one ice shelf collapse can have on other nearby glaciers.
谈到该冰架崩塌可能会削弱附近其他冰川的影响时，斯卡姆波斯在一项声明中说道：“如果它融合了周围的冰川，可能会导致海平面进一步升高，甚至达到3米。”
Because Thwaites is changing so quickly and could significantly affect global sea-level rise, more than 100 scientists in the United States and the United Kingdom are collaborating on eight research projects to observe the glacier from top to bottom; results from several of those teams were presented at AGU.
由于思韦茨冰川融化速度非常快，可能会显著影响全球海平面上升，美国和英国100多名科学家正在合作进行8个研究项目，从上至下地观察冰川，其中几个团队的研究成果在美国地球物理联合会上展示。
Scambos said at the briefing. "We've got a few more years to go to assemble further results and integrate them, so we have a better understanding of this glacier moving forward."
斯卡姆波斯说：“我们还可以用几年的时间收集思韦茨冰川的变化情况，并以该冰川的融化进行分析整合，这样将更好地理解该冰川未来的变化趋势。”
Melt from below
冰川从底部融化
At Thwaites, scientists bored holes through the ice to peer at the ocean hundreds of meters underneath, and other researchers deployed remote-controlled diving robots to study the glacier's grounding zone. They took temperature readings and measured salinity in the ocean, confirming that waters deep under the ice were warm enough to cause significant melt.
科学家在思韦茨冰川上钻洞，观察该冰川数百米深处冰层和海水，同时，他们还部署了远程控制潜水机器人来研究冰川底部与海水接触区域，测量了相关温度读数和海洋盐度，证实了冰下深处的海水足够温暖，足以导致显著的海冰融化。
Another group of scientists found that tidal activity could interact with the ice overhead to actively pump warm water farther inland through channels that were already carved by melt, thereby accelerating Thwaites' deterioration, said presenter Lizzy Clyne, an adjunct professor at Lewis and Clark College in Portland, Oregon.
美国路易-克拉克大学客座教授丽兹·克莱因说：“另一组科学家发现，潮汐活动能与冰川露出水面部分发生交互作用，将温暖的海水通过已融化的冰川通道流至冰川深处，从而加速了思韦茨冰川融化。
"When you have low tide, the floating ice shelf portion sinks down," Clyne said at AGU. "This acts kind of like a lever, and can actually pull up a section a little bit inland that can pull water in. And then the opposite happens when you have high tide and the water level rises — the floating section rises up." This up-and-down movement, known as tidal pumping, pulls water farther inland and weakens even more of the glacier, Clyne explained.
“当处于海水低潮状态下，浮冰部分下沉，” 克莱因说,“这有点像杠杆，实际上可以将一部分内陆冰川拉起一点，将海水吸入。而海水涨潮时情况正好相反，水位上升，冰川漂浮部分也会上升。”这种冰川上下移动状况被称为‘潮汐泵’，会将海水拉向更远的内陆区域，从而对冰川起到一种融化作用，克莱因解释说。
"Hundreds of icebergs"
碎裂成数百个冰川
Once-solid ice masses on Thwaites that formerly helped to hold the ice shelf together are also breaking down; the glacier's icy "tongue" — a part of the ice shelf that protrudes seaward — on the western side is now "just a loose cluster of icebergs and no longer influences this eastern, more stable section of the ice shelf," according to AGU presenter Erin Pettit, an associate professor of geophysics and glaciology at Oregon State University. When the tongue was more solid, it slowed the flow of the eastern ice shelf toward the ocean. But with the loss of that resistance, the flow of the eastern shelf has shifted over the past 10 years. Cracks are rapidly spreading through the ice, and that portion of the shelf will likely shatter "into hundreds of icebergs" within just a few years, Pettit said.
美国地球物理联合会2021年度会议主持人，俄勒冈州立大学地球物理学副教授艾琳·佩蒂特称，曾对思韦茨冰川起到冰架固定作用的坚硬冰层正在破裂，冰川的“冰舌”——伸向海水的一部分冰架，仅是松散的几处冰山，不再影响冰川东部更稳定的部分。当冰舌更加坚硬时，会减缓东部冰架向海洋的流动，但随着阻力逐渐消失，东部冰架在过去10年里发生了变化。裂缝在冰层上快速蔓延，在几年时间里冰架很可能会碎裂成数百座冰山。
The effect would be somewhat like that of a car window "where you have a few cracks that are slowly propagating, and then suddenly you go over a bump in your car and the whole thing just starts to shatter in every direction," she said.
她说：“这种效应有点儿像车窗破碎过程，当车窗出现一些裂缝，随后裂缝会逐渐蔓延扩大，当车辆行驶颠簸时，车窗可能在某个瞬间朝向任何方向碎裂。”
While the immediate prognosis is grim for Thwaites' ice shelf, the longterm forecast for the rest of the glacier is less certain. Should the shelf collapse, the glacier's flow will likely accelerate in its rush toward the ocean, with parts of it potentially tripling in speed; other chain reactions could also play a part in driving accelerated ice fracturing and melt, Scambos said at AGU. But the timeframe for those changes will be decades rather than a handful of years, according to the briefing.
虽然科学家对思韦茨冰川的近期预测很糟糕，但对其他冰川的长期预测就不那么确定了，如果冰架崩塌，其流向海洋的速度可能会加快，部分冰川的融化速度可能会增加两倍。斯卡姆波斯称，其他连锁反应也可能在加速冰破裂和融化方面发挥着重要作用，但这些变化的时间框架是几十年，而不是几年。
Meanwhile the ITGC teams will continue to monitor and analyze changes in the ongoing interplay between glacier, ice shelf and ocean on Thwaites, to help world leaders and policy makers prepare for what comes next.
目前，国际思韦茨冰川合作组织将继续监测和分析思韦茨冰川、冰架和海洋之间的持续相互作用，从而帮助世界各国领导人和政策制定者做好应对策略。
