Thwaites為什么是“世界末日冰??川”

The massive Thwaites glacier in West Antarctica contains enough ice to raise global sea levels by 65cm if it were to completely collapse. And, worryingly, recent research suggests that its long-term stability is doubtful as the glacier hemorrhages more and more ice.

南極洲西部巨大的Thwaites冰川冰量驚人，如果它完全坍塌入海，全球海平面將升高 65 厘米。而且，令人擔憂的是，最近的研究表明，隨著冰川融化，其長期穩(wěn)定性令人懷疑。

Adding 65cm to global sea levels would be coastline-changing amounts. For context, there's been around 20cm of sea-level rise since 1900, an amount that is already forcing coastal communities out of their homes and exacerbating environmental problems such as flooding, saltwater contamination, and habitat loss.

全球海平面增加65厘米將使海岸線向內(nèi)陸進一步推進。就背景而言，自 1900 年以來，海平面上升了約 20 厘米，這已迫使沿海居民離開家園，并加劇了洪水、咸水污染和棲息地喪失等環(huán)境問題。

But the worry is that Thwaites, sometimes called the "doomsday glacier" because of its keystone role in the region, might not be the only glacier to go.Were it to empty into the ocean, it could trigger a regional chain reaction and drag other nearby glaciers in with it, which would mean several meters of sea-level rise.

但令人擔憂的是，有時被稱為“世界末日冰??川”的 Thwaites 可能不是唯一會崩潰的冰川。如果它流入海洋，可能會引發(fā)區(qū)域性連鎖反應并將附近的其他冰川卷入其中，這意味著海平面將上升數(shù)米。

That's because the glaciers in West Antarctica are thought to be vulnerable to a mechanism called Marine Ice Cliff Instability or MICI, where retreating ice exposes increasingly tall, unstable ice cliffs that collapse into the ocean.

這是因為南極洲西部的冰川被認為容易受到一種稱為海洋冰崖不穩(wěn)定性(MICI)的機制的影響，在這種機制中，退縮的冰層暴露出越來越高、不穩(wěn)定的冰崖，這些冰崖坍塌到海洋中。

A sea level rise of several meters would inundate many of the world's major cities – including Shanghai, New York, Miami, Tokyo, and Mumbai.

海平面上升幾米將淹沒世界上許多主要城市，包括上海、紐約、邁阿密、東京和孟買。

It would also cover huge swathes of land in coastal regions and largely swallow up low-lying island nations like Kiribati, Tuvalu, and the Maldives.

它還將覆蓋沿海地區(qū)的大片土地，并在很大程度上吞沒基里巴斯、圖瓦盧和馬爾代夫等低洼的島國。

Thwaites is a frozen river of ice approximately the size of Great Britain. It already contributes around 4 percent of the global sea-level rise.和英國一樣大

Thwaites是一條冰凍的河，面積大約相當于大不列顛。它已經(jīng)貢獻了全球海平面上升的4%。

Since 2000, the glacier has had a net loss of more than 1000 billion tons of ice and this has increased steadily over the last three decades. The speed of its flow has doubled in 30 years, meaning twice as much ice is being spewed into the ocean as in the 1990s.

自2000年以來，該冰川已經(jīng)凈損失了超過1萬噸的冰，而且在過去30年里，這一數(shù)字還在穩(wěn)步增加。它的流速在30年內(nèi)翻了一番，這意味著流入海洋的冰量是20世紀90年代的兩倍。

Thwaites glacier, the widest in the world at 80 miles wide, is held back by a floating platform of ice called an ice shelf, which restrains the glacier and makes it flow less quickly.

Thwaites是世界上最寬的冰川，寬80英里。它被一個叫做冰架的漂浮冰平臺擋住，這個平臺限制了冰川，使其流動速度變慢。

But scientists have just confirmed that this ice shelf is becoming rapidly destabilized. The eastern ice shelf now has cracks crisscrossing its surface and could collapse within ten years, according to Erin Pettit, a glaciologist at Oregon State University.

但科學家剛剛證實，這個冰架正在迅速變得不穩(wěn)定。據(jù)俄勒岡州立大學(Oregon State University)的冰川學家艾琳·佩蒂特(Erin Pettit)說，東部冰架的表面現(xiàn)在有縱橫交錯的裂縫，可能在十年內(nèi)坍塌。

This work supports research published in 2020 which also noted the development of cracks and crevasses on the Thwaites ice shelf. These indicate that it is being structurally weakened.

這項工作支持 2020 年的一項研究，后者還指出 Thwaites 冰架上裂縫和裂縫的發(fā)展趨勢，表明它的結(jié)構(gòu)正被削弱。

This damage can have a reinforcing feedback effect because cracking and fracturing can promote further weakening, priming the ice shelf for disintegration.

這種破壞可以產(chǎn)生強化反饋效應，因為開裂和破裂導致進一步削弱，為冰架解體埋下伏筆。

If Thwaites' ice shelf did collapse, it would spell the beginning of the end for the glacier. Without its ice shelf, Thwaites glacier would discharge all its ice into the ocean over the following decades to centuries.

如果冰架真的崩塌，那將意味著冰川終結(jié)的開始。在沒有冰架的情況下，冰川在接下來的幾十年到幾個世紀里會將所有的冰排到海洋中。

However, scientists are still getting to grips with MICI and questions remain about the future of West Antarctic glaciers. While the collapse of Thwaites certainly could trigger a wholesale collapse event, not everyone believes this will happen.

然而，科學家們?nèi)晕赐耆錗ICI。雖然 Thwaites 的崩潰肯定會引發(fā)大規(guī)模的連鎖反應，但并不是每個人都相信 Thwaites會徹底解體。

Other work suggests that the destabilization of the Thwaites ice shelf and glacier may not lead to the kind of catastrophic outcomes that some fear. Sea ice and chunks of ice that break away from the collapsing ice shelf and glacier might have a similar restraining effect to the intact ice shelf, nipping the chain reaction in the bud and preventing the sustained collapse of the entire West Antarctic ice sheet.

其他工作表明，冰架和冰川的不穩(wěn)定可能不會導致某些人擔心的災難性后果。從崩塌的冰架和冰川上脫離的海冰和冰塊可能對完整的冰架具有類似的抑制作用，將連鎖反應扼殺在萌芽狀態(tài)，防止整個南極西部冰蓋持續(xù)崩塌。

But while uncertainty remains about exactly what will happen in West Antarctica, one thing is for sure – the retreating Thwaites glacier will continue to add to global sea levels for many years to come.

但是，雖然南極洲西部究竟會發(fā)生什么仍然不確定，但有一件事是肯定的——退縮的Thwaites冰川將在未來許多年持續(xù)升高全球海平面。