評論
打印
So he visited the site the following year, becoming only the second geologist known to have done so, and took some samples.
因此，他在第二年訪問了該地點，成為了唯二這樣做的地質學家，并采集了一些樣本。
Examining the surrounding cliffs for signs of a collapse, he noticed that a peak known as Annapurna IV offered a relatively smooth, steep face which seemed to fit.
在檢查周圍的懸崖是否有崩塌的跡象時，他注意到一個被稱為安納普爾納四峰的山峰有一個相對光滑、陡峭的表面，適合采樣。
Back home, he sent samples from the rubble field, the rock core and others from the path the landslide might have taken for dating.
回到家后，他把從碎石場、巖心和滑坡可能經過的路徑上采集的樣本送去進行年代測定。
Should their ages roughly correspond, that would suggest they were linked to the same event.
如果它們的年代大概一致，那就表明他們與同一事件有關。
By measuring the abundance of chlorine-36 (a radioactive isotope which accumulates in surface rocks and decays once they are buried), and carbon-14 (another which accumulates in living matter and decays after death), his colleagues dated the samples to the late 12th century, and to within a couple of decades of each other.
通過測量氯-36(一種放射性同位素，在地表巖石中積累，一旦被掩埋就會衰變)和碳-14(另一種放射性同位素，在生物物質中積累，在生物死后會衰變)的豐度，他的同事們將這些樣本的年代定在了12世紀晚期，彼此相差不到幾十年。
That is within the accuracy limits of the dating techniques themselves.
這在年代測定技術本身的精度范圍內。
Besides shedding light on a previously unknown cataclysm, Dr Lave’s work could plug a gap in the dominant explanation for why mountains stop growing, which is known as the “glacial buzzsaw” hypothesis.
除了揭示之前未知的大災難之外，拉維博士的工作還可以填補關于山脈停止生長的解釋空白處，即眾所周知的“冰川電鋸”假說。
Under this model, it is glaciers, which are extremely effective at carving scoops out of mountains, that are mostly responsible for curbing their growth.
在這個模型下，冰川是抑制山脈生長的主要原因，因為冰川能極其有效地在山脈上鋸出鏟狀的空隙。
The problem with that theory, says Dr Rowan, is that there are some peaks that manage to escape the erosive effect of glaciers, and then grow so steeply that glaciers can no longer stick to their sides.
羅文博士說，這一理論的問題在于，有些山峰能夠逃脫冰川的侵蝕作用，然后變得非常陡峭，以至于冰川再也不能粘在它們的兩側。
“The question is,” she asks, “what stops these mountains getting bigger?”
“問題是，”她問道，“是什么阻止了這些山脈變得更大?”
Landslides could well be one answer.
山體滑坡很可能是一個答案。
While the exact trigger for the Annapurna landslide is unknown, Dr Lave’s idea is that, with nothing to shave rock off their tips, very high mountains simply keep growing until their weight is too much for their lower slopes—which do still experience erosion—to support.
雖然引發安納普爾納山崩的確切原因尚不清楚，但拉維博士的想法是，由于沒有任何東西可以刮掉山尖上的巖石，非常高的山脈只會繼續生長，直到它們的重量超過了它們的較低的斜坡——它們仍然會受到侵蝕——無法支撐。
Working out exactly how and when the tipping point is reached will require examining other such rockslides.
要想確切地知道如何以及何時達到臨界點的話，還需要研究其他類似的巖崩。
Unfortunately, due to the actions of both glaciers and swollen rivers during the monsoon season, the rubble from the Annapurna landslip is vanishing fast.
不幸的是，由于季風季節冰川和河流暴漲的作用，安納普爾納山崩的碎石正在迅速消失。
Dr Lave reckons that only about 10% of the dislodged material now remains in place.
拉維博士估計，現在只有被移走物質大約10%的碎石還留在原地。
Older rockslides, assuming there were any, may already be impossible to reconstruct.
更早的滑坡，假設存在過的話，可能已經無法重建了。
