文章來源：《經(jīng)濟(jì)學(xué)人》Sep 30th 2023 期 Science & technology?欄目 Ice and fire 冰與火

[Paragraph 1]

Mapping glaciers?was once a difficult and?arduous?job. So was monitoring volcanoes for the?grumblings and rumblings?that might herald an eruption.?In recent decades, the old methods of hiking boots and mountaineering gear have been joined by satellites and remote sensing, making things both easier and safer.

繪制冰川地圖曾經(jīng)是一項(xiàng)困難而艱巨的工作。同樣，監(jiān)測火山噴發(fā)前的咆哮與轟鳴也很艱巨。近幾十年來，徒步登山裝備與衛(wèi)星遙感技術(shù)相結(jié)合，使得這些任務(wù)更容易、更安全。

?

[Paragraph 2]

But looking from afar has its drawbacks too. If a volcano is high enough to?sport?glaciers on its flanks (and many are), then the thick layer of ice can make it harder, or impossible, to get accurate temperature readings from the rock beneath.

但遠(yuǎn)觀方法也有缺點(diǎn)。如果火山的側(cè)面高到被冰川覆蓋（很多火山都是這樣），那么厚厚的冰層會(huì)使監(jiān)測冰下巖石溫度讀數(shù)變得更加困難，甚至不可能。

[Paragraph 3]

And that is a particular problem, for glacier-topped volcanoes are some of the most dangerous of all.?If they do erupt, the heat can melt the glaciers, forming torrents of fast-moving mud called?lahars?that can flatten anything in their path.?In 1985 the Nevado del Ruiz volcano in western Colombia erupted. The glaciers on its summit and flanks formed several gigantic lahars, one of which buried the nearby town of Armero, killing more than 20,000 of its inhabitants. It remains the worst natural disaster in the country’s history.

這是一個(gè)特殊的問題，因?yàn)楸ǜ采w的火山極其危險(xiǎn)。如果火山爆發(fā)，熱量會(huì)融化冰川，形成快速流動(dòng)的泥流，稱為“火山泥流”，可以毀了所到之處的一切。1985年，哥倫比亞西部的內(nèi)瓦多德爾魯伊斯火山爆發(fā)?；鹕巾斉c側(cè)面的冰川形成了幾條巨大的火山泥流，其中一條火山泥流掩埋了附近的阿爾梅羅鎮(zhèn)，導(dǎo)致2萬多居民死亡。這仍然是哥倫比亞歷史上最嚴(yán)重的自然災(zāi)害。

[Paragraph 4]

In a paper published last month in Geology, Matteo Spagnolo and Brice Rea, a pair of volcanologists at the University of Aberdeen, suggest a possible solution to the problem.?The internal heat of volcanoes, they conclude, has a notable impact on the glaciers that sit on top of them.Monitoring those glaciers, rather than the volcano itself, may serve as an early-warning system for anyone living nearby.

上個(gè)月《地質(zhì)學(xué)》雜志發(fā)表了一篇論文，作者是阿伯丁大學(xué)的兩位火山學(xué)家馬特奧.斯帕尼奧洛和布萊斯.雷亞，他們提出了一個(gè)可能的火山預(yù)警方案。他們得出結(jié)論，火山的內(nèi)部熱量對火山頂部的冰川有著顯著影響。監(jiān)測火山表面的冰川，而不是火山本身，可能作為附近居民的早期預(yù)警系統(tǒng)。

[Paragraph 5]

The researchers and their colleagues studied 600 glaciers in the Andes (including those on Nevado del Ruiz) of which 74, being less than a kilometre from the mouth of an active volcano, were classed as “volcanic”.?One of the main features the scientists were looking for was the “equilibrium?line”. This is the point on a glacier that separates the “accumulation zone”, where snow adds to the glacier’s mass, from the “ablation?zone”, where melting subtracts from it.?One of the things that affects the equilibrium line is the weather. Plenty of snowfall, or a cool summer, and the line will move downhill. A dry winter or a scorching summer will move it higher.

研究人員及其同事們研究了安第斯山脈上 600 座山峰冰川（包括了內(nèi)瓦多德爾魯伊斯火山上的冰川），其中有74 座山的冰川距離活火山口不到一公里，被歸類為 "火山冰川”?？茖W(xué)家們尋找的主要特征之一是“平衡線”，即火山冰川上的 "積雪區(qū) "和 "消融區(qū) "之間的分界線。"積雪區(qū) "的積雪增加了冰川的質(zhì)量，而 "消融區(qū) "的融雪則減少了冰川的質(zhì)量。影響平衡線的因素之一是天氣。如果降雪量大或夏季涼爽，平衡線就會(huì)向下移動(dòng)。而干燥的冬季或炎熱的夏季則會(huì)使平衡線上移。

[Paragraph 6]

In theory, though, any source of heat—including volcanic heat from beneath the ground—ought to affect the height of the equilibrium line.?When the researchers examined the data, that is exactly what they found.?Glaciers on volcanoes had equilibrium lines notably higher than those on ordinary mountains.?In some cases, as on Copahue, a volcano on the border between Chile and Argentina, which last had a major eruption in 2016, the difference could be several hundred metres.?Glaciers on?quiescent?volcanoes, such as Parinacota, a 6,400-metre mountain that sits between Bolivia and Chile, had equilibrium lines similar to glaciers on mountains that had never been volcanic at all.

然而，從理論上講，任何熱源——包括地下的火山熱——都會(huì)影響平衡線的高度。當(dāng)研究人員研究數(shù)據(jù)時(shí)，他們正是發(fā)現(xiàn)了這一點(diǎn)。火山上的冰川平衡線明顯高于普通山脈上的冰川平衡線。例如，位于智利和阿根廷邊境的科帕韋火山，它的平衡線與普通山脈的平衡線高度相差數(shù)百米。該火山最近一次大規(guī)模噴發(fā)是在 2016 年。死火山上的冰川（例如位于玻利維亞和智利之間的一座 6,400 米高的帕里納科塔山），它們的平衡線與普通山脈上的冰川平衡線高度相似。

[Paragraph 7]

With so many glaciers in their sample, the researchers were able to rule out other explanations, such as differences in the local microclimate.?And on the 13 volcanoes for which the best data were available, they were able to map the correlation in detail.?Those data showed a strong link between changes in the amount of volcanic heat seeping to the surface and the movements of the equilibrium line.

由于樣本中的冰川數(shù)量非常之多，研究人員能夠排除其他解釋，如當(dāng)?shù)匚夂虻牟町?。根?jù)13 座火山的最佳數(shù)據(jù)，他們成功繪制出了相關(guān)性圖表。這些數(shù)據(jù)表明，滲入地表的火山熱量變化與平衡線移動(dòng)之間存在密切相關(guān)性。

[Paragraph 8]

This means, say the researchers, that, although volcanic glaciers?obscure?what is going on underneath, they could themselves serve as?telltales.?Sudden changes in the equilibrium line, particularly if they are?out of kilter with?those of other glaciers nearby, could be evidence that something is brewing beneath the surface, and that further attention is warranted.?Although they are getting better, volcanologists still cannot predict exactly when eruptions will occur. But a rise in heat suggests more?magma?is accumulating below, and makes a valuable early-warning sign.

研究人員說，這意味著盡管火山冰川掩蓋了地表下的情況，但它們本身可以作為線索。平衡線的驟然變化，特別是如果它們與附近其他冰川的變化不一致時(shí)，可能表明地表下的巖漿正在醞釀，需要進(jìn)一步關(guān)注。盡管火山學(xué)日益完善，但火山學(xué)家仍然無法預(yù)測火山爆發(fā)的準(zhǔn)確時(shí)間。但熱量的上升表明有更多的巖漿正在地表下積聚，這是一種有價(jià)值的提前預(yù)警信號(hào)。

[Paragraph 9]

The findings have implications beyond volcanology and warning nearby inhabitants of a looming disaster.?Measurements of glaciers around the world provide one way for climate researchers to track the long-term effects of climate change.?A warmer planet should mean that glaciers are receding everywhere, and?by and large?they are.?But Dr Spagnolo and Dr Rea’s results suggest that not all glaciers make equally reliable thermometers.?Those on the sides of volcanoes can advance and recede for reasons entirely unrelated to global warming.?Climate scientists, they argue, should consider excluding such glaciers from their databases.

這項(xiàng)研究的意義除了給附近居民提供火山預(yù)警信號(hào)，意義還超越了火山學(xué)的范圍。世界各地冰川的測量為氣候研究人員提供了一種追蹤氣候變化長期影響的方法。地球變暖意味著各地的冰川都在消退，而且大體上確實(shí)如此。但斯帕尼奧洛博士和雷亞博士的研究結(jié)果表明，并非所有冰川都能提供同樣可靠的溫度數(shù)據(jù)?；鹕絺?cè)面的冰川可能會(huì)增加和消退，但可能與全球變暖完全無關(guān)。他們認(rèn)為，氣候科學(xué)家應(yīng)該考慮刪除研究數(shù)據(jù)庫中的火山冰川的溫度數(shù)據(jù)。