厄瓜多爾“火喉”火山出現(xiàn)早期崩塌跡象

厄瓜多爾“火喉”火山出現(xiàn)早期崩塌跡象

Tungurahua, an active stratovolcano in Ecuador, is an ancient mountain that's picked up many names over the centuries.

通古拉瓦是厄瓜多爾一座活躍的層狀火山，是一座古老的山，幾個世紀以來，它被取了很多名字。

In the indigenous tongue of the Quechua peoples, the name means 'Throat of Fire'. Others say Tungurahua is Quichua for 'crater'. One nickname is the Black Giant.

在蓋丘亞人的土著語言中，這個名字的意思是“火喉”。其他人說通古拉瓦是Quichua的“火山口”。其中一個綽號是“黑巨人”。

Something everybody can agree upon, though, is that this old volcano has been a danger for a very long time – although the latest rumblings may signify a menace greater than any ordinary eruption.

然而，有一件事是每個人都同意的，那就是這座古老的火山在很長一段時間里都是危險的——盡管最近的轟鳴聲可能意味著比任何普通火山噴發(fā)更大的威脅。

According to a new analysis, Tungurahua may be showing early warning signs of what could be a catastrophic structural collapse, thought to be due to instabilities wrought by the damage of ongoing magma activity inside the volcano.

根據(jù)一項新的分析，通古拉瓦可能顯示出可能是災難性的結(jié)構(gòu)崩潰的早期預警跡象，人們認為這是由于火山內(nèi)部持續(xù)的巖漿活動造成的破壞造成的不穩(wěn)定。

Using satellite data we have observed very rapid deformation of Tungurahua's west flank, which our research suggests is caused by imbalances between magma being supplied and magma being erupted, says geophysical volcanologist James Hickey from the University of Exeter in the UK.

英國?？巳卮髮W的地球物理火山學家詹姆斯·?；f:“利用衛(wèi)星數(shù)據(jù)，我們觀察到通古拉瓦火山西側(cè)非常迅速的變形，我們的研究表明，這是由供應(yīng)的巖漿和噴發(fā)的巖漿之間的不平衡造成的。”

Tungurahua has been persistently active since 1999, but if 20 years of relatively frequent eruptions seems like a long time, it's not – at least not in the lifespan of this very long-lived volcano.

自1999年以來，通古拉瓦火山一直很活躍，但如果說20年相對頻繁的噴發(fā)似乎是一段很長的時間，至少在這個非常長壽的火山的壽命中不是。

Tungurahua is actually on its third life, you might say, having already endured two of these structural collapses triggered by eruptions. The first Tungurahua edifice (Tungurahua I) collapsed sometime around the end of the Late Pleistocene.

你可能會說，通古拉瓦實際上已經(jīng)經(jīng)歷了由火山爆發(fā)引發(fā)的兩次結(jié)構(gòu)崩塌，已經(jīng)進入了第三次生命。第一個通古拉瓦建筑物(通古拉瓦I)在晚更新世末期的某個時候倒塌了。

For thousands of years, the volcano then slowly rebuilt itself inside the remains of its original caldera. Then, about 3,000 years ago, Tungurahua II let forth, with another eruption prompting a partial collapse of the west flank.

數(shù)千年來，這座火山慢慢地在它原來的破火山口遺跡中重建。然后，大約3000年前，通古拉華二世爆發(fā)了，另一次噴發(fā)導致了西翼的部分坍塌。

When the sides of volcanoes give way like this, massive landslides can result, with avalanches of rock that can travel for up to tens of kilometres.

當火山的側(cè)面像這樣崩塌時，就會導致大規(guī)模的山體滑坡，伴隨而來的是長達數(shù)十公里的巖崩。

The collapse 3,000 years ago is thought to have unleashed a debris avalanche laying ruin to an area of some 80 square kilometres (over 11,000 football fields in size).

3000年前的崩塌被認為引發(fā)了一場巖屑雪崩，將80平方公里的區(qū)域(超過11000個足球場大小)夷為平地。

Given a single eruption in 1999 forced the evacuation of over 25,000 people in nearby areas, it's hard to understate the threat an actual flank collapse could pose to Tungurahua's living neighbours.

鑒于1999年的一次火山噴發(fā)迫使附近地區(qū)超過2.5萬人撤離，很難低估實際的火山側(cè)翼崩塌可能對圖古拉瓦附近的居民造成的威脅。

Nonetheless, according to Hickey and his team's modelling, significant surface deformation on Tungurahua's west flank (involving temporary uplift of about 3.5 cm, resulting from recent volcanic activity), is suggestive that a collapse could perhaps occur if the stresses do not abate.

盡管如此，根據(jù)Hickey和他的團隊的模型，Tungurahua的西側(cè)表面明顯的變形(包括由于最近的火山活動造成的約3.5厘米的暫時隆起)，這表明如果應(yīng)力沒有減弱，可能會發(fā)生崩塌。

Shallow and rapid pressurisation from this inclined deformation source can generate shear stress along the collapse surface, which increases with greater volumes of magma, the authors write in their paper.

作者在他們的論文中寫道:“來自這個傾斜變形源的淺層快速增壓會在崩塌表面產(chǎn)生剪應(yīng)力，而剪應(yīng)力會隨著巖漿量的增加而增加。”

This may contribute to slope instability during future unrest episodes and promote flank failure, with general application to other volcanoes worldwide displaying asymmetric deformation patterns.

“這可能會在未來的動蕩時期造成邊坡的不穩(wěn)定，并促進邊坡的破壞，而世界范圍內(nèi)其他火山的普遍應(yīng)用顯示出不對稱的變形模式。”

That said, the researchers acknowledge that their study is no prediction of certain doom. If anything, the findings could help us monitor these processes, so we can try to anticipate ahead of time what future conditions might trigger catastrophe.

盡管如此，研究人員承認，他們的研究并不是對某種厄運的預測。如果有什么不同的話，這些發(fā)現(xiàn)可以幫助我們監(jiān)測這些過程，這樣我們就可以嘗試提前預測未來可能引發(fā)災難的情況。

Magma supply is one of a number of factors that can cause or contribute to volcanic flank instability, so while there is a risk of possible flank collapse, the uncertainty of these natural systems also means it could remain stable, Hickey says.

“巖漿供應(yīng)是導致或促成火山翼面不穩(wěn)定的諸多因素之一，因此盡管存在翼面可能崩塌的風險，這些自然系統(tǒng)的不確定性也意味著它可能保持穩(wěn)定，”Hickey說。

Let's hope so. If not, the throat of fire may be about to speak again, and it won't be good news for anyone close enough to hear.

讓我們希望如此。否則，火喉可能會再次發(fā)出聲音，這對任何靠近它的人來說都不是好消息。

The findings are reported in Earth and Planetary Science Letters.

這些發(fā)現(xiàn)發(fā)表在《地球與行星科學快報》上。