厄瓜多尔“火喉”火山出现早期崩塌迹象

厄瓜多尔“火喉”火山出现早期崩塌迹象

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

通古拉瓦是厄瓜多尔一座活跃的层状火山，是一座古老的山，几个世纪以来，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.

在盖丘亚人的土著语言中，这个名字的意思是“火喉”。其他人说通古拉瓦是Quichua的“火山口”。其中一个绰号是“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，有一件事是每个人都同意的，那就是这座古老的火山在很长一段时间里都是危险的——尽管最近的轰鸣声可能意味着比任何普通火山喷发更大的威胁。

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.

根据一项新的分析，通古拉瓦可能显示出可能是灾难性的结构崩溃的早期预警迹象，人们认为这是由于火山内部持续的岩浆活动造成的破坏造成的不稳定。

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.

英国埃克塞特大学的地球物理火山学家詹姆斯·希基说:“利用卫星数据，我们观察到通古拉瓦火山西侧非常迅速的变形，我们的研究表明，这是由供应的岩浆和喷发的岩浆之间的不平衡造成的。”

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年以来，通古拉瓦火山一直很活跃，但如果说20年相对频繁的喷发似乎是一段很长的时间，至少在这个非常长寿的火山的寿命中不是。

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.

你可能会说，通古拉瓦实际上已经经历了由火山爆发引发的两次结构崩塌，已经进入了第三次生命。第一个通古拉瓦建筑物(通古拉瓦I)在晚更新世末期的某个时候倒塌了。

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.

数千年来，这座火山慢慢地在它原来的破火山口遗迹中重建。然后，大约3000年前，通古拉华二世爆发了，另一次喷发导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.

当火山的侧面像这样崩塌时，就会导致大规模的山体滑坡，伴随而来的是长达数十公里的岩崩。

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年前的崩塌被认为引发了一场岩屑雪崩，将80平方公里的区域(超过11000个足球场大小)夷为平地。

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.

鉴于1999年的一次火山喷发迫使附近地区超过2.5万人撤离，很难低估实际的火山侧翼崩塌可能对图古拉瓦附近的居民造成的威胁。

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.

尽管如此，根据Hickey和他的团队的模型，Tungurahua的西侧表面明显的变形(包括由于最近的火山活动造成的约3.5厘米的暂时隆起)，这表明如果应力没有减弱，可能会发生崩塌。

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.

作者在他们的论文中写道:“来自这个倾斜变形源的浅层快速增压会在崩塌表面产生剪应力，而剪应力会随着岩浆量的增加而增加。”

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.

“这可能会在未来的动荡时期造成边坡的不稳定，并促进边坡的破坏，而世界范围内其他火山的普遍应用显示出不对称的变形模式。”

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.

尽管如此，研究人员承认，他们的研究并不是对某种厄运的预测。如果有什么不同的话，这些发现可以帮助我们监测这些过程，这样我们就可以尝试提前预测未来可能引发灾难的情况。

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.

“岩浆供应是导致或促成火山翼面不稳定的诸多因素之一，因此尽管存在翼面可能崩塌的风险，这些自然系统的不确定性也意味着它可能保持稳定，”Hickey说。

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.

让我们希望如此。否则，火喉可能会再次发出声音，这对任何靠近它的人来说都不是好消息。

The findings are reported in Earth and Planetary Science Letters.

这些发现发表在《地球与行星科学快报》上。