How are these fires burning underground? - Emma Bryce

翻译人员: Arianna Malik 校对人员: Jing Quan

In 1997, a fire began in Indonesia that would rage for almost a year.

1997年，印度尼西亚 发生了一场持续将近一年的大火。

It spanned several thousand square kilometers,

它跨越了数千平方公里，

halted numerous international flights,

中断了许多国际航班，

and spread an acrid haze all the way to China.

并将刺鼻的雾霾一直蔓延到中国。

Yet, despite being one of the largest fires in recorded history,

然而，尽管它是有记录以来 最大的火灾之一，

for months at a time it burned without a flame—

但几个月来，它在没有火焰燃烧的情况下

blazing on entirely underground.

完全在地下燃烧。

This might sound like a uniquely freaky fire, but each year,

这听起来像是一场独特的怪异大火， 但每年，

subterranean fires produce roughly 15% of global greenhouse gas emissions—

地下大火产生的温室气体排放量 约占全球温室气体排放量的15％，

that’s six times more than international aviation.

是国际航空的六倍。

And these burns are virtually unstoppable,

而且这些烧伤几乎是不可阻挡的，

earning them the ominous title of zombie fires.

为他们赢得了僵尸大火的不祥称号。

So, is it possible to snuff out these bizarre blazes?

那么，有可能扑灭这些奇异的大火吗？

And how do they even form in the first place?

以及它们最初是如何形成的？

A standard fire requires three ingredients: fuel, heat, and oxygen.

标准火需要三种成分： 燃料、高温和氧气。

Every fuel has what’s known as an ignition point—

每种燃料都有所谓的着火点，

a temperature at which it begins to break down.

即它开始燃烧的温度。

This process, also known as pyrolysis,

这个过程也称为热解，

releases gaseous compounds that mix with nearby oxygen molecules

它释放出气态化合物， 与附近的氧气分子

to produce combustion.

混合产生燃烧。

And it’s this chemical reaction that releases large amounts of heat and light

正是这种化学反应以火焰的形式

in the form of flames.

释放出大量的热量和光。

But not all combustion leads to flames.

但是，并非所有的燃烧都会导致火焰。

Pyrolysis leaves behind a solid material called char—

热解会留下一种叫做焦炭的固体物质，

like what’s found in charcoal.

就像木炭中发现的那样。

Char contains no combustible gases but it’s rich in highly flammable carbon.

焦炭不含可燃气体， 但富含高度易燃的碳。

And under hot enough conditions,

在足够热的条件下，

its surface reacts with the surrounding oxygen,

它的表面会与周围的氧气发生反应，

creating a slow, glowing burn called smoldering.

产生一种缓慢而发光的燃烧， 称为闷烧。

Instead of flame, this process releases smoke;

该过程释放的不是火焰，而是烟雾；

specifically, smoke full of emissions like carbon monoxide, methane,

具体而言，排放的烟雾里充满一氧化碳、甲烷

and particulate matter.

和颗粒物等。

All these factors come into play in zombie fires,

所有这些因素都在僵尸大火中起作用，

which are more scientifically known as peat fires.

更科学地说，僵尸大火被称为泥炭大火。

Peat is a type of soil that forms when organic matter builds up more rapidly

泥炭是一种土壤， 当有机物积聚的速度

than it decomposes,

快于其分解速度时，就会形成。

and it’s typically found in regions that are very cold or very wet—

它通常存在于非常寒冷或非常潮湿的地区，

two factors that can slow down decomposition.

这两个因素可以减缓分解的速度。

When plants shed and die in peatland,

当植物在泥炭地中脱落和死亡时，

the carbon they've absorbed during their lifetime gets locked inside,

它们一生中吸收的碳会被锁在里面，

making peatlands one of the planet's largest natural carbon stores.

这使泥炭地成为地球上 最大的天然碳储存库之一。

But just like char, that also makes this carbon-rich material extremely flammable.

但是，就像焦炭一样， 这也使这种富含碳的材料极易燃。

Historically, the moisture and cold temperatures of peatlands

从历史上看，泥炭地的潮湿和低温

made them unlikely to catch fire.

使它们不太可能着火。

But today, droughts caused by climate change

但是今天，气候变化造成的干旱

are drying out these landscapes worldwide,

正在使全球的这些景观变干，

and other peatlands have been drained to make way for farms.

其他泥炭地也已被排干， 以便为农场腾出空间。

Under these conditions,

在这些条件下，

a fire at the surface can more easily ignite the peat below,

地表的火更容易点燃下面的泥炭，

transforming it into char which will continue to smolder.

将其转化为继续闷烧的焦炭。

As heat builds in the soil, it further dries the peat

随着热量在土壤中积聚， 它会进一步干燥泥炭，

and eventually, deeper layers begin to burn.

最终，更深层开始燃烧。

Peat fires are slow, creeping along at just one millimeter a minute.

泥炭火势缓慢， 以每分钟仅一毫米的速度蔓延。

But what they lack in speed, they make up for in persistence.

但是，燃烧虽然缓慢却很持久。

These fires can burn for months or even years,

这些大火可以燃烧数月甚至数年，

all while spewing smoke full of poisonous gases.

同时会喷出充满有毒气体的烟雾。

And since they show few signs of burning above ground,

而且，由于它们几乎没有在地上燃烧的迹象，

they’re incredibly difficult to track until they ignite dry surface soil,

因此很难追踪它们， 直到它们点燃干燥的地表土壤，

potentially miles away from the source.

这可能距离源头数英里远。

Zombie fires can even burn beneath snow-caked soil,

僵尸大火甚至可以在白雪皑皑的土壤下燃烧，

overwintering until they spark new blazes in the spring.

越冬直到春天它们引发新的大火。

So how can we fight these fires?

那么我们该如何扑灭这些大火呢？

Well, dousing them with water is surprisingly tricky.

好吧，用水扑灭它们出人意料地棘手。

Water's molecules form close bonds,

水的分子形成紧密的键，

resulting in a high surface tension that stops it from filtering evenly

从而产生较高的表面张力使其无法均匀地

through burning peat.

渗入燃烧的泥炭。

Researchers are experimenting with ways to reduce water’s surface tension,

研究人员正在尝试降低水的表面张力，

allowing it to permeate the simmering soil.

使其渗透到沸腾的土壤中。

And some countries are trying to stop the fires before they start

一些国家正试图通过在 泥炭地栖息地进行控制性烧毁

by running controlled burns in peatland habitats.

来在火灾开始之前将其阻止。

But many others are simply working to prevent peatland drainage,

但是，还有许多其他人只是 在努力防止泥炭地排水，

which keeps these landscapes wet and resilient to fires.

这样可以使这些景观保持 湿润并抵御火灾。

Despite accounting for only 3% of Earth's land,

尽管泥炭地仅占地球陆地的 3％，

peatlands hold more than a quarter of the planet's carbon.

但其碳含量占地球四分之一以上。

And as climate change continues to increase the risk of extreme weather,

而且，随着气候变化 持续增加极端天气的概率，

including the droughts plaguing these landscapes,

包括造成这些景观的干旱，

keeping that carbon out of the atmosphere has never been more important.

将碳排入大气层迫在眉睫。