您现在的位置: 纽约时报中英文网 >> 纽约时报中英文版 >> 科学 >> 正文

海洋世界:没有空气,在海底如何活下去?

更新时间:2019/5/20 20:39:11 来源:纽约时报中文网 作者:佚名

Can you survive if you run out of air?
海洋世界:没有空气,在海底如何活下去?

There was a sickening crack when the thick cable connecting Chris Lemons to the ship above him snapped. This vital umbilical cord to the world above carried power, communications, heat and air to his diving suit 100m (328ft) below the surface of the sea.

连接莱蒙斯(Chris Lemons)和船身的脐带缆断裂前,就有不详的裂缝出现。这条重要的线缆维系着海平面下100米(328英尺)处所需要的电力、通信、热能、空气,这条脐带缆和潜水服连接。

While his colleagues remember the terrible noise of this lifeline breaking, Lemons himself heard nothing. One moment he was jammed against the metal underwater structure they had been working on and then he was tumbling backwards towards the ocean floor. His link to the ship above was gone, along with any hope of finding his way back to it.

据莱蒙斯的同事回忆,这条生命线损坏的时候发出可怕的断裂声,但莱蒙斯自己表示什么都没听到。上一秒,他还卡在正在作业的水下金属结构中,下一秒就翻滚到了海底。他和海面上船只的联系被切断了,而且没有重新回去的希望。

Most crucially, his air supply had also vanished, leaving him with just six or seven minutes of emergency air supply. Over the next 30 minutes at the bottom of the North Sea, Lemons would experience something that few people have lived to talk about: he ran out of air.

最要命的是,莱蒙斯的氧气供应也断掉了,只有应急氧气,能供他支撑6到7分钟。接下来的30分钟里,在北海(英国东海岸附近的大西洋海域)海底,他经历了没人能活着出来的事情:他没有空气可供呼吸了。

“I’m not sure I had a full handle on what was happening,” recalls Lemons. “I hit the sea bed on my back and was surrounded by an all-encompassing darkness. I knew I had a very small amount of gas on my back and my chances of getting out of it were almost non-existent. A kind of resignation came over me. I remember being taken over by grief in some ways.”

莱蒙斯回忆道:“当时我也不知要怎么应对。我掉到海底的时候背部朝地,四周一片漆黑。我知道背上的氧气瓶只有很少的氧气,所以不可能活着出来。我很无奈完全被悲伤情绪占据了。”

Lemons had been part of a saturation dive team fixing piping on an oil well manifold at the Huntington Oil Field, around 127miles (204km) east of Aberdeen on the east coast of Scotland. To do this work, divers must spend a month living, sleeping and eating in specially constructed chambers on board the dive ship, separated from the rest of the crew by a sheet of metal and glass. In these 6m-long tubes, the three divers acclimatise to the pressures they will experience once underwater.

莱蒙斯所在的饱和潜水作业队隶属于亨廷顿油田(Huntington Oil Field),位于苏格兰东海岸的阿伯丁以东127英里(204公里)处,作业队主要负责安装修理油井歧管的各种管道。在下潜完成这份工作前,潜水员必须在潜水船上特制的舱室里生活,舱室与其他船员用一块金属玻璃隔开。下潜员要在这里饮食起居,度过一个月的时间。在这6米长的管道房间时,三名潜水员将要适应海底水下的压力。

It is an unusual form of isolation. The three divers can talk to and see their crewmates outside the chamber, but they are otherwise cut off from them. The members of each team are entirely reliant upon one another – it takes six days of decompression before they can leave this hyperbaric chamber or help can get inside.

这种隔离是不寻常的。三位潜水员能看见外面的同事并能同他们交流,但除此之外他们与船员之间是隔绝的。团队成员彼此依赖——他们需要6天减压,才能从高压舱里出去,或是帮他们进入舱内。

“It is a very strange situation,” says 39-year-old Lemons. “You are living on the ship surrounded by lots of people who are just a sheath of metal away, but you are completely isolated from them.

39岁的莱蒙斯说:“这个境况很特别。你生活在船上,周围有很多人。但却被一层金属隔离的那里。”

“It is quicker to get back from the Moon than it is from the depths of the sea in some ways.”

“在某种意义上来说,从月球回到地球上都比从海底回到地面隔离时间要短。”

Decompression is necessary because nitrogen gas from the air divers breathe while underwater dissolves into their blood stream and tissues when they are at depth. As they come to the surface, the pressure of the surrounding water is lifted and the nitrogen bubbles out. If this happens too quickly, it can cause painful tissue and nerve damage and even lead to death if the bubbles form in the brain – a condition commonly known as “the bends”.

减压是不能省的步骤,因为在深水区呼吸时,潜水员吸进的氮气会融进血液和组织中。回到水面后,周围的水压降低,氮气会从人体内释放出来。如果这一过程进行太快,会导致潜水员组织疼痛、神经损伤,大脑内部的氮气释放,严重时甚至会导致死亡——这种情况,被称为“减压病”。

The divers who do this work, however, take the risks in their stride. For Lemons, he was most concerned about spending such a long time away from his fiancée Morag Martin and the home they shared on the west coast of Scotland.

然而,真正从事这项工作的潜水员有时会缩短减压时间。就拿莱蒙斯来说,花这么长的时间来减压,会让他和未婚妻马丁(Morag Martin)分开很久,这让他想念二人在苏格兰西海岸的家。

The day of 18 September 2012 had started normally enough for Lemons and the two colleagues he was diving with – Dave Youasa and Duncan Allcock. The three climbed into the diving bell, which would be lowered from the ship, the Bibby Topaz, to the sea bed where they would carry out their repair work.

2012年9月18日那天,一切情况正常,莱蒙斯和两位同事尤阿沙(Dave Youasa)、阿洛克(Duncan Allcock)能够进行作业。于是三人爬进潜水钟,潜水钟将从比比妥帕斯号(Bibby Topaz)上放下来,放到海床上,在那里展开日常的维修工作。

“In many ways, it was just an ordinary day at the office,” says Lemons. While not as experienced as the other two men, he had been a diver for eight years and had been saturation diving for a year and a half, taking part in nine deep-water dives. “The sea was a little rough on the surface, but it was pretty clear underwater.”

莱蒙斯说:“这是我们一天中很平常的工作,海面上风浪挺大的,但水下十分平静。”他虽然没有两位同事经验丰富,但也有着8年的潜水经验,从事饱和潜水作业也已经有一年半了。这是他第9次从事深海潜水作业。

That rough sea, however, would trigger a chain of events that almost claimed Lemons’s life. Normally dive vessels use computer-controlled navigation and propulsion systems – known as dynamic positioning – to keep them over the dive site while they have people in the water.

海面波涛汹涌,会引发一系列事件,令莱蒙斯命悬一线。一般情况下,潜水船会采用计算机控制的导航和推进系统,也就是动态定位系统,来保持与下潜做业人员在相同的垂直位置。

As Lemons and Youasa began repairing the piping underwater, with Allcock supervising them from the bell, the Bibby Topaz’s dynamic positioning system suddenly failed. The ship rapidly began drifting off course.

莱蒙斯和尤阿沙开始修复水下管道,阿洛克在潜水钟上负责指导。此时,比比妥帕斯号的动态定位系统突然损坏,整艘船开始偏离航线。

On the sea floor, alarms sounded on the divers’ communications system. Lemons and Youasa were instructed to get back to the bell. But as they began following their umbilical cords, the ship had already drifted back over the tall metal structure they had been working on, meaning they had to climb over it.

海底潜水员的通信系统随即发出警报,莱蒙斯和尤阿沙得到指示,需要返回潜水钟。当两人开始顺着脐带缆返回时,船只已经后退偏航,错过他们所在的位置。也就是说,他们必须爬过这个高耸的金属结构,才能够重新回到船上。

When they neared the top, however, Lemons’s umbilical became snagged on a piece of metal sticking out of the structure. Before he could free it, the drifting ship pulled it tight, dragging him into the metal beams.

在两人快要爬到顶部时,莱蒙斯的脐带缆被金属结构上抻出来的部分勾住。在他还没能解开时,上方的船只又将其拉紧,莱蒙斯被拖入了金属横梁之中。

“Dave realised something was wrong and turned to come back to me,” says Lemons, whose story has been turned into a feature length documentary Last Breath. “We had this strange moment where we were looking into each other’s eyes. He was desperately flailing to get to me, but the boat was pulling him away. Before I knew it, I didn’t have any gas because the cable was stretched so tight.”

莱蒙斯说:“尤阿沙感觉到有事情发生了,于是就转身来找我。我们看着对方的眼睛四目相对,这个情景很特别。尤阿沙用尽办法要接近我,但船把他拖走了。我的脐带缆拉的太紧了,在我意识到之前,已经没有充足的氧气了。”后来,莱蒙斯的故事被拍成了纪录片《最后一口气》(Last Breath)。

The strain on the cable must have been immense. Composed of a tangle of hoses and electrical wires with a rope running through the middle, it creaked as the drifting boat pulled it tighter and tighter. Lemons instinctively turned the knob on his helmet to start the flow of gas from the emergency tank on his back. But before he could do anything else, the cable snapped, sending him tumbling back to the sea bed.

脐带缆的拉力是巨大的。它由一堆缠绕的软管和电线组成,中间是一根绳索。船在海面漂移,线缆越拉越紧,开始吱吱作响。莱蒙斯本能地转动头盔上的旋钮,开始用背上应急瓶中的氧气呼吸。不等他采取任何措施,脐带缆就断了,他被弹回了海床上。

Miraculously, in the pitch darkness, Lemons managed to pull himself upright and feel his way back to the well structure, climbing it again to the top in the hope of seeing the bell and getting back to safety.

在一片黑暗中,莱蒙斯奇迹般地站了起来,摸索着回到了井身的金属结构处,并且再一次爬到顶部,希望能看到潜水钟、安全回去。

“When I got there, the bell was nowhere to be seen,” says Lemons. “I took a measured decision to calm down and conserve what little gas I had left. I only had about six to seven minutes of emergency gas on my back. I didn’t expect to be rescued, so I just curled up into a ball.”

莱蒙斯说:“我爬上去的时候,并没有看到潜水钟。我理性地想,要冷静下来,节省仅剩的一点氧气。我背上的应急氧气只够呼吸六、七分钟的。我没有想到会有人来救我,于是我把自己蜷缩成一团。”

Without oxygen, the human body can only survive for a few minutes before the biological processes that power its cells begin to fail. The electrical signals that power the neurons in the brain decrease and eventually stop altogether.

没有氧气,人只能存活几分钟时间,之后,维持人体运作的生命活动就会停止。为大脑神经元提供能量的电信号也会减少,最终完全停止。

“Loss of oxygen is right at the very sharp end of survival,” says Mike Tipton, head of the extreme environments laboratory at Portsmouth University in the UK. “The human body doesn’t have a great store of oxygen – maybe a couple of litres. How you use that up depends on your metabolic rate.”

英国朴茨茅斯大学(Portsmouth University)极端环境实验室主任蒂普顿(Mike Tipton)说:“缺少氧气,让生存变得十分困难。人体内不会储存很多氧气——最多也就几升。能维持多久取决于个人的代谢速度。”

An adult at rest will typically use between a fifth and a quarter of a litre of oxygen every minute. This can rise to four litres every minute if they are exercising hard.

静息状态下的成年人,每分钟约消耗五分之一到四分之一升的氧气。如果大量运动,那么每分钟会消耗四升的氧气。

“If someone is stressed or panicked, then this can raise their metabolic rate too,” adds Tipton, who has studied people who have survived for long periods without air underwater.

蒂普顿研究过在水下长时间缺氧存活的人,他补充说:“如果人压力过大或感到恐慌,新陈代谢会加快。”

Back on board the Bibby Topaz, the crew desperately tried to manually navigate back into position to save their lost colleague. As they drifted further away, they launched a remote-controlled submarine in the hope of finding him.

比比妥帕斯号上的船员拼命想要切换到手动导航,回到当时的位置,以援救没能上船的同事。但是,船已经驶离了很远,因此只能发射一艘遥控潜水器,希望能找到莱蒙斯。

When it did, they watched helplessly on its cameras as Lemons’s movements gradually stopped, his life fading away.

在潜水器搜寻到莱蒙斯后,船上的人无助地通过潜水器的摄像头看着莱蒙斯,他逐渐停止了活动,生命一点点流逝。

“I can remember pulling the last bits of air from the tank on my back,” says Lemons. “It takes more effort to suck the gas down. It felt a bit like the moments before you fall asleep. It wasn’t unpleasant, but I can remember feeling angry and apologising a lot to my fiancée Morag. I was angry about the damage this was going to do to other people. Then there was nothing.”

莱蒙斯说:“我还记得当时吸最后一点氧气。我用了很大劲才把它吸进去,感觉就像是要入睡的前一刻并不难受,但我十分痛心,同时对我未婚妻深感抱歉。我痛心的是这次意外会对他人造成伤害。其它也无所谓了。”

It took around 30 minutes before the crew of the Bibby Topaz were able to regain control and restart the failed dynamic positioning system. When Youasa reached Lemons on top of the underwater structure, his body was still.

比比妥帕斯号的船员重启失灵的动态定位系统并控制了船体,大概花了半小时。等到尤阿沙到达金属结构的顶部,找到莱蒙斯的时候,他已经不会动了。

Through sheer will, Youasa dragged his fallen colleague back to the bell and passed him up to Allcock. When they removed his helmet, Lemons was blue and not breathing. Instinctively, Allcock gave him two breaths of mouth to mouth resuscitation.

凭着坚韧的毅力,尤阿沙终于把莱蒙斯拖回了潜水钟,把他交给阿洛克。当摘下莱蒙斯的头盔时,发现他脸色铁青,已经没有了呼吸。阿洛克出于本能,给莱蒙斯做了两次人工呼吸。

Miraculously, Lemons gasped back into consciousness.

莱蒙斯竟奇迹般地醒了过来。

“I felt very groggy and there were some flashing lights, but I don’t have many lucid memories of waking up,” says Lemons. “I recall Dave sitting crumbled on the other side of the bell looking exhausted and not really knowing why. It was only a few days later that I realised the gravity of the situation.”

莱蒙斯说:“我觉得昏昏沉沉的,看到了闪烁的灯光。怎么醒过来的,记不清了。只记得尤阿沙瘫坐在潜水钟的另一侧,看上去筋疲力尽,并不知道他为什么疲惫不堪。几天之后,我才知道那时情况有多么紧张。”

Nearly seven years later, Lemons is still perplexed as to how he managed to survive for so long without oxygen. Common sense suggests he should have perished after so long at the bottom of the sea.

七年过去了,莱蒙斯仍然困惑在没有氧气的情况下,自己是怎么存活那么久的。在海底待那么长时间,按常识他应该已经死了。

But it seems likely the cold water of the North Sea may have played a role –around 100m (328ft) down, the water was probably below 3C (37F). Without the hot water flowing through the umbilical cord to heat his suit, his body and brain will have quickly cooled.

北海冰冷的海水可能是一个原因。在水平面以下100米(328英尺)处,水温低于3摄氏度(37华氏度)。因为脐带缆断了,莱蒙斯的潜水服没有热水加热,他的身体和大脑很快被冷却下来。

“Rapid cooling of the brain can increase survival time without oxygen,” says Tipton. “If you reduce the temperature by 10 degrees the metabolic rate drops by a half to a third. If you lower the brain temperature down to 30C (86F), it can increase the survival time from 10 to 20 minutes. If you cool the brain to 20C (68F), you can get an hour.”

蒂普顿表示:“大脑快速冷却,在没有氧气状态下能够延长生存时间。温度降低10度,新陈代谢的速度会下降一半到三分之一。大脑温度降低至30摄氏度(86华氏度)时,生存时间会增加10至20分钟。当大脑温度降至20摄氏度(68华氏度)时,这个数字就会达到一个小时。”

The pressurised gas that saturation divers usually breathe may have given Lemons an additional chance. When breathing high levels of oxygen under pressure, it can dissolve into the blood stream, giving the body additional reserves to draw on.

饱和潜水员经常吸入加压气体,这也增加了莱蒙斯的生存机会。在压力下吸入高纯度的氧气,多余的部分会溶解到血液中,给身体提供额外的氧气储备。

Going hypoxic

缺氧状态

Divers are perhaps the most likely people to experience a sudden loss of their air supply. But there are many other situations where the oxygen supply can be cut off. Firefighters often rely on breathing equipment when entering smoke-choked buildings, while high-altitude fighter jet pilots also use breathing masks.

潜水员是常经历氧气供应突然中断的人。当然,也有其它许多情况,会导致氧气供应出现问题。比如,消防员进入浓烟滚滚的建筑物时,必须依赖呼吸设备;高空战斗机的飞行员也会使用呼吸面罩。

At the less extreme end, a lack of oxygen – known as hypoxia – can affect many other people. Mountain climbers experience low levels of oxygen when they are on high mountains, a condition which often has been blamed for accidents. When levels of oxygen drop, brain function can suffer, leading to poor decisions and confusion.

在一般状况下,会有很多的缺氧情况。比如登山运动员到达海拔较高处时,会有轻微缺氧情况,只是很多时候人们将其归咎于意外。氧气浓度低会影响大脑功能,导致决策失误,令人局促不安。

Patients undergoing surgery will also often undergo mild hypoxia, which is thought to impact their recovery. Strokes are also caused by a patient’s brain being starved of oxygen, leading to cell death and damage that can have lasting effects on their lives.

患者在接受手术时,也经常出现轻度缺氧状况,有人认为这会影响康复。中风也会造成患者大脑缺氧,导致脑细胞的死亡和损伤,对身体产生永久性伤害,影响患者日后生活。

“There are a lot of diseases where the final stage is hypoxia,” says Tipton. “One of the things that happens is that people who are hypoxic start to lose their peripheral vision and they end up looking at a point. It is thought to be the reason why people report seeing a light at the end of the tunnel in near death experiences.”

蒂普顿说:“很多疾病,最后的阶段都是缺氧。缺氧状态下,人的外围视觉开始丧失,最终只能看到一个点。有人提出,这可能就是为什么有过濒死体验的人,会说自己当时看到了一束光。”

Lemons himself survived his time without oxygen unscathed. He found only a couple of bruises on his legs after his ordeal.

莱蒙斯在无氧条件下安然无恙地活了下来,脑细胞并没有受损。只是发现腿上有几处淤伤。

But his survival is not unheard of either. Tipton has examined 43 separate cases in the medical literature of people who have been submerged in water for long periods. Four of these recovered, including a two-and-a-half-year-old girl who survived being under water for at least 66 minutes.

他并不是第一个这样活下来的人。蒂普顿在医学文献中找到了43个案例,都是在水中历经长时间无氧而存活下来的人。其中四个案例都成功康复了,还有一个两岁半的小女孩,她在水下至少待了66分钟。

“Children and women are more likely to survive because they are smaller and their bodies tend to cool much faster,” says Tipton.

蒂普顿说:“儿童和女性的存活概率更大。这是因为他们的体型更小,身体更容易冷却下来。”

The training of saturation divers like Lemons may also be inadvertently teaching their bodies to cope with extreme situations. Researchers at the Norwegian University of Science and Technology (NTNU) in Trondheim have found that saturation divers adapt to the extreme environment they work in by altering the genetic activity of their blood cells.

像莱蒙斯这样的饱和潜水员,在训练中可能无意地教会了身体该如何应对极端状况。挪威科技大学(NTNU)在特隆赫姆的研究人员发现,饱和潜水员能够改变血细胞的基因活动,来适应所处的极端环境。

“We saw a marked change in the genetic programs for oxygen transport,” says Ingrid Eftedal, head of the barophysiology research group at NTNU. Oxygen is carried around our bodies in haemoglobin, a molecule found in our red blood cells. “We found the activity of genes at all levels of oxygen transport – from haemoglobin to the production and activity of red blood cells is turned down during saturation diving,” Eftedal adds.

我们体内的氧气以血红蛋白形式携带于身体各处。血红蛋白是在红细胞中发现的一种分子。NTNU气压生理学研究组负责人埃夫特达尔(Ingrid Eftedal)说:“我们发现,氧气运输相关的基因程序发生了明显的变化。饱和潜水期间,无论是血红蛋白的产生还是红细胞的生成,所有和氧气传输相关的基因,其活动性都降低了。”

She and her colleagues believe this might be a response to the high concentrations of oxygen they breathe while underwater. It is possible that the slow-down of oxygen transport in Lemons’s body allowed it to make the meagre supplies it had last longer.

埃夫特达尔和她的同事们认为,这可能是由于他们水下呼吸过高浓度氧气造成的。莱蒙斯体内氧气运输速度缓慢,因此氧气能用得更久。

Exercising before diving has also been shown to help reduce the risk of developing the bends.

潜水前的锻炼,也被证明有助于降低罹患潜涵病的风险。

Studies of indigenous people who habitually free dive without additional air have also shown just how much the human body can adapt to life without oxygen. The Bajau people in Indonesia can reach depths of up to 70m (230ft) while holding their breath as they hunt for food with spears.

在研究了没有额外氧气供给,自由潜水的原住民后发现,人体即使没有额外的氧气补给,也能很好的适应无氧环境。印度尼西亚的巴瑶族人(Bajau)就可以潜入水深70米(239英尺)处,同时屏住呼吸用长矛捕食。

Melissa Ilardo, an evolutionary geneticist at the University of Utah, has found that the Bajau have genetically evolved to have spleens that are 50% larger than the their land-dwelling neighbours, the Saluan.

犹他大学的进化遗传学家伊拉多(Melissa Ilardo)发现,通过遗传进化,巴瑶族人的脾脏要比陆地为生的邻居撒鲁安人大50%。

The spleen is thought to play a key role in enabling humans to free dive.

人们认为,在自由潜水时,人类的脾脏发挥了关键的作用。

“There is something called the mammalian dive reflex, which in humans is triggered by the combination of holding your breath and submerging yourself in water,” says Ilardo.  “One of the effects of the dive reflex is contraction of the spleen. The spleen acts as a reservoir for oxygen-rich red blood cells, and when it contracts these red blood cells are pushed into circulation, providing an oxygen boost. It can be thought of as a biological scuba tank.”

伊拉多表示说:“有一种东西叫哺乳动物潜水反射。人们在屏住呼吸、潜入水里时,就会经历这种反射。这种潜水反射会使脾脏收缩。当脾脏收缩时,脾脏内储藏的富氧红细胞,会进入血液循环,提供氧气供给。也可以说,脾脏就是人体内的生物潜水罐。”

With larger spleens, it is thought the Bajau benefit from a greater injection of oxygenated blood and so can hold their breath for longer. One Bajau diver that Ilardo met told her he had spent 13 minutes underwater.

有人认为,脾脏大的巴瑶族人储藏的富氧血液更多,因此水下憋气的时间就更长。伊拉多见过一个巴瑶族人,能在水下待13分钟而不呼吸。

Lemons himself returned to diving about three weeks after his accident – at the very spot where it had happened, to finish the job they had started. He has also married Morag and they have a daughter together.

事故发生三周后,莱蒙斯重新回到当时出事的地方。把之前没有完成的工作做完。他和未婚妻结了婚,现在有了一个女儿。

Reflecting on his brush with death and his miraculous survival, he doesn’t take much credit for his own actions.

回忆起自己和死亡擦肩而过的经历,他觉得功劳并不在自己采取的措施。

“One of the greatest reasons I survived was the quality of the people around me,” he says. “In truth, I did very little. It was the professionalism and the heroics of the two in the water with me and everyone on the ship. I was very lucky.”

莱蒙斯说:“我能幸存,重要原因是我周围同事的努力。我自己做的不多,主要靠水下两名同事、和船上人员过硬的专业技术和顽强的毅力。我是个幸运的人。”

His accident has triggered a number of changes in the diving community. They now use emergency tanks that carry 40 minutes of air rather than five. The umbilical cords are now festooned with fairy lights so they can be seen more easily under water.

意外之后,潜水行业发生了很多变化。如今,人们用的应急氧气瓶必须贮有足够呼吸40分钟的量。现在的脐带缆都带有奇幻的灯光,以便在水下清晰可见。

The changes in his own life have not been so dramatic.

莱蒙斯的生活并没有发生什么改变。

“I’ve still got to change the nappies,” he jokes. But he does find himself thinking about death differently. “I don’t see it as something to be feared any more. It is more about what you leave behind.”

他开玩笑说:“我还得为孩子换尿布。”但是,他对死亡的看法发生了改变,他说:“死亡并不可怕。重要的是你留下了什么。”

“全文请访问纽约时报中文网,本文发表于纽约时报中文网(http://cn.nytimes.com),版权归纽约时报公司所有。任何单位及个人未经许可,不得擅自转载或翻译。订阅纽约时报中文网新闻电邮:http://nytcn.me/subscription/”

相关文章列表