地球 独一无二的星球 Earth, a unique planet,
瞬息万变 永不休止 restless and dynamic.
大陆板块迁移碰撞 Continents shift and clash.
火山爆发 Volcanoes erupt.
冰川凝结消融 Glaciers grow and recede.
巨大的力量不断作用 Titanic forces that are constantly at work,
留下一系列地质谜题 leaving a trail of geological mysteries behind.
本次调查深入俄罗斯腹地 This investigation ventures deep into remote Russia
探寻一片名为西伯利亚暗色岩的巨型石海 in search of a vast sea of stone called the Siberian Traps.
专家们通过钻研地球遥远的过去 Experts will dig deep into Earth's ancient past
来解释这片岩石荒原的形成过程 to discover how this rocky wilderness formed,
在意想不到的地方发现的证据 and unearth evidence in surprising places
证明了在西伯利亚的致命火山爆发 to prove how deadly volcanic eruptions in Siberia
如何毁灭了地球上几乎所有物种 wiped out nearly every living thing on Earth.
目前为止 最激动人心的一集 The most dramatic episode yet in the story of "How The Earth Was Made."
地球起源
最致命火山爆发
彻底改变地球的 The investigation into the cataclysmic event
灾难性事件的调查 that radically changed planet Earth
开始于遥远的冰冻之地 西伯利亚 begins in the deep frozen land of Siberia.
比美国整整大一半 50% bigger than the entire United States,
这里大多数时候都被冰雪覆盖 this land is locked in ice for most of the year.
气温可降至零下70摄氏度甚至更低 Temperatures plummet to minus 90 degrees Fahrenheit and below.
但在夏天 But in summer,
冰雪融化 显露出地球上范围最大 the ice melts and reveals one of the largest
并且最神秘的地质构造之一 and most mysterious geological formations on Earth,
西伯利亚暗色岩 the Siberian Traps.
地球上将近5%的大陆 Nearly 5% of Earth's land mass is covered
都被这片古老的石海覆盖 by this ancient sea of rock.
深深的峡谷暴露出几百米厚的岩层 Deep canyons expose layers hundreds of feet thick.
这些巨型的阶梯式构造叫做圈闭 These giant stepped formations are called traps,
源自瑞典语中"楼梯"一词 from the Swedish Word for "Stairs."
一个特殊的情况下发现了它们 They were discovered under unusual circumstances.
波兰地质学家亚历山大·切克诺斯基 Polish geologist Aleksander Czekanowski
于1863年因反对沙俄 was exiled to Siberia in 1863
以政治罪犯的名义被流放至西伯利亚 for "Political crimes" against Russia.
在此期间 他调研了这里的地貌 While banished, he surveyed the landscape
并踏足了这片独特 and stumbled upon this unique,
辽阔得不合常理的层状岩石区 unexplained expanse of layered rock.
今天 为彻底理解 Today, the journey to fully understand
这种奇怪的岩石构造是如何形成的 how this strange stone formation was made
我们的研究从一片沼泽开始 begins in a swamp.
詹姆斯·霍华德博士 地质学家 剑桥大学地质系CASP研究组织
我坐在这片沼泽里并不是为了好玩 I'm not sitting in this swamp just for fun.
实际上这个沼泽反映了 This swamp's actually very characteristic
在西伯利亚暗色岩形成以前 of what Siberia was probably like
西伯利亚可能的样子 before the Siberian Traps formed.
这些植被以及浅浅的死水 This vegetation, this shallow, stagnant water
与我们今日看到的西伯利亚非常不同 is very different to the environment we see in Siberia today.
令科学家能够推测出 The clue that enabled scientists to figure out that
西伯利亚曾是沼泽的线索 Siberia was once a swamp
来自于在暗色岩底发现的一种特殊的岩石 came from a particular kind of rock found beneath the traps.
煤 数万亿吨煤 Coal... trillions of tons of it.
这块石头是煤 This rock here is coal.
煤在西伯利亚十分重要 It's very important in Siberia.
它是植物组织 树木 茂密的植被 It forms when plant matter, trees, the thick vegetation
枯萎后沉入沼泽形成的 dies and falls into a swamp,
经过几百万年的地质作用 and over millions of years of geological time,
它们被压缩成一种坚硬的岩石物质 they're compressed into a hard rock substance
就像我手里拿着的这个一样 like the one I'm holding in my hand today.
为了确定煤的形成年代 The age of the coal was determined
我们可对岩石内部植物化石进行年代测定 by dating the plant fossils trapped inside the rock.
通过测定得知 这片区域的煤 The process revealed that the coal was formed
是在三亿多年前形成的 more than 300 million years ago.
在随后的五千万年间 It continued to collect and be compressed
它继续积聚并被压缩 over the next 50 million years.
所以当时的环境十分稳定 So, the environment was very stable
沼泽 茂密的植被 swamps, thick vegetation.
然后在两亿五千万年前 Then suddenly, 250 million years ago,
煤的形成忽然停止了 it all stops,
西伯利亚暗色岩覆盖在煤上方 and you have the Siberian Traps lying on top of the coal.
所以那个时期一定发生了巨大的变化 So, something fairly dramatic must have happened at that time,
我们必须研究这个现象 so we really need to study this phenomenon
调查地质情况 to investigate the geology
来看看是否能有所获 and see what we can find out.
但是调查西伯利亚暗色岩的地质情况 But investigating the geology of the Siberian Traps
并不是一项简单的任务 is no easy task,
因为它是地球上最偏远 because they're located in one of the most remote
最人迹罕至的地区之一 and least explored areas of the planet.
对霍华德和团队来说这是一次艰难的旅程 It's an arduous journey for Howard and his team,
在西伯利亚跋山涉水一千六百多公里 a 1,000-mile trek through Siberia over land and water,
在蚊虫猖獗的森林里扎营 camping out in mosquito-infested forests.
我们花了差不多七天 It's taken us nearly 7 days
才到达西伯利亚这个偏远的角落 to get to this remote corner of Siberia,
但今天下午 but this afternoon,
我们终于找到了 we've finally found the rocks
我们想要研究的岩石 that we were hoping to study.
这些高耸的石塔 These towering pinnacles of rock
标志着西伯利亚暗色岩的边界 mark the edge of the Siberian Traps.
即使在这样的距离 不用下船 Even from a distance, without leaving their boat,
地质学家也能认出这独特的地质结构 the geologists can identify this distinctive formation.
在我身后的岩石 The rocks you can see behind me
是由玄武岩形成的一座座石塔 are basalts forming wonderful towers.
我们在几个不同的地点停下并研究它们 We've stopped and studied these in several locations.
大部分西伯利亚被玄武岩覆盖 And what we've seen is only a tiny part of the basalt
我们所看到的的只不过是一小部分 which covers such a large part of Siberia.
这个证据揭开了暗色岩形成的秘密 This evidence unlocks the mystery of how the traps were made.
玄武岩被地质学家称为火成岩 Basalt is what geologists call "Igneous rock."
它们只有一种来源 And that only comes from one source
火山爆发 a volcanic eruption.
西伯利亚暗色岩一定曾经是一片广阔的 The Siberian traps must once have been a vast,
炽热的熔岩原 red-hot lava field.
我认为西伯利亚暗色岩曾经的景象 I think the Siberian Traps would have been 1,000 times
一定比我所有实地考察见到的猛烈一千倍 more intense than anything i've seen doing my own fieldwork.
克莱夫·奥本海默博士 火山学家 剑桥大学
如果我可以回到过去 And if I could go in a time machine
看到它发生 and watch it all happen,
光看它的规模就已经很不可思议了 it would be really just fantastic to see the scale of it.
熔岩流的长度 火焰喷射的高度 The length of the lava flows,and the height of the fire fountains
一定会非常值得一看 would have been really something to see.
熔岩石分成好几类 There are several types of lava rock.
这种玄武质熔岩刚从地底喷发出来时 This basaltic lava is a free-flowing liquid
是自由流动的液体 when it first erupts from the ground.
只要观察一下这个岩石有多像流体 Just looking at how fluid this rock appears
就能大致猜到如果我们回到过去 gives us some of the clues what it might have been like
会看到怎样的西伯利亚 in Siberia if we could have gone there.
粘稠的岩浆朝四面八方流动蔓延 There would have been really gooey, goopy, runny lava
覆盖了周围一千六百公里内的地表 flowing across the land surface for 1,000 miles in all directions.
半流质的岩浆使得这些岩石平原被人称为 This semi-liquid lava gives these rocky plains their name
泛布玄武岩 flood basalts.
夏威夷基拉韦厄火山现今仍喷发这种熔岩 They still erupt today in Kilauea in Hawaii,
基拉韦厄火山
而它也是目前世界上最活跃的火山 currently the world's most active volcano.
在25年的持续爆发后 After 25 years of constant eruption,
玄武熔岩原已经吞没了 the basalt lava field has engulfed
超过十平方公里的夏威夷岛屿 more than 4 square miles of Hawaii's Big Island.
但西伯利亚暗色岩规模更大 But the Siberian Traps are bigger
大上五十万倍 500,000 times bigger.
每一层阶梯都是由不同的熔岩流奠定的 Each distinct step is laid down by an individual lava flow.
一层叠一层 Layer pours out upon layer
直到岩层1.6公里厚并形成黑色硬顶盖 until the traps are more than a mile deep in black hardtop,
覆盖面积几乎有整个美国大陆那么大 over an area nearly the size of the continental U.S.
想象一下整个美国被起伏不平的 So, imagine the entire United States covered in a lumpy,
斯蒂芬妮·英格尔博士 火山学家 南安普敦大学
停车场覆盖 uneven parking lot,
放眼望去 到处都像是被沥青覆盖 like asphalt, everywhere as far as the eye can see,
那就是西伯利亚暗色岩 and that is what the Siberian Traps looked like
刚形成时的样子 when it first formed.
地质学家发现了岩层是如何形成的 Geologists have discovered how the traps were made.
下一步则是计算 The next step is calculating
这次西伯利亚超级火山爆发持续了多久 how long this vast Siberian super eruption lasted.
幸运的是 火山岩含有少量 Fortunately, volcanic rocks contain little minerals
岩石结晶时产生的矿物质 that formed when the rock crystallized
就是当岩石冷却凝固的时侯 when the rock cooled and solidified.
部分矿物质是放射性的 And some of these minerals are radioactive,
并随着时间衰变 and they decay over time.
所以它们就像小计时器一样 And so they're like little time clocks.
岩石冷却时计时开始 They start when the rock cools,
在我们测量时 and then when we measure them,
计时就停止了 the clock stops.
那么我们就能知道岩石是在 And we know how much time has passed
多久以前形成的 since that rock formed.
对这里最古老的火山岩的年代测定 Dating the oldest lava here reveals that
表明西伯利亚暗色岩在两亿五千万年前 the Siberian Traps first ripped the landscape
首次出现 并破坏了当地的地貌 apart 250 million years ago.
通过对最年轻的火山岩的年代测定 And by also dating the youngest lava,
科学家们也发现了这场爆发的持续时间 scientists can figure out exactly how long the eruptions lasted.
结果非常令人吃惊 The results are surprising.
它们表明岩浆不断溢出 They show that lava carried on pouring out
并不断加厚岩层 and building up into ever-deeper layers
持续了将近一百万年 for an almost unimaginable one million years,
形成了地面上最大的熔岩流 forging the largest lava flow on land.
接下来的旅程将会找出 The next step in the journey is to figure out
这场超级爆发发生在西伯利亚的原因 why this vast eruption happened here in Siberia.
大多数火山出现在板块边界 Most volcanoes exist at plate boundaries,
地壳较薄的部分 thin spots on Earth's crust
就是支撑大陆的浮动板块 where the floating plates that support the continents
在地表移动时互相挤压的地方 jostle together as they drift across the face of the Earth.
可西伯利亚暗色岩正处在巨型大陆的中央 Yet, the Siberian Traps are right in the heart of a huge continent.
所以专家们必须找到一个解释 So experts have to come up with an explanation.
这好比是一个地幔柱 This is a mantle plume.
可能看上去不像 It may not look like it.
你得想象它 And you have to imagine that
高度约为2400千米 this is going on over about 1,500 miles,
而不是像瓶子这么短 rather than a bottle.
但这可以很好地模拟地幔柱的活动 But it's quite a good simulation of how mantle plumes work.
瓶子底部正在受热 They're heated from below.
蜡烛相当于地核在提供热量 This candle is the Earth's core supplying heat.
这是地幔的底部 And this is the bottom of the mantle.
热量正在加热一些地幔 And the heat is heating up some of the mantle.
并使其像这些液泡一样向顶部的 And it rises up as these blobs up towards the Siberian Traps
西伯利亚暗色岩上升 which are up at the top here.
地幔柱是地质学中最神秘的东西之一 Mantle plumes are one of geology's great mysteries.
没人知道它们是如何形成 No one knows why they switch on or off.
但它们的形状为找到 But their shape is a crucial clue
热流柱喷发如此猛烈与巨大的原因 as to why plume eruptions are so fierce
提供了关键的线索 and so massive.
在现实中这个蘑菇形的顶部 That mushroom head in reality
直径可达2400千米 can be 1,500 miles across.
因此 And so,
火山爆发能覆盖大片地区 the volcanic eruptions can cover huge areas
几十万平方千米 hundreds of thousands of square miles.
同时 And also,
这个蘑菇顶持续的时间很短暂 the actual head is a very short-lived phenomenon
在几十万年中就可能爆发 that probably erupts in hundreds of thousands of years,
最多不过一百万年 at most, a million years.
科学家们发现了证据来解释 Evidence has been uncovered to reveal
西伯利亚暗色岩是何时及如何形成的 how and when the Siberian Traps formed.
2亿5千万年前 250 million years ago,
一个巨大的岩浆泡炸裂 a vast magma bubble burst,
击碎冲破地壳 cracking and slashing open Earth's crust.
对于地球上的生物来说 And for life on Earth,
一个全新的毁灭性纪元到来了 a new devastating era began.
两种岩石证实古西伯利亚的地貌 Two types of rock are proof of very different landscapes
煤
与现在完全不同 in ancient siberia.
煤揭露了在暗色岩形成前 Coal reveals that before the traps existed,
这块地方是一片沼泽 this area was a swamp.
玄武岩
玄武岩熔岩则证明了那个纪元结束于爆炸 Basalt lava is evidence this era ended with a bang
一次超大的火山爆发 a super volcanic eruption.
但现在 地质学家们有证据证明 But now, geologists have evidence that
西伯利亚的超级火山 the Siberian super volcano
即将成为地球上有史以来最厉害的杀手 was about to become Earth's greatest-ever killer.
地球历史上最致命的一百万年 The deadliest million years in Earth's history
即将开始 were about to begin.
3亿年之前 300 million years ago,
西伯利亚是一片沼泽 Siberia was a swamp.
但在地球深处 But deep underground,
滚烫的地幔岩石柱正在上升 a plume of hot mantle rock was rising.
2亿5千万年前 250 million years ago,
鼓胀的地壳被冲破 the bulging crust burst open,
沸腾的熔岩喷发至地表 and boiling lava erupted onto the surface.
自地球诞生起 最具灾难性和毁灭性的 The most cataclysmic and destructive million years
一百万年将要开始了 in Earth's existence was about to begin.
随着每次爆发 With every eruption,
玄武岩熔岩流汹涌地覆盖了西伯利亚 basalt lava surged across siberia in rivers and waves.
可怕的森林大火四处肆虐 Terrifying forest fires raged.
动物被活活烧死 Animals were burnt alive.
一个全新而致命的时代即将开始 A new deadly Earth story was underway,
并将给地球上所有的生物 one which would have catastrophic consequences
带来惨重的后果 for all life on Earth.
为了找出这次巨大的爆发 To figure out what chaos
对地球造成了怎样的混乱 this mega-eruption caused for the Planet,
地质学家们要近距离地观察 geologists are taking a closer look at
西伯利亚古老的火山岩 Siberia's ancient lava rocks.
这岩石是典型的泛布玄武岩区石头 This rock is very typical of what you see in flood basalt provinces.
这上面有很多我们称为气孔的东西 And we have many what we call vesicles.
它们是石头上的小孔 They're small holes in the rock,
这表明气体从岩石中逸出了 and those suggest that gases left this rock.
斯蒂芬妮·英格尔博士 火山学家 南安普敦大学
当岩石开始在地表慢慢冷却时 They escaped from this rock
气体从岩石中跑了出来 when this rock started cooling at the surface of the Earth.
研究西伯利亚产生的是哪种气体 The search for what kind of gas Siberia was producing
开始于近13000千米外的 begins nearly 8,000 miles away
猛犸象山
加州猛犸象山 at Mammoth Mountain in California.
那是一座古老的休眠火山 This is an ancient dormant volcano.
数年来 人们都认为它是无害的 For years, it was thought to be harmless.
但在1989年 But then in 1989,
一个护林人在此有了一次可怕的经历 a ranger had a terrifying experience.
那是冬天 护林人在林子里巡逻 It was wintertime, and a ranger was just checking on the area.
他想休息一会儿 避避风 And he wanted to take a break from the wind,
克里斯托弗·法勒 水文地质学家 美国地质勘探局
于是他从小木屋顶的窗子 so he crawled in through a hatch
爬进了屋里 that's in the roof of this cabin.
他在里面感到眩晕不适 And he became very dizzy inside and didn't feel well.
凭借常识他意识到 And he had the commonsense to think that
也许木屋里有毒气 maybe there was some bad air in the cabin,
于是他顺着梯子安全地爬出来了 and he crawled back up the ladder and got out safely.
但最初人们觉得这是个不解之谜 But it always kind of remained a mystery initially.
几个月后 Then just a few months later,
树木开始枯死 the trees here began to die.
显然 事有蹊跷 Clearly, something strange was happening.
这需要一个解释 是什么能够 So it required an explanation of what could combine with
既让一个人感到头晕目眩迷失方向 making a person feel dizzy and disoriented,
同时又能杀死树木呢 and what would also kill trees at the same time.
法勒的研究发现一种有毒气体是罪魁祸首 Farrar's research revealed that a poisonous gas was to blame,
这种气体是从地面渗出的 one that was seeping upwards out of the ground.
分析表明这种气体是二氧化碳 Analysis proved that the gas was carbon dioxide,
是一种火山活动的副产品 a byproduct of volcanic activity.
岩浆从地底深处上升时就会释放二氧化碳 It's released when magma rises from deep underground.
所以就像这瓶苏打水 So, just like this bottle of soda water,
我们脚下的岩浆中含有溶解的二氧化碳 the magma beneath us contains dissolved carbon dioxide.
当它接触到地表 And when it reaches the surface of the Earth,
气压减小 the pressure is released.
就像这样 当你打开瓶盖 Just like this, when you... open the water,
气压急剧减小 the pressure is released
二氧化碳从苏打水中跑了出来 and carbon dioxide is coming out of this bottle of soda water,
从猛犸象山上渗出的就是这种气体 and that's the same gas that's coming out here at Mammoth.
如今 猛犸象山地底的岩浆每天产生 Today, lava deep beneath Mammoth Mountain pumps out
危险 天然毒气危险区 请勿入内
1000吨二氧化碳 1,000 tons of carbon dioxide every day.
这种现象提示了科学家们 This suggests to scientists that
在2亿5千万年前的西伯利亚 trillions of tons of gas could have been released
那次地球上最大的爆发 into the atmosphere by one of the Earth's largest eruptions
可能向大气排放了数兆吨的气体 in Siberia 250 million years ago.
而证据的来源却很让人意想不到 And evidence comes from an unlikely source.
这是一棵银杏树 Well, this is a ginkgo tree.
银杏树很特别 And ginkgo trees are very special,
因为银杏树种已经存活了很长时间 because the ginkgo family has been around for a very long time
长达2亿7千万年 270 million years.
在地球的历史长河中 And it's remained fairly unchanged
它的样子几乎没有改变 over the course of Earth's history.
由于银杏自古以来很少变化 Because the ginkgo changes so little over time,
它是用来进行古今对比的理想样本 it is the ideal specimen for comparing the present with the past.
它叶子的表面布满微小的细孔 The leaf's surface is peppered with microscopic pores
我们称之为气孔 called stomata.
植物将这些气孔当做小嘴巴 Plants use these stomata like tiny mouths
来吸收二氧化碳 to breathe in carbon dioxide.
银杏叶上气孔的数量 The number of stomata on the leaves of a ginkgo
表明了可供吸收的二氧化碳 indicate how much carbon dioxide is available to them
在空气中的含量 in the atmosphere.
当大气中有很多二氧化碳时 When there's a lot of carbon dioxide in the atmosphere,
它们只需要少量的气孔 they only need to have a few.
当我们观察2亿5千年前形成的 When we look at fossils of ginkgo leaves
银杏叶化石时 that formed 250 million years ago,
我们发现它们拥有非常少量的气孔 we notice that they have very, very few stomata
来吸收二氧化碳 to take up carbon dioxide.
这意味着 And this means that
那时的大气中含有大量的二氧化碳 there was a lot of carbon dioxide available in the atmosphere.
研究员们研究了 Investigators have studied
世界各地的古树叶 ancient leaves from locations all over the world
算出2亿5千年前地球上二氧化碳的含量 and calculated that there was 3 times more carbon dioxide
是如今的四倍 in Earth's atmosphere 250 million years ago than there is today.
那是一个致命的全球性气体灾难 This was a deadly and global gas disaster.
而唯一能产生 And the only culprit capable of producing
如此大量二氧化碳的罪魁祸首就是 such substantial quantities of carbon dioxide is volcanic activity,
一次超大规模的火山活动 on a truly massive scale.
像西伯利亚暗色岩 When you have an eruption
那样规模的爆发 the size of something like the Siberian Traps,
会使你联想到世界末日 you imagine something almost apocalyptic in nature
灰尘肆虐 遮天蔽日 ash blocking out the sun.
然后你会感到祸不单行 But then you have a kind of double whammy
因为爆发还释放了大量的 where you also have the release of volcanic gases
火山气体 from the eruptions.
这些气体阻止热量散发 And these gases trap in the heat,
气温变得越来越高 so it gets hotter and hotter.
暗色岩中的熔岩 Lava from the traps
将西伯利亚变成了死寂的灾区 turns Siberia into a lifeless disaster zone.
但二氧化碳可以进入大气中 But carbon dioxide can mingle and mix in the atmosphere,
把热量锁在内部 就像暑天静止的车内 trapping heat inside like a parked car on a hot day.
南非卡鲁盆地距西伯利亚11000千米 7,000 miles away from Siberia is South Africa's Karoo Basin.
这里 岩石中的证据向地质学家们表明 Here, evidence in rocks gives geologists a tip-off that
卡鲁
爆发产生的二氧化碳所导致的气候灾难 carbon dioxide from the eruption provoked a climate disaster
不仅局限于西伯利亚 that wasn't confined to Siberia.
一条古老河槽截断该地区 An old river channel slices through the landscape,
露出层层岩石 exposing the layers.
经测定这些岩石 These rocks have been dated to
形成于西伯利亚暗色岩火山喷发期间 just before and just after the Siberian Traps began to erupt.
这些是泥岩 These are mudstones.
是湖底的淤泥受到挤压后形成的 They form on lakebeds from squashed mud,
它们证明 就像西伯利亚一样 so they're evidence that, just as in Siberia,
这里的地面曾经是沼泽并被水覆盖 the land was once swamp-like and covered in water.
它们也证明 这里曾经有所变化 But they're also evidence of change.
我脚下的绿色岩石 These rocks beneath my feet, which are green in color,
布鲁斯·鲁比奇博士 古生物学者 威特沃特斯兰德大学
是这里较老的岩石 are the older rocks here.
而这些红色的岩石 And then these rocks, which have got a more red color,
是较新的岩石 are the younger rocks.
红色表明这里的环境曾发生过变化 And the red color indicates that there's an environmental change.
气候可能曾变得干燥暖和 That the climate was possibly drying out and becoming warmer.
泥土里含有丰富的铁 The mud is rich in iron.
当泥土被植物或水覆盖时 When it is shaded by plants or covered by water,
它呈绿色 it stays green.
当它暴露于阳光下 When it's exposed to the sun,
则变成锈红色 it turns rusty red.
这些红色岩石证明 So the red stones are evidence that plants and water,
曾经覆盖泥土的植被和水消失了 which shaded the mud, had disappeared.
2亿5千万年前 250 million years ago,
就在西伯利亚的火山气体大量涌入空气时 as Siberia spewed volcanic gases into the air,
南非的气候变得干燥暖和 South Africa was drying out, warming up,
然后变成沙漠 and turning to desert.
在卡鲁盆地 人们最先发现了证据 The Karoo Basin is also where the first evidence was discovered
表明不止是植物消失了 that it was not just the plants that were dying.
这个动物化石发现于1934年 Well, this animal was found in 1934.
我的姑妈 当时还是一个小姑娘 My aunt, who was then a little girl at school,
有一天她放学回家后 she came home from school one day
问她的父亲 and she said to her father,
爸爸 什么是化石 "Daddy, what is a fossil?"
我祖父回答说 And my grandfather's response was,
我们去山里郊游 "Let's go off into the hills for a picnic
看看能不能找到一个 "and see if we can find one."
然后他们就去了山里 So they went off to the hills.
在一堆骨头中 他们发现了这个 And amongst other bones, they found this.
在他们自己的后院 In their own backyard,
鲁比奇一家挖出了 the Rubidge family had unearthed the remains of an animal
一种前所未见的动物残骸 completely unknown to science.
这是一只丽齿兽 This creature is a gorgonopsid.
长达3米多的食肉巨蜥 It was a carnivorous lizard 10 feet long
在二叠纪时期横行于南非 which roamed South africa during an era called the Permian,
比恐龙还要早数亿年 hundreds of millions of years before even dinosaurs evolved.
化石的年龄显示当西伯利亚火山爆发时 But dating these fossils reveals that as Siberia began to erupt,
这些动物走向消亡 these animals were dying.
丽齿兽是二叠纪时期的主要捕食者 Gorgonopsids are the dominant predators of the Permian period,
我们在二叠纪的各层岩石中都发现了它们 and we find them in all these different layers in the Permian rocks.
约2亿6千万至2亿5千1百万年前 Gorgons lived in this area
丽齿兽曾生活在这里 about 260 to about 251 million years ago.
当进化到二叠纪食物链中如此高的地位 And then suddenly, when you get higher up at this sort of level
它们却突然消失了 in the Permian sequence, they disappear.
然而消失的不仅仅只有丽齿兽 And the gorgonopsids were not alone.
这里几乎没有2亿5千万年以后的 There are virtually no animal fossils here
动物化石 younger than 250 million years.
虽然距离西伯利亚火山11000公里 7,000 miles from the Siberian super volcano,
某种东西却使这里土地干涸 植物枯萎 something caused the land to dry up, plants to die,
几乎所有陆生动物灭绝 and nearly every land animal to go extinct.
导致这次全球灾难的一个重要原因 And one critical cause of this global disaster
就是熔岩释放出来的二氧化碳 is carbon dioxide from the lava rocks.
然而 这场由西伯利亚火山喷发引起的 Yet, this deadly, million-year-long chain reaction,
持续百万年的致命连锁反应 triggered by Siberian eruptions,
才刚刚开始 is only just starting.
调查揭示了西伯利亚的火山喷发 The investigation has uncovered how volcanic activity
如何酿成了全球性的大灾难 in Siberia created a global catastrophe.
叶化石
银杏叶化石显示 Fossil leaves of the gingko tree reveal evidence
因为火山喷发 大气充满了二氧化碳 that the atmosphere was full of volcanic carbon dioxide.
丽齿兽
丽齿兽头骨说明动物在同一时期灭绝 Gorgonopsid skulls show animals were dying out at the same time.
但更大的灾难还在后面 But worse was to come.
西伯利亚火山喷发 The catastrophic Siberian eruptions
将引发另一场空前绝后的大灾难 were about to unleash a new murderous nightmare.
3亿年前 300 million years ago,
西伯利亚是一片被水覆盖的沼泽 Siberia was a waterlogged, swampy bog.
5千万年以后 50 million years later,
地球史上最大的一次火山大喷发 Earth's biggest-ever volcanic eruption on land
用数百英尺坚固的 银色的玄武熔岩 was smothering Siberia in layer after layer of solid,
将西伯利亚层层裹住 silvery basalt lava hundreds of feet thick.
大气中弥漫着火山喷发出的二氧化碳 An atmosphere saturated with volcanic carbon dioxide
使得全球温度陡升6摄氏度 had raised global temperatures by around 10 degrees Fahrenheit.
地面上的生命开始灭亡 Life on land was dying.
下面要寻找的证据将解释 Now the hunt is on to uncover evidence of
西伯利亚火山大喷发 how Siberia's super volcano precipitated
是如何引发全球海洋大灾难的 a marine catastrophe in all of Earth's oceans.
但科学家并不在大海里寻找答案 But scientists aren't looking for answers in the sea.
他们爬上了海拔3000米的 They're climbing 10,000 feet above sea level
白云石山脉 up into the Dolomites Mountains.
白云石山脉
在意大利北部的山脉里 Here in the mountains of northern Italy,
这些岩石见证了地球历史上 these rocks give evidence of one of the greatest crises
一次最大的危机 in the history of the planet.
敲开层层岩石便可揭开引人入胜的秘密 Crack open the layered rocks and fascinating secrets are revealed.
岩石里保存着数百万只三叶虫 Mysterious and long-extinct sea creatures called trilobites
灭绝已久的神秘海洋动物 are preserved in their millions.
其存在证明了 这些山峰曾经是海床 Their existence here proves these peaks were once a seabed.
三叶虫被困在海底的沉淀物之中 The trilobites were trapped in sediment settling on the ocean floor.
数百万年来 Over millions of years,
地质大变动将海床推高了3千多米 geological upheavals have thrust them two miles up in the air.
这里的岩石层完好无损地记录了 The rock layers here are a perfect record of
古代海洋生物 life in the ancient oceans.
我们能够看到的是 What we can see is,
在我手下方 just below the level of my hand,
有许多完好的化石 there's lots of nice fossils,
保罗·威格纳尔博士 地质学家 利兹大学
各种各样的生物化石 a big diversity of things we can find in here.
上面的较新的岩石层里 And then these younger rocks just above,
稍微高一点的岩石层里 just a little bit higherbasically,
化石非常少 there's very few fossils in here,
化石种类也少 and a much lower diversity.
在两种不同的化石层之间 In between the two different layers of life,
威格纳尔敲开了一个黑矿层 Wignall hacks into a black band.
在这里 不是有更少的化石 In here, there are not just fewer fossils.
而是什么化石也没有 Here, there are none at all.
这就是地质学家所称的"消失带" This is what geologists call the extinction zone.
据检测这层岩石形成于2亿5千万年前 It has been dated as 250 million years old.
这些令人不安的证据表明 Worrying evidence that,
在摧毁了大部分陆地生物之后 having killed off most of the life on land,
西伯利亚大爆发又将灾难扩散到了海洋 the Siberian super volcanic disaster was spreading to the seas.
黑色的石头中含有微小的发光物质 This black clay contains microscopic, glittering clues
是一种叫做黄铁矿的矿物晶体 crystals of a mineral called iron pyrites.
其发光特性为其赢得了绰号"愚人黄金" Its shiny appearance has earned this rock the nickname "Fools' Gold."
它只值几美分 It's worth just a few cents,
却包含了2亿5千万年前岩石形成之处 but it holds priceless information about ocean waters
海水的重要信息 where the rock formed 250 million years ago.
这种矿石 黄铁矿 This mineral, this iron pyrites
只有在缺氧的情况下才能形成 will only form in the absence of oxygen.
因此黄铁矿可以直接证明 And so therefore, it's a nice, very direct line of evidence
在那段时间发生的事 for what's going on at this time.
"愚人黄金"的存在证实了 The presence of fools' gold is evidence
在它形成的时候 海水中没有氧气 that the water in which it formed had no oxygen at all.
科学家们相信造成海水缺氧的直接原因 And scientists believe the warming effect of volcanic carbon dioxide
就是西伯利亚火山喷出的二氧化碳 from the siberian eruptions was directly to blame
导致的温室效应 for this lack of oxygen.
海洋环流的动力 The ocean circulation is driven by the fact that
是温度梯度 we have a good temperature gradient.
两极气温低 赤道气温高 It's cold at the poles and it's warm at the equator.
所以海水在两极和赤道之间循环流动 And so, the water circulates between the poles and the equator,
像传送带一样 like a conveyor belt.
如果到处气温都高 But if you make everywhere warm,
传送带就停止工作 the conveyor belt turns off,
水就不再流动 变为死水 and the water just sits there and stagnates
同时丧失了补给氧气的能力 and no longer has the ability to sort of resupply oxygen.
海洋就像浴缸里的暖水 静止不动 The ocean had become as still and warm as bath water.
暖水吸收的氧气少 And warm water absorbs less oxygen.
实际上 我们可以在鱼缸里 It's possible to recreate these nasty conditions
模拟这个糟糕的情况 in a fish tank, in fact.
你只需选一个阳光灿烂的天气 All you need do with a fish tank is to put it
把鱼缸放在窗台上 in the window on a bright,sunny day.
阳光会使水温升高 The sun will warm the water up,
水就开始失去氧气 and the water will start to lose its oxygen,
水就会停滞 and it'llbasically, it'll stagnate.
在窗台的放置时间久了 鱼就会死去 If you leave it for too long,your fish will die,
这就是史上空前绝后的 and you'll have a sort of mini-recreation of
生物大灭绝事件的迷你再现 one of the greatest extinction events of all time.
当火山喷发将西伯利亚撕裂的时候 As volcanic eruptions tore siberia apart,
生物在缺氧的海水中挣扎求生 life was fighting for survival in the oxygen-depleted seas.
但是西伯利亚的火山喷发 But the Siberian eruptions were about to
即将向大海释放更加致命的毒药 flood an even more deadly poison into the oceans.
为了调查接下来发生的事情 To find out what happened next,
研究者们寻找到了一个现代的地点 researchers hunted for a modern-day location
可以重现被西伯利亚喷发 that could recreate life
破坏掉的二叠纪海洋中的生命状况 in the Siberian-damaged Permian Ocean.
绿湖州立公园
出人意料的是 他们在纽约州中部的 Unexpectedly, they found it in central New York state
绿湖州立公园中找到了答案 Green Lakes State Park.
这片不寻常的小湖含盐量极高 This unusual, little lake is extremely salty,
且有近60米深 and nearly 200 feet deep,
使其恰好能成为远古海洋的微缩模型 making it a model in miniature of the ancient seas.
有人问我们 We get asked,
你们怎么在湖里研究二叠纪的海洋 "Why do you go to a lake to study the Permian Ocean?"
李·康普博士 地质学家 宾夕法尼亚州立大学
实际上这片湖很像当时的海洋 It turns out this lake is a lot like the ocean,actually.
它的含盐量相当高 It's fairly salty.
并且它的循环系统 and its circulation system
也就是将氧气运送至湖底的过程 the process that brings oxygen down deep into this lake
已经停止了 is shut down,
正与我们所推想的二叠纪海洋一样 just like we think happened to the Permian Ocean.
湖的顶层是健康而生机盎然的 The top layer of the lake is healthy and thriving.
但湖的底层却是静止而死寂的 But deep down, the bottom layer is stagnant and still.
通过取样45米深处的湖水 By lowering a water sampler 150 feet down,
康普仿佛回到了当西伯利亚火山 Kump's diving deep into the past to a time
喷发时的远古世界 when the Siberian Traps were erupting.
从这个水样中我们能得到一些线索 Well, we have a couple clues from this water
它们可以告诉我们 that's telling us about
现在湖底的状况 what's going on down there at the bottom of the lake,
其中之一就是它的颜色 one of which is its color.
水样是粉色的 And this water is pink
因为在每30克的水中就含有 because it's loaded with tens of millions of purple bacteria cells
数以千万计的紫色细菌 in each ounce of water.
另一条线索就是气味 And the other is the smell.
打开盖子嗅一下 So if I open up the lid here and take a whiff,
它有一种浓烈的臭鸡蛋味道 it's a very potent smell of rotten eggs.
这就是硫化氢的标志性味道 And that's a very characteristic smell of hydrogen sulfide.
氧气对紫色细菌是有毒的 Oxygen is toxic to purple bacteria,
所以死水才是它们最佳的繁殖地 so stagnant water is a perfect breeding ground.
若这些单细胞细菌繁衍兴旺 These single-celled survivalists flourish
就说明其他的海洋生物缺氧窒息了 where other sea life suffocates.
它们还有一个讨厌的副作用 But they have a nasty side.
它们会产生一种刺激性有毒气体 They produce a noxious and pungent poison gas
硫化氢 called hydrogen sulfide.
哪怕是极小量也是致命的 The tiniest amounts can be fatal.
这种细菌也生活在下水道中 The same bacteria live in sewers,
所以那里的工作人员必须携带气体检测器 so workers there must carry gas detectors.
硫化氢能使人体失去氧气 Hydrogen sulfide deprives your body of oxygen.
它还是极强的神经毒素 It's also a strong neurotoxin,
能够造成中枢神经系统伤害 so it has that detrimental effect, as well.
硫化氢的阴险之处在于 And the really insidious thing about hydrogen sulfide
它能够麻痹我们的嗅觉神经 is that it paralyzes our olfactory nerve.
也就是说我们闻不出它来了 In other words, we can't smell it anymore.
所以它可怕就在于 And that's what's so terrible,
当你没法闻出它来之后 because right after you stop being able to smell it,
如果其浓度继续上升 if the level keeps building up,
就会立即使人中毒 it can become instantly poisonous.
康普想要找到该致命微生物 Kump's trying to figure out if the same lethal microbes
是否曾肆虐过因西伯利亚大喷发 plagued the seas stripped of oxygen
而缺少氧气的海洋 by the Siberian eruptions.
他在2.5亿年前的岩石中寻找证据 He's searching for proof in rocks from 250 million years ago.
但是细菌是不会变成化石的 But bacteria don't leave fossils.
所以他研究了它们留下的化学痕迹 So instead, he's pursuing the chemical traces they leave behind.
我们要找的是叫做生物标记的化合物 So, the clues we're looking for are compounds called biomarkers.
这些就是化学化石 These are chemical fossils.
这些生物残余在岩石中 They're fragments of the organism that have been preserved
被保留了很长一段时间 over long periods of geologic time in these rocks.
从这些残余 也就是化学化石中 And from these fragments from these chemical fossils,
也许可以找到都有哪些生物遭遇到了 we can try to identify what organisms might have been involved
这次大灭绝 in this mass extinction.
就像骨或壳的碎片一样 Like a fragment of bone or shell,
化学化石使我们能够 a chemical fossil is a fingerprint
辨认出制造这些成分的微生物 identifying the micro-organism which made it.
康普的运气不错 And Kump's struck lucky.
就是这个 这就是我们要找的线索 This is it. This is the clue we've been looking for.
在这块化学化石中 This is the chemical fossil,
生物标记告诉我们 the biomarker that tells us that
在这次最大规模的生物灭绝中 these organisms were existing
该生物从始至终都存在着 at the time of the greatest mass extinction of all time.
当西伯利亚喷发时 As Siberia erupted,
紫色细菌仿佛置身天堂 the purple bacteria were in paradise,
不遗余力地向水中排放硫化氢 vigorously poisoning the water with hydrogen sulfide.
大海变成了一个缺氧的剧毒臭水沟 The sea became a suffocating, toxic cesspool.
三叶虫以及其他几乎所有的海洋物种 The trilobites and virtually every other species of sea life
都随之灭绝消失 died out and never returned.
该证据解释了西伯利亚的巨大火山喷发 The evidence is building up as to how massive volcanic eruptions
如何使几乎所有的海洋生物灭绝 in Siberia wiped out nearly all marine life on Earth.
黄铁矿
黄铁矿说明海洋曾缺少氧气 Fools' gold shows the sea lost its oxygen.
生物标记说明海洋被致命的硫化氢污染 Biomarkers show it was also poisoned with lethal hydrogen sulfide.
生物标记
地球喘不过气来了 The Earth was choking.
生命无法再依赖其最重要的两样资源 Life could no longer depend on its two most vital resources
空气和水 air and water.
但是新的威胁出现了 But a new threat loomed,
西伯利亚地下贮存的煤矿 as Siberia's underground coal reserves
为大火增添了燃料 added fuel to the flames.
2.5亿年前 250 million years ago,
西伯利亚突然开始火山喷发 a sudden violent volcanic eruption began in Siberia.
喷发持续了一百万年 The traps erupted over the next million years,
形成了近千米厚的玄武岩层 forging basalt lava layers thousands of feet thick.
在玄武岩下埋藏有5万亿吨煤 Buried underneath the basalts were 5 trillion tons of coal.
当西伯利亚喷发时 As Siberia erupted,
强劲的燃料将被点燃 a powerful fuel was about to catch fire.
对地质学家而言 For geologists,
煤提供了重要线索 coal is a crucial clue
解释一次巨大的火山喷发 in figuring out how a huge volcano
如何几乎使地球所有生物灭绝 wiped out nearly all life on earth.
煤是由古植物的遗骸形成的 Coal is the remains of dead plant material.
当煤燃烧时 就会释放挥发性气体 And when coal burns, the volatile materials are released,
马修·萨尔兹曼博士 地质学家 俄亥俄州立大学
其中就包括甲烷 and these include gases such as methane.
而火山喷发的岩浆 And lava from the volcanic eruption
就是将其点燃的火源 was the ultimate source of ignition.
就像是火上浇油 It was like pouring gasoline on a barbecue.
现在萨尔兹曼想要找到 Now Saltzman is hunting for evidence of
巨大的煤矿火灾是如何伤害我们星球的 how this colossal coal fire damaged the planet.
他的研究由一片荒芜的沥青废路开始 His search begins in a barren blacktop wasteland.
但这里不是西伯利亚 But this is not Siberia.
这里是宾夕法尼亚的一座小镇 This is a town in Pennsylvania.
我站的这个位置看起来就像是战场 I'm standing here in what looks like a war zone.
森特勒利亚
很难想象它曾是一条通向 It's hard to believe this was the main road
一座拥有数千人的繁荣小镇的主干道 into a thriving community of several thousand people.
我身边的这些裂缝和气体 These cracks and these gases all around me
不仅仅是小镇被荒废的原因 are a clue not only to what extinguished this town,
它们还是解开大灭绝 but also provide one of the key clues
这一谜团的重要线索 into the mystery of the greatest mass extinction of all time.
1962年 In 1962,
这座名为森特勒利亚的矿业小镇 the mining town of Centralia
喜迎森特勒利亚百周年纪念日
曾有近4千的居民 was a community of 4,000 people.
但是一场意外的大火点燃了一个煤层 But an accidental fire ignited a coal seam
宾夕法尼亚国家银行 森特勒利亚办公室
并导致了无法控制的地下大火 and caused an uncontrollable underground blaze.
危险的甲烷气体开始渗出地面 Dangerous methane gas began to seep from the ground.
现在 当地居民早已离开了小镇 Today, the residents have abandoned the town.
但是大火仍在森特勒利亚下燃烧 The fire still rages underneath Centralia...
而燃烧又在不断地排放甲烷 and methane is still released into the air.
所以现在问题是 The situation raises the question of
2.5亿年前被岩浆所点燃的 whether the burning of Siberia's far greater coal reserves,
储量要大得多的西伯利亚煤层 set alight by lava 250 million years ago,
是否也曾将极大量的甲烷排入 also released catastrophic levels of methane gas
空气中呢 into the air.
西伯利亚的火山喷发时 The volcanoes in Siberia would have erupted
要穿过煤层才能抵达地表 through the coals to get to the surface.
在此过程中 岩浆加热了煤 On their way, they would have cooked these coals.
而这些煤的燃烧又会释放出各种气体 And this burning of coal would have released methane,
包括甲烷 amongst other gases,
而甲烷又对全球气候产生了 and this methane would have had an extreme effect
极大的影响 on the global climate.
随着西伯利亚火山的持续喷发 As Siberia continued to erupt,
全球温度进一步上升了6摄氏度 temperatures all over the planet rose by a further 10 degrees.
这样的急剧气候变化 It's a climatic change too dramatic to be
不是仅靠二氧化碳就能完成的 caused by carbon dioxide alone.
一定还有其他凶手 There must be an additional culprit.
甲烷的嫌疑最大 Methane is top of the list,
因为其将热量截留在大气中的能力 because it's over 20 times more effective
比二氧化碳要高20倍 in trapping heat in the atmosphere than carbon dioxide.
现在 科学家们在岩石中寻找证据证明 Today, scientists are analyzing rocks for proof that
西伯利亚煤层大火产生的甲烷正是凶手 methane from the Siberian coal fire was the culprit.
他们发现了一样化学线索 They've discovered a telltale chemical clue,
轻碳 light carbon.
它就是甲烷留下的痕迹 It's a fingerprint of methane gas,
全球所有的灭绝区都有这种轻碳的发现 and it has been recorded in every extinction zone all over the globe,
从南极洲到意大利都是如此 from Antarctica to Italy
这证明了这次喷发影响了全球 proof of the eruption's global reach.
地质学家发现轻碳含量 The levels of light carbon geologists have discovered
非常非常高 are so incredibly high,
相当于突然释放了万亿吨的甲烷 it equates to the sudden release of a trillion tons of gas.
气温随着甲烷从西伯利亚扩散到全球 Temperatures surge as the methane from Siberia
而迅速上升 spread across the globe,
令全球都陷入了 leaving every part of the planet
气候恶变与大规模灭绝之中 devastated by climate chaos and mass extinction.
当时的地球实在是不宜居住 This would have been a very nasty place to live.
海洋中的氧气比现在更少 There would have been less oxygen in the oceans.
陆地上也要更热更干 There would have been much warmer and drier conditions on land.
而且大气中极高的 There would have been problems
甲烷含量还会导致 with the depletion of the ozone layer
臭氧层变薄 as a result of this methane-rich atmosphere.
所以这真的不是一个适宜生存的地方 And so it just would have been a very, very inhospitable place to be.
但燃烧的煤并不是两亿五千万年前 But burning coal isn't the only possible source of the methane gas
温室气体甲烷的唯一来源 that warmed the world a quarter of a billion years ago.
布鲁克海文国家实验室
在布鲁克海文能源实验室 At the Brookhaven Energy lab,
科学家们正在制作一种冰块 scientists are making ice.
然而这是可以燃烧的冰 But this is ice that burns
甲烷冰 methane ice.
在自然界中 它被深埋在海床之下 In nature, it's buried beneath seabeds
封存于永冻层中 and locked into permafrost.
它的发现让地质学家们非常兴奋 Its discovery got geologists very excited,
因为地球上甲烷冰中蕴藏的能量 because there's more energy locked inside methane ice
比所有其他化石燃料蕴含的能量总和还多 than all Earth's other fossil fuels put together.
它可以是未来的能源 It could be the fuel of the future,
也可以是通往过去的钥匙 but it could also be the key to the past.
在大爆发的几十万年间 After hundreds of thousands of years of eruption,
燃烧的煤和融化的甲烷冰共同产生的甲烷 burning coal and melting ice together released enough methane
将温度提高了大约11摄氏度 to raise temperatures by some 20 degrees fahrenheit.
地球上的生命正走向湮灭 Life on Earth was heading for total wipeout.
在最致命的火山喷发了一百万年后 Finally, a million years after the Earth's deadliest eruption began,
这颗星球历史上的最大灾难 the most catastrophic event in the planet's history
迎来了它的终结 is at an end.
但地球上的生命为此付出了巨大的代价 But life on Earth paid a high price.
超过95%的物种因此灭绝 Over 95% of species have been driven to extinction.
这项研究揭示了火山喷发的影响范围 The investigation reveals the reach of the volcanic eruption
轻碳
以及地球是如何继续演变的 and how planet Earth continued to change.
岩石中发现的轻碳表明大气中曾富含甲烷 Light carbon found in rocks is evidence of a methane-rich atmosphere.
燃烧的煤
西伯利亚燃烧的煤产生了这些甲烷 Burning coal in Siberia is thought to be the source of this gas.
在一百万年间地球产生了巨大的变化 The Earth is a different place from just a million years ago,
自天空至大陆再到海洋 from the air to the land to the sea.
幸存的少数物种成为了 The few species that have survived are pioneers
这个新世界的开拓者 in a brave, new world.
它们将会改变地球历史的进程 They are about to change the course of history.
两亿五千万年前 250 million years ago,
一座火山突然喷发 a volcano erupted into life,
留下了西伯利亚两千四百米厚的玄武岩层 paving Siberia with basalt lava layers a mile and a half thick.
在地球史上最险恶的一百万年即将结束时 At the end of the worst million years in Earth's existence,
当地球上全部生命在灭绝边缘挣扎时 as life teetered on the brink of total wipeout,
喷发终于停了下来 the eruptions finally stopped.
现在地质学家们要查明火山究竟是消失了 Now geologists want to find out whether the volcano died,
还是仅仅改变了位置 or whether it simply changed location.
地幔柱碰撞地表的地方 The place where a mantle plume hits the surface
被称为"热区" is called a "Hotspot".
地幔柱的形状说明了热区随时间的变化 The plume's shape is a clue to the hotspot's activity over time.
其顶部是一个巨大的熔岩球 The head is a huge lava bubble
可以促成短暂而猛烈的喷发 which feeds short-lived, but massive,eruptions.
当熔岩球耗尽的时候 When the lava plume head is all used up,
大规模喷发便停止了 the mega eruptions stop.
但熔岩的尾部依然存在 But the narrow tail can live on,
就像烟囱一样进行小规模喷发 like a chimney spouting small eruptions
持续数亿年 for hundreds of millions of years,
而同时地球板块在其上方不断迁移 while earth's tectonic plates are shifting above it.
假设这是一个地幔柱 Here is a mantle plume.
克莱夫·奥本海默博士 火山学家 剑桥大学
可以是西伯利亚火山 或是夏威夷火山 It could be Siberia, it could be Hawaii.
而这就是大陆板块 And here is the plate.
显而易见 热区是静止的 And the hotspot, obviously, is stationary,
但我们将看到大陆板块在它上方漂移 but we're going to see that the plate is actually moving above it.
于是大陆板块一直移动 So the plate is continuously moving.
而热区固定不动 The hotspot's staying put.
你可以想像这时 And you've goto imagine lots and lots of lavas
有大量岩浆正喷发出来 are erupting out at the same time.
现在我们得到的东西 So I think what we've achieved
很好地表明了热区的踪迹 is actually a rather good representation of a hotspot track.
这条古老痕迹的起点 At this end,the old end,
就是地幔柱第一次撞击地球表面的地方 that's where the plume had first hit the top of the mantle.
随时间推移 地幔柱留下了一条 Over time, it's left a track that would in reality
由许多火山组成的轨迹 have been lots of other volcanoes just like the one
就像今天的夏威夷群岛 that we find in the Hawaiian islands today.
太平洋板块在地幔柱上方移动的速度 The Hawaiian chain was forged by a plume
是每一百万年四十八公里 as the Pacific Plate passed above it
夏威夷群岛就在这一过程中形成 at a speed of 30 miles every million years.
但在西伯利亚寻找地幔柱痕迹的科学家们 But scientists searching for a plume track in Siberia
却一无所获 are left scratching their heads,
因为那里没有任何证据证明痕迹存在 because there's no evidence of a trail.
研究表明西伯利亚的热区 The investigation has discovered Siberia's hotspot
造成了长达一百万年的全球混乱和毁灭 caused a million years of worldwide chaos and destruction.
但在那之后 热区就冷却下来 But after that, the hotspot trail goes cold.
西伯利亚暗色岩也许曾因热区的变化 The Siberian Traps would have left a line of volcanic landforms
而留下一连串的火山地貌 that relate it to that movement.
但在漫长的岁月里 But over such a long period of time,
地质运动已将这些证据掩盖并隐藏起来 the geological processes have hidden the evidence, buried it,
部分痕迹也许已经隐没回地幔层中 and parts of it may have been subducted back into the Earth's mantle.
在西伯利亚暗色岩后 热区发生了什么 What happened to the hotspot after it forged the Siberian Traps
也许将成为永远无解的谜题 is a mystery that may never be solved.
不断变化的地球抹去了所有证据的痕迹 The dynamic Earth has wiped away all trace of the evidence.
但可以肯定的是 One thing is certain.
西伯利亚火山没能消灭地球上所有的生命 Siberia didn't succeed in destroying all life on Earth.
但可以算是千钧一发 But it was a very close call.
这是生命史上最惨烈的一次大灭绝 This is the worst extinction of all time.
行星从这样的灾难中恢复过来所用的时间 And a part of the measure of that is just how long it took
就可以说明惨烈程度 to the planet to recover from this.
我们估测 八百到一千万年后 We estimate 8 to 10 million years later,
复苏的迹象才刚刚开始出现 there was still only the very beginnings of recovery,
地球上的生物种类开始日益增长 the increasing diversity of life on Earth.
我们从煤开始了对西伯利亚暗色岩的研究 Coal, which opened the investigation into the Siberian Traps,
证实了火山的毁灭性影响 testifies to the volcano's devastating effects.
之后两千五百万年内都没有新煤矿形成 No new coal formed for another 25 million years
不光在西伯利亚 整个世界范围内都是 not just in siberia, but around the entire world.
这确凿地证明了 It's conclusive proof that,
尽管生命之树在大灭绝中幸免于难 although tree life survived the mass extinction,
但其并未能在其后的数千万年间繁荣兴盛 it could not and did not thrive for tens of millions of years.
对生活在南非的陆生动物们来说也一样 And the same is true for South Africa's land animals.
在他的家族的土地上 On his family's land,
鲁比奇发现了另外一件 Rubidge has discovered yet
对研究至关重要的化石证据 another fossil crucial to the investigation.
如果洞穴被泥沙填充 If burrow holes fill up with sand or mud,
它们就会自然地变成化石 they can themselves become fossils.
所有困在洞里的东西也会变成化石 Anything trapped inside is fossilized, too.
这是一个古老洞穴的填充物 This is the plug of an ancient burrow.
这件标本令人兴奋之处在于 But the exciting part about this particular specimen
有一只小动物蜷缩在内 is that it's got a little animal actually curled up,
布鲁斯·鲁比奇博士 古生物学家 威特沃特斯兰德大学
被保存在洞穴中 preserved in the burrow.
这只动物大概于两亿五千万年前 This animal died here in this burrow
死在这个洞穴中 about 250 million years ago,
它看起来是这样的 and that is what he looks like.
你可以看到这里是它的头 There you can see is the head,
而那里是它小小的尾巴 and you can see there's his little tail over there.
令人惊异的是 这个小生物在随后 Amazingly, this tiny creature plays an enormous role
两亿五千万年的地球生命史中至关重要 in the last 250 million years of life on this planet.
这件化石代表了地球生物的发展方向 This fossil represents the future of life on Earth.
这个洞穴对我们人类的存在有着重要意义 This burrow has huge significance for our presence here today.
因为这小小的动物 Because this little animal
正是哺乳类生物的远祖之一 is one of the distant ancestors of mammals.
这就是我们的祖先 This is our ancestor.
它能在大灭绝之后出现在这个洞穴的原因 And the reason why he's preserved in a burrow
也许正是这个洞穴保护了它 after the extinction event is because this burrow maybe protected him
让它免受其他生物所遭受的灭顶之灾 from what was causing other animals to go extinct.
也许正是因为有这样的洞穴存在 And so maybe it's thanks to a hole like that
才有了你我的存在 that you and I are here today.
西伯利亚暗色岩的火山喷发 The eruption of the Siberian Traps
触发了一场残酷的种族生存竞赛 triggered a brutal race for survival.
超过95%的竞争者在这场竞赛中被淘汰 Over 95% of the competition was eliminated.
只有适应性强和幸运的物种抵达了终点 Only the well-adapted and the lucky made the finish line.
这是地球历史上最糟的一百万年 It was Earth's worst million years.
但在幸存至今的物种看来 But from the perspective of life on Earth today,
这也是发生过的最好的事情 it was the best thing that ever happened.
这是生命所遭遇过的最严重的危机 This was the greatest crisis that life has ever suffered.
但若不是因为这样 But if it wasn't for this,
生命的进化将沿一条不同的轨迹行进 then evolution would have taken a different course,
现在的人类也就不会出现 and humans wouldn't be here today.
西伯利亚暗色岩持续百万年的火山喷发 The million-year eruption of the Siberian Traps
彻底改变了整个地球 drastically altered the entire Earth.
从大气到海洋深处 From the atmosphere to the ocean depths,
这颗星球改变得过于迅速 the planet changed at a rate so rapid,
以至于生物进化速度难以与之并驾齐驱 evolution could not keep pace.
在新的地质环境下 In this new geologic world,
已有的生物过时了 life was hopelessly outdated.
少数存活的物种造就了新世界 The few animals that survived shaped the future,
将它们对环境的适应性遗传给后代 passing adaptations on to their descendants.
恐龙 鸟类 Dinosaurs, birds,
哺乳动物 还有人类 mammals, and humans.
生命之树历经多次严苛的修剪 The tree of life had undergone some drastic pruning,
但这也保证了我们这一枝杈的繁荣 but it allowed our branch to flourish,
以及人类的进化 and humans to evolve.
但在西伯利亚火山喷发两亿五千万年后的今天 Yet, today, 250 million years after Siberia erupted,
生命依旧脆弱 life is still fragile,
依然任由那阴晴莫测 still at the mercy of the ever-changing,
变化无常 难以捉摸的地球所摆布 volatile, and unpredictable earth.