It was a deep rumble, a seismic wave, but one that didn't look anything like a regular earthquake.

那是一種深沉的隆隆聲，一種地震波，但看起來一點也不像普通的地震。

The noise was made up of just one frequency, like the sound that comes out of a tuning fork.

聲音只有一個頻率，就像音叉發出的聲音。

And it kept ringing for nine full days.

鈴聲整整響了九天。

Earthquake scientists had no clue what they were looking at, so they spent nearly a year tracking down the source of this planet-wide shakeup.

地震科學家們對自己所看到的情況毫無頭緒，是以他們花了近一年的時間來追蹤這次地球範圍震動的源頭。

And what they found is something we've never seen before, but something that's bound to shake up our planet again.

他們的發現是我們從未見過的，但一定會再次震撼我們的星球。

After this mysterious signal showed up on detectors around the world, dozens of scientists from 15 different countries teamed up to track down the source, or what they called the Unidentified Seismic Object.

這個神祕信號出現在世界各地的探測器上之後，來自 15 個不同國家的數十名科學家聯手追蹤信號源，他們稱之為 "不明地震物體"。

Given how long it took for the vibration to reach each one, scientists could estimate how far away that station was from the source.

根據振動到達每個臺站所需的時間，科學家們可以估算出該臺站距離振動源有多遠。

They used that data to trace the event back to somewhere in East Greenland, and that's where they found their next clue.

他們利用這些數據追溯到東格陵蘭島的某個地方，並在那裡找到了下一條線索。

On the same day the mystery signal started, sea-level gauges in East Greenland recorded an absolutely massive tsunami.

就在神祕信號發出的同一天，東格陵蘭島的海平面測量儀記錄到了一次絕對巨大的海嘯。

It was around four times taller than Niagara Falls, making it the tallest recorded wave on Earth since 1980.

它比尼亞加拉大瀑布高出約四倍，成為自 1980 年以來地球上有記錄的最高海浪。

So it seemed pretty likely that this massive wave had something to do with the mystery signal.

由此看來，這個巨浪很可能與神祕信號有關。

But before scientists could figure out what, they had a new question to answer.

但在科學家們弄清是什麼之前，他們又有了一個新的問題需要回答。

What had caused this monstrosity of a tsunami?

是什麼導致了這場駭人聽聞的海嘯？

To solve this puzzle, the team of scientists turned to satellite images and seismic data to piece together the events leading up to the tsunami.

為了解開這個謎題，科學家團隊利用衛星影像和地震數據，拼湊出了海嘯發生的前因後果。

And what they found was, on the day that the signal began, a colossal chunk of land broke off a mountain more than a kilometer above the water.

他們發現，就在信號發出的當天，一塊巨大的陸地從高出水面一公里多的山體上斷裂開來。

On its way down, it shattered a glacier, sending 25 million cubic meters of rock and ice, enough to fill 10,000 Olympic swimming pools, crashing into a nearby fjord.

在墜落的途中，它撞碎了冰川，將 2 500 萬立方米的岩石和冰塊（足以填滿 1 萬個奧林匹克游泳池）衝入附近的峽灣。

And this wasn't just any rock slide.

這可不是普通的岩石滑道。

It was really a perfect storm.

這真是一場完美的風暴。

It had all that extra debris from the shattered glacier, plus an icy slope acting like a natural slip and slide.

這裡有冰川破碎後產生的額外碎石，還有一個冰坡，就像一個天然的滑梯。

All that energy got funneled into a narrow gully.

所有的能量都匯入了一條狹窄的山溝。

So by the time the rocks and ice splashed down into the fjord, they packed a massive punch and kicked up an absolutely enormous wave.

當岩石和冰塊飛濺到峽灣中時，它們已經形成了巨大的衝擊力，掀起了滔天巨浪。

So scientists finally had a picture of what happened the day the signal began, but that still didn't answer the question of what caused the noise.

科學家們終於知道了信號開始的那天發生了什麼，但這仍然沒有回答是什麼導致了噪音的問題。

Because the landslide was over in minutes, how could it explain a signal that went on for nine days?

因為山體滑坡在幾分鐘內就結束了，怎麼能解釋持續九天的信號呢？

There was only so much scientists could figure out from the data they happened to have on this event.

科學家們只能從他們碰巧掌握的有關這一事件的數據中找出這麼多東西。

So to piece together the finer details, they created a simulation that would let them model how the whole disaster unraveled.

為了拼湊出更精細的細節，他們創建了一個模擬模型，讓他們模擬整個災難是如何發生的。

But to do that, they needed funding, and so do we.

但要做到這一點，他們需要資金，我們也一樣。

So let's tell you about ours.

那麼，讓我們來談談我們自己吧。

Thanks for watching this SciShow video.

感謝觀看本期 SciShow 影片。

In fact, thank you for watching all of our SciShow videos.

事實上，感謝你觀看我們所有的 SciShow 影片。

Let us know in the comments if you've been around for all 13 years.

請在評論中告訴我們你是否已經陪我們走過了 13 個年頭。

But 13 isn't enough.

但 13 年還不夠。

We want to fill the internet with human-made, well-researched, and fact-checked videos.

我們希望網上充斥著人類製作的、經過充分研究和事實核查的影片。

But we can only do that with your help.

但只有在你們的幫助下，我們才能做到這一點。

We hope you've enjoyed watching and maybe learned a fun fact or two along the way.

我們希望你能喜歡觀看，或許還能從中瞭解到一兩件趣事。

And for more fun facts, check out our new SciShow postcards.

要了解更多有趣的知識，請查看我們新推出 SciShow 明信片。

Each one contains a link to a secret video that you can only get by ordering a postcard.

每張明信片都包含一個祕密影片連結，只有訂購明信片才能獲得該連結。

To help keep SciShow going for another 13 years, get your SciShow postcards at complexly.com slash postcard.

為了讓 SciShow 延續 13 年，請登錄 complexly.com slash postcard 獲取 SciShow 明信片。

And do it now because they're only available until February 3rd.

現在就去，因為它們只在 2 月 3 日之前提供。

Now back to the researchers and their landslide model.

現在回到研究人員和他們的山體滑坡模型。

Simulating the details of the event was a great call, and it turned up something really surprising.

模擬事件的細節是一個偉大的呼籲，它發現了一些非常令人驚訝的東西。

Instead of crashing and dissipating like a typical tsunami, their wave got trapped between the walls of the fjord.

他們的海浪並沒有像典型的海嘯那樣衝擊和消散，而是被困在了峽灣的牆壁之間。

And for days, it sloshed back and forth, just like a wave between the walls of a bathtub, if that wave were about 60 stories tall.

一連幾天，它來回晃動，就像浴缸壁間的浪花，如果浪花有 60 層樓那麼高的話。

Now, a wave like this isn't unheard of.

現在，這樣的浪潮並非聞所未聞。

It's called a seiche, and you get one now and then in bodies that are partly or fully closed off, like lakes and harbors.

這就是所謂的 "海潮"，在湖泊和港口等部分或完全封閉的水體中，時不時就會發生。

They can happen any time some force, like a strong wind or a tsunami, pushes a bunch of water up against a shoreline.

任何時候，只要有某種力量（如強風或海嘯）將海水推向海岸線，就會發生這種情況。

When the thing doing the pushing lets up, all that water slides back and bounces off the opposite shore.

當推力減弱時，所有的水都會向後滑動，並在對岸反彈。

And this wave can keep going for hours or days until it gradually loses its energy and dies off.

這種波浪可以持續數小時或數天，直到它逐漸失去能量而消失。

The seiche in their simulations bounced off opposite shorelines every 87 seconds, and that's when scientists realized they might have just cracked the case.

他們模擬的海潮每隔 87 秒就會從對岸的海岸線上反彈一次，這時科學家們才意識到，他們可能剛剛破解了這一難題。

Because one cycle every 87 seconds was awfully close to the period of the mystery signal they detected the day of the landslide.

因為每 87 秒一個週期，與他們在山體滑坡當天探測到的神祕信號的週期非常接近。

To check if their simulation was really capturing what had happened, scientists looked at a few other lines of evidence, and everything seemed to line up.

為了檢查他們的模擬是否真的捕捉到了所發生的事情，科學家們查看了其他一些證據，一切似乎都很吻合。

The sloshing wave moved in the same direction as the waves detected at the monitoring stations.

蕩波的移動方向與監測站探測到的波浪方向一致。

Small variations in the real signal lined up with the tidal cycles in the fjord, and the simulated seiche petered out at about the same rate as the real signal.

真實信號的微小變化與峽灣的潮汐週期一致，模擬海潮的消退速度與真實信號的消退速度大致相同。

So there was their answer.

這就是他們的答案。

As best anyone can tell, a tsunami trapped in the fjord shook our whole planet for nine days.

據人們所知，被困在峽灣中的海嘯震撼了整個地球九天。

Nearly a full year after the signal was first detected, the case was finally closed.

在首次檢測到該信號將近一整年後，該案件終於結案。

But it wasn't all happily ever after once scientists got their answer, because they realized that this whole thing wasn't just a random catastrophe.

但是，科學家們得到答案之後，並沒有從此過上幸福的生活，因為他們意識到，這一切並不只是一場偶然的災難。

The seiche that shook up our planet was like the final step in a Rube Goldberg machine that got going decades ago.

震撼我們星球的海嘯就像是幾十年前開始運作的魯布-戈德堡機器的最後一步。

It all started with climate change and some unusual configurations of geology.

這一切都源於氣候變化和一些不尋常的地質構造。

See, this spot has a whole mountain leaning on a glacier that had lost tens of meters of ice over the years.

你看，這個地方的整座山都靠在冰川上，冰川多年來已經流失了幾十米。

Finally, it got so thin that it could no longer hold up the mountain.

最後，它變得如此單薄，以至於再也無法支撐起這座山。

That's when a massive chunk collapsed, kicking off the tsunami and then the seiche, which means that ultimately this planet-wide seismic signal was triggered by climate change.

就在那時，一塊巨大的岩石坍塌，引發了海嘯，然後是海嘯，這意味著最終是氣候變化觸發了這次全地球範圍的地震信號。

Scientists have never detected something like this before in Greenland, but as more glaciers melt, more landslides are inevitable and possibly more global shakeups.

科學家們以前從未在格陵蘭島發現過類似情況，但隨著越來越多的冰川融化，更多的山體滑坡將不可避免，並可能引發更多的全球震盪。

So this mystery signal turned out to be more than a geological puzzle.

這個神祕的信號原來不僅僅是一個地質難題。

It was a signal that we're living in a world that's changing in unpredictable ways.

這是一個信號，表明我們生活在一個變化莫測的世界。

As we get better at cracking the cryptic messages our planet is sending us, it's also up to researchers, as well as the rest of us, to listen to what it's saying.

當我們越來越善於破解地球向我們發出的神祕資訊時，研究人員和我們一樣，也要傾聽地球在說什麼。