This region is home to plenty of valleys and peaks, but this valley is eerily straight.

這個地區有很多山谷和山峰，但這個山谷卻異常筆直。

Some interesting geology had to happen there at some point, and it wasn't just one event.

在某個時刻，那裡一定會發生一些有趣的地質現象，而且這不僅僅是一次事件。

About 520 million years ago, most of Earth's landmass was split between two big continents,

大約 5.2 億年前，地球的大部分陸地被兩大塊大陸分割開來、

Laurentia and Gondwana.

勞倫提亞和岡瓦納。

This meant the modern-day island of Great Britain was separated, with the north of Scotland sitting on Laurentia, and the southern half of the island on Gondwana.

這意味著現代的大不列顛島被分開，蘇格蘭北部位於勞倫提亞大陸，而南半部則位於岡瓦納大陸。

Then, the two landmasses collided around 430 million years ago, during a period known as the Caledonian Orogeny, which joined the two pieces through the collision, forming the island we now know as Great Britain.

然後，這兩塊陸地在大約 4.3 億年前發生了碰撞，碰撞時期被稱為喀裡多尼亞造山運動（Caledonian Orogeny），通過碰撞將兩塊陸地連接在一起，形成了我們現在所知的大不列顛島。

This process resulted in the crumple and buckle of the Earth's crust, which also formed new mountains and fault lines all around the world.

這一過程導致了地殼的褶皺和彎曲，也在世界各地形成了新的山脈和斷層。

One of those new faults was the Great Glen, which is a strike-slip fault.

其中一個新斷層就是大格蘭斷層，它是一個走向滑動斷層。

This kind of fault happens when two tectonic plates shear, or move horizontally, past each other.

當兩個構造板塊相互剪切或水準移動時，就會出現這種斷層。

Other types of faults typically move one of the plates vertically, which creates mountains and all kinds of elevated terrain above the fault.

其他類型的斷層通常會垂直移動板塊之一，從而在斷層上方形成山脈和各種高地。

But because of how these two plates collided with each other during its formation, the pieces of the Great Glen fault move horizontally.

但是，由於這兩個板塊在形成過程中相互碰撞，大格倫斷層的斷塊是水準移動的。

And they've actually moved a few times since the formation of the fault.

實際上，自斷層形成以來，它們已經移動過幾次。

The Great Glen fault has occasionally reactivated, and the two landmasses, Laurentia and Gondwana, moved anywhere from 8 to 29 kilometers each time.

大格倫斷層偶爾會重新激活，勞倫提亞和岡瓦納兩塊大陸每次移動的距離從 8 公里到 29 公里不等。

This is a thing that faults do from time to time to dissipate built-up stress.

這是斷層時常做的一件事，以消除積聚的壓力。

When force is applied by the two landmasses punching against each other, stress is created.

當兩塊陸地相互衝撞產生力時，就會產生應力。

And when it reaches a tipping point, the plates shear and move in opposite directions to relieve that built-up stress.

當達到臨界點時，板塊會發生剪切並向相反的方向移動，以釋放積聚的應力。

The biggest reactivation happened relatively recently, sometime in the last 66 million years, possibly prompted by other parts of Earth's crust spreading apart nearby.

最大的重新激活發生在相對較近的時期，即過去 6600 萬年的某個時候，可能是由於附近地殼的其他部分發生了擴張。

But why don't we see straight lines like this more often?

但為什麼我們不經常看到這樣的直線呢？

Well, these days, the Great Glen fault line is even more visible due to a string of lakes, or locks.

如今，大峽谷斷層線因一連串的湖泊或水閘而更加明顯。

That's because most of the islands of Great Britain and Ireland were covered in enormous ice sheets during a handful of ice ages over the last few hundred thousand years.

這是因為在過去幾十萬年的冰河時期，大不列顛和愛爾蘭的大部分島嶼都被巨大的冰原所覆蓋。

The glaciers around the Great Glen started receding over 10,000 years ago, carving a deep valley along the fault line that actually goes below sea level, making that straight line through Scotland even more visible.

大峽谷周圍的冰川在 1 萬多年前開始後退，沿著斷層線刻畫出一條深谷，實際上一直延伸到海平面以下，使這條穿過蘇格蘭的直線更加清晰可見。

So this straight fault line is the product of half a billion years of time and geology, and it's evidence of the large-scale events that formed Earth as we know it today.

是以，這條筆直的斷層線是 5 億年時間和地質學的產物，也是形成我們今天所知地球的大規模事件的證據。

Thank you for watching this episode of SciShow!

感謝您收看本期科學秀！

At this point, we've made thousands of educational videos over the years, and we've been able to offer them for free because of our patrons on Patreon.

目前，我們多年來已經制作了數千部教育視頻，我們之所以能夠免費提供這些視頻，多虧了 Patreon 上的贊助人。

So to all of our patrons, thank you for what you do to make SciShow happen.

是以，對於我們所有的贊助人，感謝你們為科秀的發展所做的一切。

If you're not a patron but want to learn more about what that means, you can go to patreon.com slash scishow.

如果你不是贊助人，但想了解更多有關贊助的資訊，可以訪問 patreon.com slash scishow。

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