Why There's a Straight Line Through Scotland

If you take a look at a map of Scotland, you'll notice an eerily straight line running through the highlands, this is the Great Glen Fault the product of half a billion years of time and geology.

Hosted by: Stefan Chin

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[SciShow]

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[wpb]

I remember a Scottish person telling me that Scotland was wandering around the oceans and it could have run into any country, but it had to run into fookin' England.

[danpictish]

Greetings from Scotland. I'm a highlander and it's definitely my fault!

[bendenisereedy]

Have a look at the Highland Boundary Fault further south, which separates the Highlands from the Lowlands. The small town of Comrie in Perthshire is known as "shaky toun" as it's right on the fault and gets dozens of small tremors a year. It even has the world's first seismology station, built in 1840. It's a lovely area to visit with fantastic scenery.

[YvonTripper]

This shows that Scottish independence is inevitable in the next 66 million years

[talideon]

Slightly further south is the Iapetus Suture, which is what separates the Laurentian plate from the Avalonian plate. It runs close to the Scottish border, down through the Isle of Man where you can actually see the bare rocks, and through Ireland down to the Shannon Estuary. It's had a huge effect on history.

[mechan]

hello a scotsman here from glasgow, another thing also is we built the caledonian canal along this fault, so we connected all the lochs and waterways along the full length of scotland, so you can get a boat from the atlantic ocean on the left to the north sea on the right, you can hire boats and do it if you wish.

[draziraphale]

A lot of my PhD was on this. I studied how magnetic fields interact with the carbon in the Iapetus Suture and Variscan orogenic faults and this enabled me to find where the former ancient ocean bed residue was, and allowed me to make 3D models of the Earth's crust in Ireland.

[Hjaelteomslag]

It did this to make a perfectly straight line for Nessie to swim through when she wants to leave Loch Ness.

[dougaltolan]

It's all Feng Shui.
Since dragons can only run in straight lines, this feature makes Nessie feel at home.

[Mirandorl]

When you travel from one side of the fault line to the other, due to the plates being made of different types of rock the scenery changes completely. From a brownish, rounded-off quality to the hills and mountains in the east, to pure grey granite with very little coverage of moss and plants in the west. It's like suddenly stepping into Austria 🙂

[MeterLP]

SciShow: Straight line through a country
GeoWizard: heavy breathing

[MP-fwub]

Always amazes me as you drive north across it. The total and pretty abrupt change in the scenery. It's a very special place.

[BOb-lupc]

Fun fact! Nearly every Loch in the Great Glen has its own Loch Monster.
"Nessie" in Loch Ness
"Wee Oichy" in Loch Oich
"Lizzie" in Loch Lochy
And even some rare sightings of one in Loch Linnhe
Many of the surrounding Lochs also have their own sightings in Loch Garry, Loch Quoich, Loch Arkaig, Loch Morar, and Loch Sheil.
Personally I think they're all the same species migrating across the highlands through the river systems that connect the lakes together.

[tj]

I live in that valley. The Great Glen. Very scenic.

[nicktallfox]

1:20 i too like to move 8 to 29 kilometers away from my current location from time to time to dissipate built up stress.

[lisalabar]

I can tell you that here in Connecticut, on the East side of the river, is definitely proof that Scotland and America did indeed collide. The soil and rocks are the same as they are in Scotland. On the western side of the Connecticut River, the soil and rocks are completely different and have almost none of the same qualities. I’ve lived here for over 50 years and I also enjoy Geology. Specimens are VERY different! 🇺🇸🕊

[drawingboard]

It's so we can have lochs deep enough to hold monsters in.

[jimf]

My fault too. Those of us educated locally who took Geography to Higher are pretty familiar with all the details. That straight line extends way beyond the sea shore at Caol or Inverness and can be seen extending at least to Mull and perhaps Islay and Jura in the South and to Tarbat Ness and maybe even Wick in the North. As major faults go, it's pretty quiet. Earthquakes in the UK are almost all less than 4.5 and activity here is usually a lot less than that. Only one event directly on the fault in the last 60 days (BGS) and it was 0.8.
The glaciation has carved out a trench that reaches down to around 300m to 400m below sea level and at four places along this trench it is filled with glacio-fluvial deposits to above sea level. These allow Fort William, Laggan, Fort Augustus and Inverness to provide home for around 70, 000 people and prevents there being two separate islands. Loch Ness is the largest and best known of the lochs that fill the gaps between these plugs of sand and gravel. It has a muddy flat-bottom due to deposition from huge catchment area and is a maximum of 223m deep (surface elevation 16m).
I always get a laugh when construction projects run by people from elsewhere start drilling in central Inverness trying to find bedrock without understanding that it is several hundred metres down. The BGS database clearly shows results from a 19th century drill exploration to nearly 100m and all it shows is sand and gravel with occasional minor clay deposits. The buildings all seem to stay up!

[piplupcola]

Scishow: It happened recently
Me: oh cool when?
Scishow: 66 million years ago
Me: huh. For some reason I was expecting it to be like more recent than that