Scientists Explain Science Behind the Giant ‘Scar’ That Slices Through Scotland

Earth is filled with many intriguing features. One of them is the Great Glen Fault in Scotland, according to IFL Science. This feature looks like a massive scar that runs diagonally in Scotland's upper reaches. It begins in the northeast and ends in the southwest of the reaches. 

Experts have identified the feature as a strike-slip fault. This means it is a fracture that was caused when two giant blocks from Earth's crust slid horizontally past each other. It has been estimated to be 430 to 390 million years old. This implies that the feature originated at the end of the Caledonian Orogeny. Experts speculate that the fracture came into being during a mountain-building event, which continued for 150 million years. This phenomenon happened because ancient continents like  Laurentia, Baltica, and Avalonia were colliding with each other. 

In Scotland's map, the fault line seems to be cutting right through the nation, according to Indiana Public Media. Researchers believe that Laurentia and Gondwana collided with each other to form the island where the Great Glen now stands. The visible fault line emerged because of erosion that took place during the last glacial period. Most of the fault zone was covered in ice, but the erosion caused the glaciers to recede, and the ice got embedded in the land along the fault area. The resultant grooves were labelled the Great Glen. Moderate seismic activity is still detected in this area. 

The Great Glen, where the fault resides, is supposedly visible from space, according to the Geological Society. Geologists think that the place was eroded more than 10,000 years ago by glaciers. These glaciers carved a valley, which is now the Great Glen. It is below the present-day sea level and has a series of deep lakes, the largest of which is Loch Ness. 

The Great Glen fault is the most prominent of its kind in the British Isles. It spans from Fort William to Inverness in the Highlands. There is a long history of reactivation associated with this fault. Researchers have already determined that the north-west and south-east sides of the Great Glen Fault continue to move in opposite directions. However, experts are yet to figure out how much these two sides have moved. Based on the records available from the Devonian period, researchers think that the displacement is at least as long as the exposed fault's length on the mainland. 

Great Glen has been recognized as a fault zone for over a century, however, it became popular after the work of an expert named William Kennedy in the 1930s. Kennedy was the first one to recognize the fault as a strike-slip (or wrench) fault. At that time, it was the first of its kind to be identified and publicized worldwide. For researchers, it was one of the first evidence of the then-speculated large-scale lateral earth movements. 

Apart from being evidence of a significant geological phenomenon, the fault zone also holds an important place in Scotland's history, according to Indiana Public Media. The place played a pivotal role in uniting highlanders against the British, and also hosted the canals and railway system, which modernized Scotland's economy. Some aficionados also believe that the famous Loch Ness Monster came into being in popular culture due to the rumbles and waves produced by the fault.