A 2D length-profile and transverse sonar cross-section of the Great Glen — the fault-controlled trough holding Loch Ness — built from the same bed-elevation formulas as the 3D terrain model.
Loch Ness occupies a straight strike-slip fault later deepened by glaciers. The top panel traces the trough floor from Fort Augustus to Inverness; the bottom panel is a live sonar-style cross-section at the scan point.
Adjust vertical exaggeration to read the relief, drag the water level to drain the loch, and slide the sonar position to sweep both panels along the glen.
Loch Ness is exceptionally deep (around 230m) but narrow, because it fills a glacially over-deepened fault trough rather than a wide basin.