The Earth-shattering Monster of Loch Ness

The first purported photo of Nessie was published in The Daily Mail" on April 21, 1934.  The image, taken by a London surgeon named Kenneth Wilson, was touted for decades as the best evidence for Nessie — until it was admitted as a hoax decades later.

In 2001 Italian geologist Luigi Piccardi presented at the Earth Systems Processes meeting in Edinburgh a hypothesis, explaining the supposed appearance of the lake monster in Loch Ness as a result of the local geology. According to Piccardi, the historical description of the monster - appearing on the surface with great (earth)shakes and waves - could be based on seismic activity along the Great Glen fault. The Great Glen fault is a transcurrent fault where two bits of Earth - the Grampian Highlands, composed of early Paleozoic plutonic rocks, and the Northern Highlands, composed mostly of Neoproterozoic rocks with Palozoic sedimentary covers - are sliding sideways against each other.

 BRETON; COBBOLODY & ZANELLA (2013).

Loch Ness is a 36 km long lake, located just above the fault zone. As the fault moves, earthquakes happen and cause bubbles and waves on the lake's surface. In an interview published in the Italian newspaper "La Repubblica" Piccardi explains:

"There are various effects on the surface of the water that can be related to the activity of the fault ...[]... the beast appears and disappears with great shakes. I think it's an obvious description of what really happened…[] We know that there was a period [1920-1930, a period characterized by many reported sightings of Nessie] with increased activity of the fault, in reality, people have seen the effects of the earthquakes on the water."

According to the biography of St. Columba, the scene described by Piccardi happened in the year 565. Trying to cross the river Ness the missionary is attacked by a beast. However, Columba implores the protection of god and the monster promptly disappears. The original text, however, is very vague and gives no detailed description of the event, stating only that it was an "unknown beast" and it approached with the mouth wide open and a loud roar. In the myth, the supposed lake monster is of much less importance than the ability of St. Columba to tame beasts and demons and doing so to impress the local pagans. It is quite possible that the supposed encounter with the monster was added to make Colomba´s legend bigger than real life. The vague description presented doesn't really support any proposed scenario, neither seismic activity nor a presumed surviving plesiosaur, living in a lake formed by glaciers during the last ice age some 18,000 years ago. Modern sightings in Loch Ness can more reasonably be explained by a combination of hoaxes, misidentification of common animals or waves and the local tourist industry, keeping the myth alive to attract tourists. Research done in the lake has never produced any clue for the possible existence of a population of larger animals in the Loch.

Also, historic seismicity doesn't seem to support the existence of an earth-shaking monster in the Loch. Earthquakes along the Great Glen fault range between a magnitude of 3 to 4, too weak to cause any observable effects on the lake. Stronger events are exceptionally rare and were recorded only in 1816, 1888, 1890 and 1901. These earthquakes don't coincide with the years of supposed increased activity of Nessie, like in the decade around 1933.