Legendary beast, or harmless geological activity? That is the question raised after a scientist's surprising theory about the Loch Ness Monster resurfaced recently.
Italian geologist Luigi Piccardi first floated his theory in 2001, telling a meeting of colleagues organized by the Geological Society of London and the Geological Society of America that seismic activity may underlie the majority of supposed monster sightings around the Scottish lake from which the fabled creature takes its name.
The first claimed sighting of "Nessie" occurred in the sixth century, according to Scientific American. Legend has it that the creature appears along with earth tremors and bubbling from the bottom of Loch Ness, one of Britain's largest freshwater lakes.
Formed as a result of a long-ago collision between the northern tip of Scotland and the rest of Britain, the loch sits over the 62-mile Great Glen fault line. Piccardi argues that this position may have fueled centuries of Loch Ness Monster rumors.
"Loch Ness is exactly on the fault zone," Piccardi said in 2001, according to The Telegraph. "When there are small shocks, it can create a commotion on the water surface. Along the fault there can be gas emissions, which can create large bubbles on the surface. There are many surface effects which can be linked to the activity of the fault."
But Piccardi's theory is not without critics, especially among Loch Ness Monster enthusiasts like Gary Campbell, president of the Loch Ness Monster Fan Club in Inverness, Scotland.
"Most of the sightings involve foreign objects coming out of the water. There's two most common -- one's a hump, and the other is a head and neck," Campbell told ABC News. "At the end of the day, there's still sightings that are inexplicable. There's something physical in there."
Some of the more recent sightings of the long-necked "monster" include Marcus Atkinson's 2012 sonar images of a large object that he claimed followed his boat around 75 feet beneath the lake's surface. That same year, Scottish Nessie expert George Edwards snapped a picture of an unexplained hump-like object that eventually sank back beneath the waves -- though skeptics say he probably just saw a bobbing log.
Throughout the years, high-profile sightings of Nessie have been suspected or outed as hoaxes, according to PBS. What was once arguably the most iconic photo of Nessie (seen below), published in the London Daily Mail in 1934, was later revealed to have been staged.
Even still, is Piccardi's theory likely to close the book on the Loch Ness controversy? Probably not.
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Loch Ness Monster
A view of the Loch Ness Monster, near Inverness, Scotland, on April 19, 1934. The photograph, one of two pictures known as the "surgeon's photographs," was allegedly taken by Col. Robert Kenneth Wilson, though it was later exposed as a hoax by one of the participants, Chris Spurling. On his deathbed, Spurling revealed that the pictures were staged by himself, Marmaduke and Ian Wetherell, and Wilson. References to a monster in Loch Ness date back to St. Columba's biography in 565 A.D. More than 1,000 people claim to have seen "Nessie," and the area is, consequently, a popular tourist attraction.
In England, a kayaker took this photo on Lake Windemere, near Bowness in Cumbria. "At a distance, I thought it was some sort of large dog," said Tom Pickles. "Then I realized just how long it was." Ever since the first reports of Bow-Nessie emerged in 2006 from Lake Windermere, a legend has taken root with people wondering if this could be a not-too-distant relative of the legendary Loch Ness Monster of Scotland.
Loch Ness Sighting
This is a photo of boats at Urquhart Bay, Loch Ness, Scotland, on Aug. 6, 1983, made by American wildlife photographer Erik Beckjord. It shows splashes on the surface of Loch Ness made by an unidentified object (white mark at center right), which Beckjord claimed could have been made by the Loch Ness Monster.
Loch Ness Monster Fin
Robert H. Hines, president of the Academy of Applied Science, released this photo during a 1972 investigation of Loch Ness. Hines said his expedition took photo, which he said showed the fin of the Loch Ness Monster, and that it was substantiated by sonar and other scientific data that strongly suggests there is a large marine creature inhabiting Scotland's Loch Ness.
This mysterious shape was captured by photographer Mark Harrison while riding on a ferry off the Seacombe district of Wirral in the United Kingdom on the morning of May 25. Experts claim that it could be a harbor porpoise or a basking shark, but Harrison says, "Me? Clearly, I believe it's Nessie on her hols!"
Nessie and Alaska's Illie May Be Sleeper Sharks
This 2000 image shows biologist Bruce Wright in salt waters in southeast Alaska with a small Pacific sleeper shark that was caught on a research cruise. He believes much bigger versions of this shark group could be the true identity of Scotland's Loch Ness Monster and Alaska's Lake Iliamna creature known as Illie.
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Phylis Canion holds the head of what she called a Chupacabra at her home in Cuero, Texas, on Aug. 31, 2007. She found the strange-looking animal dead outside her ranch and thinks it is responsible for killing many of her chickens.
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East River Monster
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Bigfoot in Rutherford County, N.C.
Thomas Byers snapped this photo of "Bigfoot" along Golden Valley Church Road on March 22, 2011.
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Washington State Sasquatch
This is a black and white print from a color movie Frank White said he took in the forest near Bellingham, Wash., on Oct. 8, 1977. "I'd call it a North American ape," said White. "You can call it a Sasquatch or anything you like."
This still-frame image from video provided by Bigfoot Global LLC shows what is claimed by them to be a Bigfoot or Sasquatch creature in an undisclosed area of a northern Georgia forest in June 2008.
The legend of Bigfoot has baffled many people for decades, especially when images like this one are released. A footprint measuring 17-and-3/4 inches long and 7-and-1/2 inches wide was discovered Aug. 26, 1980, at a residence in the Conemaugh Township area of Johnstown, Pa. A very well-defined print was left behind, if indeed it was Bigfoot, plus a left print was found eight feet away in a more wooded area. Along with the footprints, reports of strange noises and a very unusual but strong odor coincided with the account.
Bigfoot Plaster Cast
Ken Gerhard of Houston holds a duplicate plaster cast footprint at the Texas Bigfoot Conference in Jefferson, Texas, on Oct. 15, 2005. The event was hosted by the Texas Bigfoot Research Center.
Al Hodgson, a volunteer guide at the Willow Creek-China Flat Museum, holds up a plaster cast of a Bigfoot imprint displayed at the museum's Bigfoot Wing in Willow Creek, Calif., on June 5, 2000. The wing was built to bring tourists interested in the legendary creature to the economically depressed ex-lumber town.
This photograph obtained Aug. 15, 2008, from <a href="www.searchingforbigfoot.com" target="_hplink">Searching For Bigfoot</a> shows what is purported to be the body of the legendary ape-like creature that has been the subject of decades of hoaxes and dubious sightings. Matthew Whitton and Rick Dyer claimed before a crowd of skeptical reporters in Palto Alto, Calif., that they were hiking in a northern part of Georgia when they stumbled upon the body near water. The corpse was said to be 7 feet, 7 inches tall, weighing more than 500 pounds. Many scientists believe Bigfoot is folklore instead of fact.
Abominable Snowman Footprint
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The Jersey Devil
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