ODD TRUTHS: THE MYSTERIES OF LAKE PAVIN
“It was out of the ‘bottomless’ Lac Pavin that the sorcerers conjured wind and storm by casting a stone into its enchanted waters…”
-from France by Margaret Roberts (1881)
Situated inside a volcanic crater in the Dore Mountains, Pavin is the deepest lake in Auvergne. Its entrancing appearance, which has been a subject of interest for travel writers and geographers for the past four hundred years, has all the hallmarks of an elfin scene from a chivalric romance. Undines seem to hide beneath its glittering, motionless surface, and goblins (especially in the moonlight) seem to haunt the forest of fir trees that lines its banks. And so it should come as no surprise to find that for years, Pavin’s depths were thought to be fathomless, the abysmal abode of dragons, spirits, and even the Devil himself. Some of these tales date back to the Renaissance, others, such as the story that the old shoreside town of Besse was engulfed by the lake in a catacylsmic flood, are much more recent. Although the legends about Pavin vary, they all seem to agree about one thing: Pavin hides infernal forces, forces that—from time to time—bubble up through its surface and disrupt the weather.
One of the earliest accounts of Pavin’s strange geological and meteorological activity comes from Paul Merula’s Cosmographia (1614). Merula doesn’t mention Pavin by name, but he does describe a lake near “Besse in Auvergne” which produces hail, lightning, and rain whenever a stone is thrown into it. Merula’s description is also similar to a passage in Francois Belleforest’s supplemented translation of Sebastian Münster’s Cosmographia (1575). In the work, Belleforest writes that the “terrifying” and volatile lake is located in the vicinity of the village of Besse near “Mount Dore”.
According to folklorist Paul Sébillot, these stories about a dangerous mountain lake have their antecedent in a report from Gervais of Tilbury, a thirteenth-century historian. In his Otia Imperialia, Tilbury mentions a demon-infested, tempest-raising lake on the summit of an inaccessible mountain in Catalonia. Like Pavin, this lake has an “inscrutable” depth and doesn’t take kindly to projectiles that pierce its surface. More variants of the stone throwing trope also appear in folk stories about other European lakes, such as the Mummelsee. What differentiates Pavin from other bodies of demonic water however, is the likelihood that some features of its mythology were derived from amateur observations of its seismicity. In fact, according to Michel Meybeck, an emeritus professor and geologist at the University of Paris VI, Pavin’s legends have more than a grain of truth in them.
In a recently published study, Meybeck collates his lifelong interests in Pavin and his scientific research on maar lakes and limnic eruptions. Referencing the work of Thierry del Rosso, Pierre Lavina, Emmanuel Chapron and others, Meybeck argues that “degassing” events in the lake had a hand in shaping and perpetuating Pavin’s folklore. Meybeck’s theory is fairly straightforward. Pavin is meromictic, which means that it has layers of water that rarely mix. The bottom layer, which is rich in carbon dioxide, sometimes ejects gas into the atmosphere when the lake bed is disturbed by intense seismic activity or sudden landslides.
To support his thesis, Meybeck provides evidence for two major sedimentary shifts in Pavin which took place in the seventh and fourteenth centuries. He also cites witness descriptions of an eruption which occurred at lake Nyos (a similarly gas-saturated maar) in Cameroon in 1986. The Nyos event caused mass casualties and produced rare, Biblical-like phenomena, such as brief lightning strikes, gurgling waves, thunderclaps, clouds of toxic vapour, and rising columns of water. All these effects were triggered by a tremor that caused the abundant CO2 in the lake to violently rise to the surface. These facts, Meybeck surmises, show that Pavin could have generated similar spectacles during its two prominent sediment slumps. Thus, Meybeck posits that Pavin’s legends are useful tools for understanding how pre-modern peoples might have interpreted geological anomalies.
As for the stone throwing trope, Meybeck proposes two possibilities: the trope is either a metaphor for rock slides or an exaggeration of a real phenomenon. Fascinatingly, Meybeck confirms the seemingly impossible reality that stones and other debris could have set off detonations at key moments in Pavin’s history. To back up his argument, he cites studies on Cameroon’s Monoun lake (which indicate that minor explosions in heavily saturated lakes can be triggered by splashing or stirring the surface). Overall, Meybeck’s findings, while impressive and thought-provoking, are still open to debate. Nevertheless, he has succeeded in recovering and popularising Pavin’s unique, centuries-old geomythology. Without a doubt, Pavin, which has long captured the imagination of Auvergne’s inhabitants, will continue to inspire further enquiries into its mysteries.