The Voids Beneath

[Image: Drone footage of a Cornwall garden sinkhole, via the BBC].

One of the peculiar pleasures of reading Subterranea, a magazine published by Subterranea Britannica, is catching up on British sinkhole news.

In more or less every issue, there will be tales of such things as “a mysterious collapse in a garden behind a 19th-century house,” that turns out to be a shaft leading down into a forgotten sand mine, or of “abandoned chalk mine sites” heavily eroding in winter rain storms, “resulting in roof-falls.”

“As most chalk mines are at relatively shallow depth,” Subterranea reports, “these roof-falls migrate upwards to break [the] surface as ‘crown holes’ or craters, which in the said winter [of 2013/2014] have been appearing in lawns and driveways, and even under houses, newly built in chalk districts.”

The earth deceptively hollow, the landscape around you actually a ceiling for spaces beneath.

Worryingly, many of these mines and underground quarries are difficult, if not impossible, to locate, as insufficient regulation combined with shabby documentation practices mean that there could be abandoned underground workings you might never be aware of hiding beneath your own property—until next winter’s rains kick in, that is, or the next, when you can look forward to staring out at the grass and shrubbery, with growing angst, waiting for sinkholes to appear. Rain becomes a kind of cave-finding technology.

Even in the heart of London, the underworld beckons. Last Spring, Subterranea reminds us, “a woman and her shopping trolley rather suddenly disappeared into a four metres deep hole in North End Road, Fulham.” The culprit? It “appears to have been a disused under-street coal cellar.”

Perhaps the most incredible recent example, however, comes from the town of Scorrier, in Cornwall.

[Image: Photo courtesy The Sun].

There, a “deep mine shaft has appeared” beneath the patio of a house in the process of being prepped for sale. “The shaft drops approximately 300 feet deep to water but could be four or five times deeper [!] below that,” Subterranea reports. It “is a remnant of Cornwall’s tin mining industry in the 18th century.”

It is a straight vertical shaft, more like a rectangular well, yawning open behind the house.

And there are many more of these mines and quarries, still waiting to be discovered: “As mines closed,” we read, “many [mining companies] put very large blocks of timber, often old railway sleepers, across shafts and backfilled them, thinking this would be safe. Gradually all evidence of the engine houses and covered shafts disappeared from view and memory and in the past builders assumed there was nothing there. Had they consulted old maps they would have known about the shaft. The timbers rotted over the years and collapses like this often happen after long periods of rain, which they have had in this area.”

There’s something both uncanny and compelling about the idea that, with seasons of increased rainfall due to climate change, the nation’s mining industry might stage an unsettling reappearance, bursting open in subterranean splendor to swallow the surface world whole.

Think of it as an industrial-historical variation on the El Niño rains in Los Angeles—where huge storms were suspected of “unearthing more skeletal human remains” in the parched hills outside the city—only here given the horror movie ambience of murderous voids opening up beneath houses, making their abyssal presence felt after long winter nights of darkness and endless rain.

In any case, consider joining Subterranea Britannica for a subscription to Subterranea for more sinkhole news.