A Sense of Sinkholes, the Dummies Version

Sinkhole, House for Scale

Once upon a time, there were dozens )maybe hundreds) of so-called content farms competing for eyeballs (and ad revenue) across the web. Google's Panda changed all that in late 2011, although some people apparently didn't get the message. One of the folks who still kept pounding out articles peppered with keywords and other tricks inspired by self-proclaimed SEO gurus was Deborah L. Osae-Oppong of HubPages, who – despite her background in health sciences and communications – opted to explain "The Science of Sinkholes: How to Survive" back in 2013.¹ Presumably,  Deborah's interest in the topic was solely financial, given a recent mini-rash of sinkhole incidents in Florida and Illinois about that time. But "how to survive"? Let's see what she says...

Osae-Oppong opens with horror stories: two of them, sinkholes that swallowed up innocent bystanders. As befits modern-day sensationalist journalism, Deb turned this into a horrifying trend (never mind its statistical improbability). Given the "trend," she felt it necessary to explain the phenomenon:

"Sinkholes are…well, holes, that form over time due to erosion, and gravity..."

Well, she got the "gravity" part right. Whether "erosion" is correct depends on your definition of the word; our staff geologist prefers to refer to the process as "solution." Osae-Oppong then proceeds to make a complete hash out of the process of sinkhole formation. We're reproduced her "explanation" in full:

"They are usually caused by water that flows below that topsoil; the water turns acidic due to the absorption of carbon dioxide and byproducts of plant metabolism. The acidic water can dissolve limestone or bedrock, and can create underground channels through which more water will eventually flow. This is the process by which underground basins occur. The constant flow of acidic water continues to erode the bedrock; meanwhile, the top layer of Earth usually stays in tact. However, as the area under the surface dissolves, the lower levels will eventually be unable to support the weight of the topsoil, or the house, or the golf course above it. When this happens, the ground caves in, creating the sinkhole."

We asked our geologist to sort out this mixture of misinformation, facts and factoids. Here's  his take:

• Naturally occurring sinkholes are always caused by water, not usually.
• "...below that topsoil..." means nothing. Sinkholes are a bedrock phenomenon, not a soil phenomenon, unless it's an anthropogenic sinkhole caused by a ruptured water main.
• Acidic groundwater can only dissolve limestone, dolomite or evaporite rocks, all of which are "bedrock" -- it can't dissolve other species of bedrock.
• WTF is an "underground basin"? Is Osae-Oppong talking about caves? then she should say "caves"!
• The staff grammarian says, "Learn the word 'intact': it's not 'in tact'!"
• WTF are these "lower levels" of which she speaks? We presume she's speaking of the unsupported roof of a cavern, but...

Deborah then reproduced a U. S. Geological Survey map of "the states most affected by sinkholes" -- except that she misconstrued the meaning of the map, which is actually a map of "areas of the United States where certain rock types that are susceptible to dissolution in water occur." USGS then goes on to point out that "Evaporite rocks [cross-hatched areas on the map] underlie about 35 to 40 percent of the United States, though in many areas they are buried at great depths"; something Osae-Oppong glossed over completely.
Besides this level of scientific illiteracy -- we hope this self-proclaimed professional "science writer, editor and communicator" does better when helping actual scientists write up their own work -- Osae-Oppong never delivers on the promised "How to Survive." Her best advice is to "check with your county office, local or state geological surveys, and the USGS to see if you live in areas underlain by soluble rock..." That's her best shot? No wonder she's our Dumbass of the Day: playing on people's fear for hits? that's clickbait!

¹ The original is no longer at HubPages, but can still be accessed using the Wayback machine at archive.org. Its URL was   hubpages.com/education/The-Science-of-Sinkholes-How-to-Survive

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