Scarred and pockmarked is how we're leaving our planet, according to a recent study. There is extensive damage being done by our digging, drilling and mining and the effects may be irreversible.
As we disturb the areas underneath the surface of our earth, we put in place a set of motions that will permanently affect our planet, says a team of researchers in the journal Anthropocene.
The researchers liken human mining and drilling to worm and rabbit burrowing, or bioturbation. To stress the similarity (both underground, both digging) but mark the difference (we are breaking several kilometers deep into Earth's crust, while those pesky moles are just killing your garden bed), they've deemed this phenomenon "anthroturbation".
"These human phenomena range from simple individual structures to complex networks that range to several kilometers in depth (compared with animal burrows that range from centimeters to a few meters in depth) while the extraction of material from underground can lead to topographic subsidence or collapse, with concomitant modification of the landscape," say the authors in their paper.
The biggest issue concerning geologists is the fact that such deep tunneling and mining is unprecedented in Earth's history and many of the potential effects are difficult to predict. There are at least a million active wells in the U.S. and about the same amount of boreholes in the U.K. mines disturb the underground environment more so than any natural geological phenomenon as they don't follow any pattern. But the most unsettling scars left by humans are probably those left by nuclear weapons, such as shattered rocks from bomb tests, researchers say.
The lead author of the paper, Jan Zalasiewicz, says that the amount of anthroturbation that has occurred in recent modern history may be enough to declare the Anthropocene a valid geologic epoch. 500 million years ago, digging and burrowing by animals began and changed the geology so much that scientists deemed it the Cambrian period. Another historical shift might be in the works.
Despite this research and the University of Leicester team's hope of making recommendations in 2016 to cut back on the subterranean disturbances by humans, this phenomenon is unlikely to stop, or even slow down. Between mining for elements, pollution storage and subsurface machinery (sewers and subway systems), anthroturbation is most likely here to stay-as are its effects.
"As these traces are made well below the reach of erosion, many will last over geological timescales: for millions of years or even hundreds of millions of years," says Zalasiewicz. He adds that some may stay for the rest of our planet's existence.
