Drilling is Permanently Scarring Our Planet

Humans have made many lasting marks on our planet, but possibly one of our most devastating is through our drilling, which is scarring the subterranean "underworld" of rocks beneath our feet, according to a new study.

"The underground realm for most of us is out of sight, out of mind," geologist and lead author Jan Zalasiewicz, of the University of Leicester in England, told Scientific American.

"Yet it is seeing significant change that in some ways is as striking as any that humans have made to the Earth's geology, and that is permanent, even geologically."

Zalasiewicz and colleagues have coined a term for this damaging drilling, digging and mining: anthroturbation. They liken human drilling to burrowing by animals such as ants or wolves, referred to as bioturbation.

Though both of these involve digging underground, anthroturbation is much more scarring given the fact that it involves breaking several kilometers deep into Earth's crust - compared to pesky animals simply burrowing a few feet underground.

For instance, while certain tree roots can reach as far as 68 meters (223 feet) deep in the Kalahari Desert of South Africa, miners in that same region have tunneled a whopping five kilometers (3.1 miles) below Earth's surface in search of gold.

"Things like mines and boreholes, even compacted by pressure and chemically changed by underground fluids, are big and obvious punctures in the rock. They're not subtle," Zalasiewicz noted.

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 one million active borehole wells in both the United Kingdom and United States, and they disturb the underworld geometric pattern in a way never before seen. But the most disconcerting human-made scars come from those left by nuclear weapons, such as shattered rocks from bomb tests, researchers say.

"Anthroturbation has created textures and structures underground that are unique within the animal world. No other organism has made igneous and metamorphic rocks - and yet we have made many tons of these in underground nuclear tests, in shock-fracturing and by melting the rock around the blast," Zalasiewicz explained in a statement.

Despite this unsettling research, the University of Leicester team hopes to make recommendations in 2016 to cut back on the subterranean disturbances by humans.

The findings were published in the journal Anthropocene.