It’s a mental exercise many have pondered: if humanity were to go extinct, and alien explorers descended on the Earth, what would serve as the final reminder of our civilizations? Major buildings? Roads? Landfills? USB drives? Roving zombie remainders of beings that were once human?
According to a recent research, it’s a less obvious feature: our subterranean landscape . . . or our tunnels.
The Diggers That Could
The geologist authors conjecture that our longest-lasting impact as proud owners of massive craniums will be a practice that is foundational to the animal kingdom in general. The researchers note that geologists look at tunnels burrowed by animals as an important tool for classifying eras of life on Earth. Likewise, human burrowing—in the form of millions of tunnels, boreholes and mines that exist for construction, resource extraction, disposal, etc.—has created major changes to the surface of the Earth’s crust that may be permanent forget-me-nots from humanity.
To be sure, our burrowing completely dwarfs that of any other animal. Our digs can create tunnels extending miles into the Earth, and our carvings into the crust has "no analogue in the Earth's 4.6 billion year history,” as the authors state. The length of all the boreholes on Earth, according to their calculations, would be roughly equal to the distance from the Earth to Mars.
The authors conjecture that these sturdy holes may cease to exist only when the Earth as a whole is consigned to oblivion, and that this aggregate modification of the Earth “arguably has the highest long-term preservation potential of anything made by humans."
We can only hope that millions of years in the future—long past the erosion of our books, computers and Lady Gaga—that alien archeologists don’t make the assumption that the creatures who burrowed these massive tunnels were likely fleshy ant-like creatures. For that truly would be the final insult.