Are humans impacting the deep Earth?
Human forays deep underground, such as boreholes, mines and nuclear bomb tests, are leaving a mark on the planet's geology that will last for hundreds of millions of years, say scientists.
In a new report, published in the journal Anthropocene, they say we are altering Earth's rocks in a way that's unique in the planet's 4.6 billion-year history.
The phenomenon adds weight to the 'Anthropocene' concept — the idea that we have changed the planet so dramatically that it has now entered a new, distinctive phase in its history.
Scientists disagree about whether the Anthropocene should be officially recognised as part of the geological timeline.
Until now, much of the focus has been on changes at the surface, to the atmosphere, oceans and ecosystems. But according to Dr Jan Zalasiewicz of the University of Leicester, who led the research, our influence below ground is just as pronounced.
'The underground world is not one that most of us experience directly,' he says. 'Effectively it's out of sight, out of mind.'
'But we're leaving a mark on the geology that will last for millions of years, probably more. Whatever we do in the future, that influence is only going to grow — we've set in motion a new phase in the planet's history.'
Coal miner with drill image via Shutterstock.
Read more at Planet Earth Online.