Another 15 million years off the clock,and magma from the mantle burns a giant hole into western North America, periodically erupting onto the surface.Today, this hotspot feeds an active supervolcano beneath Yellowstone National Park.
It hasn't erupted in the last 174,000 years,but if it did,its sheer force could blanket most of the continent with ash that would blacken the skies and threaten humanity.
The Yellowstone supervolcano is just one reminder that the Earth continues to seethe below our feet.
Its mobile plates put the planet in a state of constant flux.In another few hundred million years,who knows how the landscape of North America will have changed.
As the continent slowly morphsinto something unfamiliar, only geological time will tell.