Thursday, September 28, 2017

The Changing Face of Earth

Since forming from molten stardust some 4.6 billion years ago, the face of our planet has been constantly changing.  The earliest Continents had no resemblance to those we find today and have changed their size, shape and position as they have been rifted apart and sutured together by the opening and closing of oceans.  Of course, that process continues today but is too gradual to be noticed during our short life spans; hints of that relentless activity are offered by observable rift zones and the earthquakes that result from the collision, lateral scraping or subduction of Earth's tectonic plates.

Today's surface geography has only settled into place over the last 50 million years or so, a very brief period in Earth's natural history.  While volcanic islands continue to appear and Continental shorelines expanded and contracted throughout the Pleistocene (2 million to 10 thousand years ago), humans did not have the technology to adequately map and view our planet's surface until the last few centuries.

Indeed, the coming generations will be the first in human history to directly observe the changing face of Earth as our climate warms, sea levels rise and coastal geography changes dramatically.  Hopefully, that reality will ignite a more fervent commitment to minimize human impact on both the atmosphere and the natural ecosystems of our home planet.