After all-encompassing images of Earth from the edge of the solar system and a trip the the Moon, we finally arrive back to the surface of our rocky little heaven.
I could write novels about this one image. To an untrained eye, it shows a summer afternoon in the Columbia River Gorge. To an observant and inquisitive eye, it reveals quite a bit of interesting information to help explain why our planet is such an awe-inspiring place to live.
Between 15,000 and 12,000 years ago, the Earth was warming and continental glaciers were in retreat. Melt water backed up behind ice “dams”, and sporadically broke free to send massive floods across Washington and Oregon. These floods have been estimated to flow at 10-15 cubic MILES per hour (that’s a whole lot), and in constrained areas such as the gap through the Cascade Mountain range, the water could reach up to 80 miles per hour (that, incidently, is also a whole lot). These floods transformed the Pacific Northwest into the place we see today: The dry, poor soils of the channeled scablands of Eastern Washington, the deep, majestic Columbia River Gorge seen here, and the rich soils of the Willamette Valley were all created during these flood events.
The primary reason the walls of the Gorge are so steep is they were formed from basaltic lava flows, which harden to a relatively solid rock. This basalt resisted erosion (as much as it could) to constrain the flood waters and increase their powers to model the landscape. The deep gorge with plentiful water has allowed many diverse ecosystems to develop, from wet lush forests to semi-arid grass savannas, from gentle lakes and streams to sub-alpine old growth forests.
The Earth is a wondrous place, filled with an amazing assortment of natural diversity. This one photo from the Columbia River Gorge shows just a sampling of what the world has to offer. I could take a million such photos, and not even come close to documenting everything I love about our home.