The Geology behind the Landscapes of our Planet
Living on a perpetually changing planet
Documenting the Earth’s unparalleled beauty through photography and accompanying geo-scientific explanations of how the planet perpetually evolves over eons evokes a greater awareness and appreciation of just how precious our planet's remaining wilderness is and how much it calls to be protected from human exploitation. Bearing witness to the rapid and extensive destruction of these last bastions of beauty, I can't over-emphasize just how desperately we need to expand our respect for nature and in turn protect, preserve and expand the remaining sanctuaries of our fragile natural world.
Now while it's true that the Earth’s climate is ever changing, it does so naturally at a very slow pace over thousands of years so that the planet's ecosystems and inhabiting species can adapt. However, man is currently accelerating these changes in climate at alarming speeds. What Earth has altered in 10,000 years naturally, humans have produced in a mere 100 years.
A consequence of this rapid change is an ongoing mass extinction purely because adaptation can not keep up. Interestingly, similar rapid changes occurred before humans appeared. These are known as catastrophic mass extinction events caused by extraterrestrial impacts from space or times when global volcanic activity devastate the Earth with global consequence for climate. Each time such events occurred, the ecosystems and its inhabitants changed forever.
This is about to happen again if we don’t rapidly amplify our care for the planet we live on and that feeds us. Whether we admit it or not, we are currently conducting an experiment with our planet that is nothing but a leap in the dark. The Earth's compartments – the atmosphere, the oceans, the ice, the rocks and the biosphere – all interact and feedback with one another at totally different temporal and spatial scales.
In doing so, the planet is amazingly fragile to rapid disturbances and pushing the system beyond tipping points may alter it forever with devastating consequences for its inhabitants. We are only now learning to appreciate these interactions and their impact on our planet. What is clear though, is that this presents us with both a great challenge and tremendous chance to change things for a sustainable future.
Of course, time is relative. The Earth's internal geodynamic processes have been producing ancient continental land surfaces out of granitic rocks almost since the formation of the planet, a whopping 4,550 million years ago! In parts of Canada, Greenland and Australia we find stable rock platforms that are respectfully an awe-inspiring 4,000, 3,800 and 3,500 million years old. Incredibly, there's evidence that even older land surfaces and oceans existed up to 4,400 million years ago.
In contrast, the vast expanses of our ocean sea floors are comprised of a completely different rock type – volcanic basalt – that on average never gets older than 190 million years because of recycling processes back into the Earth's interior. The reasons for this discrepancy are small density differences between the more light-weight continental granite and the heavier oceanic basalt. These density differences cause the continents to "float" upon the Earth’s ductile mantle, just as icebergs flow on and protrude out of water.
Consequently, the Earth's surface organizes itself into a puzzle of tectonic plates – global wanderers that periodically form supercontinents only to break apart again. Drifting apart forms new ocean basins while collisions close ocean basins to subsequently form mountain ranges and volcanic belts. These elevated surfaces are then immediately eroded by weather and climate, transporting the sediments back to the oceans.
On a human time scale of 100 years, we experience occasional earthquakes, tsunamis, landslides or volcano eruptions. However, on geological time scales of many millions of years, this expresses into huge rock cycles that are at play acting both horizontally and vertically. All of them are driven by heat generated in the Earth's interior.
Remarkably, all of these deep-time processes are written in the rocks lying beneath our feet, forming the variety of landscapes we see today. Picking up a rock and reading its eventful geologic history inevitably leads to a deep respect and awe.
That's why documenting and deciphering the geological history of a landscape is for me among the most fascinating adventures of our times.