For those of us who write dystopian/apocalyptic fiction, doesn’t seem to be any shortage of theories on what could steer humanity (and other life forms) toward the extinction exit ramp. Current scare of the year is pandemic disease, aka Ebola, and any evil progeny that mutates. Modern NASA satellite tracking hardware has made us more aware of the many PHAs (Potentially Hazardous Asteroids) with our name on it. Anders Sandberg has an “existential list” compiled of Five Biggest Threats to Human Existence, number one being the ever-popular nuclear war jitters.  I found his fifth candidate interesting, if not thought provoking; – unknown unknowns – or something deadly out there that we have no clue about.

I have my own list, which includes that which bubbles beneath our feet; – millions of tons of molten Mother Earth, looking for an exit. No finer example of it is right here in North America, a super-caldera beneath Yellowstone National Park.

For those of you unfamiliar with calderas, Wikipedia defines it as:  “a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption. They are sometimes confused with volcanic craters. The word comes from Spanish- caldera, and this from Latin caldaria, meaning “cooking pot”.

Think of it as geologic, aortic aneurism spanning over 1,100 square miles, with a reservoir of magma six miles deep (Nat Geo – Ker Than), just waiting for the right conditions to burst from the thinnest of crust.  Now that’s a whole lotta volcanic destruction, just waiting to blow its top.

We’ve seen a few super-volcanoes in recent centuries. Mount St. Helens gave us a reminder of how deadly these things are. But when you look at the chart of volcanic debris released, St. Helens was a the equivalent of popping a pimple. Three of the biggest blowouts in earth history, just happened to be in the back yard, two of them at – yep – Yellowstone.

Thankfully for us hominids, most of earth’s penchant to sneeze destruction on a cosmic scale, happened before our mammalian ancestors learned to walk upright. However, one earthen nosebleed 70,000 years ago, buried 20,000 square kilometers, spewing 5,000 megatons of stratospheric sulfuric aerosols (ExtremeScience.com).  Ash 20 feet thick fell as far away as India.  Yellowstone’s Indonesian twin sister, Lake Toba Caldera, is believed to have been apocalyptic for humans of the middle stone age. Two weeks of non-stop belching created a volcanic winter lasting several years, affecting global food chains.  Fossil evidence indicates a larger diversity in human genetic lineage existed before Toba.  Recent mapping of today’s human genome found very little genetic variability, suggesting we descended from a few thousand survivors from about the time Toba erupted. The Yellowstone eruptions were far more powerful and violent.  As cited in the Extreme Science article; “if Toba can reduce the human species to a few scrappy survivors, can you imagine what another eruption of the Yellowstone Caldera could do to us?”

How bad would a Yellowstone Eruption be? One modern survivalist, Ken Jorgustin, tallied it’s possible effects, which included near devastation of North America, economic collapse, mini ice age from resultant volcanic winter, 20 degree drop in global temperatures, eradication of 75% global plant life, mass starvation, human survival as we know it threatened.  Put simply, pretty much the scariest thing imaginable.

Studies concluded Yellowstone erupted three times in the last 2.1 million years, about 600,000 to 800,000 years apart, the most recent 640,000 years ago. Are we standing on a ticking time bomb?  Some scientists believe the caldera is still in a quiet part of its cycle, and unlikely to burst a blood vessel for another 1-2 million years, but quickly point out, “everything is possible in geology, and not very precise” (EarthSky Org).

 

So, while many writers are drafting the next zombie epidemic, or an asteroid aimed at planet earth, you’ll find me on a park bench near Yellowstone’s Prismatic Spring with a notebook, hoping the tremor beneath my feet is just a burp, and not the apocalypse pressing against a frangible, flimsy cork, ready to return all living things, to ash, whence it came.

 

 

Many good references on the subject. A list of articles used for researching this post.

• When Yellowstone Explodes. Joel Archenbach, National Geographic
• Huge Magma Pocket Beneath Yellowstone Supervolcano. Ker Than, National Geographic
• Wikipedia – Calderas
• Wikipedia – Supervolcano Eruptions
• Wikipedia – List of Largest Volcanic Eruptions
• Five Biggest Threats to Human Existence. Anders Sandberg, Science & Technology, The Conversation
• Calderas. Extreme Science
• Yellowstone Caldera Eruption. Extreme Science
• Lake Toba Caldera. Earth Observatory
• How Bad Would a Yellowstone Eruption Be? Ken Jorgustin, Modern Survival Blog
• Will Yellowstone Supervolcano Erupt in Your Lifetime? EarthSky Org