We Are NOT Talking About Jellystone

Yellowstone is one of the most popular National Parks in the United States, drawing millions of visitors every year.  Those visitors marvel at the geysers, hot springs, and the fantastically colored mineral pools in the park.  Few of those visitors realize what powers those geysers, springs, and pools.  Fewer still have any inkling of the ticking time bomb below the surface of the beautiful wonderland that is Yellowstone.

Yellowstone National Park sits on top of caldera, a depression left by a supereruption.  The Yellowstone caldera is more than 50 kilometers by 70 kilometers.  This is one huge mother of a volcano; its largest eruption whose geological traces we can read covered about half of the continental United States with a bed of volcanic ash.

While it has no scientific definition, supervolcano is a very descriptive term.  There have been numerous eruptions in the same class as those produced by Yellowstone, and all of them make Tambora look like a wet firecracker.  It did not take me long to find information describing one volcano of this class that ejected 5,000 cubic kilometers of material.  Even the smaller of the supervolcanoes can trigger long-term climate changes, and start a cascade of environmental events that lead to extinction of species.

Is it likely we will experience one of these eruptions?  No.

Neither are we likely to get smacked by an asteroid next week.

I will stop bringing up various ways we could get snuffed out or blasted back to a Stone Age existence.  There are many avenues to disaster, some less likely than others.  Some are the result of happenings as random as the Universe throwing rocks in our general direction.  Some are ways we might cook up do the dastardly deed to ourselves.

Let us just say it has been shown that there are numerous ways we could face extremely dire circumstances, and that the chances of those things happening are greater than zero.  All of that leads to one very important question.  This is the question I have been approaching all along.  (Sorry it took so long but if you want to do it better, write your own.)  Here is the question:

What are we going to do about it?

The Year Without A Summer

In 1815 Mount Tambora, located in Indonesia, exploded in history’s most calamitous volcanic eruption.  More than 70,000 people were killed.  The summit of the mountain was reduced from 4,300 meters to less than 2,900 meters.  The explosive yield of this eruption has been estimated at about 800 megatons.  This was a nasty neighbor.  The larger effects would not be felt for a while, though.

Tambora was to have a lasting impact on the global climate, but it did have some help.  In 1812 La Soufriere in the Caribbean erupted, as did Mayon in the Philippines in 1814; those two volcanoes had already put a significant amount of ash into the atmosphere.  Additionally, the Sun was in a period of lower activity, so the stage was set for Tambora’s dramatic entrance.  When Tambora’s 800 megaton blast occurred, more than ninety cubic miles of volcanic ash was blasted into the atmosphere.  That tremendous load of ash coupled with the ash already present in the atmosphere from the two previous eruptions, as well as the sun’s lower activity resulted in 1816 being called the Year Without a Summer.

Unusually late frost hit New England and Eastern Canada in the spring of 1816 virtually wiping out the crops that were already in the ground, and the following month two huge snowstorms killed many people.  This snow also killed the crops that had survived the earlier frost, leading to famine; people, their vitality sapped by hunger and malnutrition, began to die from disease.  So little rain fell in July and August, drought damage stunted the crops that had managed to hold on.  Reduced sunlight prevented crops from growing and maturing, even if they could survive the cold and drought.

Other parts of the world fared no better.  England experienced greatly increased rain, and reduced temperatures; this resulted in crop failures.  Many parts of mainland Europe experienced crop failures.  Because of the Napoleonic wars, Europe was already having problems with shortages of food; the crop failures exacerbated this problem.  Riots and looting ensued, as did famine.  There was extensive flooding of numerous rivers because of increased rainfall.  About 200,000 people died as the result of famine and disease.  Asia had unusually low temperatures (including frost), and heavy monsoons.  Rice production was drastically reduced, and famine and disease were widespread.

That was quite a party Tabora threw.  It is just a good thing it doesn’t go to that much trouble very often.  There have been worse eruptions, though.  I will talk about just one more next time.

Our planet has pimples

Just as some pubescent humans have problems with acne, so too does the Earth have its face dotted with zits.  Just as a teenager’s pimples can release viscous fluids, Earth’s can spew also.  The analogy breaks down at this point, because while a teenager’s acne can be very embarrassing, our planet’s volcanoes can be incredibly dangerous.

Even the most predictable and mild-mannered volcano is not something you would want to have as a neighbor.  The polite volcanoes are not the subject of this discussion, though.  Neither are the locally obnoxious mountains of fire; the citizens of Pompeii and Herculaneum had their day ruined by Vesuvius in the first century AD, and while that eruption was a terrifying disaster for the people of the area, that event had little impact on the lives of people around the world.  We are looking for volcanic events that tinkered with the climate, or had an effect on life around the world.

When Mt Pinatubo erupted in the early 1990s, it was the second biggest eruption to take place in the Twentieth Century.  In less than two hours the ash and gases produced by Pinatubo penetrated the atmosphere to an altitude of over thirty kilometers.  During this eruption Pinatubo produced as much as thirty million tons of sulfur dioxide, and within a year this cloud of gas was distributed worldwide, cooling the planet by more than half a degree.  Admittedly, half a degree doesn’t sound like much, but when you are talking about the global climate it is pretty amazing that the eruption of one little volcano can have that much influence.

Next time let’s look at a little bigger eruption.

A nasty neighbor that won't stay away

In late 2004 a near-Earth asteroid was discovered that considerably reduced the giggle-factor usually associated with discussions of asteroid impacts.  It was called 2004 MN4.  In mid-2005 it received a permanent number, 99942, and a month later it got a name:  Apophis, after the Greek name for the Egyptian god of darkness, destruction, and evil; it was an appropriate name.

As preliminary data came in and was analyzed, a chilling picture started to take shape.  While this rock was not nearly as big as the Chicxulub asteroid, it would dwarf the Barringer and Tunguska impactors; Apophis is almost three hundred meters in diameter.  The calculated yield for its impact was nearly a thousand megatons.  By comparison, the Tunguska and Barringer impacts gave about one to three per cent of that yield, and the Krakatoa volcanic explosion of the late 1800s produced only (ha, only) about 200 megatons.  

If Apophis hit a populated area the casualties could number in the tens of millions.  An impact in the middle of the north Atlantic would produce cataclysmic tsumanis for the east coast of the United States and the west coast of Europe; the Caribbean islands could be wiped clean.  The news got worse: the first calculations gave odds of an impact in 2029 at 1 in 233, and it received a 2 rating on the Torino scale for impact hazard.  Not bad odds, but the potential consequences as summarized above were horrific.  As more data became available over the next several days the odds got much worse, at one point the chances worsened to 1 in 37 for that 2029 meeting.  Fortunately, given our pathetic state of readiness to take any remedial action, the observations and subsequent calculations over the following weeks and months revealed much better forecasts for us.  Apophis will almost certainly miss the Earth in 2029.  During that encounter, Apophis will pass within the orbit of our geosynchronous satellites; that encounter will be on Friday, April 13.  In 2036 we will have another close approach with Apophis.

What happens during our 2036 encounter with Apophis will depend on the exact trajectory of Apophis in the 2029 encounter.  The orbit of Apophis will change because of its 2029 encounter; the amount of change hinges on how closely it approaches Earth.  If Apophis passes through a gravitational keyhole, a tiny region of space near Earth so that our gravity gives it precisely the right (or should that be the wrong?) nudge, Apophis will collide with Earth in 2036.  The chances for hitting that keyhole stand at 1 in 45,000.  That sounds like very long odds, but it is many times more likely than for any one individual dying in an airplane accident.

We have an identified threat, and we have some time to do something about it.  We do not know if there are other threats of the same kind with a shorter time-frame.  We should not wait until the last minute to develop the capability to mitigate this kind of threat.  Likewise, we should not wait to develop the capability to detect other potential threats of the same nature.

All right, I am through beating you over the head about rocks from space.  Next I want to explore some other ways we could be knocked back to the Stone Age.

How big of a hole does it take to worry you?

I have been away for too long.  My excuse is that I experienced a turkey-induced food coma, and with all the turkey leftovers it lasted quite a while.  That is my story and I am sticking with it!

Let's get on with the search for the big holes, the ones from the truly scary rocks.  

The name is Chicxulub.  It sounds exotic.  Chicxulub is not a high-dollar, trendy resort frequented by equally high-dollar, trendy people.  Chicxulub is not a vacation destination, but it is tropical.  Chicxulub is straight south of New Orleans across the Gulf of Mexico, and a little over 300 kilometers west of Cancun.  Once upon a time, more than just a few years ago, the place that would become known as Chicxulub was a scene of unimaginable destruction.  We do not know if the day was sunny or overcast, indeed we do not know if it was daytime at all.  There were no people around to witness the event; that is a good thing, because most of the life on this planet was probably snuffed out.  An asteroid approximately 10 kilometers in diameter slammed into our lovely planet.  (Just to get an idea of the size of this thing, at the instant the asteroid first touched the surface of the Earth, the other side of the asteroid was just about at the cruising altitude of our airliners.)  The ground splashed, like a mud puddle when a child throws a pebble into it.  Uncountable tons of rock and dust was blasted into the upper atmosphere.  Hot debris rained down world-wide, and estimates as high as ninety percent of the world’s biomass burned.  Some of the biggest megatsunamis this poor planet has ever seen resulted from the impact; some of them were perhaps a half a mile high.  The blast yield of this impact has been estimated to exceed 100 million megatons.  The shock likely triggered earthquakes around the world, as well as extensive volcanic activity.  The dust and other debris in the atmosphere would have lingered for years, blocking out sunlight and therefore putting a halt to plant life.  The resulting crater (as measured today) is more than 180 kilometers across.  This little party is referred to as the K/T event; it ended the Cretaceous Period and began the Tertiary Period.  (There is still some debate whether the Chicxulub impact killed off the dinosaurs or not.  However, even some of the critics of asteroid as dino-killer theory accept it as a contributor to their demise.)

Are there even bigger holes?  Well, yes.  There are, although there are not many and they are not a great deal bigger.   Are we likely to experience a similar event?  Eventually, with certainty.   Soon, almost certainly not.  However, we do not need to be threatened with the sterilization of our planet to have a very bad day.

I am almost through talking about party-crashers.  I do want to mention a rather unsavory neighbor that paid us a fleeting visit fairly recently, and has promised to come back.  I will deal with that topic next time.

Are we almost there, daddy?

Where am I going with all this?  It occurred to me that some may be asking that very question, and with justification.  Is this Generalissimo jerk just going to spew doom and gloom at us in a steady stream?

I should have made a post earlier setting forth, in general terms, where this journey is headed, and what rest stops will be taken along the way.  It just wouldn't be right to herd you all onto the bus, set off down the road; and deprive you of any toilet stops or opportunities to grab something to eat.  (I can hear it now, "Who does the Generalissimo think he is, my father?  We aren't on a family road trip.  Hungry?  Have a peanut butter sandwich.  Gotta pee?  Use this soda bottle."  Well, I am a dad, but I don't play that way.)

Where the hell is this bus headed?

The early stops on our trip will be doom and gloom.  I intend to explore various threats to humans and their home planet.  Those threats will include unsavory guests with origins both on and off planet.  Some of those threatening agents include those that could sterilize this lovely blue marble we call Mother Earth.  Others might wipe out all the higher life forms, including human beans.  While still others could pound us back to the Stone Age.  I do not want any of those fates to be visited on my children, or grandchildren.  I know, it sounds like a familiar tune: death, destruction, doom, and gloom.  Yeah, well hold on.  Those are just the early stops on this road trip.

The second phase of our journey is certain to bring out the worst in the neo-Luddites.  I am sure you have encountered some of those people; they are the ones that have some cockeyed reason why we should turn back the clock and abandon the technological advances achieved by modern humans.  (“If god had wanted us to go into space, he would have given us rocket motors up our kazoos.”  Or how about: “We have no business colonizing the moon until we take care of our problem here on Earth.”  I could go on, but I lack the stamina and the bandwidth.)  I will present possible solutions, or remedies, or work-arounds to these catastrophic events.  For many of these problems, there is no remedy, as such.  We can only take steps to limit the damage, but that is far better than doing nothing.  To badly misquote Elon Musk, “We backup data, shouldn’t we backup the biosphere?”  We must have that offsite backup, but that is just a start.

So, while there will be elements of calamitous death and destruction, this will not be a 

This Is a Doom and Gloom Prediction of the End of the World. 

 It will be more of a 

This Is the Front Desk Calling With Your Wakeup Call.  

Next time: Let’s look for some of the big holes.

That will leave a mark

From Siberia let's take a little trip.  It is not a short distance, so I suggest we go real fast; I don't have a lot of time to waste, and I am sure you are in a hurry also.  We are going to the desert southwest of the United States, in the state of Arizona, to a fairly substantial hole in the ground named Barringer Crater, also known as Meteor Crater.

 

About 50,000 years ago, an object penetrated the atmosphere over the Colorado Plateau.  This asteroid had an estimated diameter of about 50 meters, about the same size as the Tunguska object.  However, whereas the Tunguska asteroid was made of rock and exploded several miles above the surface, the Barringer asteroid was composed of nickel-iron and therefore could handle much more atmospheric stress.  The Barringer object survived to impact the surface.  Early research indicated an impact speed of over 72,000 kilometers per hour, but later models suggest a speed a little more than half that.  To put that speed in perspective, the SR-71 had a top speed of about 3,600 kilometers per hour.  When the Barringer object impacted, its mass of perhaps 150,000 metric tons of nickel iron vaporized.  That explosion tore open a wound in the earth more than a kilometer in diameter, and well over 150 meters deep. The rim of the crater is almost 50 meters above plateau around it.  All life was extinguished from the impact site to beyond three kilometers, and everything combustible within nearly ten kilometers was incinerated.  The shock wave that traveled through the air from ground-zero flattened everything for more than 130 square kilometers.

 

Neither the Tunguska explosion nor the Barringer impact was sufficient to cause any global damage.  Neither was big enough to cause any real problems outside their own region.  However, put either event into a modern population center and see how many people are obliterated.  A rock from space landing on your head could ruin your whole day.

 

Neither event is by any means a worst case scenario; things could be much worse, because both these rocks were small.

 

Next time let’s look for the big boys.