Ash: Rise of the Republic (16 page)

“The most famous example of a hotspot is
that which is responsible for the creation of the Hawaiian
archipelago. I assume most have you have at least seen this on a
map before, but just in case, will illustrate what I mean." He
moved back to the blackboard and drew several blobs in a curving
line, increasing in size from left to right. "This is a rough
approximation of the islands of Hawaii. The largest island, Hawaii
itself, is the peak of an active volcano. Each smaller island is
also the peak of a volcano, but they are all extinct, meaning they
are no longer geologically active. Each of these volcanoes was
actually created by the same stationary source of heat. As the
crustal plate moved to the left, the stationary heat source was
constantly forming melt and that melt was erupting and cooling at
the surface. Each of the peaks represents a period when the speed
of the plate slowed and the erupting lava had more time to
accumulate. The larger the island, the slower the plate was moving.
It's worth noting that the volcanism in action here is not the
violent, explosive variety driven by volatile gases on the margins
of subduction zones. The composition of the source material for the
melt, oceanic 'basalt', is such that the magma which is produced is
low in viscosity and low in volatile gases, allowing it to erupt in
a constant but calm and docile manner, patiently piling up into
mountains. Once again, I must stress that the composition of the
material which erupts determines the style of eruption, and that
the composition is entirely dependent on the source rock…Hah!”

The old man moved surprisingly quickly; the
eraser bounced off Stone’s forehead in a milky cloud of chalk dust.
The startled scout, caught dozing off, looked around the room,
blinking.

"Now, we grow closer to an answer to our
original question: where did all the ash come from? Hawaii is, of
course, not the only hot-spot in the world. There are a number of
other examples, but most of them are currently located under
oceanic crust, forming chains of volcanic islands. Yellowstone,
however, is one of the few known examples of a continental
hot-spot.

"The Northwest United States is a region
with a long history of volcanism. The majority of this can be
attributed to the subduction of a small section of oceanic crust
known as the Jaun de Fuca plate. There is evidence in the region of
a number of extremely violent and large scale eruptions from the
past hundred million years. Early geological studies of the area
attributed these to subduction volcanism, but some of these
eruptions occurred hundreds of miles inland. When the geologists
discovered the large magma chamber under Yellowstone, they took a
second look at the evidence of ancient eruptions. Rather than the
squat cones of coastal subduction volcanoes, these ancient calderas
resembled the result of huge explosions. Careful study revealed
that, just like Hawaii, the ancient eruptions were arranged in a
curving line, the product of a stationary heat source burning
through a moving crustal plate. If a relatively constant plate
speed was assumed, the eruptions were clearly fairly regular,
occurring every seven hundred thousand years or so. The scary thing
was, it was overdue. The magma they had discovered was clearly
ready to erupt. For this reason, the government set up sensors to
monitor the situation, hoping for some warning. They watched it for
fifty years.

"We don't know if they had much warning,
despite the years they spent watching it. I knew a few people who
worked on the project, but had no contact with them in the weeks
before the eruption. When it blew, it was much bigger than they had
expected. Bigger than any before. The last eruption from that
caldera produced around a thousand cubic kilometers of material. We
estimate this one threw out nearly ten times that on the first day.
There was so much force behind the initial explosion that the
majority of the ejecta ended up in a low orbit. It’s been falling
ever since. The caldera itself has continued to erupt violently for
the last thirty years, although we have little hard evidence of
that other than the fact that we have three meters of ash on the
ground and it’s still falling. The question is, why is there so
much?

"Now, to answer the young lady's very astute
point about the quantity of ash, we must turn to theory. Let us
consider the concept we have revisited several times: that the
material which is erupted is directly related to the material from
which it is created. For this reason, as we have discussed,
continental eruptions are necessarily more violent and produce
large amounts of ejecta, including ash. We think Yellowstone was a
special case, unique in modern geology. The magma which accumulated
beneath the park was not the product of partial melting brought on
by a chemical change like that of a subduction zone, but rather
formed through the direct application of heat from the mantle.
Because of the degree of heat which was applied, a much more
comprehensive melt could occur.

“We will call this 'majority-melt' to
differentiate it from the partial-melt which occurs at subduction
zones. When a portion of rock undergoes majority-melt, a
significant percentage of its volume is lost to magma. When this
magma rises to the surface to collect in magma chambers, something
must fill the volume which it vacated. As the rocks exposed to the
hot-spot majority-melt and lose volume, the surrounding rock
presses in from all sides. This fills the volume left by the rising
magma, and it provides fresh rock to be cooked by the mantle heat.
This turns into a vicious cycle of magma production and constant
volatile eruption.

“Only two things can disrupt this cycle:
One, the heat source is taken away, or two, the lithostatic
pressure of the surrounding rock decreases enough to slow down the
introduction of fresh source material for magma production. Since
hot-spots are geologically long-lived, as evidenced by a certain
long string of islands in the Pacific, the first is unlikely to
happen. The second is more likely, but will take a significant
amount out time, especially if the cycle is occurring in the middle
of a huge continent with tremendous lithostatic pressures at work.
The amount of material that must be removed from the area in
question before the stress in the rock relaxes enough to kill this
melt cycle is immense. Something on the order of tens of millions
of cubic kilometers...

“That, ladies and gentlemen, is essentially
where all the ash came from. It wasn’t just a volcano, it was the
volcano; the largest eruption ever recorded. It was, and continues
to be, an explosive caldera derived from an extraordinarily active
hot-spot and stuck in a majority-melt cycle. You can just call it a
supervolcano for the sake of brevity.

“I must stress once again that this is all
just an oversimplified theory. We have not visited the caldera
since it blew. We do, however, occasionally receive anecdotal
reports from travelers. If they are to be believed, then
Yellowstone is still active. The occasional ashfalls which still
occur are ample evidence to support that. We’re also told that
thirty years’ worth of eruptions have created a supervolcano which
rivals the size of Olympus Mons. Perhaps one day we will have the
resources to mount an expedition to investigate, but I fear I will
not live to see the day. The pursuit of science has always been
hampered by the petty squabbles of men and government.

“Questions?”

****

His agent told him the Republic was finally
mobilizing. It was time. His army had grown steadily, in size and
in confidence, for over a month. The region’s citizens had
shuddered in terror at the tumor in their midst. Dozens of villages
and homesteads lay smoking and lifeless from his men’s savagery. He
had let the planes fly over unmolested, welcoming the exposure. He
hoped the soft men of the Republic were trembling behind their
walls of ash.

The ranger companies watched him too. They
crouched in the brush in the hills around the camp. The irony
amused him. They had relentlessly pursued these ragged outlaws
until they were desperate. He had used that desperation to build an
army. Now those rangers hid from those same ragged outlaws,
desperate for their own army to come.

Before he left he made sure it came too late
for some. He regretted the old ranger wasn’t with them, his first
and greatest enemy. His hatred for the old man festered like an
open sore. He relished the thought of their next meeting.

The pathetic screams of the once hard men,
bleeding in the bushes, were but a pale appetizer for his coming
triumph.

He let the fathers and brothers of hanged
men do the work. When they had finished, the Chief marched his army
to war.

Chapter 7

September, 0 PC (2015 AD)

*

“
There existed a sharp dichotomy
within the survivors; it was apparent even in the first few weeks.
There were those who worked to rebuild, and those who worked to
destroy.”

-Kristen Harrisburg, ‘The Grey Panic’; RNT
University Press, 36 PC (2051 AD);

*

They didn’t bother following us. We lay trembling and
exhausted in the bed of the truck for the first two miles, risking
a glance over the tailgate every few minutes to check for the
headlights which would betray a pursuit.

We stopped when we reached the first
crossroad. An ashfall had begun at some point during the short
fight. It was coming down thick now, a dusty blizzard. Deb and I
walked up the line of vehicles, checking that everyone had some
form of breathing protection and performing a quick head count.
Close to thirty people were missing, I assumed either dead or dying
at the hands of the Fellowship. When we returned, discouraged, to
the truck at the back of the line, we found Mike and Clint leaning
under the raised hood. The light from their flashlight reflected
wildly off the fluttering ash. I approached as they pulled the
cover off of the engine air intake. Mike pried the filter out,
raising a cloud of fine ash. He shook it out and replaced it,
shooting me a worried glance.

"We'd better check them all," I said in
response, "Deb and I will keep watch back here. And tell Scott to
stop every couple of miles. We need these trucks to last."

We turned right on the next highway and
stopped at the first underpass we came to. The wide expanse of road
decking had kept the ash from accumulating too thickly beneath it,
but wind driven drifts had piled the stuff high on either side. The
resulting cavern was barely wide enough for our convoy to squeeze
in, but it provided much needed shelter from the intensifying ash
storm. After emptying the trucks' air filters again, we gathered
for a meeting at the side of the road. My surviving neighbors
arranged themselves on the sloping concrete embankment there, the
thin light of a small fluorescent lantern illuminating their weary,
ashen faces. They looked like I felt. Adrenaline had left them now.
They were drained; physically and mentally exhausted. Their eyes
were downcast, struggling to balance the shame of losing their
homes and friends with the relief that comes from narrowly escaping
death.

I gave everyone a moment to reflect on the
night's events, then began to speak, my voice reflecting back to me
from the thick concrete pillars.

"I wish I could stand here and deliver a
rousing speech. I wish I had words which could heal your pain and
inspire you to keep going. The fact is, I don't know what to say.
They beat us. They burned our homes and killed our friends. They're
probably following us right now to finish the job.

"It's my fault. I let you all down; I got
those people killed; I lost our home. There are no words to convey
the sorrow and regret I'm feeling right now. We should hold an
election right here. You deserve a new leader, someone who can
protect you. Please, I won't blame any of you, choose someone
else."

There was a loaded silence. One by one, my
neighbors looked up at me, eyes hooded in shadow from the cold
lantern light. I could feel the anger buzzing in the air. I
deserved it. I had proposed the majority of the defenses which had
just collapsed. I had negotiated with the Fellowship. I had failed
to shoot the enemy leaders when they stood in front of me issuing
threats. The young psychopath at the helm of the madness had slept
in my home and eaten my food.

I had killed their friends and family. I had
burned their homes.

They began to mutter to each other, glancing
with scorn in my direction. Their words, inaudible to me, seemed to
seethe with rage. I stood silent, hanging my head in shame, waiting
for them to denounce my poor leadership. When they finally spoke,
however, their anger was directed at my apology rather than my
failings.

"Are you done?" Janet Borger, the
veterinarian, began in a cold voice, "because if you're done
feeling sorry for yourself we can make some plans. How dare you try
to take all the responsibility for this mess? What, you think you
can fall on your sword and the rest of us will just move on,
consciences clear? The last thing we need right now is you feeling
sorry for yourself. We need you making decisions. Tell us what to
do! Where are we going to go?"

Shocked, I turned to the rest of the group.
Many were nodding in agreement. "I just thought..."

"You just thought what? That we'd tar and
feather you because a twelve year old psychopath and a group of
religious fanatics decided to attack us? How could that be your
fault? If anything, we should be praising you: you're the reason
we're still alive right now. Remember: it was your idea to plan for
an escape. You saved all of our lives and most of our supplies."
More nods from the small crowd. "If it hadn't been for you, we
wouldn't have had a neighborhood to defend in the first place.