In a matter of days,
a nearby volcano will erupt,
spewing debris and lava,
and decimating your city.
You know that fighting fire with fire
usually makes things worse,
but maybe you could fight fire
with ice.
You wouldn’t be the first
person to try and stop lava
by cooling it.
Back in 1973,
local authorities in Iceland
attempted to stop a lava flow
by using ice-cold seawater.
But 5 billion liters (1.5 billion gallons)
of seawater later,
they still weren’t able to stop
the advancing lava.
At least they managed to divert the flow
away from the island’s harbor.
Learning from this past failure,
you decide to ramp it up
by dropping a giant chunk from an iceberg
into the middle of the volcano.
Before you go dumping an iceberg
into your local active volcano,
let’s run a simulation first.
Mount Michael,
in the South Sandwich Islands,
would be a good testing ground.
It has a 110 m (360 ft) wide lava lake
that bubbles at about 988 ºC to 1,279 ºC (1,812 °F to 2,334 °F).
And it’s located in a desolate area,
so very few life-forms would be in danger.
You’d need a pretty large iceberg
to throw into Mount Michael’s lava lake,
about the size of
one and a half football fields.
This sounds massive.
But don’t despair because
huge icebergs are not that unusual.
In 2017,
a massive iceberg broke off
the east side of Antarctica’s peninsula.
When it first broke off,
it was bigger than Luxembourg and
200,000 times larger than Mount Michael’s lava lake.
So once you have your iceberg,
or chunk of an iceberg,
and you drop it into the lava,
what would happen?
The first thing that you’d see
is an immediate blast of steam.
The meeting of these two extremes,
ice and lava,
would cause the ice
to go from its solid state
to a gaseous state instantaneously,
skipping the liquid form.
This is called sublimation.
Next, two things could happen.
The ice might turn into steam faster than it can escape,
creating a massive steam explosion.
This steam would create
even more pressure inside the volcano,
causing it to explode.
Hardened magma,
called tephra,
would fly through the air.
Some of the pieces could be as large
as a house.
Uh, yeah,
not exactly what you were going for.
What about the second possibility?
Well, alternatively,
the ice could cool the surface temperature of the lava.
The lava would look like it’s boiling
as the vapor tries to escape,
and it would harden into a texture like Bubble Wrap.
Mission accomplished, right?
Not exactly.
The hard shell would trap volcanic gas.
Over time,
pressure from the trapped gas
would build until
boom!
The volcano blasts its top off.
Instead of stopping a volcanic eruption,
dumping an iceberg into an active volcano
would make the explosion
even worse.
This isn’t the best idea
if you need to save your city
from an impending volcanic explosion.
Are there any other ways
to stop a volcano?
In a previous episode,
we looked at nuking a volcano.
But that’s a story for another WHAT IF.