Next up, my journey
600 feet into the crater
of a volatile inferno,
where scientists
are looking for
signs that could end
up saving thousands of lives.
Masaya in Nicaragua is so feared
that religious crusaders once
tried to exorcise the
devil out of its heart.
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Lake Nicaragua, the largest
body of fresh water in Central
America, and home
to Jicaro Island,
a "National Geographic"
unique lodge.
Nicaragua has 19
active volcanoes,
including Masaya, a
ticking time bomb that
could go off at any moment.
That's where I'm headed.
Just look at the size
of this volcanic crater.
It's about seven miles across.
And in the center of
it, another volcano
was born, Masaya, one of the
most volatile in the world,
that's erupted 13 times
in just the last 30 years.
I'm making my way around
the crater of Masaya volcano
to some volcanologists
who risk their lives out
here on this deadly beast.
Part of what makes
volcanoes so dangerous
is that they're unpredictable.
And no one really knows when
this one will erupt again.
With a million people
living just 15 miles away,
geologists have set up shop
in the heart of this ticking
time bomb to figure that out.
Guys, nice to see you.
Working on one of the sensors?
Yes, Phil.
Yeah?
We are taking care
of the maintenance
of the gas instruments
that we use
to monitor the mouth of hell.
(LAUGHING) The mouth of hell.
Yes.
Yeah, where did that
name come from, by the way?
It's from the Spanish
conquistadors, you know?
PHIL KEOGHAN: Yeah?
A few hundred years ago.
They thought that it was gold
and fire coming from hell.
So that's why it's named
after that, you know?
PHIL KEOGHAN:
Armando and his team
monitor a network of 80 sensors,
gauging Masaya's conditions
and surrounding
atmosphere so they can try
to predict the next eruption.
It seems to me that without
these warning systems,
the people would be
really vulnerable.
This is the only means
of defense for them?
As you say, when we detect
something that is dangerous,
we send information immediately
to the local authorities.
PHIL KEOGHAN: In
the spring of 2018,
earthquake sensors captured
vital data on Hawaii's Kilauea
volcano, which after it erupted,
reduced 600 homes to ashes.
That intel is crucial
to missions like this.
ARMANDO SABALLOS:
It's getting unstable.
You can see--
Yeah, this edge is
starting to break away.
Yeah, it's falling apart.
PHIL KEOGHAN: Oh my!
ARMANDO SABALLOS: Yes,
that's the mouth of hell.
PHIL KEOGHAN: Oh, my god!
That is really scary-looking.
Where in the world
can you see this?
Very few places.
ARMANDO SABALLOS:
Yeah, very few places.
PHIL KEOGHAN: The lava lakes
that form in active volcanoes
typically don't last long.
But Masaya's has been churning
consistently for centuries,
making it one of the most active
members of the Ring of Fire.
I've used some volcanic rocks
to make a very rough map.
But I want to show you exactly
where the Ring of Fire is.
It's 25,000 miles long, and
completely circumnavigates
the Pacific Ocean.
It runs right
through New Zealand--
that's why there's a
lot of volcanoes there--
through Indonesia, Japan,
through the top of Russia,
all the way down the
west coast of America,
and then down through Central
America, where Nicaragua is.
And it continues right down
to the end of South America.
Almost all of the volcanoes
in the Ring of Fire
occur along the edges of
the Pacific tectonic plate.
But Masaya was formed
between two smaller plates.
About 20 million years ago,
the Cocos plate began sliding
under the Caribbean plate.
The energy from this
subduction turns
solid rock into liquid magma.
And when that magma escaped
through the Earth's crust,
Masaya was born.
That's a long way down.
So--
So we're good?
It's a 60-story drop into
this cauldron of toxic gas.
This mask will
actually filter out
the sulfur dioxide that
we're expecting down below.
You can also get the
gases in your eye.
Then this helmet,
for obvious reasons,
'cause at the rim of
the crater, there's
a lot of falling debris.
I'm going in to meet up
with Rodolfo Alvarez,
the engineer behind
this pulley system
built to get scientists in and
out of this massive crater.
And it is a lot further
down there than it looks.
Everything turned on properly?
This is the exciting part.
Just the enormity of this
volcano is incredible, really.
The roar from the volcano is
getting louder and louder.
Look at that.
That is absolutely magnificent--
the glow of the lava.
And in the distance, I can see
the vent we're heading for.
Descending into this
hostile environment
of heat and toxic gas
is extremely dangerous.
But for Rodolfo
Alvarez, it's as if it's
just another day at the office.
All right.
Rodolfo, how are you doing?
Well, welcome
to a gate of hell.
Oh, my goodness me.
That was like-- that was
just insane, Rodolfo.
Are you OK?
PHIL KEOGHAN:
Yeah, I'm all good.
Wow, it got dark
so quick, right?
Why are you not
wearing your gas mask?
What's wrong with you?
Oh, because I wear
it when I need it.
How do you know?
You watch the gases coming up?
Well, right now you
don't need the mask.
But if you want to keep
it, it's no problem.
PHIL KEOGHAN: There is an
overwhelming odor down here,
like a match that's
just been lit.
That's sulfur dioxide.
And when that gas mixes with
the moisture in the air,
it forms sulfuric acid.
It eats everything, from the
cables ferrying the team in
and out of Masaya, to
the sensors that raise
the alarm when there's danger.
This is a box that we got
in to protect the sensors,
the sensor inside.
Because of the--
RODOLFO ALVAREZ:
The sulfuric acid.
PHIL KEOGHAN: The sulfuric acid.
There are little sensors
down the bottom here?
RODOLFO ALVAREZ: Different
sensors for different gases.
Those are the ones
that are damaged.
The corrosion
is really bad, eh?
Yes, actually it's
amazing, if you--
All around I see like--
You can look in here.
I mean, this is
actually a cable.
And we can--
PHIL KEOGHAN: Wow!
Look at these joints have
just completely eroded away.
RODOLFO ALVAREZ: I mean,
it's completely destroyed.
PHIL KEOGHAN: And that's
from the sulfuric acid?
RODOLFO ALVAREZ: Yes.
You know, you have all
this cloud of sulfur,
and you can feel your eyes.
Your eyes will start
itching like hell.
PHIL KEOGHAN: Yeah,
so it's that strong.
RODOLFO ALVAREZ: I mean,
it's not pure sulfuric acid,
but it's very high percentage.
Man, I just want to
keep putting on the mask.
And I look at you,
you got no mask on.
Right.
I don't know how you do it.
We can go that way and you
can actually get to the edge.
We have ropes set up so
you can get to the edge.
We're going to go here.
PHIL KEOGHAN: Oh!
RODOLFO ALVAREZ:
Now I need a mask.
I just got this
swirling of gases.
Yeah, I can feel
the heat right here.
Really see it there.
RODOLFO ALVAREZ: Yes.
PHIL KEOGHAN: We
got a good look.
I've never seen anything of
this magnitude and power.
And you can feel the
power in the ground.
What is it about the
lava that you love?
People are afraid of
this, but this is what
really makes you feel alive.
This is one of
those things amazing
of nature or the universe that
you can actually see in person.
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