(rocks rumbling)
- [Narrator] Mount Saint Helens continues
to surprise scientists.
She rumbles and gurgles and gives off clues,
but frankly, the mountain speaks a foreign language.
Scientists would like to learn
to translate volcano fluently.
Now, they can take their lessons up close.
It's safer to walk in the crater because three years
of eruptions have come to an end.
- [John] We're at the mouth of the crater
and we're standing right in front of
about a hundred foot high wall of the west arm
of the glacier.
It's the glacier that was bulldozed and pushed aside
and that's flowed down and is encroaching on us
even as we speak.
For the glacier is one of the few glaciers that's advancing
rather than retreating.
It is moving forward very rapidly.
It's the youngest glacier in North America.
- [Narrator] Even as the depth of the volcano
have gone silent, the new glacier in the very mouth
of the crater continues to talk.
- [John] Right now, I think the most dramatic thing in the crater
is what we're looking at.
- [Narrator] John Pallister
has been studying Mount Saint Helens vocabulary since 1986
for the US Geological Survey.
He and his colleagues got a sudden wake up
in October of 2004.
Mount Saint Helens roared back to life.
Spewing ash to 15,000 feet in the air.
Then over the course of three years,
it put on an astounding show of force.
Day after day, month after month,
new magma shoved its way out of the earth.
A new dome was forming, twice as fast as the dome
that came up in the late 80s.
Now the eruptions are over and John can pay attention
to something other than the massive new dome.
- There are blocks of rock that are transported
on the surface of the glacier, basically rock slides
that came down off the crater walls.
They got inter layered with the ice.
So we're standing here at a hundred meters or so
from the glacier front.
The reason we're not standing right up there,
is occasionally one of those big blocks
will come down rapidly and without warning
and we don't want to be right there.
- [Narrator] In little more than three years,
the glacier has doubled in thickness.
Ice now looms 10 stories tall.
- [John] We're dealing with rates of motion
that are 10 times what you would see
at even a fast-moving glacier somewhere else.
- [Narrator] John expects the glacier
to advance several hundred feet farther down hill
in the next year.
It would continue a trend that their aerial photographs
have modeled in vivid detail.
The glaciers' arms
have been reaching out farther and farther.
In 2008, the arms met.
Crater glacier is now a donut,
completely encircling the old and new domes.
- Five years ago, if you were standing right here,
you would be looking up, instead of seeing a glacier
in front of us, you would be looking up at the lava dome
from 1980 to 86' and in fact from here,
we could have walked right up to the face
and climbed the lava dome.
No longer, there's now a glacier in the way.
- [Narrator] Unlike most glaciers in the world,
this one is growing.
Because rock and ash fall on it so often, it insulates it.
And prevents the ice from melting.
It has grown so quickly in fact,
scientists have had to move sensitive instruments out
of the way.
- [John] We've watched it move forward.
It overran our Yellow Rock seismic station.
We went in, we plucked it out.
We moved it out further down on the flats out here in front.
- [Narrator] There's one station a quarter mile away
that's safe from the encroaching glacier.
At least temporarily.
Seismologist, Seth Moran, a USGS earthquake expert,
arrives to inspect one of the most sensitive sensors
anywhere on Mount Saint Helens.
- This has been our most problem-free seismic site
for the last two years.
Pretty much every other site that we've had running
at St. Helens since 2006 has gone off for one reason
or another, but this one's been pretty bulletproof.
- [Narrator] Seth discovers one solar panel
could not withstand projectiles of pumice flying
at glass shattering speed.
- There's an impact point up here.
There's no impact point here, so it looks like
you had a couple of pieces of pumice get lift off.
And one of the big wind storms and hit this panel.
- [Narrator] The solar panels power a seismometer.
They've buried inside a weather proof box.
They call "the Vault".
24 hours a day, it's on alert.
Listening to what the mountain and the glacier have to say.
- [Seth] This has been remarkably dependable.
It gets a lot of snow, a lot of wind,
but it's not had an outage in two entire years.
- [Narrator] The environment and the crater is so harsh,
scientists never know what kind of damage they'll find.
- This is just laying on the ground.
Solar panel shattered, so there's nothing I could do
about that, but I can...
- [Narrator] Watch the extraordinary lengths they go to
in this brutal environment.
They haul in heavy construction equipment,
load by load by helicopter.
To give their sensors a fighting chance of survival.
In an extreme environment full of wind,
ice and avalanches of rock.
- What we usually do when we can get out the helicopter
and it's safe for us to do this is we dig a hole,
bury the seismometer in a hole, then we sink a mast.
Sometimes put cement as sort of a root ball
to hold the mast in place and then put a solar panel
or put a antenna on that mast.
- [Narrator] Few people outside the agency realized
just how frequently the scientists have gone
into the crater...
Even during the recent eruption years.
They even installed equipment
on the constantly changing spine
of an actively growing dome.
Sometimes it's just too risky.
That's when they resort to their most famous invention.
The spider is a homemade box full of sensors and batteries
that a helicopter can snag and sling in,
where humans dare not go.
Their efforts have paid off.
No matter what the conditions are,
scientists can still visit the crater
without ever leaving the office in Vancouver.
- From this desktop, you don't have to get your parka on
or your gloves or anything
and you can make your measurements from afar.
- [Narrator] Steve Schilling can fly through the crater
and track the growth of the glacier and the dome, over time.
- [Steve] This has been incredible.
To see a dome split apart a glacier
and essentially shove it aside.
It's just been spectacular to watch.
- [Narrator] It's not just a cool video game.
The renditions are precise enough for scientists
to take accurate measurements without actually going
into the crater.
- That gave us an idea to see what's going on
at the surface and actually make measurements.
Not just to observe it and look at it,
which was important, but also to be able to tell people
how high is the dome.
- [Narrator] They've managed to plot the source of most
of the big quakes too.
Every dot is an earthquake over magnitude three.
The computers in their office are evolving just as quickly
as the technology they deploy in the crater.
They've seized the power of infrared cameras
to see just how hot the spines are
when that fresh magma surges from the depths of the earth.
- [Seth] What it allows us to do is to have some viewpoints
that we've never had before.
- [Narrator] The technology has become so precise,
they've picked up one change no one could have noticed,
just a few years ago.
As that massive new dome came up over three years,
the home of the nearby visitor center,
Johnston Ridge actually sank.
Just a little.
- Johnson Ridge has sunk very very small amount.
You're talking about millimeters.
As you remove mass in one place, the surrounding region
has to compensate.
So the flanks go down as the summit goes up.
- [Narrator] It is in their measurements
that the scientists try to deduce what Mount St. Helens
will tell us next.
The dome that provided such sudden dramatic change,
appears mute now.
On the other hand, crater glacier seems as noisy as ever.
- If the rate continues at the rate it was going last year,
then by next year, we will have glacier
where I'm standing right now.
You know, we say the eruption has stopped,
but it could well resume.
It only takes a little bit of a change
in that magnetic pressure to turn this thing on and off.
So we'll have to wait to see.