00:00:00.952 --> 00:00:07.140
[MUSIC PLAYING]

00:00:07.140 --> 00:00:17.920
The glaciers of Alaska, the
Canadian Rocky Mountains, the

00:00:17.920 --> 00:00:24.760
foothills of California, the
Atacama Desert and Andes of

00:00:24.760 --> 00:00:29.730
Chile, they may seem
worlds apart.

00:00:29.730 --> 00:00:33.612
But they are all connected along
a geologic front line,

00:00:33.612 --> 00:00:38.031
the eastern Pacific Rim.

00:00:38.031 --> 00:00:40.950
They're characters in the
ongoing tectonic story of our

00:00:40.950 --> 00:00:47.390
planet, a story of the
relentless subterranean forces

00:00:47.390 --> 00:00:55.770
that have convulsed our cities,
scarred the landscape,

00:00:55.770 --> 00:00:57.440
and overshadow our future.

00:01:04.390 --> 00:01:07.820
Travel with University of
Toronto geologist, Professor

00:01:07.820 --> 00:01:12.270
Nick Eyles, on a geologic
journey as he explores the

00:01:12.270 --> 00:01:15.775
Pacific Rim of fire from
Alaska to the Andes.

00:01:19.118 --> 00:01:34.556
[MUSIC PLAYING]

00:01:42.040 --> 00:01:45.900
Yakutat, southern Alaska, is one
of the most remote places

00:01:45.900 --> 00:01:48.480
on Earth, and one of
the most dangerous.

00:01:51.480 --> 00:01:56.048
A tectonic intersection where
plates collide, rocks are

00:01:56.048 --> 00:02:00.490
uplifted and folded into high
mountains that reach 6,000

00:02:00.490 --> 00:02:01.850
meters above sea level.

00:02:07.654 --> 00:02:10.630
[AIRPLANE]

00:02:10.630 --> 00:02:13.770
It's amazing how big
in class these--

00:02:13.770 --> 00:02:17.120
To geologists like Nick Eyles
and earthquake specialist

00:02:17.120 --> 00:02:20.770
Peter Haeussler of the US
Geologic Survey, it's an

00:02:20.770 --> 00:02:24.060
opportunity to explore a
tectonic show plate.

00:02:28.530 --> 00:02:33.240
It's a world where ice has the
final word, and glaciers

00:02:33.240 --> 00:02:34.490
sculpt the landscape.

00:02:38.860 --> 00:02:44.350
The size and scale of the
Alaskan glaciers is stunning,

00:02:44.350 --> 00:02:50.290
giant expanses of ice each the
size of a large city, a modern

00:02:50.290 --> 00:02:52.290
version of the last ice age.

00:02:56.470 --> 00:02:59.830
It's also a changing world.

00:02:59.830 --> 00:03:03.290
The impact of global warming
is clearly evident.

00:03:03.290 --> 00:03:06.053
So the ice is thinning quite
quickly here, isn't it?

00:03:06.053 --> 00:03:06.900
Yeah, that's right.

00:03:06.900 --> 00:03:09.350
I guess I had that map that was
showing that the ice was

00:03:09.350 --> 00:03:14.140
at the mouth of the bay
something like 800 years ago.

00:03:17.340 --> 00:03:20.940
The landscape here is
operatic in scale.

00:03:20.940 --> 00:03:23.510
Giant mountains form
a high wall that

00:03:23.510 --> 00:03:27.450
fronts the Pacific Ocean.

00:03:27.450 --> 00:03:30.430
These mountains are some of
the fastest growing on the

00:03:30.430 --> 00:03:34.520
planet, forced upwards by
crustal impact between the

00:03:34.520 --> 00:03:37.050
Pacific and North
American plates.

00:03:37.050 --> 00:03:39.850
It's amazing where you can look
from the Pacific Ocean

00:03:39.850 --> 00:03:42.060
and, presumably, out
there a little ways

00:03:42.060 --> 00:03:42.980
is the Pacific Plate.

00:03:42.980 --> 00:03:45.030
And here's this Yakutat
microplate.

00:03:45.030 --> 00:03:47.200
And then there's North
America right

00:03:47.200 --> 00:03:49.361
there, so good collision.

00:03:53.200 --> 00:03:57.060
The collision is especially
intense because the Pacific

00:03:57.060 --> 00:04:01.060
Plate carries a tectonic
passenger, a large piece of

00:04:01.060 --> 00:04:03.935
crust the size of a small
European country.

00:04:03.935 --> 00:04:07.550
As it dives down beneath its
North American tectonic

00:04:07.550 --> 00:04:10.770
neighbor, the Yakutat
Block slams into

00:04:10.770 --> 00:04:12.020
the coast of Alaska.

00:04:14.520 --> 00:04:18.990
Rocks that, until recently, lay
well below sea level have

00:04:18.990 --> 00:04:23.520
been folded and uplifted
high above the coast.

00:04:23.520 --> 00:04:27.930
It's a strange surreal world
that constantly surprises,

00:04:27.930 --> 00:04:30.390
where even trees grow on ice.

00:04:41.436 --> 00:04:45.300
On the ground, Nick and Peter
are met by guide Nick Cole.

00:04:48.820 --> 00:04:51.610
Weather conditions in
the aptly named Icy

00:04:51.610 --> 00:04:53.560
Bay can shift quickly.

00:04:53.560 --> 00:04:57.552
It's not a good place
to be on your own.

00:04:57.552 --> 00:05:00.428
Yeah, I've also wondered about
these terraces over there.

00:05:00.428 --> 00:05:01.862
See those flat surfaces?

00:05:01.862 --> 00:05:04.960
Right, whether they're
tectonic or glacial?

00:05:04.960 --> 00:05:05.980
Yeah.

00:05:05.980 --> 00:05:08.740
The obvious interpretation
is that they are

00:05:08.740 --> 00:05:09.830
strong uplift events.

00:05:09.830 --> 00:05:11.726
Yeah.

00:05:11.726 --> 00:05:14.610
But they could equally
be raised as a

00:05:14.610 --> 00:05:15.685
result of glacial isostatic.

00:05:15.685 --> 00:05:18.456
You know, when you get rid of
the ice, as you [? were ?]

00:05:18.456 --> 00:05:19.402
[? told. ?]

00:05:19.402 --> 00:05:21.767
So what else would you look
for in the landscape?

00:05:25.080 --> 00:05:28.696
There is an amazing diversity
of rock scattered on this

00:05:28.696 --> 00:05:29.950
beach, isn't there?

00:05:29.950 --> 00:05:31.270
Sure are.

00:05:31.270 --> 00:05:34.050
Yeah, this is incredible.

00:05:34.050 --> 00:05:37.170
This area is the most
tectonically active part of

00:05:37.170 --> 00:05:38.190
North America.

00:05:38.190 --> 00:05:42.190
And we've got all this glacial
landscape we're looking at.

00:05:42.190 --> 00:05:45.450
This enormous erratic
that's here.

00:05:45.450 --> 00:05:46.360
It's really cool.

00:05:46.360 --> 00:05:48.310
And you can be quite specific
about where that's

00:05:48.310 --> 00:05:49.380
from too, can't you?

00:05:49.380 --> 00:05:50.400
Yeah, that's right.

00:05:50.400 --> 00:05:53.670
That probably came from at least
100 kilometers on the

00:05:53.670 --> 00:05:56.700
other side of the
mountains here.

00:05:56.700 --> 00:06:00.480
So high uplift, formation of
glaciers, the glaciers start

00:06:00.480 --> 00:06:02.950
cutting deeply down into
the mountains.

00:06:02.950 --> 00:06:05.010
And they start dragging
all this debris out.

00:06:05.010 --> 00:06:05.910
Right, yeah.

00:06:05.910 --> 00:06:09.720
The glaciers really act like
a conveyor belt, really

00:06:09.720 --> 00:06:13.070
effective at removing material
from the mountains, bringing

00:06:13.070 --> 00:06:17.020
it outward, and leaving bigger
[? attics ?] and stuff behind.

00:06:22.460 --> 00:06:26.840
Glacier ice roads carry rock
back to the ocean, tearing

00:06:26.840 --> 00:06:28.370
down the mountains
in the process.

00:06:42.210 --> 00:06:46.510
Lines of rocky debris, called
medial moraines, stretch for

00:06:46.510 --> 00:06:47.760
tens of kilometers.

00:06:51.240 --> 00:06:54.940
The ice itself is hundreds of
meters thick and is pushed by

00:06:54.940 --> 00:07:00.430
gravity over a slurry of
wet sediment and water.

00:07:00.430 --> 00:07:03.640
There are open crevasses
everywhere as the flow

00:07:03.640 --> 00:07:04.890
accelerates.

00:07:08.300 --> 00:07:13.140
Elsewhere, giant folds record
compression as the ice slows

00:07:13.140 --> 00:07:14.685
towards the glacier's margins.

00:07:25.640 --> 00:07:28.280
Alaska is slowly growing.

00:07:28.280 --> 00:07:32.330
Large pieces of crust, carried
by the Pacific Plate, collide

00:07:32.330 --> 00:07:35.600
with North America and they're
moved north along major

00:07:35.600 --> 00:07:38.740
faults, such as the Fairweather
Fault and further

00:07:38.740 --> 00:07:42.120
south the San Andreas Fault.

00:07:42.120 --> 00:07:44.840
These blocks have been
in transit for

00:07:44.840 --> 00:07:47.300
around 200 million years.

00:07:47.300 --> 00:07:52.070
And their ultimate fate is to
attach, to accrete, to western

00:07:52.070 --> 00:07:53.320
North America.

00:07:55.820 --> 00:08:00.100
Much of Alaska didn't even exist
200 million years ago,

00:08:00.100 --> 00:08:01.790
probably about the same
for British Columbia.

00:08:01.790 --> 00:08:04.090
About half of British Columbia
didn't exist 200

00:08:04.090 --> 00:08:04.610
million years ago.

00:08:04.610 --> 00:08:07.150
It's pieces that were somewhere

00:08:07.150 --> 00:08:08.960
else out in the oceans.

00:08:08.960 --> 00:08:12.000
So there's like little open
pieces of crust, which have

00:08:12.000 --> 00:08:15.180
come from long way away, maybe
thousands of kilometers, and

00:08:15.180 --> 00:08:18.110
ended up colliding with western
North America and

00:08:18.110 --> 00:08:22.290
being stuck on like
a jigsaw puzzle.

00:08:22.290 --> 00:08:23.540
That's right.

00:08:25.630 --> 00:08:29.860
Turnagain Arm, near Anchorage,
illustrates both the scale and

00:08:29.860 --> 00:08:32.909
the differing speeds of
the accretion process.

00:08:32.909 --> 00:08:37.940
The vistas that so impress may
look fixed and immutable.

00:08:37.940 --> 00:08:42.780
But the rocks have all come
from someplace else.

00:08:42.780 --> 00:08:44.800
Did notice as we drive
along these rocks,

00:08:44.800 --> 00:08:46.400
they're highly deformed.

00:08:46.400 --> 00:08:48.780
What do they tell us about
the past tectonic

00:08:48.780 --> 00:08:50.180
activity along here?

00:08:50.180 --> 00:08:51.570
Yeah, they sure are.

00:08:51.570 --> 00:08:53.080
This is part of the
accretionary

00:08:53.080 --> 00:08:54.520
complex that's in here.

00:08:54.520 --> 00:08:58.790
And basically, this larger
package of rocks reflect

00:08:58.790 --> 00:09:01.400
something like 200 million
years of Earth history.

00:09:01.400 --> 00:09:05.230
So it's a really beautiful
record of accretion along the

00:09:05.230 --> 00:09:07.120
southern Alaska margin.

00:09:07.120 --> 00:09:12.400
These rocks right here were
probably related to the oldest

00:09:12.400 --> 00:09:14.530
phase of that accretion.

00:09:14.530 --> 00:09:20.030
And so a relatively narrow belt
of rocks, but the time

00:09:20.030 --> 00:09:23.220
span that's within it is
probably on the order of 120

00:09:23.220 --> 00:09:24.810
million years.

00:09:24.810 --> 00:09:28.490
And the next group that's kind
of outward, the next chapter

00:09:28.490 --> 00:09:35.260
of Earth history that you see
within this, actually reflects

00:09:35.260 --> 00:09:37.500
probably only about 20 million
years of history.

00:09:37.500 --> 00:09:41.095
And yet it's probably the most
volume of the entire Chugach

00:09:41.095 --> 00:09:41.570
[INAUDIBLE]

00:09:41.570 --> 00:09:42.820
Mountains.

00:09:47.280 --> 00:09:51.700
This part of the American rim is
also earthquake country, a

00:09:51.700 --> 00:09:54.325
consequence of the Earth's
crust on the move.

00:09:59.490 --> 00:10:03.200
The tidal flats in Girdwood,
near Anchorage, contain a rich

00:10:03.200 --> 00:10:07.510
seismic history preserved as
ghost forests and in layers of

00:10:07.510 --> 00:10:08.885
peat and mud below.

00:10:12.580 --> 00:10:15.770
The last major quake
was in 1964.

00:10:15.770 --> 00:10:19.340
And its impact on landscapes
across southern Alaska

00:10:19.340 --> 00:10:21.650
provided the key to
reading the record

00:10:21.650 --> 00:10:23.510
preserved in the sediments.

00:10:23.510 --> 00:10:24.080
Oh, wow.

00:10:24.080 --> 00:10:26.040
Look at these tree
roots right here.

00:10:26.040 --> 00:10:27.130
Those are gorgeous.

00:10:27.130 --> 00:10:28.680
That is beautiful.

00:10:28.680 --> 00:10:33.040
So that would have been the '64
forest floor, beautiful

00:10:33.040 --> 00:10:34.090
interlocking roots.

00:10:34.090 --> 00:10:36.720
So you say approximately two
meters of subsidence during

00:10:36.720 --> 00:10:37.540
the earthquake.

00:10:37.540 --> 00:10:39.950
So these guys would have
been up there.

00:10:39.950 --> 00:10:41.190
Way up there, yeah.

00:10:41.190 --> 00:10:43.300
Growing well above the
high tide area,

00:10:43.300 --> 00:10:44.745
well above salt water.

00:10:44.745 --> 00:10:45.110
Yep.

00:10:45.110 --> 00:10:46.923
And then they were dropped
down and killed.

00:10:46.923 --> 00:10:47.710
Yeah.

00:10:47.710 --> 00:10:50.270
Yeah, so two meters would
have put them up like

00:10:50.270 --> 00:10:52.240
that level or something.

00:10:52.240 --> 00:10:56.060
And then the gray shelf on top
is all the marine sediment

00:10:56.060 --> 00:10:56.980
that flooded over that bank.

00:10:56.980 --> 00:10:57.890
That's come in since
then, yep.

00:10:57.890 --> 00:10:59.980
That's exactly right.

00:10:59.980 --> 00:11:04.700
Discoveries here and elsewhere
have led to a new scientific

00:11:04.700 --> 00:11:08.020
discipline called
paleoseismology, which

00:11:08.020 --> 00:11:12.180
calculates the timing and
frequency of past earthquakes.

00:11:12.180 --> 00:11:15.870
In this way, geologists can
assess the risk to modern

00:11:15.870 --> 00:11:17.305
communities.

00:11:17.305 --> 00:11:19.110
So what are we looking
at here, Peter?

00:11:19.110 --> 00:11:22.260
Well, you can see, with a little
bit of work here, we've

00:11:22.260 --> 00:11:26.940
been able to expose this
really nice sequence.

00:11:26.940 --> 00:11:30.860
So up here are these silts and
muds that were deposited since

00:11:30.860 --> 00:11:32.970
the 1964 earthquake.

00:11:32.970 --> 00:11:36.310
So all of this has been
deposited since then.

00:11:36.310 --> 00:11:42.850
And then this horizon right
there, that's March 27, 1964.

00:11:42.850 --> 00:11:45.040
That's 46 years ago.

00:11:45.040 --> 00:11:49.170
And then below that is the
forest floor from before the

00:11:49.170 --> 00:11:50.780
'64 earthquake.

00:11:50.780 --> 00:11:53.090
And then, presumably,
we'll go downward.

00:11:53.090 --> 00:11:58.686
And we have roughly 900 years
of history below that.

00:11:58.686 --> 00:12:01.160
By studying a sequence like
this, it helps you know what

00:12:01.160 --> 00:12:04.500
to look for in other places
for older earthquakes.

00:12:04.500 --> 00:12:07.770
And so, for example, after
seeing this kind of thing, one

00:12:07.770 --> 00:12:12.200
worker then went back down to
Oregon and Washington and

00:12:12.200 --> 00:12:15.770
found similar evidence for big
earthquakes down there.

00:12:15.770 --> 00:12:20.080
And since then, there's been a
strong case made for something

00:12:20.080 --> 00:12:23.570
like a magnitude nine earthquake
in Oregon,

00:12:23.570 --> 00:12:24.880
Washington, and southern
British

00:12:24.880 --> 00:12:39.120
Columbia in the year 1700.

00:12:39.120 --> 00:12:44.240
The great Alaskan earthquake of
March 1964 is the largest

00:12:44.240 --> 00:12:47.910
ever recorded in North
America, 9.2

00:12:47.910 --> 00:12:50.540
on the Richter scale.

00:12:50.540 --> 00:12:55.520
It had a devastating effect
on the city of Anchorage.

00:12:55.520 --> 00:12:57.940
Coastal cliffs collapsed,
carrying

00:12:57.940 --> 00:12:59.620
houses far out to sea.

00:13:03.340 --> 00:13:06.200
Before the earthquake, there
was a big bluff here, had

00:13:06.200 --> 00:13:08.250
houses on the top.

00:13:08.250 --> 00:13:10.890
So this whole area must be
underlain by debris from those

00:13:10.890 --> 00:13:12.340
large landslides.

00:13:12.340 --> 00:13:13.570
Yeah, that's right.

00:13:13.570 --> 00:13:16.490
Sometimes, if you're walking
around out here, you can see

00:13:16.490 --> 00:13:19.130
either bricks or pieces of pipe,
sometimes a piece of

00:13:19.130 --> 00:13:21.810
porcelain that came from
the houses that were

00:13:21.810 --> 00:13:23.580
on the bluff here.

00:13:23.580 --> 00:13:27.830
There were about 75 houses that
were destroyed in that

00:13:27.830 --> 00:13:29.505
landslide that occurred
right here.

00:13:44.900 --> 00:13:47.940
When the earthquake occurred,
the epicenter was about 100

00:13:47.940 --> 00:13:49.760
kilometers away from here.

00:13:49.760 --> 00:13:52.310
And the initial traveling of
those seismic waves, you can

00:13:52.310 --> 00:13:55.360
think about a bit like dropping
a pebble in a pond in

00:13:55.360 --> 00:13:59.190
that the waves sort of travel
outward from that.

00:13:59.190 --> 00:14:02.470
But all earthquakes generate
waves that have different

00:14:02.470 --> 00:14:04.390
speeds to them.

00:14:04.390 --> 00:14:08.970
So the first waves would have
hit the Anchorage area roughly

00:14:08.970 --> 00:14:11.940
20 to 30 seconds after the
earthquake started in the

00:14:11.940 --> 00:14:13.740
middle of Prince
William Sound.

00:14:13.740 --> 00:14:15.930
And that initial shaking
would have sort of

00:14:15.930 --> 00:14:17.970
been this big jolt.

00:14:17.970 --> 00:14:20.500
But then a few seconds
later, the big

00:14:20.500 --> 00:14:21.510
shaking would have occurred.

00:14:21.510 --> 00:14:23.890
And that would have been so
violent that it probably would

00:14:23.890 --> 00:14:28.120
have been hard to actually
stand at that point.

00:14:28.120 --> 00:14:31.550
This is a city built on
soft marine sediment.

00:14:31.550 --> 00:14:36.020
And in 1964, much of its
downtown sank when the

00:14:36.020 --> 00:14:38.525
seemingly solid earth
turned to quicksand.

00:14:43.700 --> 00:14:47.600
Downtown Anchorage
was badly hit.

00:14:47.600 --> 00:14:49.880
Multi-story buildings took
the brunt of the damage.

00:14:52.940 --> 00:14:55.240
In a matter of minutes,
thousands of

00:14:55.240 --> 00:14:57.810
people were made homeless.

00:14:57.810 --> 00:15:01.620
Before long, the seismic shaking
actually subsided.

00:15:01.620 --> 00:15:04.130
But the effects of the
earthquake weren't done in

00:15:04.130 --> 00:15:09.990
that the tectonic tsunami then
hit the coast of Alaska within

00:15:09.990 --> 00:15:12.420
roughly 20 to 30 minutes
of the earthquake.

00:15:12.420 --> 00:15:17.320
That devastated both Seward as
well as Kodiak and some of the

00:15:17.320 --> 00:15:19.490
villages down in that region.

00:15:19.490 --> 00:15:23.280
One of the saddest stories was
at the village of Chenega.

00:15:23.280 --> 00:15:25.655
The water initially receded
from the village.

00:15:25.655 --> 00:15:28.270
And a lot of people saw
fish flopping around

00:15:28.270 --> 00:15:29.240
in the tidal flats.

00:15:29.240 --> 00:15:30.980
They went down to get them.

00:15:30.980 --> 00:15:34.680
And then the waves came in and
killed 33 people there, a

00:15:34.680 --> 00:15:35.930
third of the community.

00:15:38.760 --> 00:15:41.400
After the earthquake, the
tsunamis happened.

00:15:41.400 --> 00:15:42.580
And that was done.

00:15:42.580 --> 00:15:45.990
But down at the village of
Portage then, within the next

00:15:45.990 --> 00:15:49.140
couple of days, these very high
spring tides came in,

00:15:49.140 --> 00:15:51.950
inundated that community, and
basically made Portage a place

00:15:51.950 --> 00:15:53.530
where people could
no longer live.

00:15:53.530 --> 00:15:54.780
It killed the community.

00:15:58.420 --> 00:16:02.420
Right here there was about two
meters of subsidence that

00:16:02.420 --> 00:16:04.830
happened in 1964, which
would have been almost

00:16:04.830 --> 00:16:06.080
instantaneous.

00:16:10.330 --> 00:16:12.720
And as a result of that, all
of a sudden, the buildings

00:16:12.720 --> 00:16:14.275
were within the tidal zone.

00:16:14.275 --> 00:16:18.490
And so after the earthquake,
there were high tides that

00:16:18.490 --> 00:16:20.830
were coming all around
this community here.

00:16:20.830 --> 00:16:23.110
So it's not just this
plot either, is it?

00:16:23.110 --> 00:16:26.330
You've mapped it over a much
larger area, that area of

00:16:26.330 --> 00:16:27.090
subsidence.

00:16:27.090 --> 00:16:27.900
Yeah, that's right.

00:16:27.900 --> 00:16:31.250
There was a huge area that was
mapped out that subsided.

00:16:31.250 --> 00:16:33.720
And this was kind of the
axis of where the

00:16:33.720 --> 00:16:36.260
most subsidence was.

00:16:36.260 --> 00:16:39.030
The tides brought in the silt,
which filled in the floor.

00:16:39.030 --> 00:16:43.275
And now we feel like giants
in a little house here.

00:16:50.440 --> 00:16:54.150
Large earthquakes and the rapid
uplift of mountains are

00:16:54.150 --> 00:16:57.070
all expressions of tectonic
accretion as

00:16:57.070 --> 00:16:59.540
crust is added to Alaska.

00:16:59.540 --> 00:17:01.925
And the impact doesn't
stop there.

00:17:01.925 --> 00:17:05.720
The collisional forces that were
unleashed along the rim

00:17:05.720 --> 00:17:11.550
pushed far inland, deep into the
interior of North America.

00:17:11.550 --> 00:17:15.849
In Canada, the iconic Rocky
Mountains were carved by

00:17:15.849 --> 00:17:19.630
glaciers into rocks buckled and
pushed far to the east.

00:17:22.801 --> 00:17:26.390
Running south along the rim
there is other striking

00:17:26.390 --> 00:17:30.710
evidence of tectonic
forces at work.

00:17:30.710 --> 00:17:35.050
The infamous San Andreas Fault
is one of the most extensively

00:17:35.050 --> 00:17:39.170
studied fault lines
on the planet.

00:17:39.170 --> 00:17:41.986
It's a seemingly endless
gash in the landscape.

00:17:45.280 --> 00:17:48.970
The fault is part of the seismic
grid that reaches as

00:17:48.970 --> 00:17:52.630
far south as Mexico and which
makes the region and its

00:17:52.630 --> 00:17:54.810
cities particularly
vulnerable.

00:18:00.469 --> 00:18:03.840
At ground level, it's
a different picture.

00:18:03.840 --> 00:18:07.350
The setting of the DeRose winery
near Hollister, south

00:18:07.350 --> 00:18:11.840
of San Francisco, looks idyllic
and hardly precarious.

00:18:11.840 --> 00:18:15.580
But it sits astride the
San Andreas Fault.

00:18:15.580 --> 00:18:19.467
As the fault moves, so does
the winery above it.

00:18:22.330 --> 00:18:25.560
Alphonse DeRose and his father
took over the business in the

00:18:25.560 --> 00:18:29.950
1980s, though the vineyard
itself and some of its vines

00:18:29.950 --> 00:18:32.320
date back to the 1800s.

00:18:32.320 --> 00:18:35.100
On average, we have about
five earthquakes a day.

00:18:35.100 --> 00:18:36.600
But they're below a 3.0.

00:18:36.600 --> 00:18:38.770
So we don't feel them.

00:18:38.770 --> 00:18:42.480
Alphonse is philosophic about
the geological pressure cooker

00:18:42.480 --> 00:18:44.130
beneath his feet.

00:18:44.130 --> 00:18:47.810
So we're looking down right
at the San Andreas Fault.

00:18:47.810 --> 00:18:51.520
Yes, and you can get a good
idea of the movement by

00:18:51.520 --> 00:18:54.100
looking at this crack here.

00:18:54.100 --> 00:18:56.700
We've actually had to lay cement
here a couple of times

00:18:56.700 --> 00:18:58.940
over the last 10 or 15 years.

00:18:58.940 --> 00:19:02.150
So it's real, real evident
of the movement.

00:19:02.150 --> 00:19:05.500
And actually, if you take a look
at this wall right here,

00:19:05.500 --> 00:19:09.540
this wall used to be flush with
that post over there.

00:19:09.540 --> 00:19:12.060
So over the last 50 years,
it's moved about

00:19:12.060 --> 00:19:13.330
15 inches or so.

00:19:13.330 --> 00:19:15.630
So the buildings are actually
being torn in two.

00:19:15.630 --> 00:19:16.940
What else is happening?

00:19:16.940 --> 00:19:18.940
Actually, you can see
some buckling on

00:19:18.940 --> 00:19:20.470
both ends of the building.

00:19:20.470 --> 00:19:21.910
Have you ever had a
major earthquake

00:19:21.910 --> 00:19:23.750
while you've been here?

00:19:23.750 --> 00:19:26.130
We did have one back in 1989.

00:19:26.130 --> 00:19:28.060
But the epicenter wasn't here.

00:19:28.060 --> 00:19:30.790
So I don't even think we broke
a wine glass here.

00:19:33.650 --> 00:19:36.440
Follow the San Andreas Fault
north, and there's

00:19:36.440 --> 00:19:38.200
even more at stake.

00:19:38.200 --> 00:19:42.030
It travels right through the
heart of San Francisco.

00:19:42.030 --> 00:19:47.120
And that's only one of the
city's geologic challenges.

00:19:47.120 --> 00:19:49.960
The rocks have been really
highly deformed, haven't they?

00:19:49.960 --> 00:19:54.790
Yeah, the process of abducting
them up onto the continent

00:19:54.790 --> 00:19:57.400
from the sea floor wasn't
a pretty process.

00:19:57.400 --> 00:20:00.530
Mark Zoback is one of America's
leading authorities

00:20:00.530 --> 00:20:04.430
on earthquakes and an advisor
on risk management to the

00:20:04.430 --> 00:20:06.220
United States government.

00:20:06.220 --> 00:20:10.060
There's a fault to the west of
the San Andreas, the San

00:20:10.060 --> 00:20:11.140
Gregorio Fault.

00:20:11.140 --> 00:20:12.277
That's an active fault.

00:20:12.277 --> 00:20:14.240
The San Andreas is
the big player.

00:20:14.240 --> 00:20:18.100
But as we go east to the Hayward
Fault, there are many

00:20:18.100 --> 00:20:21.300
ideas and many models that
suggest that, over geologic

00:20:21.300 --> 00:20:24.880
time, the Hayward Fault is going
to be the main actor

00:20:24.880 --> 00:20:27.930
accommodating the motion
between the plates.

00:20:27.930 --> 00:20:31.240
And so it's a constantly
evolving process, although it

00:20:31.240 --> 00:20:35.760
takes millions of years for
that evolution to occur.

00:20:35.760 --> 00:20:39.760
The Bay Area may be cradled
between the San Andreas Fault

00:20:39.760 --> 00:20:43.500
to the west and the Hayward
Fault to the east, but there

00:20:43.500 --> 00:20:46.370
are myriads of smaller
faults and likely

00:20:46.370 --> 00:20:48.760
others that remain unknown.

00:20:48.760 --> 00:20:52.601
The city lies above a seismic
subway system.

00:20:52.601 --> 00:20:57.310
The Cal Memorial Stadium at UC
Berkeley is especially at

00:20:57.310 --> 00:21:01.690
risk, the Hayward Fault running

00:21:01.690 --> 00:21:03.265
from goalpost to goalpost.

00:21:06.370 --> 00:21:10.650
Look closely, and the
cracks appear.

00:21:10.650 --> 00:21:13.320
The football stadium at
Berkeley has a dubious

00:21:13.320 --> 00:21:15.390
distinction of being
built right on top

00:21:15.390 --> 00:21:16.425
of the Hayward Fault.

00:21:16.425 --> 00:21:18.610
And the fault pretty
much runs along the

00:21:18.610 --> 00:21:20.366
center line at the stadium.

00:21:20.366 --> 00:21:24.760
And as a result of slow creep
along the fault, this half of

00:21:24.760 --> 00:21:28.420
the stadium has moved north
relative to that half.

00:21:28.420 --> 00:21:30.420
And we can see evidence of that

00:21:30.420 --> 00:21:32.000
movement here in the wall.

00:21:32.000 --> 00:21:33.840
This is a deep crack.

00:21:33.840 --> 00:21:36.566
You can see this wall
has been offset.

00:21:36.566 --> 00:21:40.280
And on a larger plate tectonic
setting, that is North

00:21:40.280 --> 00:21:42.300
America over here.

00:21:42.300 --> 00:21:44.140
This is the Pacific Plate.

00:21:44.140 --> 00:21:46.705
And we are right on top
of a plate boundary.

00:21:50.100 --> 00:21:52.750
The signs of damage can be found
all the way around the

00:21:52.750 --> 00:21:57.090
stadium, such as these
deep cracks here.

00:21:57.090 --> 00:22:00.600
And the building has now been so
severely deformed by fault

00:22:00.600 --> 00:22:04.430
movement that it requires
a comprehensive retrofit

00:22:04.430 --> 00:22:08.180
involving the use of braces
to keep these walls up.

00:22:13.870 --> 00:22:17.150
San Francisco is renowned
for its setting,

00:22:17.150 --> 00:22:20.840
its imposing scale.

00:22:20.840 --> 00:22:25.840
The Paris of the West, it's
famed for its street cars, its

00:22:25.840 --> 00:22:29.790
hills, and the elegance of its
architecture, which at the

00:22:29.790 --> 00:22:32.380
turn of the last century
sought to rival

00:22:32.380 --> 00:22:35.600
Chicago and New York.

00:22:35.600 --> 00:22:39.190
The city is also known as the
scene of one of America's

00:22:39.190 --> 00:22:42.520
worst disasters, which struck
early on the morning

00:22:42.520 --> 00:22:47.230
of April 18, 1906.

00:22:47.230 --> 00:22:51.900
28,000 buildings
were destroyed.

00:22:51.900 --> 00:22:56.890
3,000 people killed, half
the population of

00:22:56.890 --> 00:23:00.348
the city left homeless.

00:23:27.040 --> 00:23:30.450
The earthquake actually
nucleated just offshore, very

00:23:30.450 --> 00:23:31.615
close to Golden Gate Park.

00:23:31.615 --> 00:23:34.635
That fault ruptured both to the
north and to the south.

00:23:34.635 --> 00:23:37.800
The strong waves from the
earthquake hit San Francisco

00:23:37.800 --> 00:23:38.585
almost immediately.

00:23:38.585 --> 00:23:41.530
It was so close to the epicenter
of the event.

00:23:41.530 --> 00:23:45.100
The shaking was most intense
around the periphery of the

00:23:45.100 --> 00:23:48.080
bay where structures were
built on soft sediments.

00:23:48.080 --> 00:23:50.560
The shaking was much less
intense up on the hills where

00:23:50.560 --> 00:23:53.340
the houses were being
built on bedrock.

00:23:58.120 --> 00:24:00.840
Down in the streets by the
harbor, the earthquake's

00:24:00.840 --> 00:24:03.560
effects are still evident
a century later.

00:24:07.070 --> 00:24:08.990
When this area was violently
shaken in

00:24:08.990 --> 00:24:11.360
1906, this area collapsed.

00:24:11.360 --> 00:24:14.085
And you can see that on the
street level behind me.

00:24:14.085 --> 00:24:17.010
The effects are dramatically
seen here in the buildings

00:24:17.010 --> 00:24:20.890
today where second story windows
are almost at street

00:24:20.890 --> 00:24:26.274
level and entryways are now
well below street level.

00:24:26.274 --> 00:24:29.030
Now the shaking itself, of
course, is what knocks

00:24:29.030 --> 00:24:30.060
buildings down.

00:24:30.060 --> 00:24:32.210
But in the case of San
Francisco, the damage was

00:24:32.210 --> 00:24:35.170
caused first by the shaking
but then by the fires.

00:24:35.170 --> 00:24:38.960
As fires broke out, it turns out
that the water lines were

00:24:38.960 --> 00:24:39.900
badly damaged.

00:24:39.900 --> 00:24:42.120
And it was impossible
to fight the fires.

00:24:42.120 --> 00:24:45.040
So in fact, it was the great San
Francisco earthquake and

00:24:45.040 --> 00:24:48.065
fire that really destroyed
the city.

00:24:50.970 --> 00:24:53.330
But that was a long while ago.

00:24:53.330 --> 00:24:55.530
How do San Franciscans,
like Raymond

00:24:55.530 --> 00:24:58.210
[INAUDIBLE], feel today?

00:24:58.210 --> 00:25:00.320
Living in an area that
subsided during the

00:25:00.320 --> 00:25:03.240
earthquake, and in a house that
might collapse during the

00:25:03.240 --> 00:25:04.820
next one, that doesn't
worry you?

00:25:04.820 --> 00:25:05.510
No.

00:25:05.510 --> 00:25:08.736
No, I could run outside.

00:25:08.736 --> 00:25:10.770
I'm cool with it.

00:25:10.770 --> 00:25:13.035
And you knew the history of the
area when you moved in?

00:25:13.035 --> 00:25:14.370
Oh, yeah.

00:25:14.370 --> 00:25:16.336
I'm not really too
afraid of it.

00:25:16.336 --> 00:25:18.890
Is the building still
settling?

00:25:18.890 --> 00:25:21.600
Yeah, sometimes.

00:25:21.600 --> 00:25:24.980
But the one apartment I lived
in out in North Beach, the

00:25:24.980 --> 00:25:26.590
whole building shook.

00:25:26.590 --> 00:25:29.345
And I was actually watching The
Day the Earth Stood Still.

00:25:29.345 --> 00:25:30.510
And the earthquake came.

00:25:30.510 --> 00:25:31.790
Yeah, it was really weird.

00:25:40.270 --> 00:25:44.700
Back in 1906, the university
campus in the nearby community

00:25:44.700 --> 00:25:48.930
of Stanford was also
badly damaged.

00:25:48.930 --> 00:25:54.570
Even the geology building took
a hit, the imposing spire of

00:25:54.570 --> 00:25:58.900
the Memorial Church crashing
through the roof.

00:25:58.900 --> 00:26:01.990
The campus is now being steadily
retrofitted in

00:26:01.990 --> 00:26:05.320
preparation for the next
earthquake, an event which

00:26:05.320 --> 00:26:09.490
Stanford Professor Mark Zoback
believes is coming soon.

00:26:09.490 --> 00:26:13.060
There are about six dangerous
faults, six capable faults of

00:26:13.060 --> 00:26:16.210
producing damaging earthquakes
in what is considered really

00:26:16.210 --> 00:26:20.252
the next 30 years is the way
we've been looking at it.

00:26:20.252 --> 00:26:23.850
If you look at the cumulative
probability that an earthquake

00:26:23.850 --> 00:26:27.360
on one of these six faults will
cause severe shaking in

00:26:27.360 --> 00:26:30.470
the San Francisco area, the
cumulative probability is

00:26:30.470 --> 00:26:34.600
about 60% in the next 30 years,
which means it's about

00:26:34.600 --> 00:26:38.050
twice as likely to occur
as not to occur.

00:26:38.050 --> 00:26:42.100
So from the perspective of the
people who live here, from the

00:26:42.100 --> 00:26:46.540
perspective of the people who
have to respond to the

00:26:46.540 --> 00:26:49.300
earthquakes, we have to
think of it as just

00:26:49.300 --> 00:26:50.550
about a sure thing.

00:26:54.730 --> 00:26:58.460
Leaving California, Nick heads
south to one of the most

00:26:58.460 --> 00:27:05.040
earthquake prone regions on
the planet, Chile, where

00:27:05.040 --> 00:27:10.020
thousands of kilometers of
coastline are at risk.

00:27:10.020 --> 00:27:14.500
Back in 1960, it was the scene
of the largest earthquake ever

00:27:14.500 --> 00:27:18.730
recorded, which triggered a
devastating tsunami felt right

00:27:18.730 --> 00:27:19.980
across the Pacific.

00:27:26.340 --> 00:27:30.200
Northern Chile is one of the
driest places on Earth, the

00:27:30.200 --> 00:27:34.340
Atacama Desert where rainfall
can be as low as one

00:27:34.340 --> 00:27:36.970
millimeter a year.

00:27:36.970 --> 00:27:41.390
The low lying coast is flanked
by imposing volcanic cliffs,

00:27:41.390 --> 00:27:45.170
which increase the potential
impact of tsunamis, which have

00:27:45.170 --> 00:27:48.380
been known to be as
high as 25 meters.

00:27:55.330 --> 00:27:59.790
Cities like Antofagasta perch
precariously on the narrow

00:27:59.790 --> 00:28:04.212
strip of land beneath the 1,000
meter high Cordilleras,

00:28:04.212 --> 00:28:06.340
squeezed between ocean
and desert.

00:28:10.030 --> 00:28:13.574
Antofagasta is home to a quarter
of a million people.

00:28:17.930 --> 00:28:22.070
Its prosperity is dependent
on its rocks.

00:28:22.070 --> 00:28:25.610
Minerals from the giant mines of
the Atacama are carried to

00:28:25.610 --> 00:28:28.770
the coast by rail and shipped
around the world.

00:28:38.050 --> 00:28:40.090
Earthquakes are common here.

00:28:40.090 --> 00:28:44.115
The last, in 1995, shifted
the city 80

00:28:44.115 --> 00:28:45.450
centimeters to the west.

00:28:50.500 --> 00:28:54.330
Deep under the coastal strip,
the floor of the Pacific Ocean

00:28:54.330 --> 00:28:58.730
and its underlying crust, the
Nazca Plate, is being forced

00:28:58.730 --> 00:29:01.700
under South America.

00:29:01.700 --> 00:29:05.960
A never-ending cycle of stick
and slip between the two

00:29:05.960 --> 00:29:10.050
triggers sequences of large
damaging earthquakes.

00:29:10.050 --> 00:29:16.760
Far inland, recycled ocean crust
feeds Andean volcanoes.

00:29:16.760 --> 00:29:20.980
The descending Nazca Plate acts
as a giant wedge, each

00:29:20.980 --> 00:29:24.970
earthquake pushing up the
Chilean coast by many meters,

00:29:24.970 --> 00:29:26.985
abruptly raising it
from the ocean.

00:29:29.810 --> 00:29:33.960
At Portada, raised marine rocks
illustrate the ongoing

00:29:33.960 --> 00:29:38.760
cycle of earthquakes and uplift,
a process that was

00:29:38.760 --> 00:29:42.015
first interpreted by
Charles Darwin.

00:29:42.015 --> 00:29:44.930
Well, these cliffs are really
important in what they tell us

00:29:44.930 --> 00:29:47.595
about the origin of the
Andes but also in

00:29:47.595 --> 00:29:49.040
the history of science.

00:29:49.040 --> 00:29:52.650
Because in 1834 to 1835, a
very young Charles Darwin

00:29:52.650 --> 00:29:55.405
sailed along this part of the
coastline in the Beagle.

00:29:55.405 --> 00:29:58.340
He came ashore and noticed
these shells, now

00:29:58.340 --> 00:29:59.720
high above sea level.

00:29:59.720 --> 00:30:03.590
And in 1835, he witnessed a
major earthquake, which

00:30:03.590 --> 00:30:05.810
destroyed the city
of Concepcion.

00:30:05.810 --> 00:30:08.340
And he noticed that the
coastline was uplifted.

00:30:08.340 --> 00:30:10.250
Shells that were living
in the sea were now

00:30:10.250 --> 00:30:11.920
raised above sea level.

00:30:11.920 --> 00:30:14.880
And he interpreted these rocks
here as a result of repeated

00:30:14.880 --> 00:30:18.190
earthquakes and jacking
up of the coastline.

00:30:18.190 --> 00:30:22.150
It was a major insight into how
mountains are formed and

00:30:22.150 --> 00:30:26.855
also, for him, into the origin
of a dynamic evolving planet,

00:30:26.855 --> 00:30:29.300
which was, of course, a
springboard for his later

00:30:29.300 --> 00:30:30.665
ideas on evolving species.

00:30:39.310 --> 00:30:43.120
North of Antofagasta, the ruins
of the once flourishing

00:30:43.120 --> 00:30:47.456
port of Cobija are a testament
to the destructive force of

00:30:47.456 --> 00:30:51.030
tsunamis and the continuing
vulnerability of coastal

00:30:51.030 --> 00:30:53.820
settlements.

00:30:53.820 --> 00:30:58.410
The port was hit by an
earthquake in 1868 and then,

00:30:58.410 --> 00:31:02.860
less than a decade later, was
engulfed by a tsunami when 10

00:31:02.860 --> 00:31:05.767
meter high waves crashed
through its streets.

00:31:08.970 --> 00:31:12.380
The community, which had also
been hit with a yellow fever

00:31:12.380 --> 00:31:14.930
epidemic, decided that
the place was

00:31:14.930 --> 00:31:16.800
cursed and best abandoned.

00:31:22.470 --> 00:31:25.940
Moving inland towards the Andes,
Nick's journey takes

00:31:25.940 --> 00:31:29.656
him across the Atacama Desert
and its Mars-like topography.

00:31:34.950 --> 00:31:39.580
The landscape is seemingly
sterile, devoid of vegetation.

00:31:39.580 --> 00:31:42.640
But geologically, it's
anything but empty.

00:31:47.470 --> 00:31:51.430
The Santa Elena Mine was once
the world's primary source for

00:31:51.430 --> 00:31:55.480
nitrates used in the production
of both fertilizer

00:31:55.480 --> 00:31:59.740
and gunpowder and played a key
role in fueling the rival

00:31:59.740 --> 00:32:02.330
armies facing each other
in the trenches of

00:32:02.330 --> 00:32:05.670
the first World War.

00:32:05.670 --> 00:32:10.260
The scale of production was
immense, so to are the giant

00:32:10.260 --> 00:32:12.050
heaps of tailings that remain.

00:32:20.610 --> 00:32:24.760
The Atacama Desert still has
many mineral resources.

00:32:24.760 --> 00:32:28.900
But today, it's copper that's
king and is the backbone of

00:32:28.900 --> 00:32:32.700
the nation's economy.

00:32:32.700 --> 00:32:36.847
The Chuquicamata Mine is the
world's largest open pit

00:32:36.847 --> 00:32:37.741
copper mine.

00:32:37.741 --> 00:32:43.770
Its scale is simply immense,
4.9 kilometers long, 3

00:32:43.770 --> 00:32:46.796
kilometers wide, and
a kilometer deep.

00:32:51.630 --> 00:32:55.310
The copper here is found in the
giant roots of long dead

00:32:55.310 --> 00:33:00.090
volcanoes where ancient Pacific
crust melted at depth,

00:33:00.090 --> 00:33:04.590
and magma forced its
way to the surface.

00:33:04.590 --> 00:33:08.366
Deep waters under great pressure
and temperatures

00:33:08.366 --> 00:33:12.170
gleaned the metal from the hot
rock, concentrating it into

00:33:12.170 --> 00:33:15.223
rich veins of green and
turquoise colored minerals.

00:33:18.965 --> 00:33:22.821
Soon to be expanded still
further, the pit and its

00:33:22.821 --> 00:33:25.810
enormous piles of waste
rock looms above the

00:33:25.810 --> 00:33:28.400
former company town.

00:33:28.400 --> 00:33:30.070
It's deserted now.

00:33:30.070 --> 00:33:34.300
But the buildings have been
kept, a sideshow for the

00:33:34.300 --> 00:33:35.550
curious tourist.

00:33:41.870 --> 00:33:44.350
About 100 kilometers
inland, the

00:33:44.350 --> 00:33:47.200
landscape changes yet again.

00:33:47.200 --> 00:33:49.710
Far in the distance, the
Andean Mountains

00:33:49.710 --> 00:33:52.526
dominate the skyline.

00:33:52.526 --> 00:33:57.590
Massive volcanoes rising 5,000
meters above sea level warn of

00:33:57.590 --> 00:33:59.111
other forces at play.

00:34:02.000 --> 00:34:05.420
The impact of all that explosive
power, along with

00:34:05.420 --> 00:34:08.569
the influences of time and
climate, is everywhere.

00:34:11.510 --> 00:34:17.270
The landscape appears pummeled,
rocks bent and

00:34:17.270 --> 00:34:25.010
broken, shaped into strange
and contorted forms by

00:34:25.010 --> 00:34:29.489
tectonic collision
and erosion.

00:34:29.489 --> 00:34:33.000
It's no accident that Valley de
la Luna, or Valley of the

00:34:33.000 --> 00:34:37.090
Moon, is named after our lunar
cousin and is used as a

00:34:37.090 --> 00:34:38.610
training ground for
astronauts.

00:34:42.329 --> 00:34:45.860
But as so often on Nick's
journey, there are surprising

00:34:45.860 --> 00:34:47.230
twists to the geologic plot.

00:34:49.780 --> 00:34:54.100
The strangeness of this alien
landscape is made all the more

00:34:54.100 --> 00:34:56.340
dramatic by the presence
of salt.

00:35:09.446 --> 00:35:13.920
The salt beds are remnants of
ancient lakes long since

00:35:13.920 --> 00:35:15.460
evaporated.

00:35:15.460 --> 00:35:19.300
The deposits add yet another
texture to a landscape

00:35:19.300 --> 00:35:20.705
sculpted by wind.

00:35:30.570 --> 00:35:34.510
The Valley de la Luna is a
junction where vanished lakes

00:35:34.510 --> 00:35:38.110
meet the longest and highest
volcanic mountain chain

00:35:38.110 --> 00:35:39.920
anywhere on the planet.

00:35:39.920 --> 00:35:44.840
To a geologist like Nick, it's
a euphoric experience.

00:35:44.840 --> 00:35:47.410
These are some of the most
wonderful, beautiful

00:35:47.410 --> 00:35:50.510
landscapes I've seen anywhere
on planet Earth.

00:35:50.510 --> 00:35:51.680
They're just fantastic.

00:35:51.680 --> 00:35:54.520
And equally dramatic is the
plate tectonic story that

00:35:54.520 --> 00:35:56.430
these rocks tell us.

00:35:56.430 --> 00:35:59.280
Because about 100 kilometers
below us is the descending

00:35:59.280 --> 00:36:02.730
floor of the Pacific Ocean,
the so-called Nazca Plate.

00:36:02.730 --> 00:36:05.620
That's melting at those depths
under very high pressure and

00:36:05.620 --> 00:36:06.445
temperature.

00:36:06.445 --> 00:36:10.460
And the molten rock is rising
back to the surface as these

00:36:10.460 --> 00:36:14.580
giant volcanoes that we see in
the distance, making up the

00:36:14.580 --> 00:36:17.410
main range of the Andes.

00:36:17.410 --> 00:36:20.020
South America is moving
this way.

00:36:20.020 --> 00:36:22.800
The descending plate is
moving against it in

00:36:22.800 --> 00:36:24.170
the opposite direction.

00:36:24.170 --> 00:36:27.730
And these rocks here
are being tortured.

00:36:27.730 --> 00:36:30.050
And they're being folded
into these beautiful

00:36:30.050 --> 00:36:32.030
shapes that we see today.

00:36:32.030 --> 00:36:36.620
So they're literally in a vice
created by these opposing

00:36:36.620 --> 00:36:38.285
plates moving together.

00:36:50.290 --> 00:36:53.230
It's the driest desert
on the planet.

00:36:53.230 --> 00:36:56.750
And it's also the oldest.

00:36:56.750 --> 00:37:00.440
The scale and thickness of the
salt beds tell another more

00:37:00.440 --> 00:37:04.180
ancient story of climatic
cycles causing lakes to

00:37:04.180 --> 00:37:08.750
repeatedly fill and
then dry out.

00:37:08.750 --> 00:37:13.800
Salt has been mined in this area
for thousands of years.

00:37:13.800 --> 00:37:17.170
The remains and relics of
abandoned salt mines are a

00:37:17.170 --> 00:37:18.930
familiar character
in the landscape.

00:37:23.560 --> 00:37:25.340
That process is still at work.

00:37:30.040 --> 00:37:33.690
Salt continues to accumulate
in enormous evaporating

00:37:33.690 --> 00:37:37.380
basins, called solars, that
cover hundreds of square

00:37:37.380 --> 00:37:38.630
kilometers.

00:37:42.080 --> 00:37:43.922
This is a barren wasteland
today.

00:37:43.922 --> 00:37:46.720
But 10,000 years ago, it was
completely different.

00:37:46.720 --> 00:37:48.950
And we would've actually been
under water, under a fresh

00:37:48.950 --> 00:37:50.250
water lake.

00:37:50.250 --> 00:37:52.640
And the climate here would have
been much more humid.

00:37:52.640 --> 00:37:54.910
There would've been trees
growing around there.

00:37:54.910 --> 00:37:57.030
There would have been large
animals, people

00:37:57.030 --> 00:37:58.940
hunting those animals.

00:37:58.940 --> 00:37:59.850
And then it changed.

00:37:59.850 --> 00:38:03.200
About 8,000 years ago, it got to
the present condition where

00:38:03.200 --> 00:38:05.755
it's hyper arid, desert.

00:38:05.755 --> 00:38:08.020
And people began to
live in oases.

00:38:08.020 --> 00:38:09.520
You can see one behind me.

00:38:09.520 --> 00:38:11.800
People lived in close proximity
with animals.

00:38:11.800 --> 00:38:14.040
And that's the start
of domestication.

00:38:14.040 --> 00:38:17.860
So there was a profound effect
of climate change on society

00:38:17.860 --> 00:38:19.420
in these Andean countries.

00:38:26.160 --> 00:38:29.470
Just a few kilometers from the
Valley de la Luna and its

00:38:29.470 --> 00:38:32.980
adjoining solars, there are
other indicators of a

00:38:32.980 --> 00:38:34.610
weathered more fertile past.

00:38:40.410 --> 00:38:45.690
These deep canyons were
cut by ancient rivers.

00:38:45.690 --> 00:38:49.780
Ash beds within the steep canyon
walls document the 20

00:38:49.780 --> 00:38:52.510
million year history of the
growth of the Andes.

00:38:56.590 --> 00:39:00.070
Each chapter is embedded in
the rock and records the

00:39:00.070 --> 00:39:04.060
extraordinary violence of past
eruptions in which enormous

00:39:04.060 --> 00:39:09.580
volumes of ash were hurled
into the atmosphere.

00:39:09.580 --> 00:39:13.130
The canyons are also a vital
source of water and shade.

00:39:17.125 --> 00:39:21.160
The springs and adjoining oases
have, for millennia,

00:39:21.160 --> 00:39:25.150
provided a lifeline for the
Atacameno people, who have had

00:39:25.150 --> 00:39:27.460
to learn how to live
with periods of

00:39:27.460 --> 00:39:28.900
rapid climate change.

00:39:33.780 --> 00:39:35.480
They've also had to
live with the

00:39:35.480 --> 00:39:37.263
continuing threat of volcanoes.

00:39:42.650 --> 00:39:47.120
Local archaeology suggests that
the Atacamenos have been

00:39:47.120 --> 00:39:49.930
settled in the area
for 11,000 years.

00:39:56.080 --> 00:40:00.140
The original community of
Talabre lay directly below

00:40:00.140 --> 00:40:03.600
Lascar Volcano, the most active
in the Chilean Andes.

00:40:07.680 --> 00:40:12.030
Sotero Armella, a community
leader, grew up on the slopes

00:40:12.030 --> 00:40:16.350
of Lascar and witnessed many
eruptions before he and other

00:40:16.350 --> 00:40:21.350
villagers decided to move to
higher ground to avoid the

00:40:21.350 --> 00:40:24.820
ever increasing threat posed
by lava and ash flows.

00:40:27.420 --> 00:40:31.170
The narrowness of their escape
is captured in stone by the

00:40:31.170 --> 00:40:35.950
sheer size of the now cooled
lava flow that sits menacingly

00:40:35.950 --> 00:40:37.200
above the village.

00:40:41.070 --> 00:40:45.150
Lascar Volcano may be the
most dangerous in Chile.

00:40:45.150 --> 00:40:48.960
But it's simply one of many
clustered in a molten assembly

00:40:48.960 --> 00:40:52.835
that forms the Andes.

00:40:52.835 --> 00:40:57.740
Each volcano is fed by magma
rising from Pacific crust

00:40:57.740 --> 00:41:00.690
melting deep below.

00:41:00.690 --> 00:41:05.520
When cooled, magma gels into
rocks called andesite and

00:41:05.520 --> 00:41:09.500
rhyolite, which act like a
champagne cork, preventing the

00:41:09.500 --> 00:41:13.490
release of gases until the
buildup of pressure leads to a

00:41:13.490 --> 00:41:14.750
catastrophic eruption.

00:41:22.290 --> 00:41:25.625
As a geologist, I'm just blown
away by this view.

00:41:25.625 --> 00:41:27.090
It's so spectacular.

00:41:27.090 --> 00:41:29.280
We can see the lava flow
that's come down.

00:41:29.280 --> 00:41:32.680
We can see its cooled outer
edges and then the gray

00:41:32.680 --> 00:41:33.430
colored ash.

00:41:33.430 --> 00:41:36.860
And you can see fingers of the
ash flows that have traveled

00:41:36.860 --> 00:41:38.530
down the lava.

00:41:38.530 --> 00:41:40.320
It's preserved because
it's dry here.

00:41:40.320 --> 00:41:43.240
Everywhere else in the world
that would get eroded.

00:41:43.240 --> 00:41:46.990
You were working up here during
the 1993 eruption.

00:41:46.990 --> 00:41:49.110
What was it like
to be up here?

00:41:49.110 --> 00:41:56.270
[SPEAKING SPANISH]

00:41:56.270 --> 00:42:00.780
Back in April 1993, as luck
would have it, I had gone up

00:42:00.780 --> 00:42:04.050
the far side of the mountain
to get my sheep and llamas

00:42:04.050 --> 00:42:07.420
when I saw a mushroom-shaped
cloud.

00:42:07.420 --> 00:42:12.170
I put up my hands to shield
myself because, suddenly, lots

00:42:12.170 --> 00:42:14.730
of tiny stones begin to fall.

00:42:14.730 --> 00:42:17.940
At first they were very
light, like sponges.

00:42:17.940 --> 00:42:21.550
But then they started getting
heavier and heavier.

00:42:21.550 --> 00:42:25.270
And if one of those would
hit you, then forget it.

00:42:28.750 --> 00:42:31.620
Given such extremes of
temperature and seismic

00:42:31.620 --> 00:42:35.720
threat, local communities are
especially respectful of the

00:42:35.720 --> 00:42:38.650
earth and of the power
of volcanoes.

00:42:38.650 --> 00:42:42.190
And all across the Andes, there
are ceremonies that

00:42:42.190 --> 00:42:43.655
ritualize that awe.

00:42:47.010 --> 00:42:53.900
[SPEAKING SPANISH]

00:42:53.900 --> 00:42:56.390
The most important thing
you have to have for

00:42:56.390 --> 00:42:59.820
the offering is cocoa.

00:42:59.820 --> 00:43:02.610
We also bring corn,
flamingo feathers,

00:43:02.610 --> 00:43:04.950
incense, quinoa, all that.

00:43:04.950 --> 00:43:08.480
[SPEAKING SPANISH]

00:43:08.480 --> 00:43:11.350
And we make these little
llama figurines and

00:43:11.350 --> 00:43:13.080
offer those up too.

00:43:13.080 --> 00:43:14.980
That's what we bring.

00:43:14.980 --> 00:43:20.810
As far as alcohol goes, it
has got to be 90% proof.

00:43:20.810 --> 00:43:25.320
And then there is other drinks,
like beer and wine,

00:43:25.320 --> 00:43:27.440
food, that kind of thing.

00:43:37.200 --> 00:43:40.850
Further south in Patagonia,
the climate may be very

00:43:40.850 --> 00:43:44.510
different and the vegetation
more burden, but the deep

00:43:44.510 --> 00:43:47.230
subterranean forces
are the same.

00:43:52.880 --> 00:43:56.010
The coastal ferries still
stop at Chaiten.

00:43:56.010 --> 00:43:58.895
It's a transit point for local
people heading south.

00:44:06.990 --> 00:44:10.430
The few adventurous tourists
who stop by

00:44:10.430 --> 00:44:13.440
don't stay for long.

00:44:13.440 --> 00:44:18.680
In May 2008, the entire town
of Chaiten was evacuated

00:44:18.680 --> 00:44:22.310
shortly before being engulfed in
a wave of wet volcanic ash.

00:44:28.310 --> 00:44:29.310
Hola.

00:44:29.310 --> 00:44:31.250
Only a few people returned.

00:44:31.250 --> 00:44:31.880
Hi, how's it going?

00:44:31.880 --> 00:44:32.552
Good.

00:44:32.552 --> 00:44:33.590
Good to see you.

00:44:33.590 --> 00:44:38.360
Among them, Nicolas La Penna,
who runs a local travel agency

00:44:38.360 --> 00:44:39.630
and the post office.

00:44:39.630 --> 00:44:40.650
The volcano's over there.

00:44:40.650 --> 00:44:42.805
And [INAUDIBLE] a bit later.

00:44:42.805 --> 00:44:44.700
So you're still living here
after the mud flows?

00:44:44.700 --> 00:44:45.950
Of course.

00:44:54.250 --> 00:44:57.540
The scattered possessions speak
of the urgency of the

00:44:57.540 --> 00:45:06.050
threat, telling of the
sudden death of a

00:45:06.050 --> 00:45:07.340
once vibrant community.

00:45:11.180 --> 00:45:14.830
This whole eruption
was very quick.

00:45:14.830 --> 00:45:17.990
Basically, within two and a half
days, the volcano blew

00:45:17.990 --> 00:45:21.400
from the first signs of a tremor
before it blew at night

00:45:21.400 --> 00:45:24.340
on Thursday night, basically.

00:45:24.340 --> 00:45:27.050
And then Friday morning, when
we woke up, there was a 15

00:45:27.050 --> 00:45:30.550
kilometer plume over our
town, which went to

00:45:30.550 --> 00:45:32.240
30 kilometers, basically.

00:45:32.240 --> 00:45:34.270
What was the reaction
of the townsfolk?

00:45:34.270 --> 00:45:37.430
Complete surprise because many
people here had no idea there

00:45:37.430 --> 00:45:40.050
was a volcano right
next to the town.

00:45:40.050 --> 00:45:40.820
[INAUDIBLE]

00:45:40.820 --> 00:45:43.110
amazing forest, it's so dense.

00:45:43.110 --> 00:45:44.225
It was quite low.

00:45:44.225 --> 00:45:47.010
It's not a high volcano,
very well hidden.

00:45:47.010 --> 00:45:48.550
It blends in very well.

00:45:48.550 --> 00:45:52.220
Luckily, it was very good
weather that day.

00:45:52.220 --> 00:45:54.280
And the major ferries
were in the area.

00:45:54.280 --> 00:45:56.370
So the government basically
arranged everything.

00:45:56.370 --> 00:46:00.730
And we had the largest civilian
evacuation by ocean

00:46:00.730 --> 00:46:02.140
ever in the history
of our country.

00:46:02.140 --> 00:46:04.890
Something like 3,500
people in 24 hours

00:46:04.890 --> 00:46:07.330
left town by the ocean.

00:46:07.330 --> 00:46:09.640
And it was all full
of Navy boats.

00:46:09.640 --> 00:46:14.620
And since people here have we'll
say brothers and family

00:46:14.620 --> 00:46:18.180
in Chiloe, on the island out
there, even they came over,

00:46:18.180 --> 00:46:20.660
their family members who were
fishermen, and brought them

00:46:20.660 --> 00:46:24.360
all back, like family,
personally to safety.

00:46:24.360 --> 00:46:26.150
A very, very emotional
moment actually.

00:46:33.020 --> 00:46:37.060
Most volcanic eruptions are hot,
noisy, and fiery events.

00:46:37.060 --> 00:46:41.760
But volcanoes can also be stone
cold silent killers.

00:46:41.760 --> 00:46:45.230
What happens is, during a major
eruption, huge volumes

00:46:45.230 --> 00:46:48.840
of fine ash mantle the slopes
around the volcano.

00:46:48.840 --> 00:46:51.140
Weeks, months pass.

00:46:51.140 --> 00:46:55.360
All that ash, wetted by intense
rain, moves down

00:46:55.360 --> 00:46:58.730
valley as a lahar, a mud flow.

00:46:58.730 --> 00:47:02.170
And, as it happened in Chaiten,
buries the town under

00:47:02.170 --> 00:47:03.650
meters of ash.

00:47:08.870 --> 00:47:13.070
Further up the valley, dead
trees tell of hot gases

00:47:13.070 --> 00:47:15.765
expelled like a shock
wave down the slope.

00:47:26.630 --> 00:47:28.950
There's a real sense of danger
here, isn't there?

00:47:28.950 --> 00:47:30.470
We're looking up
to the volcano.

00:47:30.470 --> 00:47:33.750
I suppose every time that
collapses, all the red hot

00:47:33.750 --> 00:47:35.560
debris is just swept
through here.

00:47:35.560 --> 00:47:36.960
Oh, yeah.

00:47:36.960 --> 00:47:42.320
It's a very dangerous place
because Chaiten town is 10 or

00:47:42.320 --> 00:47:46.200
12 kilometers from the site.

00:47:46.200 --> 00:47:50.840
Dr. Luis Lara is Chile's
foremost volcano watcher and

00:47:50.840 --> 00:47:53.350
has been monitoring the
volcano since it's

00:47:53.350 --> 00:47:58.040
reawakening in 2008.

00:47:58.040 --> 00:48:02.650
Before that, radiocarbon dating
confirms that Chaiten

00:48:02.650 --> 00:48:06.650
hadn't erupted in more than
9,000 years and was presumed

00:48:06.650 --> 00:48:08.060
to be dormant.

00:48:08.060 --> 00:48:12.710
So this is the side slope for
the volcano collapsing, huge

00:48:12.710 --> 00:48:15.257
boulders and a lot
of ash debris.

00:48:15.257 --> 00:48:16.507
Yes.

00:48:23.580 --> 00:48:28.440
The volcano is still very
active, a smoking molten mass

00:48:28.440 --> 00:48:31.000
where the damage from
pyroclastic flows and

00:48:31.000 --> 00:48:32.570
explosions is shocking.

00:48:44.290 --> 00:48:48.560
The dome of the new volcano is
forcing its way up through the

00:48:48.560 --> 00:48:51.990
collapsed crater of the old.

00:48:51.990 --> 00:48:54.860
The growth of the gigantic
dome has been

00:48:54.860 --> 00:48:57.140
extraordinarily fast.

00:48:57.140 --> 00:48:58.875
And this is where
the danger lies.

00:49:05.928 --> 00:49:09.670
The entire dome here
was [INAUDIBLE]

00:49:09.670 --> 00:49:13.770
during the last eruption,
during the last year.

00:49:13.770 --> 00:49:17.545
So this volcano has yet to
have its first birthday?

00:49:17.545 --> 00:49:18.410
Yeah.

00:49:18.410 --> 00:49:19.660
That's amazing.

00:49:24.210 --> 00:49:28.620
There are close to 100 active
volcanoes in Chile, of which

00:49:28.620 --> 00:49:31.840
20 are thought to
be high risk.

00:49:31.840 --> 00:49:36.030
And it's Dr. Lara's unenviable
responsibility to monitor

00:49:36.030 --> 00:49:38.030
their health.

00:49:38.030 --> 00:49:42.694
He worries what the
future may bring.

00:49:42.694 --> 00:49:44.850
What's very impressive too is
the amount of ash that's

00:49:44.850 --> 00:49:48.948
trapped in this old crater.

00:49:48.948 --> 00:49:52.500
If these walls ever get broken,
the natural discharge

00:49:52.500 --> 00:49:53.580
is down slope.

00:49:53.580 --> 00:49:55.750
Be a huge disaster,
wouldn't there?

00:49:55.750 --> 00:50:01.440
Yeah, that's the big problem
with this kind of volcano.

00:50:01.440 --> 00:50:05.460
After the eruption, the lahar,
or mud flow, blocked the

00:50:05.460 --> 00:50:09.210
course of Chaiten's Blanco
River, causing it to flood the

00:50:09.210 --> 00:50:11.540
downtown streets with
water and silt.

00:50:16.310 --> 00:50:19.740
Despite all of these obstacles,
no power, a

00:50:19.740 --> 00:50:25.370
compromised water system, some
people are determined to stay.

00:50:25.370 --> 00:50:28.240
The government maintains that,
given the threat of new

00:50:28.240 --> 00:50:31.385
eruptions, the town
is best abandoned.

00:50:31.385 --> 00:50:35.580
But Nicolas thinks otherwise.

00:50:35.580 --> 00:50:37.360
What do you think of government
suggestions that

00:50:37.360 --> 00:50:41.200
the town effectively should be
killed and everybody moved

00:50:41.200 --> 00:50:41.660
somewhere else?

00:50:41.660 --> 00:50:43.400
Well, everyone has different
opinions.

00:50:43.400 --> 00:50:45.470
And every opinion is
worth listening to

00:50:45.470 --> 00:50:46.720
because there's reasons.

00:50:46.720 --> 00:50:51.830
If it was just a flood and say
our town was destroyed by a

00:50:51.830 --> 00:50:54.705
flood, in a week we come
back and fix it.

00:50:54.705 --> 00:50:58.500
But just like you were saying,
it's a volcano, a very maybe

00:50:58.500 --> 00:51:00.740
atypical volcano
here in Chile.

00:51:00.740 --> 00:51:01.460
And we don't know its

00:51:01.460 --> 00:51:03.930
characteristics, what it can do.

00:51:03.930 --> 00:51:05.590
So there's caution here too.

00:51:05.590 --> 00:51:08.475
So there's this fine line,
I think, here.

00:51:08.475 --> 00:51:11.285
But what would you do, Nick, if
you were in this situation?

00:51:11.285 --> 00:51:12.790
Would you just--

00:51:12.790 --> 00:51:13.590
As a geologist?

00:51:13.590 --> 00:51:15.380
It's a very dangerous
situation.

00:51:15.380 --> 00:51:16.250
Yes, yes.

00:51:16.250 --> 00:51:18.050
And it can only get worse.

00:51:18.050 --> 00:51:18.600
Yes.

00:51:18.600 --> 00:51:20.620
Lahar's already been
through the town.

00:51:20.620 --> 00:51:23.240
And what would happen if
a pyroclastic flow--

00:51:23.240 --> 00:51:24.105
Sure, it's dangerous.

00:51:24.105 --> 00:51:27.874
If the dome collapsed, what do
you think would happen here?

00:51:27.874 --> 00:51:30.109
I don't think it would be
a good scene at all.

00:51:30.109 --> 00:51:30.560
It wouldn't be good at all.

00:51:30.560 --> 00:51:31.570
People would be killed.

00:51:31.570 --> 00:51:32.820
Yes, it's dangerous.

00:51:45.470 --> 00:51:49.060
But to a geologist like Nick
Eyles, what's happening at

00:51:49.060 --> 00:51:53.510
Chaiten is a tiny part of the
big picture, the inevitable

00:51:53.510 --> 00:51:56.950
geologic journey of the Earth.

00:51:56.950 --> 00:51:59.410
The volcano may look
like a malevolent

00:51:59.410 --> 00:52:01.260
destructive slag heap.

00:52:01.260 --> 00:52:04.840
But it's part of a tectonic
process that is building new

00:52:04.840 --> 00:52:08.340
land, reconfiguring
our planet.

00:52:08.340 --> 00:52:11.580
It's been a dangerous journey
in many respects.

00:52:11.580 --> 00:52:14.490
Chaiten Volcano, this is what
we have here, is just one of

00:52:14.490 --> 00:52:16.720
thousands that dot
the extremities

00:52:16.720 --> 00:52:18.415
of the Pacific Rim.

00:52:18.415 --> 00:52:20.925
And there's about a billion
people that live on the Rim in

00:52:20.925 --> 00:52:24.025
constant fear of volcanic
eruptions, major earthquakes,

00:52:24.025 --> 00:52:26.550
and, of course, tsunamis,
tidal waves.

00:52:26.550 --> 00:52:30.200
But on a bigger geological
picture, we're looking at the

00:52:30.200 --> 00:52:32.640
transformation of the
Earth's surface.

00:52:32.640 --> 00:52:36.570
Because, slowly over time, the
floor of the Pacific Ocean is

00:52:36.570 --> 00:52:37.110
being destroyed.

00:52:37.110 --> 00:52:40.400
It's being subducted by being
pushed down below the

00:52:40.400 --> 00:52:42.375
surrounding land masses.

00:52:42.375 --> 00:52:46.000
Those land mass are slowly
moving inwards.

00:52:46.000 --> 00:52:49.220
And in about 120 million years
time, instead of a large

00:52:49.220 --> 00:52:51.010
ocean, there will be
a supercontinent.

00:53:03.130 --> 00:53:06.930
This process has been at work
since the birth of the planet

00:53:06.930 --> 00:53:12.380
billions of years in the past,
the continents enlarging at

00:53:12.380 --> 00:53:13.750
the expense of the oceans.

00:53:20.890 --> 00:53:32.990
Land and water locked in an
eternal collision, a grand

00:53:32.990 --> 00:53:36.970
battle that defines the course
of Earth history.

00:53:36.970 --> 00:54:15.070
[MUSIC PLAYING]