How the Earth Was Made

>> Earth. A 4.5-billion-year-

old planet, still evolving.

As continents shift and clash,

volcanoes erupt, and glaciers

grow and recede, the Earth's

crust is carved in numerous

and fascinating ways, leaving

a trail of geological

mysteries behind.

In this episode, Krakatoa, one

of the deadliest volcanoes in

the world.

More than 100 years ago, it

erupted with such devastating

fury that it wiped itself off

the face of the Earth.

In the process, it sent out

the loudest sound in recorded

history and killed more than

36,000 people. And now, this

deadly volcanic beast is back.

Geologists investigate one of

the world's fastest-growing

volcanoes to hunt for clues

that will tell them if, and

when, Krakatoa will explode

once again with the same

cataclysmic force.

As they prize apart the rocks,

the answers they find will be

another piece of the puzzle of

How the Earth Was Made.

S01x03 Krakatoa Original Air Date on February 24, 2009

Krakatoa is one of the most

dangerous volcanoes the world

has ever seen. When it

exploded apart in 1883, the

blast was heard over nearly

ten per cent of the Earth's

surface. It was a worldwide

clarion call, announcing the

awesome power of volcanoes.

The site of this monstrous

eruption lies between the

Indonesian islands of Java and

Sumatra, in a channel known as

the Sunda Straits.

Today, a new volcano has

staked its claim in exactly

the same spot. It's called

Anak Krakatau, meaning "the

child of Krakatoa."

Right now, it's in the middle

of a new and extremely

dangerous phase.

Dr. Charles Mandeville

traveled here to see if the

child will one day be as

deadly as its parent--to see

if history is about to repeat

itself. The stakes are high.

At risk now are the one

million people of Java and

Sumatra who live within 50

miles of the volcano.

>> Oh, wow. Look at that.

We've got a little explosion

going on. I've kind of been

following this from the

internet, from my office, but

it's actually good to kind of

see the thing, uh, live again.

I've noticed in coming here

that, uh, the volcano itself

has grown possibly as much as

250 to 300 feet since the last

time I've actually stood on

its crater, back in 1990.

>> Growing at a rate of 12 feet

a year, the 1,033-foot volcano

is both one of the

fastest-growing and youngest

volcanoes on the planet.

This remarkable footage shows

its explosive birth in June

1927, when it first broke

through the sea floor and

erupted out of the water.

Its rapid growth is clear

evidence that this new volcano

is extremely active, but will

it be as deadly as its parent?

These eruptions are always

accompanied by a series of

ground-shaking tremors.

For geologists, these small

earthquakes are evidence that

this volcano is entering a

more destructive phase.

Seismographs have been buried

deep on Anak's slopes to

record this underground

activity. But these small

quakes are not the only sign

of a dangerously active

volcano. A more subtle clue is

right beneath Mandeville's

feet.

>> Black sand beaches are very

common in volcanic areas.

Uh, the minerals and the glass

fragments that comprise the

ash that the volcano erupts is

typically dark charcoal gray

colored, and usually, these

materials don't stand up to

weathering over long

protracted periods of geologic

time, but you find them in

relatively fresh, pristine

form when you are near an

active volcano.

>> Anak Krakatau is rarely

completely quiet, but the

level of activity in 2008

shows that the volcano has

become unusually violent.

To discover just how much of a

threat it could pose in the

near future, volcano

detectives must turn to their

history books to learn what

made its parent Krakatoa so

destructive. This is a story

that has fascinated geologists

for over a century.

>> What got me switched on to

volcanology was the 1883

eruption, I learned about this

at school, and I remember

thinking how incredible that

an island could just blow

itself into oblivion. You

know, what was going on?

What was that all about?

What was special? You know,

how does that happen? And

could it happen again

elsewhere on Earth?

>> Before it exploded in 1883,

Krakatoa was an uninhabited

island with three jagged

peaks, covered in lush

vegetation. It was part of the

Dutch East Indies, a thriving,

bustling hub of international

trade. Indonesia's wealth of

minerals and spices attracted

many Western traders,

journalists and geologists.

Their reports provide

first-hand accounts of what

happened before and during

Krakatoa's deadly and shocking

eruption. There had been no

hint of volcanic activity in

anyone's memory. No one had a

clue that Krakatoa was about

to blow. Beneath its green and

placid surface, Krakatoa was a

time bomb waiting to explode.

>> So the first idea the

locals would have got that

anything was--anything strange

was happening on their island

would have been in May 1883.

Earthquakes, earth tremors.

>> These tremors reached as

far as the capital Batavia,

more than 100 miles away.

Few suspected that the island

of Krakatoa, seen on the

distant horizon, was to blame,

and that these earthquakes

were the first clue to its

deadly potential.

Then, on May 20th, 1883,

Krakatoa announced that it was

no mere island.

One of Krakatoa's three peaks

exploded with extreme force,

shooting a plume of ash

hundreds of feet into the air.

But after these initial

fireworks, the activity

appeared to cease. The local

population breathed a sigh of

relief. Thinking it safe, the

governor of the Dutch East

Indies sent a research party