Hello. This is 6 Minute English
from BBC Learning English.
I'm Sam. And I'm Neil. The 20th of
July 1969 was a big day in
history. Do you know why, Sam? Wasn't that when Neil Armstrong
first set foot on the Moon? Right. But it's often forgotten
that some of the most dramatic
photographs taken on the
Apollo space mission weren't
of the Moon at all - they
were of Earth. It wasn't
until we went to the Moon
that we really saw the
size of Earth's oceans
and named ourselves,
the Blue Planet. Despite most of our planet
being covered by water,
the ocean remains of place
of unexplored mystery, of
sea monsters like
Moby Dick, and the Kraken.
In this programme, we'll
be diving into the
deep seas, seeing some
of its strange sights,
and as usual, learning
some related vocabulary too. But before that I have a
question for you, Sam.
You were right when you
said that most of the
Earth is covered
by water. But do you
know exactly how much
of the Earth's surface
is ocean? Is it: a) 50 percent?
b) 60 percent? or, c) 70 percent?
Well, it is called
the Blue Planet, so
I ll say c) 70 percent. OK. I'll reveal the answer
later in the programme.
The first thing to say
about the deep ocean is
that the rules of life
down there are very
different from the rules
on land. Sunlight
cannot reach the very
bottom of the ocean,
a place between two and
three kilometres down
known as the 'deep abyss',
so it totally dark and
extremely cold. And the
weight of water creates
massive amounts of pressure. This extreme environment is
stranger than fiction, and
home to things which seem
to be from another planet;
things like hydrothermal
vents - volcanic hot springs
which break through the
ocean floor. Oceanographer,
Alex Rogers, joined an
expedition which discovered
a hydrothermal vent in
the ocean near Antarctica.
He told his story to BBC
World Service programme,
Discovery: Well, the first problem is
actually finding them
because they cover a very
small area so it's
literally like trying to
find a needle in a haystack,
but when you do come across
them, I mean, the deep ocean
is food limited, so life
is quite thin on the ground,
and then suddenly your
camera just stumbles into
this area where there is
just abundant life all
over the sea floor and
around these vents. Alex says that finding
these small thermal vents
at the bottom of the ocean
is like finding a needle
in a haystack, an idiom
meaning almost impossible
to find because the area
you have to search
is so large. Because there's no sunlight
on the ocean floor, it's
hard for plants and
creatures to survive, so
forms of life are thin
on the ground - there are
only a few of them. Alex
cannot find anything to film
with his camera, until
suddenly he nears the vent
and sees plants and animals
everywhere. Here, there is
more than enough, or
abundant life. To picture a hydrothermal
vent, imagine an underwater
volcano. Billowing clouds of
what looks like smoke
heat the seawater to a
temperature of 386 degrees C.
This creates a warm
environment of all kinds
of weird and wonderful
creatures, including vent
mussels, tube worms and
blind 'yeti crabs', so
called because of their
hairy claws, some of
which get cooked because
the water is so hot. What's amazing is that
while these vents may be
as old as Earth itself,
they were only discovered
in the 1970s. So, are
there more mysteries hiding
in the deep ocean? That's
the question BBC World
Service's, Discovery, asked
marine biologist, Kerry Howell.
Here's what she said. I have absolutely no doubt
that there is plenty more to
discover down there. It's really
vast, I mean it's quite hard to
get your head around how vast
the deep sea is, and it is
most of our planet. So... and
we've barely scratched the
surface of exploration of this
unique environment, and if
you think that vents were
only discovered in the 70s,
you know, there's great
potential for a lot else
to come, I think. We've only
been exploring this
environment for the last
150 years, I mean. Before
that we didn't think
there was any life down
there at all. So, it's
a very young science is
Deep Sea biology. And so,
there's... yeah, there's
a lot more to discover.
I have no doubt. In terms of ocean
exploration Kerry thinks
we've only scratched the
surface - found out a
little bit about something,
but not enough to
fully understand it. That's because the ocean
is vast - extremely big.
So vast, in fact, that it's
hard to get your head
around it, or difficult
to really understand. But how vast, exactly,
Sam? In my question I asked
how much of the Earth's
surface is covered by water.
And I said it was c) 70 percent. Which was the correct answer!
Well, 71 percent to be precise,
but either way it's hard to
get your head around or
difficult to fully understand. OK, we'd better recap the
other vocabulary too,
starting with the idiom,
finding a needle in a haystack
meaning that something is
almost impossible to find
because you have to
search so widely for it. If something is thin on the
ground, there's very little
of it, but if it's abundant,
there's plenty or
more than enough. When you only scratch the
surface, you find out a
little about something,
but not enough to
fully understand it. And finally, vast is
another way of saying
extremely large,
huge or enormous. Unlike the vast oceans,
our time is limited to
just six minutes and
it's up. So, join us
again soon for more
amazing adventures and,
of course, useful
vocabulary, here at 6 Minute
English. Goodbye for now! Goodbye!