Episode 8 Blow Your Mind

TOGETHER: We are Dr Chris and Dr Xand van Tulleken.

And we're tracking down the most awesome,

incredible and epic things in the universe!

TOGETHER: Come with us and discover unbelievable things...

..that will blow your mind!

Blow Your Mind will be bringing you loads of top experts

and scientists to help you find out more about some amazing stuff.

From the Arctic to elephants, spaceships to sharks

and this week, it's all about ice.

Yes, frozen water.

So, hold on to your brains...

BOTH: Here's what's coming up!

Chris Packham has mighty polar bears in his sights,

but how many are there on the berg?

The team have a decision to make,

should they dive when polar bears are around?

We get a fascinating glimpse of the underside of an iceberg

and the weird stuff that lives there.

This morning we saw loads more amazing icy stuff

when the team finally made it onto the iceberg despite terrifying

polar bear danger.

Yeah, that was all amazing,

but I think my favourite bit was watching Andy fall on his behind.

Look.

Brilliant.

Chris, do you think he learned to break his fall

-when he was in the army?

-I'm sure he did learn that,

along with how to deal with people that take the mickey out of him.

Anyway, back to those polar bears.

Chris Packham was in his element on this expedition.

He's fascinated by polar bears

and how an iceberg can support a population of them.

I wondered that too. I mean, what do they eat?

There isn't anything growing there,

there doesn't seem to be much other wildlife around,

and there isn't a burger joint for a few thousand miles.

Maybe they eat ice-berg-ers.

Actually, Xand, they're more likely to eat you.

Here are the team of icy explorers you're going to meet today.

That's a bear.

Chris Packham, wildlife and nature expert.

Andy Torbet, extreme explorer and glacial diver.

Doug Allan, polar cameraman and glacial diver.

Peter Wadhams, ocean physicist and ice expert.

Chris wanted to study the wildlife on and around the berg.

He wanted to know how so many bears could survive on the iceberg.

There's a group of four seals here.

They are bear burgers, they are exactly what the bears are here for.

And the seals wouldn't be here unless there was seal food here.

Fish, krill, other crustaceans.

So, this iceberg is supporting an entire ecosystem.

That's very exciting. This is like a little lost world

we might be able to study in some detail.

Divers Doug and Andy were helping Chris investigate this lost world.

They were hoping to find out if the sea nearest the berg

supports more life than the rest of the ocean.

But their biggest concern at that moment

was the animal at the very top of the food chain.

-Hello, bear.

-He's on the move, he's seen you.

No way!

We could have a diving buddy, mate.

Let's just see what this bear does.

So, would you still dive, Andy, if it jumped in?

Erm, if he jumped in, I think that would be a bold move.

They have been recorded diving to 24 metres.

I wouldn't like to go in the water with him hanging around, no.

-Not a good sign.

-What's that?

It's usually what they do when they're a little bit, you know...

-Hungry?

-Yeah, getting ready to do something.

Look, he's looking. He's like, "Can I do it?"

It might be easier going from there.

-He's thinking about it.

-He is thinking.

Their sense of smell is absolutely astonishing,

so they'll smell people from some way away. Maybe they heard it, too.

And if it was just over the back of that rise,

the sound of the engines and them talking, it would have heard it.

And it's just come over.

Well, I say it has come over to have a look, it's just run off.

But then, the first time I saw Doug Allan,

I looked at him and I ran off as well!

So, to be quite honest with you, I'm not surprised.

Is this closed? OK.

Doug and Andy were now happy to dive, as the bear had gone.

We all hoped it didn't return and fancy a swim.

-Yep.

-Clear to go. Go when ready.

This place is stunning.

I've never seen walls of ice, the colours of blue and white.

It's absolutely beautiful.

From the surface,

this ice wall looks like tiny little dimples all across it,

it is the whole surface.

It looks like a golf ball.

I have to say, I don't think I would have jumped into that water at all.

It looks absolutely freezing

and there are polar bears prowling around.

I think I'd have been back in my cabin, tucked up safe and warm.

These guys are either very brave or very crazy.

I suspect probably a bit of both, Xand.

But doesn't it look stunning down there?

But imagine you're swimming around in that beautiful blue water

and suddenly, there's a splash above you and you look up

and there's a huge polar bear popped in, and he's looking for lunch.

Yeah, I think I would suddenly become a much, much faster swimmer.

Faster than a polar bear, I hope.

I can't wait to see what the guys found

down in that enchanting underwater world.

Well, they saw some really amazing-looking creatures

and came back with some rather interesting samples

for Chris Packham to examine.

Take a look at this.

Andy was amazed at how rich the waters were around the berg.

I can't believe how much plankton there is down here.

The size of these things.

And I was really amazed at just how weird these things looked.

What was that?

Is that a lion's mane?

These creatures formed part of an intricate food chain that feeds

the fish, that feeds the seals, that feeds the polar bears.

That's that sample, for Chris.

That should keep him happy.

OK, let's go up.

Moment of truth.

Whatever's in here, it's unlikely that I've ever seen it before.

And meeting a new animal is always very, very exciting.

Oh my goodness.

Look at them, they may as well be from another planet.

Absolutely fantastic.

Guys, come and look at this.

I know you've seen it already but you might be able to see it more

-clearly here than you were through your masks.

-Oh, yeah.

Aren't they beautiful?

-Who needs science-fiction when you've got this?

-Absolutely, I agree.

The common name for these things is sea gooseberries.

Look at the cilia going, can you see it?

It's covered in tiny beating cells, rippling there,

with the light going through them.

But frankly, it's nothing compared to this other thing down here.

The common name for these is sea angels.

This is very closely related to the slug

and the snail that you'll find in your back garden.

They're very bonny animals, very handsome.

Is that his gut that you can see?

It is his gut and those beating wings are its modified foot.

Because it's a mollusc

and that equates to the foot,

the bit that a snail or a slug moves around on.

And in this animal, it has divided it into two

and it uses them to literally fly through the water.

-And I love the fact it is see-through.

-Yeah.

I've got to tell you, this is the highlight of my entire trip so far.

I've seen two animals the likes of which I've never seen before.

They are extraordinary, they are beautiful

and obviously very important in the ecosystem around the ice.

Get your suits back on, get these two back in.

We're done with these, and I want some more.

These little creatures really do look like something

from another planet, don't they?

It's almost like they have Christmas tree lights all around them.

True, but what's really interesting is that there seems to be

no shortage of life around the berg.

The plankton that we just saw are food for fish that then

become food for seals, that then become food for the polar bears.

That's why we call it a food chain, because it's all linked.

Oh, I get it. So, if you lose one link in the chain,

-it's disastrous for every link after that?

-Exactly.

So, the number of bears there are will be dependent

on the number of these little creatures there are

-swimming around the berg.

-Absolutely.

OK, so how many polar bears are on the berg?

Well, I'm glad you asked because that gives us

an excuse to watch this brilliant bit of film

that Chris Packham made when we were there.

Check this out.

Throughout the expedition, we faced a constant threat from polar bears.

Although they made life difficult,

Chris was completely fascinated by them.

He wanted to work out how many bears the berg could support,

so he decided to do a count of how many were living there.

We've got the chopper.

Now we're going to go out and take a look round.

I'm really excited to be a part of it.

I've waited a long time to be able to do this,

so I'm hoping we'll find some bears.

So far, they'd only been able to see bears

around the edge of the iceberg.

But there was also a gigantic inland area, 40 square kilometres of ice,

about the same as 5,000 football pitches.

By flying over all of this ice,

Chris would get a more accurate estimate

of how many bears lived there.

We've got one just down here now. It's on the side of a small lake.

A single adult bear.

It's cream-coloured against the white snow, which means that we can see it.

I'm just going to grab a couple of shots of it with my still camera.

The presence of even more bears, which Chris saw on his flight,

had confirmed the bears seen at the edge of the berg must have

just been a small part of the population.

So, in total, looking at the circumference,

which was around 27km, and how frequently we saw them,

I'd go for mid-teens to 20 bears on this berg.

What there is there for them is a security

and I think they are taking advantage of that.

So I think they are hanging out on this berg, basically,

to stay safe and just wait for that sea ice to come back in,

and then they can all charge out and hunt.

Chris' count of the bears was really valuable

because it was the first time that a population of polar bears had

been counted on one of these big bergs.

With the Arctic spring temperatures becoming warmer,

there was far less sea ice,

which was making it harder for polar bears to survive,

which is why they use the megaberg to keep themselves safe.

Sometimes it's hard to believe they're such fierce hunters,

because they just look so cute and cuddly, I want to give them a hug.

But I don't think it's a cuddle that Mr Bear would be looking for

-if you bumped into him on your way home across an iceberg.

-Fair enough.

So, we have seen what Chris Packham was up to with the wildlife.

What else was happening on the berg?

Well, the scientists were trying to work out what happens to bergs

once they're out at sea and they hope to learn

from this berg about the forces that eventually lead to it disappearing.

Like ice melting in a glass of water?

Well, yes, like that, but it's also more complicated than that.

Because there are all sorts of other things at work on an iceberg

like waves, wind and current.

And so they wanted to find out

what effects these forces have on the berg.

-So, you need to change the scale...

-It's much more if it's above that.

The scientists had two different ideas about what was helping

to slowly break up the berg.

The melt team believed that sea water was melting it over time.

So, that's the main...

The wave team thought the ocean's waves were rocking

and bending the ice, snapping it into smaller chunks.

Waves do have a big effect and we need to understand that

relationship between waves and icebergs as part

of understanding the relationship between waves and ice in general.

Aha! It's the battle of the glaciologists.

Two competing theories about the fate of the berg.

Only one can triumph. So, come on, Chris, which team do you support?

I support them both, Xand.

Science is like that, competing theories are good.

It makes everyone think much harder to work stuff out.

I'd be interested to see how they get on, then.

I reckon there is probably a bit of truth in both camps.

Well, you're going to have to wait a bit to find out, though,

because we're out of time again.

Why are you teasing us, showing us that clip, then?

I wasn't teasing you.

I just wanted you to see how fascinating it is that although they

are really clever scientists, they don't all agree on the same thing.

And to show you there is lots more interesting stuff to come.

So, remember to join us later

to find out more stuff that will blow your mind.