Episode 4 Blow Your Mind

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

-And we're tracking down the most awesome...

-Incredible...

BOTH: And epic things in the universe!

BOTH: 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.

-Here's what's coming up.

From the enormous to the tiny,

I take on the smallest inhabitants of the glacier - mosquitoes.

And we find out a huge surprise about sea temperature

at the bottom of the glacier.

And, we see a mammoth new mega-berg being created,

140 million tonnes of ice.

Another load of cracking stuff for us to see today, Chris.

And I, for one, can't wait. I've already seen so many exciting things!

Those spectacular holes, the moulins, and Andy discovering all those

massive ice tunnels below the moulins.

And it was really scary when the tunnel roof collapsed,

he doesn't have an easy time of it, does he, Andy?

Well, he's an explorer, Xand.

That's the job description, that's how it got to go,

and that's why we went to Greenland in the first place.

To try and find out more about the glaciers and the icebergs.

And the team were learning things the whole time, but we weren't just

learning up on the glacier, there was plenty happening in the sea,

as well.

There were over 20 experts involved in the expedition.

The main team members in today's show are...

Chris Packham. Wildlife and nature expert.

Expedition doctor, and all round brave guy, me.

Andy Torbet, extreme explorer and glacial diver.

Alun Hubbard and Nolwenn Chauche, glaciologists and ice experts.

The team were aboard the research ship Gambo,

carrying out an exciting experiment.

Alun had some clever equipment, called Side Scanning Sonar,

which would help map the front of the glacier.

That's the actual equipment that sends out the sound wave,

the acoustic wave, which bounces off the glacier and we pick it up.

So, Alun fired sound signals at the glacier,

which pinged back to his computer.

It then converted those signals into a map of what the ice will

look like underwater.

But, to get a good scan, the research boat needed to sail

up close to the cliff, near to where the icebergs could break off.

RUMBLING

-Just a little bit.

-Just a little bit.

The results from this experiment could be ground-breaking.

But, before they could complete the scan,

the giant glacier reminded them who's boss.

What happened?

We had a carving event, and what it triggered off was a large

lump from under the water that shot up really high out of the water.

That is quite a minor carving event, I hate to say, Chris.

Whoa! How scary is that?

And there's no way of knowing

when these things are going to happen, is there?

That's exactly right.

They were really lucky on that occasion because they had

just gone past the area where that had happened just minutes before.

Did they still manage to get the results of their survey?

I bet they didn't. I bet they chickened out.

Xand, explorers like me know no fear.

After the experiences I had in Greenland,

nothing can surprise, shock or frighten me.

Boo!

Wow, it's true.

Back on the Gambo, the fearless experts were still out at sea,

analysing the results as they came in.

What can you see there?

OK, so we've got the glacier from here on the sea bed here.

-That's the boat, here.

-Yeah.

The floor at the moment is about 400 metres here.

So, we're looking at cliffs outside that are about 80 to 100 metres

tall at their highest, but there's 400 metres beneath the water.

Yeah, at least, yeah.

So, the scan showed that there was four times as much

ice below the water as above it.

But it also revealed something else -

the base of the ice wall was undercut, which meant it was

cut back into the glacier so the top was unsupported and overhanging.

How deep is that undercut?

At the moment, it's about 150 metres.

-150 metres?

-At least.

So, the undercut went back 150 metres, which is

longer than a football pitch,

and all the ice hanging above it was unsupported and unstable,

which could explain why it collapses into the sea so often.

-That is amazing, how much ice is below the water.

-Exactly, Xand.

And the undercut is interesting. Let me show you, using this iceberg.

-Now, hold that.

-This is an iced cake.

-No, Xand, it's an iceberg.

Now, the water, at the bottom near the sea bed,

erodes the iceberg like this.

Melting it gradually until this top part here forms an overhang,

weighing sometimes thousands or millions of tonnes.

And eventually, this bit just breaks off and forms a new berg.

Chris, there are now millions of tonnes of cake all over the floor!

-I was going to eat that!

-Yeah, sorry about that.

I'm afraid the rest of the cake is mine, as well.

'Nice, Xand.'

Now the team knew of the massive undercut in the glacier,

they wanted to investigate why it formed.

Nolwenn thought the temperature of the ocean may be one of the

reasons, so he lowered a temperature measuring probe to the sea bed.

And the temperature readings were astonishing.

-On the surface we get relatively warm water.

-Yeah.

It's cooling down pretty quickly and, after that,

it's warming as we go further down. With a maximum at 2.7 degrees.

And all this water, from 400 metres to the bottom at 800,

is at 2.4 degrees.

These results were really surprising,

the water on the sea bed was really warm, well above freezing.

This warmer water melts the glacier at its base, forming the undercut.

-Hm, top data.

-Yeah. Really great, yeah.

Now THAT is mind-blowing.

That the sea is actually warmer the further down you go.

And that is helping to create the undercut of the ice cliff

underwater, which is what makes the bergs break off?

That's exactly right, you were paying attention, Xand. For once.

But you know, it's not just massive things, like ice cliffs

and polar bears, that you need to worry about in Greenland.

-INSECT BUZZING

-There are some really tiny things that can hurt you, too.

We came to Greenland prepared for the massive dangers

the glacier would throw at us.

But nobody expected a much smaller, more annoying threat - mosquitoes.

MOSQUITOES BUZZ

During the short Arctic summer,

the mosquitoes survive on nectar from plants.

But they prefer to drink the blood of mammals.

And that's where we came in.

Handily, I'm an expert in tropical medicine,

but I didn't expect to be using my tropical skills in Greenland.

'I decided to find out

'if some people were more attractive to the mosquitoes than others.'

Good news, everyone.

I've developed another experiment, it's going to be painful,

and I need a volunteer.

'The team volunteered brave extreme ice explorer

'Andy Torbet to join me.'

I hate you.

'Who, as you can see, was less than happy.'

We're going to sit here with our shirts off,

no insect repellent on, and see who gets more bites.

-I like straightforward experimental protocols.

-You're a genius.

So, the person bitten the most would have produced the most

chemicals attractive to mosquitoes.

So, obviously, there is a competitive element to this.

Whoever gets bitten more loses, blatantly.

So, what they'll be doing is smelling us.

And they're, first of all, attracted to our carbon dioxide,

and they'll be following the carbon dioxide trail in.

And when they get close they start to smell the sweat and body odour.

Some people have chemicals in their sweat that the mosquitoes

really like.

-Ah!

-There you are.

They're all females. And this one is swollen with blood.

Ugh! Ugh! Ugh!

-Oh, gross!

-I know, it was awful. I was there.

No, I'm not talking about that.

I'm saying, is there anything worse than seeing your twin brother

bare chested and scratching himself? Well, it turns out there is.

It's seeing your twin brother bare chested and scratching himself,

on TV!

MOBILE RINGS

Hold on. Hello? No, Mum, I can't speak at the moment. I'm on TV.

Apparently, she knows I'm on TV. Yes, Mum. Yes, yeah.

Look, I have to go. Yes, sorry. Sorry.

I'm guessing she didn't like the Tarzan impersonation either?

-She said she's told me before...

-BOTH: Keep your shirt on in public.

But the thing is, we needed to see what happened and do the experiment.

All right. And we need to see if anything good will come out of this,

like you putting your shirt back on!

There is absolutely nothing on you. So, how're we doing?

-I've got one there.

-Two. Three.

-Four.

-Four.

-Five.

-Five. My go.

Eight, nine, ten, 11, 12, 13, 14, 15, 16, 17.

So, why have you got 32 on your right side

and only two on your left side?

I think it's the downwind side.

They're attracted to the CO2 from there,

and they're not getting blown away.

'So, at the end of our highly technical mosquito experiment,

'Andy had around five bites, and I had around 34.'

So, they're more attracted to you, you're getting bitten more.

My sweat is more appealing to mosquitoes than yours

so all I've won is more mosquito bites.

I think we learned a few interesting things there about mosquitoes.

I think you might have proved a few other things, as well.

Like, how Mum was right to tell you to keep your shirt on in public.

-MOBILE TEXT ALERT

-Hold on. I knew I shouldn't have brought this phone into the studio.

-Admiring fan, is it?

-Well, sort of.

-Is it Mum again? Give me that!

"Christopher, why can't behave more like your darling brother,

"Xand, who knows when to keep his shirt on." I don't think she's happy.

Your impression of Mum is frighteningly accurate.

But she obviously hasn't heard about the time when you went...

Moving right along.

Now, I'm sure if Chris could talk right now

he would tell you that this next bit is about something else completely

awesome, so don't go anywhere, stay in that chair and prepare yourself.

Mmmph. Thank you, Xand.

The results the team gathered had been

crucial in understanding how the glaciers move and,

when the ice front reaches the sea, the base melts,

causing an overhang that breaks off, forming icebergs.

But to do these experiments, Chris Packham

and the team had to sail the research boat, the Gambo,

dangerously close to the huge, unstable ice front.

And suddenly, the worst happened.

What are we doing, Norman? Are we out of here?

Yeah, yeah, we're escaping.

Wow, look at that!

A HUGE chunk of ice split away from the glacier.

Compared to any ice carvings we'd seen so far, this was gigantic.

That is a major carving event. Look at the wave! Look at the wave!

Look at the wave!

-Is that going to be a monster?

-It looks big.

It was massive on the front.

It hasn't reached us yet, but it looks really big.

'Up at base camp, we were seriously worried about the crew on the boat.'

The Gambo, where is the Gambo? They were right down there next to it.

This was the birth of a mega-berg.

140 million tonnes of ice, travelling

so fast it could easily swamp the Gambo.

Thankfully, the crew managed to steer themselves

out of the path of this new, massive mega-berg, and away to safety.

Now that would... BOTH: Blow Your Mind!

That is just the most incredible thing I have ever seen.

And I just saw it on telly, I mean, you were actually there!

-It was just completely awesome.

-We have to see that again, Chris.

-I bet everyone at home wants to watch a replay, too.

-Absolutely.

Who wouldn't? Guys, run the replay.

Whoa! That was absolutely massive.

Look at that wall of water, it was an incredible sight.

-I am, literally, speechless!

-No you're not, you just said that.

-All right. It was awesome.

-I know, I was there.

-This has just been great.

I mean, I learned so much about icebergs and glaciers.

And I've learned not to take my shirt off

when there are TV cameras around.

Well, I think Mum is going to be extremely pleased.

Well, there are loads more incredible things to show you.

So, join us next time so we can...

BOTH: Blow Your Mind!