Frozen Planet.S1.E7 ∙ On Thin Ice
Category
📺
TVTranscript
00:00I'm going to play a little bit of it and then I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and I'm going to play a little bit of it and
00:30This white wilderness, this emptiness is the North Pole. I'm standing in the middle
00:38of a frozen ocean. Beneath my feet and for over 500 miles in every direction
00:47there are several meters of ice. But something significant is likely to happen here at the North
00:54Pole soon. Chances are that sometime within the next few decades, perhaps even as soon as 2020,
01:04there will be open water here for the first time in human recorded history.
01:12The Arctic and Antarctic are changing.
01:16Enormous masses of ice that have been frozen for thousands of years
01:20are breaking apart and melting away.
01:36Ice scientists are going to extremes to find out exactly what's going on. For them these are
01:44exciting times but the transformation that's being seen here will be felt far beyond.
01:50The polar wilderness.
01:58In this program I'll be trying to understand what these changes mean
02:03not just to the wildlife and people that live around the poles but to the whole planet.
02:21I'm starting my journey in the Arctic, the far north of our planet.
02:29It's still very cold outside by most people's standards but the Arctic
02:33has been warming fast. Twice as fast as the rest of our planet.
02:39My first mission is to find out what effect that's having on the animals. Although first
02:46we have to find them. It's April in Svalbard.
02:50We're a thousand miles north the Arctic Circle in search of the region's top predator.
03:05We need to travel away from the land and out over the frozen sea.
03:16There's some tracks right beneath us.
03:26Over there.
03:31I'm with a Norwegian team which is giving the polar bears of Svalbard their yearly health check.
03:40She's under us now. I'll come around for a clean shot.
03:46The team works together to give an anesthetic injection from a dart gun
03:55without hurting the bear. It takes tremendous skill.
04:05Ah, you've got it.
04:06I'll just back up until she's asleep.
04:24Nobody likes to see a magnificent animal like a polar bear lolling about unconscious on the ice.
04:31But it's only by darting them in this way and keeping check on them year after year
04:37that we can be sure we know what is happening to them and the population of polar bears as a whole.
04:44Over the last 30 years many teams have been seeing the condition of their local bears
04:49deteriorate. Although not every bear is suffering.
05:02How much? 96 here. 102 here. 197. Is that good? It's not too bad. It's a bit above average.
05:17So she's bearing a good condition for Svalbard to be.
05:20The trouble is that if this was underweight she would be in trouble.
05:27Not only from our own point of view but from the point of view of our cubs.
05:31Because an underweight female gives birth to underweight cubs and underweight cubs
05:36have a great problem of surviving their difficult first year in these circumstances.
05:44It can be minus 40 degrees centigrade when polar bear cubs emerge
05:49at the start of the Arctic spring from their dens where they were born.
06:06This mother hasn't eaten for half a year.
06:11She and her cubs need to fatten up fast over the next few months
06:15and their chances of survival depend on what's happening beneath their feet.
06:20These polar bears aren't walking on land. They're roaming across the frozen surface of the sea.
06:33And the bear's food lives under the ice.
06:50Ring seals are hunted by polar bears.
06:55In fact in some parts polar bears eat almost nothing else.
07:01So it's fairly understandable that this mother ring seal
07:08who's looking at me now should be a little apprehensive.
07:13That pup of hers is only about three or four days old.
07:19And the pup won't be able to swim for another two or three days.
07:26Seals have good reason to be nervous around their holes.
07:30They need the holes to breathe when the sea is frozen, but this makes them easy to find.
07:36Polar bears can sniff out seal holes even if they're covered in snow.
07:48Spring is the best hunting season.
07:53This mother's found a food store under the snow that was probably made by an Arctic fox.
08:00It's a good sign that she's found a food store.
08:05It's a time of plenty now, but the bear family need to make the best of it
08:09because the good times are about to come to an end.
08:18As the weather warms, the ice beneath the bear's feet starts to break up and then melt.
08:24And as the ice dwindles, so do the bear's chances of a successful hunt.
08:29Most of the ice is lost over the shallow coastal waters, where most of the seals live.
08:40It's now summer and these bears have a choice.
08:44Take their chances on the shrinking ice flows or make for the safety of the land.
08:54It's a case of survival.
08:57It's a case of sink or swim.
09:06Bears have always gone hungry in the summer,
09:09but the length of time when there's enough ice for them to go hunting
09:12is getting shorter and shorter across much of the Arctic.
09:19This is hitting cubs particularly hard,
09:22particularly hard,
09:24because they can't survive for as long without feeding as their mother.
09:30Cubs that were born underweight are at the greatest risk.
09:44This mother and her cubs may well not get another meal
09:47until the sea freezes again in winter.
09:50There's not much to eat on land,
09:53and the fact is that the longer the cubs have to wait until the ice returns,
09:57the more likely they are to die.
10:03Longer summers with no ice are probably the main reason
10:06why many polar bear populations are dropping.
10:10To help monitor bears into the future,
10:13this female is being fitted with a radio collar to track her movements.
10:21It's an extraordinary sensation to be so close to such a powerful animal.
10:27With luck, carrying that collar,
10:30she will have more than enough time to be able to move around.
10:35With luck, carrying that collar,
10:38she will have more years to go yet
10:42and be telling us a great deal about herself
10:46and the rest of the race of polar bears
10:49as they face this very uncertain future.
11:00The future of the ice cover on the sea isn't just an issue for the animals.
11:05It's a big concern for the people who live in the Arctic
11:08and travel across the ice every day.
11:19David Ikakolu is an Inuit from the village of Clyde River
11:24in the Canadian far north.
11:32There are very few roads up here,
11:33so David and his community, like most Inuit people,
11:37have always travelled across the frozen sea.
11:42Dog sleds are the safest way to get around
11:45because the dogs feel thin ice underfoot
11:48and won't lead travellers into trouble.
11:52Old-timers like David know the ice
11:54as well as we know the streets in our local neighbourhood.
11:57Every spring, cracks have always formed in the same places at the same time.
12:04It's going to be big very soon.
12:07After two weeks, maybe.
12:10We'll be more open.
12:14But now, cracks are appearing where they never did before,
12:18so David and his friend, Lai Miki, have taken on a new job.
12:22They are using special GPS units
12:24to record the position of new cracks or weak ice.
12:31These findings will be used by locals for their own safety,
12:34but they're also being studied by ice scientists
12:37who want to predict how the ice will change in years to come.
12:41The Inuit are keen to know what the future holds too
12:44because they've seen with their own eyes
12:47the changes that the scientists have seen from space.
12:52This satellite photo from 1980
12:54shows the Arctic Ocean at the end of the summer
12:57with the ice on the horizon.
12:58It's a picture of the Arctic Ocean
13:01and the ice on the horizon.
13:02It's a picture of the Arctic Ocean
13:04and the ice on the horizon.
13:06It's a picture of the Arctic Ocean
13:08and the ice on the horizon.
13:10It's a picture of the Arctic Ocean
13:12at the end of the summer when ice cover is at its minimum.
13:16Since then, there's been a 30% drop in the area covered by ice.
13:24But these images can't tell us about changes
13:27to the most important factor,
13:30the thickness of the ice.
13:35Measuring thickness across the whole ocean
13:38was beyond scientists for many years
13:40and was a limited source.
13:58The Arctic Ocean is of huge military importance
14:02as it's the shortest route between North America and Russia.
14:11Since the late 1950s, British, US and Russian submarines
14:15have been patrolling the Arctic Ocean.
14:21But as well as looking out for enemy activity,
14:24they've also been measuring the thickness of the ice,
14:26critical when looking for a place to surface.
14:33When scientists got permission to look at the submarine crew's records,
14:36they discovered that the ice has been thinning fast.
14:40In fact, it's nearly halved in thickness since 1980.
14:48Across most of the Arctic Ocean,
14:50there are now just a couple of metres of ice.
14:57It's so thin that it could melt away almost entirely in the summertime,
15:02and that includes the ice at the North Pole.
15:06If current trends continue,
15:08then there will be open ocean here by summer's end,
15:11sometime within the next few decades.
15:16So, the days of the Arctic Ocean
15:18being covered by a continuous sheet of ice seem to be past.
15:23Whether or not that's a good or a bad thing, of course,
15:26depends on your point of view.
15:31Nobody has had a better view of the changes to the Arctic Ocean
15:35than the people of Barrow, the most northerly town in Alaska.
15:39The people here have always survived by hunting on the frozen sea,
15:43and they celebrate this at a festival every year.
15:48The blanket toss was once the best way to spot distant animals to hunt,
15:52as lifelong resident Lewis Brower explains.
15:56When we throw ourselves up into the blanket, you know,
15:58you get that much more of an awe of seeing further and further out.
16:02So, sometimes you'll jump 15, 20 feet in the air,
16:06and hopefully you're being caught right back into the blanket.
16:11I'm OK!
16:15But the old way of life is under threat.
16:17When Lewis was young, the sea stayed frozen to the horizon until July,
16:22and some ice remained offshore all summer.
16:25But now, it's breaking up in June
16:27and melting away completely for two or three months.
16:31I used to go out on the ice all the time this time of the year,
16:35but we can't do that anymore because there's no more ice.
16:42Lewis can also see that the loss of sea ice
16:45is affecting the animals he hunts for a living.
16:50Since 2007, something very strange has been happening
16:53on this stretch of coastline close to Barrow.
17:00Mother walruses, confused by the lack of ice,
17:03are crowding onto the land with their pups.
17:08This very tight crowding isn't normal,
17:10and it's caused many youngsters to be crushed to death.
17:16Many Arctic animals are threatened by the changing conditions,
17:20and that's also bad news for the traditional hunters.
17:24But the ice loss could be good news for some people.
17:31There are trillions of dollars' worth of oil and gas under the Arctic Ocean,
17:36but the only way to get to them until now
17:39has been by building expensive artificial islands like this.
17:43But if the sea ice goes,
17:45it will be much easier to drill for the huge riches below,
17:49so the countries that surround the Arctic are scrambling to stake their claims.
18:01This daring attempt by the Russians
18:04to claim the disputed seabed at the North Pole in 2007
18:08caused fury among the competing countries,
18:11and it's unlikely to be the last such dispute.
18:16The Arctic has never been so important,
18:19and not just because of its resources.
18:24The Northwest Passage,
18:27The Northwest Passage,
18:29a legendary sea route around the north of Canada and Alaska,
18:33cleared of ice in the summer of 2007
18:36for the first time since records began.
18:39This promises a much faster and cheaper shipping route
18:43between the Atlantic and Pacific Oceans.
18:50And some wildlife could benefit from an ice-free Arctic too.
18:57Bowhead whales are one of just a few whales
19:00that can live year-round in the Arctic
19:02because they have no dorsal fin.
19:06This means they can come up for air in small spaces
19:09and travel easily under the ice.
19:13Their unique body shape used to mean
19:15that the Arctic whales had the seas to themselves for most of the year.
19:19But now some cousins from down south are moving in.
19:24Killer whales are now a much more common sight in the Arctic.
19:29Their tall fins make it difficult for them to travel under ice,
19:33but the longer summers mean they can travel much farther north
19:37and make the most of the rich Arctic seas.
19:41For animals and people,
19:43it will be those who can adapt who will thrive in a changing Arctic.
20:10But the loss of sea ice isn't just an issue for the Arctic
20:13because the state of the ice affects the climate of the whole planet.
20:20Because it's white, the ice reflects up to 90% of the sun's energy.
20:26This is called the albedo effect
20:28and it's why we often see heat haze in the Arctic
20:31even when the air feels cold.
20:40The frozen Arctic Ocean acts as a huge reflector,
20:44bouncing back the sun's heat into space.
20:47Throughout history, that has helped to cool the planet.
20:51But when the ice melts, it's a different story.
21:00Because seawater is dark, it absorbs most of the sun's heat.
21:06In the Arctic, this can trigger a chain reaction
21:09as the warming water melts more ice,
21:12exposing more water to the sun's heat.
21:20This cycle of warming, as huge areas start to absorb rather than reflect heat,
21:25is the main reason why the Arctic, a region the size of North America,
21:29is warming twice as fast as the rest of the Earth.
21:34So, melting sea ice is a big issue.
21:37But there's another kind of ice
21:39that could have an even more dramatic impact on our world.
21:44The ice that is found on land.
21:49This is freshwater ice,
21:51formed from thousands of years of accumulated snowfall.
21:56This is the front of a glacier.
21:59Quite a small one, believe it or not.
22:02Glaciers are like rivers of frozen fresh water
22:06flowing across the surface of the land.
22:09This one, like most polar glaciers,
22:12is flowing down from a vast inland ice sheet.
22:16And it's what happens when the ice melts.
22:20It's flowing down from a vast inland ice sheet.
22:24And it's what happens to those ice sheets
22:27that could radically alter the face of the planet.
22:32The Greenland ice sheet is by far the largest in the Arctic.
22:36It's two miles thick in places
22:38and six times the size of the United Kingdom.
22:42Every summer, some of the surface of the ice sheet melts,
22:46forming sapphire blue lakes of meltwater.
22:51More and more of these lakes have been forming
22:54as Greenland has warmed over the last 20 years.
22:59This lake has grown over several weeks,
23:01and now it's overflowing,
23:03carving a deep channel through the ice.
23:07A network of channels criss-crosses the ice sheet,
23:11but many of them come to an abrupt end.
23:25Huge holes are formed in the ice sheet,
23:28and the ice melts.
23:31Huge holes like this can open up quite suddenly,
23:35draining the meltwater away.
23:49Alan Hubbard is a glaciologist
23:51studying the enormous power of these waterfalls,
23:54which are known as moolands.
23:57We've got this amazing mooland going on here today.
24:01The water's overflowing from the lake,
24:03which is beginning to drain.
24:05Tons of water cascading down this pipe
24:09that is effectively plummeting to the depths of the ice sheet
24:13through over a kilometre of vertical ice.
24:27Alan is here to study where the meltwater goes
24:31and what effect it has on the remaining ice.
24:34To do that, he needs to find a mooland
24:37that has recently run dry.
24:45Just a week ago,
24:46there was a three-mile-long, ten-metre-deep lake here.
24:51The weight of all that water cracked the ice beneath,
24:54and the lake drained in just a few hours with incredible force.
25:03A thousand-tonne ice boulders were tossed about like dice.
25:14Alan's team have found the hole down which the lake disappeared,
25:18and they want to have a closer look.
25:20It's not a job for anyone with a fear of heights.
25:25HE WHISTLES
25:30As you can see, it's dry up here,
25:32but if you listen, you can hear the thunder of...
25:34There's a lot of water entering it at some depth.
25:39Alan wants to place a sensor deep into the mooland
25:42to discover how much water is flowing through the ice.
25:47FOOTSTEPS
25:52As they drop, they travel back in time.
25:5730 metres down, and they reach ice formed from snow
26:00that fell 10,000 years ago in the last Ice Age.
26:07When this lake drained and the plug got pulled
26:11and the whole lot flushed down through here,
26:14this ice sheet, it rose by a metre
26:17as that water accessed the bed and force-jacked up the ice sheet.
26:22So we know that the water in this whole plumbing cavity system down here,
26:27we know that shoots straight through that ice
26:30and actually hits the bed of the ice sheet.
26:33We've hit the water. I can see the water now.
26:36Great. Nice work.
26:38Nice work.
26:42This daring experiment is measuring how the water flowing under the ice sheet
26:47affects the speed with which the glaciers flow from it down to the sea.
26:52The theory is that the water is acting as a lubricant,
26:55so the more water there is, the faster the glacier flows.
27:01To the naked eye, glaciers don't appear to move at all,
27:05but move they do.
27:09These unique time-lapse images were captured over the last four years.
27:25Through long observations, we now know that Greenland's ice
27:29is flowing down to the sea twice as quickly as it was 20 years ago.
27:35The speed of the glaciers affects our sea levels
27:38because when they reach the water, they break apart into icebergs.
27:43Occasionally, a real megaberg is born.
27:55This is the Storr Glacier in May 2010.
28:04The ice is melting fast.
28:09The ice is melting fast.
28:14The ice is melting fast.
28:19The ice is melting fast.
28:24The ice is melting fast.
28:30The ice is melting fast.
28:35The ice is melting fast.
28:5575 million tonnes of ice that have been sitting on land for thousands of years
29:01has broken away.
29:06Events like this have become increasingly common
29:10as Greenland's glaciers flow faster into the sea.
29:26Every single one of these icebergs raises the sea level a small amount.
29:33Scientists monitoring the ice sheet predict that Greenland might add
29:37as much as a half metre to world sea levels by the end of the century,
29:41enough to swamp many of the world's low-lying islands.
30:0399% of the Arctic's freshwater ice is in Greenland.
30:09It's a staggeringly big ice sheet, but it's just a drop in the ocean
30:13compared to that at the southern end of our planet.
30:25In Antarctica, there is ten times more ice.
30:29By far the largest concentration of ice on Earth.
30:38Our exploration of the Antarctic only began a little over 100 years ago.
30:49The study of ice retreat here was unwittingly begun on an expedition
30:53led by the great early explorer Ernest Shackleford.
30:58In 1916, after their expedition boat was crushed and sunk by ice,
31:03Shackleton and two companions set off to summon help in a tiny boat.
31:12They sailed over 800 miles across the Southern Ocean
31:16to the island of South Georgia on the edge of the Antarctic.
31:21Near starving and dressed in rags,
31:23the three men walked across the ice sheet at the centre of the island,
31:27knowing there was a whaling base on the opposite coast
31:30where they could summon help.
31:39This team of Royal Marines,
31:41who had been in the Arctic for more than a century,
31:45this team of Royal Marines is retracing the steps of that journey
31:50in tribute to Shackleton and his men.
31:54But for all their efforts, they can't exactly copy the Great Walk
31:58because the ice is not as it was.
32:04A number of South Georgia's glaciers were photographed by Shackleton's cameraman.
32:09Frozen planets saw a dramatic change when they returned 94 years later.
32:33Most of South Georgia's glaciers have shrunk since Shackleton's return.
32:39And most of that has happened since I first went to the Antarctic 30 years ago.
32:46I've been to South Georgia several times
32:48and seen how greatly the glaciers there have changed.
32:56This photograph of a glacier reaching right down to the sea
33:00was taken just six years before I first visited in 1981.
33:06Now that glacier has retreated by 400 metres away from the beach.
33:17Temperatures in South Georgia have risen sharply,
33:20but the Southern Hemisphere's most dramatic warming
33:23has happened a little further south.
33:27In recent years, stronger winds blowing over the Southern Ocean
33:31have brought warmer air to the 800-mile-long finger of land
33:35that forms the northern extremity of the Antarctic continent.
33:45Here on the Antarctic Peninsula,
33:48the changing wind patterns have driven temperatures up
33:51by nearly three degrees centigrade over the last 50 years,
33:55ten times the average rate of the rest of the planet.
34:02The rapid warming is having a big effect on the bird life.
34:23The Adelie penguin is the most southerly nesting of all penguins.
34:29And like the polar bear up in the north,
34:32their lives are dependent on the sea ice.
34:37Adelies spend their whole lives near ice.
34:41These birds have spent the winter feeding at the ice edge,
34:44but now it's spring and they've started a long trek
34:47over the frozen sea towards land.
34:59They're heading for areas of exposed rock
35:02where they gather to breed in colonies that can be over 100,000 strong.
35:08But it seems that Adelies don't find the conditions on the peninsula
35:12to their liking anymore.
35:16Seventeen years ago, when I was last in the Antarctic,
35:19I was a birdwatcher.
35:21I was a birdwatcher.
35:23I was a birdwatcher.
35:25I was a birdwatcher.
35:27I was a birdwatcher.
35:29I was a birdwatcher.
35:31I was a birdwatcher.
35:33I was a birdwatcher.
35:35Seventeen years ago, when I was last in the Antarctic,
35:38there were large colonies of Adelie penguins
35:41all along the Antarctic peninsula.
35:45Now, warming temperatures have meant less sea ice
35:50and Adelie penguin numbers are in decline.
35:54Many colonies have been emptied fast.
36:01It may be that penguins are starving
36:04or it may be that they're heading south to colder climes
36:07where there's still plenty of ice on the sea.
36:11But, as in the Arctic,
36:13while ice-loving animals are feeling the heat,
36:16animals that like it a bit more cosy are moving in.
36:25In the Arctic,
36:27there's a lot of ice on the sea,
36:29but it's not as cold as it used to be.
36:32It's not as cold as it used to be.
36:34It's not as cold as it used to be.
36:36It's not as cold as it used to be.
36:38It's not as cold as it used to be.
36:43The bright orange beaks of Gentoo penguins
36:46are a much more common sight on the peninsula these days.
36:50I always used to know them as residents
36:52of the slightly warmer islands north of the Antarctic,
36:56but they've moved south in numbers.
37:00There are thought to be ten times more Gentoos on the peninsula now
37:03than just 30 years ago.
37:09The peninsula has warmed a great deal,
37:12but the same is not true further south.
37:20The Antarctic continent
37:22is smothered by the world's greatest ice sheet,
37:26one-and-a-half times the size of Australia
37:29and up to three miles thick.
37:32A staggering 75% of the Earth's freshwater
37:35is locked up in this ice.
37:42Global sea levels would rise by some 60 metres
37:46if all this was to melt.
37:52But what chance is there of that happening here
37:55in the cold Arctic?
37:58But what chance is there of that happening here
38:01in the coldest, most hostile place on Earth?
38:10The ice beneath me, up here on top of the ice cap,
38:14is so thick that I am short of breath
38:18simply because of the altitude.
38:20This is midsummer,
38:23and the average temperature is some 20 degrees below freezing,
38:29and I can tell you it feels much lower than that.
38:33And even the worst predictions don't suggest
38:37that the air is going to warm enough to melt the ice.
38:43But now scientists are asking a different question.
38:48Could the speed at which the Antarctic ice flows off the land
38:52be increased by a warmer ocean?
38:56Where the ice sheet meets the sea,
38:58scientists are going to extreme lengths to find out.
39:02Firing!
39:14Andy Smith works for the British Antarctic Survey.
39:19What we have here is one kilogram of pentelite explosive.
39:23We're going to use this to generate a shockwave
39:26and record the echoes that come back from underneath the ice.
39:34Andy is particularly interested
39:36in mapping the underside of the ice around the coast.
39:41Because here it isn't resting on land.
39:44It's floating on seawater.
39:47So if sea temperatures rise just a little,
39:50it can be melted from below.
39:54Around the coast of Antarctica,
39:56the glaciers have flowed out across the sea
39:59to form immense masses of floating freshwater ice
40:02called ice shells.
40:08These freeze to the land around them,
40:11sticking fast and acting like bath plugs,
40:14holding back the flow of the glaciers into the sea.
40:20On the Antarctic Peninsula, a one-degree sea temperature rise
40:24has helped to break apart seven major ice shelves
40:27in the last 30 years.
40:30This is the Larsen B ice shelf,
40:33three times the size of Greater London,
40:35breaking apart in 2002.
40:39Afterwards, the glaciers it had been holding back
40:42started flowing up to six times faster.
40:48In 2008, a much larger ice shelf
40:51at the southern end of the peninsula started to break up.
40:56It's an enormous event that's never been filmed before.
41:02Andy Smith is flying down the peninsula
41:05to study this phenomenon firsthand.
41:09We're flying to a place called Wilkins Ice Shelf.
41:13It's an ice shelf that over the last couple of years
41:15has shown a very sudden and dramatic breakup.
41:22The Wilkins Ice Shelf is a two-hour-long flight
41:25south from his research base,
41:27but Andy can start to see the evidence of ice shelf breakup
41:31a long way before he gets there.
41:34As we're heading further south,
41:35we can see more and more icebergs in the ocean,
41:37and most of the big ones will be ones
41:39that have broken off the ice shelves in this area.
41:48Once we cross the mountains,
41:49we should be able to see Wilkins Ice Shelf,
41:52and then it's not far then to the ice front here
41:54where it's collapsing.
42:06As Andy's team reaches their destination,
42:09the scale of what's been happening soon becomes clear.
42:12Here, for thousands of years, an area the size of Yorkshire
42:16has been covered by a sheet of ice 200 metres thick.
42:24But now, over half of that has broken apart.
42:36Andy has been studying Antarctic ice for 25 years,
42:40but even he is blown away by what he's seeing.
42:44Now, that is pretty awesome.
42:46That is remarkable.
42:48The edge of the ice shelf has just kind of disintegrated.
42:52Some of the big pieces look like they could be a mile or more in size,
42:57and some of the big pieces look like they could be a mile or more in size.
43:02It's almost like a sort of a slow-motion explosion.
43:06It all pushes outwards very quickly.
43:17Every one of these huge icebergs will slowly drift out to sea.
43:26To study how fast that happens,
43:28Andy needs to get closer to the action.
43:32We're going to look around and see if we can find a place where we can land,
43:36but if we can, we'll be able to put out an instrument
43:39that will help us monitor the big icebergs that are breaking off
43:42as the ice shelf breaks up.
43:52Landing on an iceberg is a bit of a challenge.
43:56Landing on an iceberg is another first for Andy's team.
44:14This satellite transmitter will help to track the continued breakup
44:19of this colossal ice shelf.
44:26The remainder of the Wilkins looks set to break apart soon.
44:34It's the latest ice shelf to disintegrate
44:37in a wave that's been travelling southwards,
44:40playing a major role in the loss of ice from the peninsula.
44:46Next in line, and already weakening,
44:49is a massive iceberg.
44:52Next in line, and already weakening in places,
44:56are the ice shelves that hold back
44:58Antarctica's gigantic continental ice sheet.
45:03And it would only take a small corner of this to slide into the sea
45:07to have major global consequences.
45:13We've only started to see changes in the Arctic and Antarctic recently,
45:17so it's hard to predict exactly what impact these changes will have.
45:21But we can see for ourselves that these places are changing
45:25and on a scale that is hard to ignore.
45:31The poles, north and south, may seem very remote.
45:36But what is happening here is likely to have a greater effect upon us
45:41than any other aspect of global warming.
45:44If the Arctic sea ice continues to disappear,
45:47it will drive up the planet's temperature more quickly.
45:51And the melting ice sheets could contribute to a sea-level rise of a metre,
45:56enough to threaten the homes of millions of people
45:59around the world's coasts by the end of the century.
46:04We've seen that the animals are already adapting to these changes.
46:09But can we respond to what is happening now?
46:14To the frozen planet?
46:45FROZEN PLANET
46:54The increasing unpredictability of the ice
46:57was a big issue for the Frozen Planet team,
46:59who spent three years working on top of it.
47:10Whether on sea, land, lake or river,
47:13the state of the ice was the first concern for most filming crews.
47:23Unexpected break-ups left many a cameraman in need of a swift rescue.
47:28Sometimes help came by boat and sometimes by air.
47:39I had a chance to see the changing ice conditions for myself
47:42when I visited the North Pole.
47:47I flew with the team to a temporary camp
47:50that is set up every year in the centre of the frozen Arctic Ocean
47:54to support expeditions to the pole.
48:01I had never visited the North Pole before,
48:04so this was a great highlight for me.
48:07But it was hard-going in temperatures of minus 40,
48:10so as soon as filming finished, we flew south.
48:15Little did we know that we had made it out just in time.
48:20We got back from the pole camp last night
48:24and I've just bumped into the Russian commander,
48:27who's just heard from the camp.
48:29And the news is that a little crack which I'd seen in the ice
48:33between our tent and the airstrip,
48:36which was no more than an inch or so wide,
48:40has overnight widened to 20 metres.
48:45Temporary break-ups caused by stormy weather and strong winds
48:48have happened before,
48:50but they've been getting more and more frequent over recent years
48:53as the ice has got weaker.
48:59It was only swift action by the staff
49:01that prevented a lot of valuable equipment going in the drink.
49:10The biggest concern was that the ice airstrip might break apart,
49:14but luckily it held
49:16and everyone was able to evacuate when the weather improved.
49:24The Frozen Planet team's clearest demonstration
49:27of the power and unpredictability of breaking ice
49:30came when they went to film the melting of a frozen Canadian river.
49:34Producer Mark Linfield and researcher Matt Swarbrick
49:37have travelled to the far north of Canada.
49:40Matt, when was the last time we saw a car?
49:42I don't know, about three hours ago?
49:46They've driven through the vast Northwest Territory
49:49on a mission to film the moment when this frozen waterfall breaks apart.
49:57The break-up, when the frozen river above the waterfall thaws
50:00and masses of water start to flow again,
50:02can be a spectacular event,
50:04but predicting exactly when it's going to break
50:07is the big challenge if Mark and Matt want to get the best shots.
50:14And they're not the only ones who want to know.
50:16When the waterfall breaks,
50:18it can flood the town of Hay River just downstream
50:21with millions of tonnes of water and ice.
50:24Mark is taking advice from his team.
50:28Mark is taking advice from the scientist Faye Hicks,
50:32who has the job of predicting when the ice will break.
50:35What happens is you get ice jams form upstream
50:38and they start to dam up the water and it builds and builds and builds
50:41and that can let go and that's a much bigger wave of water
50:44than just the normal flow,
50:46so it just depends upon how dramatically it unfolds.
50:50Faye takes her research helicopter
50:53to monitor the situation upstream of the waterfall.
50:58MUSIC
51:05Just ten miles upriver, the ice is starting to break.
51:11The locals are concerned
51:13because huge amounts of water can build up
51:15if these ice chunks dam the river
51:17and that can lead to devastating flooding in the town
51:20when the dams burst.
51:22Sound of it's moving through there now.
51:24Yeah, I got you. I'm on your six.
51:26Using cameras and sonar to assess the state of the river,
51:29Faye makes her best guess
51:31of when this break-up will hit the waterfall just above the town.
51:34So now, guys, I think we have about 48 hours to go.
51:38Faye's prediction of the 24th of April
51:41is exciting news for the team.
51:46Upstream from here, it's already starting to melt
51:49and Faye thinks that we may only have another one or two days
51:53before this whole thing goes,
51:55which is almost impossible to imagine looking at it now,
51:58but that's what she says.
52:00With the break-up seemingly imminent,
52:03the team set up their cameras in anticipation.
52:08Over the next 48 hours, the weather warms to well above freezing,
52:12but there's no sign of the break-up.
52:14The team waits and waits and waits.
52:20MUSIC PLAYS
52:27Mark is concerned that the crew have to return home soon,
52:30so he heads into town
52:32to get the advice of long-term resident Red McBrien.
52:36We just have to live with it
52:38and take whatever evasive action we can.
52:41Red has had 50 years of witnessing the power of the river.
52:45We're hoping that she may break up in two or three days even.
52:49Oh, no, no, no, no. That's too soon.
52:52Oh, no, no.
52:53Boys, you're looking at seven or eight days
52:57before she breaks of any significance.
53:01And if she breaks, she can jam and hold up.
53:06She can be...
53:08She'd be down here probably around the 5th or 6th of May.
53:13The townspeople are on tenterhooks, waiting for the big day,
53:17but another week goes by before anything starts to happen.
53:33Finally, it seems that things might be happening.
53:36We've just heard some cracks from upstream,
53:38so if we're lucky, we might get some action.
53:417 o'clock, which gives us two hours' light.
53:44Two hours' light.
53:45If it happens at night, we're going to miss the whole thing.
53:50Sure enough, the town is put on red alert
53:53that the river is about to break in the middle of the night.
53:58They've just called a full evacuation of the island where we're staying.
54:02If we don't move now, we're all going to be underwater
54:05and possibly get trapped here for a few days.
54:08The team have to move out and get up to the waterfall,
54:11hoping that it doesn't break before it's light enough to film.
54:20Luckily, the sun is up before the main event begins.
54:24That is a serious amount of ice coming around the corner.
54:36After weeks of waiting,
54:39sleeping giant of a river,
54:41we thought nothing was going to happen,
54:43and suddenly, look at this.
54:45This is what we're here for.
54:47Unbelievable.
54:49Absolutely unbelievable.
54:51Holy...
54:57The team is used to handling multiple cameras,
55:00but they don't usually have to dodge ten-tonne ice
55:03at the same time.
55:06You can see it's racing over at an unbelievable speed.
55:10The power, I just... If you were here to feel this,
55:13it's the deep, rumbling sound of the river.
55:15I can feel it up through my feet.
55:17The power, I just can't imagine how you can crush a house in no time.
55:22The team takes to the air
55:24to witness the destruction that's unleashed.
55:26Huge ice blocks are pushed downstream on the wave of water
55:30released by the breaking waterfall.
55:36This could devastate the town.
55:43But this year, the townspeople's luck is in.
55:46The town has escaped flooding.
55:53Crucially, the ice blocks did not dam the river.
55:56It's running free.
55:58And the date of the breakup? 6th of May.
56:01Red's got it right again.
56:05I don't use any of these here, gauges and mechanical assistance.
56:09I just go by what I see on the river as I walk it down.
56:14And I say I walk it down,
56:16I back and forth every day on the river to see what's happening,
56:20and from that, I gauge when it's going to hit here
56:24and what the situation is.
56:27You know, when it went this morning, I said to my students,
56:30guess what the date is?
56:32Red told us it's the 6th of May.
56:34And I'm not surprised, because we've been here a couple times
56:37and that's happened.
56:39Ten days, two weeks out, he just looks around and goes, 5th of May.
56:42How does he know that? It's incredible.
56:45And it's because he just has lived on this river
56:48and lived this breakup for 50 years.
56:51Ice scientists are improving the ice.
56:54Ice scientists are improving the accuracy of their predictions all the time,
56:58but in the meantime, the people of Hay River have a remarkable guardian.
57:03Red, you were completely right this year.
57:06Are you right every year?
57:08No, I'm...
57:10I missed the odd one.
57:12Yes.
57:141985, I missed it.
57:24© BF-WATCH TV 2021