- 2 days ago
Without volcanoes, life on Earth would never have begun; they are responsible for both the planet's breathable atmosphere and the oceans; mineral-rich ash from regular eruptions fertilize the land.
Category
🐳
AnimalsTranscript
00:26A perfect planet.
00:34There is only one planet in the universe, as far as we know, where there is life.
00:41The Earth, our home.
00:46The perfect planet.
00:52Life here is only possible because of a unique balance of natural forces.
01:03Energy from the sun powers the living world.
01:12Weather systems transport freshwater around the globe.
01:23And powerful ocean currents circulate life's essential nutrients.
01:32This series will reveal how these global forces have worked together to create our planet's
01:39fragile life support system.
01:46One of these forces is so important that life would never have even started without it.
02:16Across the surface of our planet, there are over 1,500 active volcanoes.
02:34This is the most active Kilauea in Hawaii.
02:54Here, magma, liquid rock from the planet's hot interior, bursts out through fractures in
03:01the Earth's crust, and it's been flowing for months.
03:16Nothing can stand in the lava's way.
03:31Volcanoes are certainly destructive.
03:33But without these powerful underground forces, there would be no breathable atmosphere, no oceans, no land, no life.
03:58We can't control volcanoes, but they're vital for all living things on planet Earth.
04:13This is Ol Doño Lenggay in Tanzania.
04:20It's one of Africa's most active volcanoes, and has erupted over 15 times in the last 100 years.
04:32On its northern flank lies Lake Natron, 400 square miles in extent, and one of the world's most corrosive bodies
04:41of water.
04:47The water wells up from deep below, carrying such a concentration of chemicals that it can burn skin.
05:07But one animal thrives here.
05:15Volcano birds.
05:17Volcano birds.
05:20Nearly two million lesser flamingos live in East Africa, and all of them come here to breed.
05:33but they can only nest here when the lake's level drops so far that in the center its bed
05:40is exposed and that rare moment is now
05:54how they know when the conditions are right is a mystery but some have flown thousands of miles
06:01to be here the flamingos head for the middle of the lake where the intense evaporation has created
06:11islands of salt it's here that the birds build their nests over three miles from the lake's edge
06:21and safe from land predators which are unable to cross the surrounding moat of caustic soda
06:39the single egg is laid on a mount of hardened salt built by the adults its height and insurance
06:47against the sudden rise in water level which often happens on lake matron
06:58as the center dries and enlarges more and more flamingos arrive to nest on it
07:07in good years such as now as many as half a million pairs breed here
07:23after 28 days of incubation a chick emerges into natron's harsh glare
07:32here temperatures can rise to 55 degrees celsius
07:43mother's wing however can serve as a sun shield
07:52the chick is fed a rich liquid made of the lake's barely digested algae and traces of its parent's blood
08:08after a few days the chick is strong enough to stretch its legs
08:20it then joins a growing crash made up of chicks of different ages
08:29soon the need for fresh water will force the infant birds to trek to springs on the lake's edge
08:38a journey they have to make on foot as their flight feathers have yet to develop
08:49every day the adults fly to these springs to feed
08:58here on the lake's margins they collect algae that flourish in the volcanic water
09:03vital food for the flamingos
09:14it's the algae that turn the flamingos feathers pink
09:19it even colors their eyes
09:26the adults spend most of their day at the springs and now their chicks are going to join them there
09:47no one wants to get left behind
09:56it's a three mile march over razor sharp flakes of soda
10:00and sticky caustic mud
10:05a life threatening trial especially for the youngest chicks
10:10a life threatening trial especially for the youngest chicks
10:2510 liberals
10:54a life threatening
10:55too great. Exhaustion overcomes the weakest.
11:13And now there is yet another threat.
11:22Marabou Storks. They have long legs like a flamingo, but a beak like a Roman sword, and they
11:36are patient, waiting for an easy target.
11:52Their very presence creates panic among the chicks.
12:02The smallest avoid being trampled underfoot by travelling on the outside of the group.
12:11But that exposes them to attack.
12:17Their only defence is to run.
12:25But you have little chance when you're barely ankle-high to your pursuer.
12:33The End
12:33The End
12:37The End
13:02Stragglers will almost certainly be taken.
13:09But there comes a point when every stalk has had its fill.
13:27This little chick is very lucky.
13:39At last, the youngsters reach the freshwater springs at the lake's margin to rejoin their
13:46parents.
13:48Almost unbelievably, each chick has a unique call that its parent can recognize.
14:16It's not just lesser flamingos that depend on volcanoes.
14:24Ultimately, so do all living things.
14:34Over 80% of the Earth's surface is the result of magma bursting up from the molten interior.
14:50The process started four billion years ago, and it still continues today.
15:01When lava cools, it solidifies into rock, and eventually weathers into land that can support
15:10life.
15:18All the Galapagos Islands in the Pacific are volcanic, and Fernandina is the youngest
15:26of them, and still growing.
15:38At its center, a volcanic crater four miles wide, and over 800 meters deep.
15:54It seems dormant, but it was erupting only two weeks ago.
16:05Even so, there are some who depend on the heat from this volcano.
16:16A female landiguana, heavy with eggs, approaches the crater's rim.
16:24It took her ten days to climb up here, but the toughest part of her journey is still ahead.
16:32She's going to descend into the crater itself.
16:49Frequent tremors make the crater walls unstable.
17:02More people have traveled in space than have visited the bottom of Fernandina's crater.
17:11But instinct drives her on.
17:16The warm volcanic ash on the crater floor has the perfect temperature for incubating her eggs.
17:25But there are no clear paths down.
17:31Any made last year have been destroyed by rock falls.
17:55The slope is steep and unstable.
18:00Tumbling rocks quickly become an avalanche.
18:17With the boulders falling down away from her, she's not in immediate danger.
18:25But behind her, higher up, two other females have also started the descent.
18:39And now, she is in the firing line.
19:00And now, she is in the firing line.
19:06She's safe.
19:13Others before her haven't been so lucky.
19:19But she's undeterred.
19:30And now, she's in the firing line.
19:51One hour descent, she reaches the crater floor.
19:59Now, she must find a suitable place to dig her nest.
20:10The best sites are already taken.
20:17And nesting females are very aggressive.
20:28And nodding head means keep away.
20:33Push off!
20:40Ignored warnings are met with force.
21:04But she's come a long way
21:05And she's not going to give up now
21:15She too starts to dig a hole
21:18In which to lay her eggs
21:25That done
21:26She will head back
21:27Leaving the volcano
21:29To provide the warmth the eggs need
21:31If they are to hatch
21:36Sometimes of course
21:38The volcano erupts
21:40And destroys not only eggs
21:42But many nesting adults
21:50But for the iguanas
21:52The benefits of nesting in the crater
21:55Are so great
21:56That it's worth all the risks
22:03Volcanic islands make up
22:05Just 5% of the planet's land
22:08But they're home
22:10To nearly 20% of its species
22:16Animals often evolve
22:18Very swiftly on islands
22:20Cut off
22:22From their mainland relatives
22:24And faced with the challenges of isolation
22:31This is wolf
22:33An extinct volcano
22:35And one of the most remote islands
22:38Of the Galapagos
22:39800 miles from the nearest large landmass
22:42And over a million years old
22:48A finch
22:51A finch
22:51A female
22:52Its ancestors doubtless
22:55Were blown here by storms
22:56Many centuries ago
22:59Like most finches
23:00Like most finches
23:01They feed on seeds
23:02Nectar
23:03And insects
23:06But there's little food of any kind
23:08On wolf
23:12And since they aren't strong enough flyers
23:15To leave the island
23:16They've had to find food
23:17From a very unusual source
23:23They depend on another of the island's inhabitants
23:34Nazca boobies
23:41Every day these seabirds commute between the island and their fishing grounds
23:45Out in the open ocean
23:50Each time a pair meet
23:52They renew their bond
23:56And then catch up with the neighbors
24:05Now is the time
24:08To hop into action
24:32Blood
24:35They are vampire finches
24:44These little birds
24:46Have become one of the world's newest species
24:54She cuts the quill of a large flight feather
24:57And the blood flows
25:03The sight of it attracts the attention of others
25:12Blood is very nutritious
25:15Worth fighting for
25:31So with this never-ending supply of food
25:34The vampire finches
25:35The vampire finches can flourish on an island
25:37Where otherwise they could not survive
25:45Why the boobies don't object?
25:48Nobody knows
25:53Perhaps the finches' behavior started
25:55When they helped the boobies to remove parasites from their plumage
26:02Maybe the boobies think that the little vampires are still providing a service
26:15Volcanic islands
26:16Volcanic islands don't last forever
26:19Changes deep in the Earth's crust bring their eruptions to an end
26:23And the forces of erosion
26:25Then begin to wear them down
26:36But the coral around them continues to grow
26:39Sea levels change
26:41And eventually all that is left is a ring-shaped island of coral rock
26:47Surrounding a lagoon
26:50An atoll
27:01There are hundreds of atolls in tropical seas
27:05All remnants of vanished volcanoes
27:16This is one of the largest and most pristine
27:19This is one of the largest and most pristine
27:20Aldabra in the Indian Ocean
27:2520 million years ago it was an island with a volcanic crater in its center
27:36Now it's an atoll
27:40Mangroves took root and seabirds came to nest
27:46One grand animal in particular reached here before man
27:54A giant tortoise
27:58These creatures can float and live without food or fresh water for long periods of time
28:09This isolated atoll is the perfect refuge
28:13Their only enemy is the sun
28:22Without shade a tortoise risks being boiled in his shell
28:31So after feeding in the cool of the morning
28:34And before the sun becomes too crushingly hot
28:37They have to find cover
28:41All of them
28:42All of them
28:48There is very little vegetation
28:51But caves in the coral rock can provide the shade they so badly need
29:04He's nearly there
29:07All that is left is a white knuckle ride to the bottom
29:16And he's in
29:21Thousands of others are still out in the sun
29:26This tree could shade a couple of hundred if they pack tight
29:45It's bumper to bumper parking
29:53Within an hour or so
29:54Within an hour or so
29:55Or must find shade of some sort
29:57If they're to survive
30:25It's a farmer
30:27It's TSAR
30:27It's very lovely
30:33Safe.
30:37But the future for Aldabra's tortoises is far from certain.
30:42The climate is changing, sea levels are rising,
30:48and Aldabra's tortoises may soon have to find a new refuge or drown.
31:00In some places, volcanoes erupt not in the ocean,
31:04but in the very middle of a continent.
31:11North America.
31:13And in its very heart, a volcanic hotspot, Yellowstone.
31:25The last major eruption here came to an end about 650,000 years ago.
31:33But this volcano is only sleeping.
31:38Not far below ground, there is still magma.
31:42And that heats the ground water to boiling point.
31:52Giesers.
31:56Some spout boiling water and steam to heights of 90 meters or so.
32:04Elsewhere, the scalding waters liquefy the ground sediments,
32:09creating pots of boiling mud.
32:17And this underground heating has proved a lifelong for some.
32:30river otters.
32:35They need a constant supply of food if they're to keep warm
32:39in these freezing temperatures.
32:46And this close-knit family know exactly where to find it.
33:07The springs are so hot that the rivers never freeze,
33:11even in the coldest winters.
33:19So, the otter family can fish the year round.
33:41So, the otter family can fish the year round.
33:45This coyote knows that in the middle of winter,
33:49a thermal river means otters.
33:52And otters mean fish.
34:00The question is, how to steal their catch?
34:28Perhaps the thing to do is to pretend you're not interested.
34:33and hope that they wander close enough for a snatch-and-run raid.
34:50It seems that cool-under-fire otters can outwit a not-so-wily coyote.
35:08Many animals benefit from the volcanic heat coming up from below.
35:17And we do as well, but not nearly as much as we could.
35:24The volcanic heat could provide us with much of the energy that we need.
35:30And then we could stop burning gas and coal
35:33that is now changing the climate worldwide.
35:47Deep in the Earth's crust, below both the oceans and the continents,
35:52there are lines of weakness along which rises liquid rock.
36:01The Kamchatka Peninsula, in the Northwest Pacific, lies along one of them.
36:22There are only a thousand known geysers in the world.
36:26And many of them are here in this isolated valley.
36:42Steam from superheated water fills the air.
36:47But the danger from the scalding pools
36:50does little to deter Kamchatka's most famous residents.
37:03In May, when the rest of Kamchatka is still covered by snow,
37:08this valley is free of it.
37:10And bears, having just woken up from their winter sleep, know that.
37:21The grass is fertilized by mineral-rich water spraying from the geysers.
37:30Much-needed forage for a large male bear that hasn't eaten for several months.
37:42And he's not the only one.
37:55The bears haven't seen one another for seven months since the start of winter.
38:03And it seems that right now they would prefer to keep it that way.
38:10Nothing should come between a bear and his first meal of the year.
38:19And in one place, Kamchatka's underground forces provide its bears with even more nutritious meals.
38:34Kural Lake lies within the crater of an immense volcano
38:38that long ago produced one of the greatest eruptions in the planet's history.
38:46The lake is still circled by active vents.
38:52And mineral-rich ash from their regular eruptions has made these waters particularly fertile.
39:02Millions of salmon come here from the Pacific Ocean in order to spawn in these fertile waters,
39:08which will provide their newly hatched young with abundant food.
39:19So grass soon ceases to be top of the menu for Kamchatka's bears.
39:27By the time spring has turned to summer,
39:31Kural Lake contains the most dense assembly of bears to be found anywhere on Earth.
39:42All hungry for salmon.
39:56But this early in the season, the fish are still strong and swift.
40:17Nothing seems to work.
40:27But one old bear knows that right now there is an easier meal to be had.
40:37He remembers that if he paddles out into the lake,
40:41away from the shoals of newly arrived salmon,
40:44there's food that doesn't need chasing.
41:07Some of the first fish to arrive have died,
41:10and their bodies can be easily collected from the bottom of the lake.
41:21Diving for them at leisure doesn't use many calories.
41:32And he can take his time.
41:47A couple of weeks later, the salmon are beginning to spawn and are less wary.
41:55Now it's worth running.
41:59Now it's worth running.
42:14The fish are so abundant...
42:19that there is plenty for all.
42:23Even those with no previous experience.
42:30There are now so many fish,
42:32it's difficult to know which one to chase.
42:50In a single day, a bear can consume 100,000 calories,
42:5650 times more than the average human being does.
42:59And one part is particularly delicious.
43:09Caviar.
43:1180 calories in every mouthful.
43:21By supporting huge concentrations of salmon,
43:26mineral ash from Curl Lake's volcanoes
43:30has made life surprisingly easy for these bears.
43:47Our planet depends on minerals brought up by volcanoes from the Earth's molten core.
43:57A single ash cloud can carry billions of tons of minerals.
44:16And as a consequence, the lands surrounding volcanoes are among the world's most fertile.
44:28Those in East Africa's rift valley support the most dynamic ecosystem on Earth.
44:40The Serengeti.
44:46This is the most productive of all natural grasslands anywhere.
44:53Every year, over a million wildebeest assemble in this particular corner of the Serengeti
44:59to feed on grass specially rich in calcium and phosphorus.
45:05Essential minerals for the pregnant females.
45:11In just three weeks, half a million calves are born on these ash-rich plains.
45:20That's 24,000 a day.
45:23A thousand an hour.
45:30The Serengeti cows do a like harvest seed and develop clo 뻔 and是我bertzi.
45:30Calfs stand up within a few minutes of being born.
45:37Though some need a little more time to find their feet.
45:53But a mother won't let her calf suckle until it's mastered a few physical skills.
46:04Walking, trotting, and running.
46:20Wildebeest calves must work if they're to stay alive.
46:39For these planes also support the greatest assembly of hunters on the planet.
46:50Each species has its own special hunting technique.
46:54But all have the same aim.
47:00To make the most of this brief superabundance of life.
47:12To be continued...
47:14To be continued...
47:43To be continued...
47:45To be continued...
47:46To be continued...
47:53To be continued...
48:02Only one in ten wildebeest calves will survive to adulthood.
48:09But that is enough to maintain the million-strong herd of wildebeest.
48:15And the planet's highest density of predators.
48:23Volcanoes fertilize the planet.
48:25But they're the source of something else so important that life could not have started without it.
48:36The first carbon dioxide in the Earth's atmosphere was brought by volcanoes from deep in the Earth's crust.
48:48And this gas is the foundation of life.
48:53Every plant needs it to grow and absorbs it from the air.
49:01Volcanoes continue to release carbon dioxide today.
49:05And for the last 10,000 years, its presence in the atmosphere has suited life perfectly.
49:15Its greenhouse properties have kept our planet's climate stable and warm.
49:28But too much carbon dioxide would make the planet's temperature rise to levels that would upset the Earth's long-established
49:36ecological balances.
49:54Today, humanity itself has become a new kind of a supervolcano.
50:07Now, every year, we ourselves release a hundred times more carbon than all the Earth's volcanoes combined.
50:17And that has brought climate chaos.
50:24We can't control volcanoes, but we can limit the amount of carbon dioxide that we produce.
50:34And if we do that, there will still be time to restore the ecological balance that once made this Earth
50:42our perfect planet.
50:56Lake Natron in Tanzania is one of the world's most toxic bodies of water.
51:03Yet once every few years, when the center dries out, it's brought to life by thousands of breeding flamingos.
51:15But to reach the colony, there's only one way to cross this soft soda sludge.
51:23It's finally here.
51:24Our secret weapon is a hovercraft.
51:30It's beautiful.
51:33Having shipped it from the UK, Darren's keen to test that all systems are go.
51:41Getting it off the trailer is one thing, but at least the hovercraft's fans that give it lift are working
51:47well enough.
52:04Come on, guys, what do you think?
52:06We know she works, but maybe some of these guys' lungs don't now.
52:11One hundred and twenty-five miles away, on the edge of Lake Natron, cameraman Matt Eberhardt is trying to camouflage
52:19his hides.
52:21Those are our blinds, so you can't camouflage those on the flats.
52:26And the best thing that we can do is actually turn them into a little cluster of flamingos.
52:36Pretty cool, huh?
52:39Hide complete.
52:40All that's needed is transport out to the colony.
52:44And after a ten-hour cross-country journey, Darren arrives with his secret weapon.
52:50And it's an instant hit.
52:53It's a new local tourist attraction.
52:56You like it?
52:58The first job is to get the hovercraft into service and plot a route out to the nesting flamingos.
53:20The volcanic spring water is soon replaced by a crust of razor-sharp salt crystals.
53:27And for a machine that relies on a delicate blower bottom, that's a problem.
53:33So what we have here are the plates of dried-out soda, which form on the mud substrate underneath.
53:39And it just batters the hovercraft. We just cannot travel across this stuff. It's impossible.
53:45If I was to skin my hand across that, I would cut it to shreds.
53:52But crossing the soda crust is the only way out to the colonies, so Matt and Darren have to hope
53:58for their best.
54:01Unfortunately for Matt, the best position for his flamingo-covered hide has a rather soggy floor.
54:09When the mud dries, it leaves massive amounts of salt. Very scratchy, nasty and aggressive salts.
54:18But sitting shin-deep in toxic sludge is a price worth paying for the view.
54:25And Matt is soon rewarded with the birth of a chick right in front of his hide.
54:47The daily commute, however, is taking its toll on the hovercraft.
54:56And its blow-up bottom is literally being ripped apart.
55:01We've trashed 52 of these that now need to be repaired. It's like travelling over sandpaper.
55:08So what do you do when your hovercraft needs replacement skirts and you're in the middle of nowhere?
55:16Enter the local Maasai tribe, well known for their needlework skills.
55:22There are only a few places in the world that specialise in hovercraft maintenance.
55:27And Lake Natron is now officially one of those hotspots.
55:31So if you're in the need of any hovercraft services, you know where to go.
55:36Two days later, and after a lot of serious sewing, the hovercraft is ready to ride again.
55:46You look like the new Tanzanian bobsleigh team.
55:54And getting back on the lake couldn't have come at a better time as the chicks are now on the
56:00move.
56:02Sadly, the new hide position is no drier.
56:07We have an enormous creche of hundreds of thousands of birds just pouring into the lagoon from the salt mud.
56:16Just constantly chatting to each other.
56:21But the massive creche attracts some unwelcome visitors.
56:27Predators, marabou storks.
56:35These marabous, they know exactly what they are doing.
56:42Soon, thousands of panicked chicks are on the move, desperately trying to avoid the predators.
57:03And it's a scene that will live long in Matt's memory.
57:09I mean, it was literally like war had been declared.
57:15I mean, that's one of the most amazing and frightening and freaky wildlife scenes I've ever, ever seen.
57:27And believe me, I've seen a few.
57:30And few places are more challenging than Lake Natron.
57:35But to quote Matt, if you can deal with the acrid and sulfurous stink of the soda, the stinging eyes,
57:42and the chemical attack on your legs, then you can be rewarded with one of the greatest spectacles on Earth.
57:54Next time, the sun.
57:59Life on our planet is fueled by its energy.
58:08Everything must be perfectly tuned to the daily and yearly rhythms of this vital force.
58:20The Open University has produced a free poster exploring our perfect planet.
58:25To order, please call 0300 303 0901 or go to bbc.co.uk slash perfectplanet and follow the links to
58:37the Open University.
58:42A perfect planet continues at eight next Sunday here on BBC One.
58:47If you can't wait until then, all episodes are available now on iPlayer.
58:51The food we eat doesn't have to cost the Earth.
58:54A feast to save the planet with Greg Wallace, this time tomorrow on BBC Two.
58:59Here next, Love is Blind, Jenna Coleman beguiled by the serpent, our new thriller.
59:06The Admirator
59:07Alyssa
59:07Moana
59:07Moana
59:08Moana
Comments