:00:15. > :00:19.If he had been standing on this very spot in 1969, this is what you
:00:19. > :00:25.would have seen, great fiery Fountains of lock-up reaching up
:00:25. > :00:29.into the sky. Today, we discovered the incredible power of volcanoes
:00:29. > :00:39.and the influence they have over our planet. This is volcano Live
:00:39. > :01:11.
:01:11. > :01:18.Look at this incredible landscape. Good morning from Hawaii. Where
:01:18. > :01:23.broadcasting live from the Big Island. It is a place simply here
:01:23. > :01:28.because although the volcanoes that created it. Yesterday, we came to
:01:28. > :01:34.you live from the summit of this volcano, Kilauea, and it is the
:01:34. > :01:38.most active volcano in the world. Look at this crater, known as
:01:38. > :01:43.Halem'uma'u. You can see a great plume of gas coming from that
:01:43. > :01:47.greater. Beneath it is a lake of lava. You cannot appreciate its
:01:47. > :01:52.power or its beauty in daylight but at night, it is completely
:01:52. > :01:59.different. This is a time-lapse photographs taken from Albeniz
:01:59. > :02:02.crabbed researcher, Tom, showing not just the glory of the lake, but
:02:02. > :02:07.look at the Milky Way. You can see the pulses of magma
:02:07. > :02:12.coming out, fantastic. This landscape is so apocalyptic but it
:02:12. > :02:16.used to be lush rainforest until May 1969 when that eruption
:02:16. > :02:21.happened. The magma that fed that started beneath the lake of lava,
:02:21. > :02:28.and some of it came along tunnels underground, along the rift zone,
:02:28. > :02:35.and burst out there, producing that crater. It covered this area in 17
:02:35. > :02:38.cubic miles of lava. It is enough to cover Oxford. Or Cambridge, and
:02:38. > :02:42.we like to be democratic. Tonight we will be looking at the
:02:42. > :02:47.destructive power of volcanoes, but also the surprising role that they
:02:47. > :02:54.have to play in creating new land and your life. Here is what is
:02:54. > :02:59.coming up. -- new life. Tonight at visit an Icelandic town which
:02:59. > :03:04.fought back against a volcano and one.
:03:04. > :03:07.In Chile, a group of volcanologists hike through the landscape, turned
:03:07. > :03:12.white and closely by an extraordinary ongoing eruption.
:03:12. > :03:15.Ed Byrne gets his rocks off in the lab.
:03:15. > :03:25.And in or why's rainforest, I discovered a unique ecosystem that
:03:25. > :03:27.
:03:27. > :03:35.could not exist without the volcano. -- and here in Hawaii's rainforest.
:03:35. > :03:43.We are standing in an area of the Kilauea volcano, and it is not an
:03:43. > :03:46.easy landscape to navigate. I will do my best to meet Don Swanson, in
:03:46. > :03:53.research -- researcher from the Hawaiian volcano observatory on the
:03:53. > :03:56.Big Island. You had the privilege, I think, of being here in 1969 when
:03:56. > :04:02.the eruption went off, but before you tell us about that, can you
:04:02. > :04:06.give us an idea of what this landscape was like before? This
:04:06. > :04:13.landscape was smooth and forested with only a few bare areas from
:04:13. > :04:17.previous eruptions. It was vastly different from this. And in 1969,
:04:17. > :04:21.what happened? What did the scientists notice was going on?
:04:21. > :04:27.noticed that earthquakes were beginning so we rushed down here
:04:27. > :04:34.just after the eruption had started. There were fountains in the air, 20
:04:34. > :04:39.of 30 metres high. We have some dramatic pictures. Later on, the
:04:39. > :04:45.Fountains of higher than that, as the summer progressed. -- Fountains
:04:45. > :04:49.got higher. By the end of the year, it was completely mature. I think
:04:49. > :04:52.that is the thing that we do not appreciate. You think of an
:04:52. > :04:57.eruption being something that happens and then ends quite quickly.
:04:57. > :05:04.You're saying it went on for months. It lasted for four years with a
:05:04. > :05:12.little recess in between. The most exciting time was during the first
:05:12. > :05:14.nine months when it had the highest Fountains. Four geologists -- for a
:05:14. > :05:23.geologist to witness something like this must be incredibly important
:05:23. > :05:29.and exciting. It is, both exciting and important. We have a chance to
:05:29. > :05:32.see repeatedly fountains being erupted and various things that we
:05:32. > :05:37.do not normally get a chance to see. This was a very stimulating
:05:37. > :05:40.eruption frost. I cannot believe that not only did you have the
:05:40. > :05:45.presence of mind to rush down and study what was going on but you
:05:45. > :05:53.brought your camera. We have some lovely photographs taken. This one
:05:53. > :05:59.gives us a sense of the scale of those fountains. That is about as
:05:59. > :06:03.tall as the Empire State Building. We had Fountains even taller. They
:06:03. > :06:10.start slowly, build up and play for several hours and then they just go
:06:10. > :06:17.off. It is like someone has just turned the tap off. I love this one
:06:17. > :06:23.because it shows you again the tremendous scale, and puts us in a
:06:23. > :06:27.period of time, with the '60s cars. That was the observatory's car. A
:06:27. > :06:31.few minutes after right at that photograph, it was the only car
:06:31. > :06:38.left. And then there was a high fountain, continuing, and the
:06:38. > :06:42.fountain material was blown to the car. The car needed a new paint job.
:06:42. > :06:50.The more spectacular sight from that time, if I could call it a
:06:50. > :06:56.waterfall, a lava fall, is perhaps a better description. I think that
:06:56. > :07:01.is the most spectacular sight I have ever seen. It is bigger than
:07:01. > :07:07.Niagara Falls, would you believe it? It fell into the crater for
:07:07. > :07:12.several hours before the crater was almost full. Absolutely beautiful.
:07:12. > :07:17.I'm going to take advantage of unify May, because we have been
:07:17. > :07:21.having questions sent in by our viewers. One was sent in from mini-
:07:22. > :07:31.me, and she wanted to know how close you get to love but because
:07:31. > :07:36.your face melts. -- close to lava. Another viewer wants to know what
:07:36. > :07:40.would happen to your hand if you touched Malton lava. Well, you can
:07:40. > :07:44.get pretty close if there is only a little bit. You can use your arm or
:07:44. > :07:49.your jacket as a shield, and you can touch it if you're wearing
:07:49. > :07:54.gloves but not for very long. With a big fountain, there is so much
:07:54. > :08:00.heat coming off that you have to stand back quite a long way. Or you
:08:00. > :08:02.would get burned. We went out to the lava field just out there which
:08:02. > :08:07.you will see it in tomorrow's programme and the heat is just
:08:07. > :08:12.extraordinary. I felt like my face might melt if I got closer. When it
:08:12. > :08:16.gets that hot, you want to get out. Thank you very much for your time.
:08:16. > :08:22.We will be joining Don later in the programme. We have been in Hawaii
:08:22. > :08:28.for about a week, preparing for the series. One of the first things we
:08:28. > :08:35.wanted to do was go out and explore these extraordinary surroundings.
:08:35. > :08:39.We set off down the chain of craters road. On all sides, it was
:08:39. > :08:46.lush, green rainforest, but then the vegetation started thinning out,
:08:46. > :08:54.and it was like being on a completely different planet. It is
:08:54. > :08:57.like an ocean of lava. That is extraordinary. It almost looks like,
:08:58. > :09:07.and he will make me feel like I am from the great British a cough, it
:09:08. > :09:12.
:09:12. > :09:21.looks like a well-cooked a Brownie. -- Bake-off. That is as far as the
:09:21. > :09:30.eye can see. I have never seen anything on this scale. And then
:09:30. > :09:36.there was a final surprise. Does it go right across the road? I just on
:09:36. > :09:44.the road would bend around but it has completely stopped. Shelvey get
:09:44. > :09:51.out? Yes. -- shall we get out. That is great, that is the end of the
:09:51. > :09:55.road absolutely. Quite literally. One of the things we're doing this
:09:55. > :09:58.week in our volcanic control hobbit is keeping a track on the eruptive
:09:58. > :10:02.activity around the world. The Smithsonian are sending us daily
:10:02. > :10:09.updates on what has been happening and we had a map showing those
:10:09. > :10:14.volcanoes that have an alert going on. These are active volcanoes,
:10:14. > :10:21.typically to between 20 and 30 a day. They are spread around the
:10:21. > :10:27.whole planet. Yesterday we told you about a volcano in Guatemala a,
:10:27. > :10:32.called Fuego, that was erupting, but we have had the latest news
:10:32. > :10:37.from the Smithsonian, that this volcano, Santa Maria, has also been
:10:37. > :10:43.showing signs of erupting, and apparently triggering avalanches. I
:10:43. > :10:49.think we have some footage. It is one of these special satellite
:10:49. > :10:54.images. It is his saddle a light that travels around the planet and
:10:54. > :10:59.images at night time, picking out hot spots, fires or volcanoes. This
:10:59. > :11:03.is Santa Maria, and here is the volcano. This is a thermal hot spot,
:11:03. > :11:09.where magma is getting close enough to the surface to be seen from
:11:09. > :11:16.space. I expect that as it comes up, the volcano was becoming unstable.
:11:16. > :11:20.There is a small town near that volcano, and I have actually been
:11:20. > :11:25.there, it is rather beautiful. Quite a small population, just
:11:25. > :11:29.200,000 people. Do we know what sort of alert has been put on the
:11:30. > :11:34.volcano? There is no evacuation. These things happen all the time
:11:34. > :11:39.and sometimes they go to nothing. There is another one causing
:11:39. > :11:42.concern in Japan. You know this volcano quite well. I went there
:11:43. > :11:48.are few years ago and it is a volcano on an island with
:11:48. > :11:57.communities immediately below it. Across the bay, there is a big town.
:11:57. > :12:00.If we go to the webcam, the other day the plumes were a 1000 feet. --
:12:00. > :12:07.8000 feet. It is still active but it has not accelerated or
:12:07. > :12:14.intensified. With an eruption like that, can it go in ate and flows?
:12:14. > :12:18.Can you get huge plumes and then it comes down? -- ebbs and flows.
:12:18. > :12:22.will see this repeated over the next few days. They are really
:12:22. > :12:27.unpredictable, volcanoes. It could go to nothing or it could become a
:12:27. > :12:37.big eruption. You can keep an eye on all of the active volcanoes on
:12:37. > :12:39.
:12:39. > :12:44.our map, many of them have webcams. Access them on our website: Also,
:12:44. > :12:50.send your questions in. We will be asking a few more of
:12:50. > :12:56.those later. Now, we have seen how lava can transform the landscape.
:12:56. > :13:02.But so can volcanic ash. In June of last year, a volcano called Puyehue
:13:02. > :13:06.started erupting. Earlier this year, with that eruption still ongoing,
:13:06. > :13:16.Hugh Tuffen from Lancaster University joined an expedition to
:13:16. > :13:33.
:13:34. > :13:37.go and see the eruption for himself. I wanted to be a vulcanologist
:13:37. > :13:40.because I love mountains and a love the idea that mountains can be
:13:40. > :13:45.alive, they are not just static and in the background, they are
:13:45. > :13:54.actually almost living things, changing the scenery in front of us.
:13:54. > :13:58.My specialism is rile lytic magma. It is this kiss and rich in cellar
:13:58. > :14:01.Cup. We almost never watch eruptions like this taking place.
:14:01. > :14:09.They are very rare and there have only ever been two worldwide in my
:14:09. > :14:14.lifetime. In June of last year, a volcano called Puyehue erupted for
:14:14. > :14:18.the first time in 50 years. The plume was 40 kilometres in altitude,
:14:18. > :14:25.disrupting flights in the southern hemisphere for some time. By the
:14:25. > :14:29.following January, it had calmed down. I had to get out there. It
:14:29. > :14:39.was an epic journey to get there, as the volcano is in a remote
:14:39. > :14:42.
:14:42. > :14:49.location. Five -- 500 miles south of the capital.
:14:49. > :14:54.The rainforest are normally green and lush, and full hummingbirds, it
:14:54. > :15:02.is beautiful. But we found it to be desolate and quiet, stifled and
:15:02. > :15:09.covered in ash. Do what up was tough, continuous
:15:09. > :15:15.uphill, carrying 25 kilograms. -- the walk up. John Castro and Ian
:15:15. > :15:22.Skipper joined me. John is an expert in this type of volcano.
:15:22. > :15:30.to Sheikh! Tell me about it. Ian is an expert on vent processes. We are
:15:30. > :15:34.two-thirds of the way up. We are hearing persistent rumblings.
:15:34. > :15:38.booming sound got louder and louder but we still could not see anything
:15:38. > :15:41.through the trees. But there was one point when there was a clearing
:15:41. > :15:51.and suddenly we could see this billowing ash rising up from the
:15:51. > :15:56.
:15:57. > :16:00.My hairs stood on end. I was look, Duff, Duff, Duff. It's fantastic.
:16:00. > :16:05.We had to find somewhere to camp. We needed water and far enough from
:16:05. > :16:13.the vents that we were out of range of any of the large blocks of lava
:16:13. > :16:17.that were being blasted out. Being so close to the vent felt
:16:17. > :16:20.exhilarating. It's just incredibly exciting to see the vent on one of
:16:20. > :16:30.the volcanoes that we've been studying for so many years. It's
:16:30. > :16:30.
:16:31. > :16:36.live right in front of us. Wow. Textbook. One of the unsolved
:16:36. > :16:41.mysteries of rhyolites is how the gas escapes. There has to be some
:16:41. > :16:45.way of how the gas gets out. It seems as though they were valves
:16:45. > :16:48.through which gas and ash was able to escape very rapidly, but then
:16:49. > :16:55.these were blocking up and then a new valve was opening up right next
:16:55. > :17:02.to it. Wow, look. It's just cleared itself there. This really helped us
:17:02. > :17:08.to think about the way that gas is able to escape from this very thick
:17:08. > :17:18.rhyolitic magma. It gradually got darker and darker and as it did so,
:17:18. > :17:18.
:17:18. > :17:23.the vents came to life. I then realised that I had a switch on the
:17:23. > :17:27.camera, which meant we could go to watch in infrared light and we
:17:27. > :17:32.could suddenly see bombs of lava that were being ejected on the long,
:17:32. > :17:36.lazy paths before they landed on the ground. It was a beautiful
:17:36. > :17:42.thing to watch, but also very useful as we can then work out how
:17:42. > :17:47.fast the bombs are moving and this all links in to how the gas is able
:17:47. > :17:52.to escape from the magma at the vent. It's very exciting for us
:17:52. > :18:00.indeed, because we are rhyolite experts and we've been studying it
:18:00. > :18:10.for years. To actually see all the secrets being revealed by Puyehue
:18:10. > :18:12.
:18:12. > :18:16.was quite something. Great tough from hue. We'll be joining him
:18:16. > :18:20.again for the other part of his expedition later in the programme.
:18:20. > :18:25.What struck me about that eruption, was it was turning a landscape
:18:25. > :18:31.white and yet, you think of col vanic eruptions turning land black,
:18:31. > :18:41.so why was that? -- volcanic ejupgss turning the land black, so
:18:41. > :18:42.
:18:42. > :18:46.where -- eruptions turning the land black, so why is that? There is
:18:46. > :18:55.hardly any silicone, so that's why they are grey and black, but
:18:55. > :19:05.although there is no change in chemistry, threw -- there is a
:19:05. > :19:06.
:19:07. > :19:10.change in texture. This is a smooth, polished. Pahoehoe is very runy and
:19:10. > :19:16.it flows and then it kind of freezes and cools quickly, so it
:19:16. > :19:18.has the glaze on top of it. Often, the other magma, you can see, it
:19:18. > :19:22.flows underneath, but on the surface you get a feeling of the
:19:22. > :19:27.motion and flow that goes on. This would have been seeping up out of
:19:27. > :19:32.the ground as we saw in some of the footage yesterday? That's the red
:19:32. > :19:37.rivers of lava. It would run quite quickly and almost be like a sort
:19:37. > :19:41.of treacle or something? Yeah. Creeping across. Look just next
:19:42. > :19:48.door to this. Same chemistry and similarly erupted from just over
:19:48. > :19:52.there and look at it. It is rubble here. This stuff is from a much
:19:52. > :19:57.more slow-moving lava. It's stickier and so when it cools it
:19:57. > :20:01.starts to cool and slow down. does it get sticky, why from the
:20:01. > :20:05.same col vain know? Temperature. When it's lower it get stickier and
:20:05. > :20:13.it's harder to move. Think of oil. The point is, this is horrible to
:20:13. > :20:18.walk on and you'll lacerate yourself and the people called this
:20:18. > :20:24.A'a, and they tell me this is because it hurts when you stand on
:20:24. > :20:28.it. As we have seen, volcanoes can cause devastation not just on land,
:20:28. > :20:32.but unfortunately on human populations as well. Since records
:20:32. > :20:36.began, it's believed that about 250,000 people have lost their
:20:36. > :20:42.lives as a result of volcanoes. In disaster movies, it's often this
:20:42. > :20:52.stuff, the lava, that is seen as the culprit, but how accurate is
:20:52. > :20:56.
:20:56. > :21:06.that? Ed Byrne discovers. classic 1997 disaster movie,
:21:06. > :21:07.
:21:07. > :21:12.volcano. It's got Tommy Lee Jones in it. A volcano has gone off in LA
:21:13. > :21:19.and lava is incinerating all in its path. How much of this is science
:21:20. > :21:24.fact and how much Hollywood fiction? Dr Alison is one of the
:21:24. > :21:29.country's leading experts. She wants to explode some lava myths.
:21:29. > :21:33.Alison, this was once lava and presumably if you heat it up hot
:21:33. > :21:41.enough it can be lava again? Probably have to heat it to 1100
:21:41. > :21:49.degrees or so. I see a torch here. Can we do that? Yes, we can. Don't
:21:49. > :21:53.try this at home, kids. Wow. It's pretty quick. You can see the gas
:21:53. > :22:00.bubbles are growing. Yes. It melted really quickly, but it flows very,
:22:00. > :22:06.very slowly, doesn't it? Yeah. have to be pretty low-moving to get
:22:06. > :22:13.killed by a lava flow? You can generally outrun one. That's quite
:22:13. > :22:19.cool. I just made lava. You did. Pretty sweet! What about these
:22:19. > :22:26.things? Lava bombs? How dangerous are they in the real world? Lava
:22:26. > :22:34.bombs form in explosive eruptions. Lava flows are when the advice kus
:22:34. > :22:37.fluid comes out and pours out the top and -- viscous fluid comes out
:22:37. > :22:42.and pours out and bombs are relatively big pieces. The bombs,
:22:42. > :22:48.when they come out of the vent, often they go on a trajectory like
:22:48. > :22:52.a Canon ball. This one is like one and surprisingly light for a rock.
:22:52. > :23:00.There are a lot of bubbles in there, so they are gases that are driving
:23:00. > :23:05.the eruptions. This is what they look like in real life. How far
:23:05. > :23:09.from a volcano do they generally fly? It depends on how explosive
:23:09. > :23:15.the eruption is, but generally, no more than a kilometre or something
:23:15. > :23:24.like that. What is the major killer then from a volcano? The main
:23:24. > :23:29.killers during eruptions and shortly after are pyroclastic flows.
:23:29. > :23:34.They go further away from the volcano than a bomb would go.
:23:34. > :23:38.an explosive volcano erupts it throws enormous columns of hot ash
:23:38. > :23:43.particles and gases into the atmosphere. Gravity can cause an
:23:43. > :23:47.ash column to collapse and when it does it can turn into what is known
:23:47. > :23:52.as a pyroclastic flow. These can travel dozens of miles, moving at
:23:52. > :23:56.hundreds of miles an hour, at temperatures of up to 1,000 C and
:23:56. > :24:02.they destroy everything in their path and since 1600 more than
:24:02. > :24:08.40,000 people have been killed by such flows. More than any other
:24:08. > :24:13.immediate volcanic hazard. Alison, explain to me how this tank can be
:24:13. > :24:16.used to recreate the flow? As you can probably tell, there is water
:24:16. > :24:21.in here. We are going to pretend this water is actually the
:24:21. > :24:26.atmosphere. This will be gas and we'll make our pyroclastic flow in
:24:26. > :24:33.here. This will be the volcanic ash and we'll be simulating an ash
:24:33. > :24:41.column above a volcano that becomes unstable and collapses. Then when I
:24:41. > :24:46.open this gate that's the volcano collapsing. Exactly. Here it goes.
:24:46. > :24:50.Typically in a volcano it's going downhill and it might hit a flat
:24:50. > :24:56.area, but because it's gravity driving it, it wants to go down, so
:24:56. > :25:06.it tends to stay in valleys and goes downhill. The flows can travel
:25:06. > :25:09.
:25:09. > :25:14.over land, over hills and even over water. When crack toia erupted, the
:25:14. > :25:18.flows killed throws of people across the sea. How could this have
:25:18. > :25:26.happened? Not even the scientists are sure, but Alison has a theory.
:25:26. > :25:33.We have got some ash heated to 600 degrees Celsius. We are going to
:25:33. > :25:37.pour it into the water and you can see the ash bouncing off. That's
:25:37. > :25:42.because we are having a little steam explosion. This all becomes
:25:42. > :25:47.clear when filmed with a high-speed camera. As the superhot ash hits
:25:47. > :25:53.the water the steam throws the ash back up into the air. Could this be
:25:53. > :25:57.what happened in Indonesia? steam explosions are adding energy
:25:57. > :26:03.and pressure and it's like a bit of a cushion and reduces the friction
:26:03. > :26:06.at the base and also keeping that ash in the pyroclastic flows that
:26:06. > :26:14.are sinking. That's why it just goes so much further over water
:26:14. > :26:19.then? That's part of the reason. There's another idea and that is
:26:19. > :26:23.that pummice has a lot of bubbles and it floats and you often get
:26:23. > :26:26.rafts on the sea and it might be that the flows are also making use
:26:26. > :26:36.of that raft to help them travel. Skimming on the rafts as well?
:26:36. > :26:38.
:26:38. > :26:43.Right. The fit many brings home it's not the flows, but the
:26:43. > :26:49.pyroclastic flows that kill. Later this week I'll really investigate
:26:49. > :26:54.those more carefully when I go to Vesuvius in Italy. We have looked
:26:54. > :26:58.at flows and lava and ash, but something that you may not think is
:26:58. > :27:03.a volcanic distructive force is mud. But, believe me, it can be. If you
:27:03. > :27:09.have an ash eruption, followed by heavy rainfall or the ash mixes
:27:09. > :27:17.with melted ice, you can get mud and that can often change into
:27:17. > :27:24.mudflows known as lahas. That happened in 1985 in Colombia. It's
:27:24. > :27:32.a volcano called Nevado Del Ruiz. These scenes are shocking to this
:27:32. > :27:36.day. It caused the death of 23,000 people. It was the deadliest
:27:36. > :27:41.volcanic eruption in south American history. Why was it, Iain, or why
:27:41. > :27:48.did it, I suppose, cause such a great loss of life? I think there
:27:48. > :27:51.was no monitoring. This mudflow started way up the valley. People
:27:51. > :27:54.could have had 30 minutes' warning if there had been an instrument
:27:54. > :28:00.telling them there was a flow on the way and people could have found
:28:00. > :28:04.high ground or something. One of the ironies of these disasters is
:28:04. > :28:07.they kickstart changes in technology and practice that make
:28:07. > :28:13.us forecast and study them much better. It's a sad testiment, but
:28:13. > :28:18.it's true. What is interesting is just it week, though, Nevado Del
:28:18. > :28:21.Ruiz has restarted again and if we can go to see where it is. It's
:28:21. > :28:27.just over here. If we have a look at the footage that has just come
:28:27. > :28:32.back in the last week from the webcams there, you can see plume
:28:32. > :28:36.activity and ash cloud coming out of the crater. Here it is in the
:28:37. > :28:40.background. This is the modern town there. What is really interesting -
:28:40. > :28:46.there, it's a much more active scene. That's one that we will be
:28:46. > :28:51.keeping an eye open on. Do we think that - are they starting an
:28:51. > :28:56.evacuation? Is there a class of warnings as far as they are
:28:56. > :29:02.concerned? They've raised the warn to 11-2, which means it's likely in
:29:03. > :29:06.days or weeks and evacuation has started. Even if it's as bad as
:29:06. > :29:11.1985 the death toll won't be as near. That is a testiment as to how
:29:11. > :29:21.far we have come in 30 years. can keep an eye on the webcams of
:29:21. > :29:22.
:29:22. > :29:27.that and all the activity ones by going to the website: It seems they
:29:27. > :29:30.are our ultimate adversities and there's nothing we can do to stop
:29:30. > :29:34.them erupting, but there's an amazing story, which I discovered
:29:34. > :29:44.in Iceland of a community that fought against a volcano to stop
:29:44. > :29:44.
:29:44. > :29:52.what seemed to be an inevitable Five miles off the southern coast
:29:52. > :29:55.of Iceland lies a small volcanic island. This is Heimaey and the
:29:55. > :29:59.approach to the harbour is protected by looming cliffs of
:29:59. > :30:09.black rock, a clue to events which rocked this place to its
:30:09. > :30:28.
:30:28. > :30:34.At 2am on the morning of January 23rd, 1973, a fissure in my long
:30:34. > :30:41.opened up and split this part of the island in two. -- a mile long.
:30:41. > :30:46.Today, the evidence of the eruption is easy to find. This was the stuff
:30:46. > :30:53.that was coming out of that volcano. It is actually a sort of ash, but
:30:53. > :30:58.it is more like gravel. It was literally raining down. Of course,
:30:58. > :31:05.it was not in her stuff like this, it was that about 1000 degrees
:31:05. > :31:14.Celsius. -- inert. So to be here when that happened
:31:14. > :31:20.must have felt like being in a living hell. To the 5000
:31:20. > :31:24.inhabitants of this tiny island, it felt like the end. The volcano
:31:24. > :31:31.threatens to engulf everything, and although it was a heart-wrenching
:31:31. > :31:36.decision, they knew immediately that they had to leave. It was pure
:31:36. > :31:40.luck that the night the volcano erupted, the harbour was full of
:31:40. > :31:43.fishing boats. On a normal night, all of the men and all of the boats
:31:43. > :31:50.would have been out to sea. But there had been a huge storm the
:31:50. > :31:54.night before or, that had kept men and boats at home. When the volcano
:31:54. > :32:02.erupted, suddenly there was a means of escape from what must have
:32:02. > :32:05.seemed at the time an inescapable fate.
:32:05. > :32:14.During the first night of the eruption, almost the entire
:32:14. > :32:19.population was evacuated by boat to the mainland. 100 or so people,
:32:19. > :32:28.mostly young men, stayed behind to try and save as many homes as they
:32:28. > :32:35.could. At first, they concentrated on Clearing ash, hoping to stop
:32:35. > :32:45.roofs collapsing. But the ash kept falling and many houses were soon
:32:45. > :32:46.
:32:46. > :32:51.completely buried. Just this single chimney now emerges where a whole
:32:51. > :32:56.community once thrived. Worse was to come, as a huge laugh off low
:32:56. > :33:03.advance towards the town, consuming everything in its path. -- lava
:33:03. > :33:12.flow. And when the lava finally reached the coast, but began to
:33:12. > :33:18.threaten the most valuable part of the island. -- it began to threaten.
:33:18. > :33:21.The harbour entrance was just a few hundred metres wide. As lava added
:33:22. > :33:29.new vans to the coast, there was the chance that the gap might be
:33:29. > :33:33.closed forever. For those who had stayed behind,
:33:33. > :33:40.like this local welder, that was the moment when the real fightback
:33:40. > :33:44.began. TRANSLATION: We knew we had to save the harbour because our
:33:44. > :33:48.livelihood depends on our ability to be able to sail out to sea. If
:33:48. > :33:53.we're going to live here, we have to be able to fish. Our way of life
:33:53. > :33:58.would not last long without the fishing industry, that is how it is.
:33:58. > :34:05.It seemed unthinkable that anything could be done, but one
:34:05. > :34:10.volcanologists have an idea. -- one a vulcanologist had an idea.
:34:10. > :34:14.Several years earlier, he had seen how a lava flow near the coast had
:34:14. > :34:19.changed direction when it came into contact with sea water. He wondered
:34:19. > :34:24.if the same thing can be achieved deliberately this time in Nevado
:34:24. > :34:29.Del Ruiz. -- in Heimaey. whispered to work welding pipes. As
:34:29. > :34:34.soon as we began spraying sea water on the lava, it starts and to
:34:34. > :34:38.harden. We noticed that the laughter was losing ground and
:34:38. > :34:48.actually being diverted. -- the lava. Everyone was saying, it is
:34:48. > :34:49.
:34:49. > :34:53.working, spray more, spray more! The team worked around the clock. A
:34:53. > :35:03.huge network of pipes was put together, and extra pumps were
:35:03. > :35:03.
:35:03. > :35:11.shipped in to get water right into the heart of the lava flow.
:35:11. > :35:21.TRANSLATION: An unbelievable amount of sea water was sprayed onto the
:35:21. > :35:22.
:35:22. > :35:27.lava to stop the advance. Huge amounts. Constantly. I had a no
:35:27. > :35:34.idea how much, but it would be fun to know.
:35:34. > :35:39.Incredibly, cooled by the water, a huge barrier of solidified lava was
:35:39. > :35:46.built up alongside the harbour. This new wall of rock stopped the
:35:46. > :35:52.lava flow 200 metre short of the cliffs on the far side. Today, the
:35:52. > :35:57.gap remains and access to the harbour has been preserved.
:35:57. > :36:01.By standing up to the volcano, the people of Heimaey had maintained
:36:01. > :36:07.their livelihood and to this day, they continued to harvest the rich
:36:07. > :36:14.fishing grounds of the northern Atlantic.
:36:14. > :36:19.It must have been a really fantastic feeling, that somehow,
:36:19. > :36:22.against all odds, you were doing it. TRANSLATION: A volcano was not
:36:22. > :36:26.exactly an ordinary type of adversity, not a tall, so it was
:36:26. > :36:31.amazing to see the plan actually working. It is incredible that we
:36:31. > :36:38.were able to stop the lava and save our town and are -- and a harbour.
:36:38. > :36:42.It was miraculous. It just worked. In 1973, the people of Heimaey had
:36:42. > :36:47.the audacity to stand up to the worst that nature could throw at
:36:47. > :36:51.them. It was an amazing display of resilience. For Iceland, it was a
:36:51. > :36:57.rare victory for the people in their long battle against the
:36:57. > :37:00.volcanoes in their midst. Iceland's Prime Minister told me that it was
:37:00. > :37:05.5000 years since the last volcano here and perhaps it will be another
:37:05. > :37:15.5000 years until the next. As he put it, the people of Iceland live
:37:15. > :37:18.
:37:18. > :37:22.with fire beneath their feet. An incredible story. Perhaps just
:37:22. > :37:30.as incredible is the fact that 20% of the world's population live
:37:30. > :37:35.within 100 kilometres of a volcano. This is bigger island, and we are
:37:35. > :37:41.just down chain of craters road. That is the greater were we were
:37:41. > :37:49.last night, the Halem'uma'u crater. And this is the volcano that
:37:49. > :37:58.everyone has turned their attention to, the biggest volcano and the
:37:58. > :38:04.world. The lava flows, in 1984, flowed down the side here towards
:38:05. > :38:11.the main town on Big Island, Hilo. When this blows, it throws out an
:38:11. > :38:20.enormous amount of lava. It pours down the mountainside, as you can
:38:20. > :38:25.see. In that last eruption, the lava. Within four miles off Hilo.
:38:25. > :38:28.It is a fairly terrifying fact. It could happen and it is already
:38:28. > :38:35.happening down here. There are lava flowers that have taken over a
:38:35. > :38:39.Little Town that Ian and I will visit tomorrow. It is called
:38:39. > :38:47.Kalapana. The population here have got their eyes on that. I believe
:38:47. > :38:52.Ian is out on the lava and we will be interviewing gone Swanson again.
:38:52. > :39:02.-- Don Swanson. Water was the safe here in Iceland, but here, it is
:39:02. > :39:06.different? -- was the saviour. Water can cause expose of eruptions.
:39:06. > :39:11.It heats up and forms steam and the steam power as the explosions.
:39:11. > :39:21.Talking of explosions, this is the fissure that erupted in. 1969. This
:39:21. > :39:27.is. The fountain here was not very large but during the course of the
:39:27. > :39:31.summer, it became very high. Extraordinary. Why is it that
:39:31. > :39:40.volcanoes switch from a gentle, if you sit tight, too explosive?
:39:40. > :39:43.seems as if the summit region has to come maps -- has to collapse so
:39:43. > :39:50.water can get into the plumbing system. Once that happens, you
:39:50. > :39:57.generate steam explosions. Kilauea has a Dr Jekyll And Mr Hyde
:39:57. > :40:07.personality. It is by Bola! It can switch from lava flows to expose of
:40:07. > :40:11.
:40:11. > :40:16.eruptions. -- by Polar. explosive cannot get? -- can it get.
:40:16. > :40:22.We have had six eruptions in the last 1200 years sending ash well up
:40:22. > :40:26.into the jet stream, 10, 15 kilometres high. And in the tropics,
:40:26. > :40:32.that allows it to move around. is the problem with aircraft
:40:32. > :40:38.Catholic. -- aircraft traffic. It can be really dangerous. This
:40:38. > :40:42.landscape is incredible. These are trees! These are trees. The lava
:40:42. > :40:47.flowed around the tree and it was cooled by the tree. Then the level
:40:47. > :40:54.of the lava dropped, and this became an island. It shows you the
:40:54. > :41:02.personality of what we're looking at. We are exploring that in Chile
:41:02. > :41:09.a different way. The first day was all about
:41:09. > :41:14.watching events and the plumes. The second day, we wanted to get in and
:41:14. > :41:21.watch the lava flow itself. This was an obsidian lava flow. It is
:41:21. > :41:29.volcanic glass. This is solidified magma, which has not formed any
:41:29. > :41:36.crystals. It was quite a slog to get there,
:41:36. > :41:46.going up a bridge and downer Bridge, and eventually we came over a slope.
:41:46. > :41:46.
:41:46. > :41:49.-- down a ridge. Eventually we saw a spectacular lava flow.
:41:49. > :41:59.But was the first time in our lives that we had ever seen and obsidian
:41:59. > :42:00.
:42:01. > :42:04.flow, a rhyolitic lover flow in action. -- a lava flow. That is the
:42:04. > :42:08.lava float there, the material flowing out from the base of the
:42:09. > :42:14.volcano. This was as far from a river of red lava as you can get,
:42:14. > :42:24.it was like a glacier of creaking lava, groaning, almost
:42:24. > :42:25.
:42:25. > :42:29.imperceptibly moving. One to his unique is that we are
:42:29. > :42:34.seeing the explosive phase and the effusive phase, which is still
:42:34. > :42:39.evidence -- which is still active. Rhyolitic eruptions have always
:42:39. > :42:44.been couched in terms of a full serve -- explosive or effusive, so
:42:44. > :42:47.easily -- either it is producing pumice or lava. Both are happening
:42:47. > :42:51.at the same time so what we're watching here is new evidence that
:42:51. > :42:58.is telling us something detail about how these volcanoes work.
:42:58. > :43:02.John went down to the edge of the lava flow. John is collecting some
:43:02. > :43:12.samples of obsidian. I hope to see him running away from their pretty
:43:12. > :43:28.
:43:28. > :43:34.fast. Move! Definitely some hard one samples.
:43:34. > :43:41.The that samples is a nice resource for us, that we can use to study in
:43:41. > :43:45.more detail how the love for deforms and how it loses gas. --
:43:45. > :43:52.how the lava reforms. We are running out of food and water. We
:43:52. > :44:00.decided to go back down to the ballet. As we walked down through
:44:00. > :44:04.the forest, it was so quiet again. Eventually, when we got down to the
:44:04. > :44:13.valley itself, everything seemed brilliantly colourful after the
:44:13. > :44:18.black and white landscape that we had come from.
:44:18. > :44:24.We went down to a beautiful lake at the foot of the volcano. Many of
:44:24. > :44:29.the lakes around the volcano have floating rafts of pumice. It is
:44:29. > :44:37.such a light rock as it is full of bubbles. There are huge slicks of
:44:37. > :44:40.pumice floating on the surface. It is a beautiful thing to witness.
:44:40. > :44:47.When you come down from the summit, there is no better way to get
:44:47. > :44:51.cleaned up than to go for a little swim in the exfoliating pumice raft.
:44:51. > :44:55.It was one of the most exciting trips I have ever been on. It was a
:44:55. > :45:00.practical challenge, tyrant, and really exciting as well. We felt a
:45:00. > :45:06.little bit on the edge sometimes, just through being so close to the
:45:06. > :45:10.events. For me, being able to watch these processes that I had been
:45:10. > :45:20.studying for years, that was really a special thing that I will
:45:20. > :45:24.
:45:24. > :45:33.You can see why he thinks that. This is obsidian. Beautiful. This
:45:33. > :45:37.is glass. Absolutely. Have a look at this. That is the pumice. You
:45:37. > :45:42.can see all the gas bubbles. things from the same col vain know
:45:42. > :45:46.and totally different formations. There's a lot of silicone and that
:45:46. > :45:50.blasts out. You are taking glass into your lungs. Good for your feet
:45:50. > :45:54.though. Time for our viewers' questions. We have this crackers.
:45:54. > :46:00.One of the topics that has come up tomb and again is yellowstone, when
:46:00. > :46:05.is it going to blow? Big question. This is the supervolcano in America
:46:05. > :46:09.and we are going to be dealing with that on Thursday, so we'll hold off
:46:09. > :46:13.there. Tune in then. The other thing, our favourite fact of
:46:14. > :46:18.yesterday's programme was to tell you that the volcano was not only
:46:18. > :46:28.the biggest in the world, but the second biggest in the Solar System,
:46:28. > :46:34.but everyone wants to know what is the biggest? It's the one on Mars.
:46:34. > :46:41.Mr Judd and her year-nines in Malden in Essex, they want to know
:46:41. > :46:45.will there be an eruption in England? An interesting one. No.
:46:45. > :46:55.There was activity in Britain about 50 million years ago, but we have
:46:55. > :46:59.shifted our position. The source is under Iceland now. I'm pretty sure.
:46:59. > :47:04.John Hunter in Workington in Cumbria, he wants to know, does
:47:04. > :47:08.lava contain precious metals? does. The hot fluid has lots of
:47:08. > :47:12.precious metals that gets blown out in the plumes. There is a lot of
:47:12. > :47:18.metals coming out. On Mount Etna, this is my favourite fact, every
:47:18. > :47:23.year 700 grammes of gold gets ejected. You will be out there with
:47:23. > :47:27.your little bag. It's not that much, given how much stuff comes out,
:47:27. > :47:33.it's not worth going out with your panning basket. Paul Hill in Ealing,
:47:33. > :47:38.he wants to know, how far down is the deepest magma chamber? That's
:47:38. > :47:43.quite hard to tell, because often they have different chambers,
:47:43. > :47:53.there's a lower and they climb up to shallows, but tens of miles down.
:47:53. > :47:53.
:47:53. > :48:02.Did you not say it's about a mile under this Halem'uma'u one here?
:48:03. > :48:07.Typically. Keep your questions coming. It may surprise you that
:48:07. > :48:12.volcanoes can be created as well as distructive. They build new land
:48:12. > :48:17.and with that comes new life and the national park here, where we
:48:17. > :48:20.are, is a World Heritage Site not for the volcanoes, but
:48:20. > :48:26.extraordinary biodiversity. A lot of you have been in touch saying
:48:26. > :48:32.you want to see the flora and fauna, and you are in luck and so were we,
:48:32. > :48:36.because last week an ejock gist, who works here found and -- ecol
:48:36. > :48:43.gist who works here phoned and said there is a plant that flowers once
:48:43. > :48:53.in the 25-year lifespan and then it dies. And there's one, in fact more
:48:53. > :48:54.
:48:54. > :49:00.than one, in bloom right this minute and we had to go and see it.
:49:00. > :49:03.It's beautiful. You are on the volcano at 6600 feet elevation and
:49:03. > :49:13.where I'm taking you is a really special place and I think you'll
:49:13. > :49:18.
:49:18. > :49:21.enjoy it. Look. These are the flowers. They are the silver shards.
:49:21. > :49:26.I don't think I've ever seen anything like it. You don't always
:49:26. > :49:31.see them flowering. If you had come last year there would have been no
:49:31. > :49:41.flowering plants. It's the most beautiful thing. I agree. And the
:49:41. > :49:41.
:49:41. > :49:48.scent. Yes. There's a very heavy smell of honey. They live to be
:49:48. > :49:51.maybe 20 or 30 years. How rare is it? Very rare. We only know of
:49:51. > :49:59.three natural populations remaining in the world. All are on this
:49:59. > :50:09.mountain and the largest population is only 700 individuals. This
:50:09. > :50:10.
:50:10. > :50:13.amazing plant is totally indemic to this volcano? Yes Yes. There are
:50:13. > :50:21.others found on other mountains on the different islands. This is
:50:21. > :50:24.specific to here. That's extraordinary. It was so unusual,
:50:24. > :50:29.but we as a crew were actually in the right spot at the right time.
:50:29. > :50:34.How many times have you said, "You should have been here last week."?
:50:34. > :50:39.Spot on. What a great surprise and treat it was seeing that. It's
:50:39. > :50:44.lovely. That sentiment that volcanoes are places where life can
:50:44. > :50:48.flourish to such exotic things is really important. It's easy to
:50:48. > :50:58.forget through all the images of spewing lava. I went out to see the
:50:58. > :51:01.good side of volcanoes the other day. Walking through the black lava
:51:01. > :51:06.fields it's hard to imagine that volcanoes are capable of anything
:51:06. > :51:09.other than total destruction. Around 150 years ago this beautiful
:51:09. > :51:15.bay used to stretch all the way around here. Those trees over there,
:51:15. > :51:20.they were on the shoreline and beside it was a thriving little
:51:20. > :51:25.fishing village. In 1859 this happened. A huge lava flow flowed
:51:25. > :51:28.from the biggest volcano and it for through the trees and destroyed the
:51:28. > :51:37.fishing village and filled in half the bay as it spilled out into the
:51:37. > :51:41.sea. Although the eruption was devastating, the lava created new
:51:41. > :51:46.land and added almost two square miles to the shoreline, providing a
:51:46. > :51:55.new habitat for life. And it's not just here. All over the island,
:51:55. > :52:00.volcanoes are building land. They built the wol island and every
:52:00. > :52:04.other island in the entire chain. - - whole island and every other
:52:04. > :52:08.island in the entire chain. Now there's a whole string of island
:52:08. > :52:13.paradises. All of them built by volcanoes. Blanketed in forest and
:52:13. > :52:22.bathed in sunlight, the islands have become a haven for life,
:52:22. > :52:26.teaming with -- teeming with unineat species. -- unique species.
:52:26. > :52:30.This looks really rich. It is. The amazing thing about this forest is
:52:30. > :52:38.virtually everything we are seeing is found nowhere else in the world,
:52:38. > :52:45.only in Hawaii. This is a healthy forest, so in terms of plants,
:52:45. > :52:52.there's over 2,000 species found only here. I can hear some birds.
:52:52. > :52:57.The chattering is the Nectar- feeding bird and it has a curved
:52:57. > :53:06.bill to fit into the flowers, so there's an incredible pairing of
:53:06. > :53:11.the plants and birds here. important is volume cannism here?
:53:11. > :53:21.It's fundamental. It's founded by the volcano. They create the
:53:21. > :53:25.islands and they are in the ocean. It's the arena for all the
:53:25. > :53:30.evolution and adaptation to happen. Even the rain, because obviously it
:53:30. > :53:40.falls on this speck of land. Without that we wouldn't have the
:53:40. > :53:47.amazing rain forests, that's for sure. Even in this forest, you are
:53:47. > :53:51.never far from the devastation. The sun's out. It comes and goes.
:53:51. > :53:57.that's it. The forest is there and now this. We are into the lava.
:53:57. > :54:01.These flows come from an eruption in 1974. The cracks ripped open
:54:01. > :54:09.through the earth. It's incredible, that abrupt line between lush
:54:09. > :54:15.forest and suddenly, wham, black lava. It may look desolate, but
:54:15. > :54:20.life has found a way to thrive again. This is the native tree,
:54:20. > :54:25.found nowhere else in the world. They are adapted to grow out of
:54:25. > :54:28.here. What is it rooting into then? There's no soil and in many cases
:54:28. > :54:33.they don't even need to be in a crack, as you would expect. They
:54:33. > :54:41.can be just stuck to the side of a rock, with the roots goes over the
:54:41. > :54:45.top. Many think volcanoes are fertile, but it's hard for plants
:54:45. > :54:50.to get at the nutrients? Yes. Lava has all the minerals a plant could
:54:50. > :54:53.ever want, but they are locked into the lava. As near as we can figure,
:54:53. > :55:00.this tree is surviving completely off of what little nutrients there
:55:00. > :55:04.is in rainwater. It's a symbol of resilience? Absolutely. As the
:55:04. > :55:08.volcanoes age and become inactive the raw materials we are seeing
:55:08. > :55:12.here will begin to erode and be weathered away and it will
:55:12. > :55:17.contribute to the rich col vainic soils we always here about. -- hear
:55:17. > :55:25.about. In a few decades, the trees will have transformed the land back
:55:25. > :55:29.into lush forest. In a few thousand years the mineral-rich lava will be
:55:29. > :55:34.broken down into soil that will support countless more plant
:55:34. > :55:40.species. They do a lot more than provide new trepbts for plants to
:55:40. > :55:48.grow, because without -- new Trents for plants to grow, because without
:55:49. > :55:54.them there wouldn't be any plants at all. Here at the summit there's
:55:54. > :56:04.barely a plant to be seen, but it's what's in the air that's important.
:56:04. > :56:04.
:56:04. > :56:10.That huge cloud is mostly water vapour. Also sulphur dioxide and
:56:10. > :56:17.Co2, which is crucial for plants because it allows them to process
:56:17. > :56:23.the sun and store it as energy. When our planet first formed 4.5
:56:23. > :56:28.billion years ago it was volcanic activity that put Co2 into the
:56:28. > :56:34.atmosphere, so without it plants would never have evolved. We tend
:56:35. > :56:38.to think of Co2 as a greenhouse gas, keeping the planet warm. Too much
:56:38. > :56:43.and it can make the planet dangerously warm, but too little is
:56:43. > :56:49.also dangerous too. If there was none in the atmosphere then heat
:56:49. > :56:54.would just leak out into space. If there was no greenhouse gases at