DISCOVERY ‘67: HAWAII, LAND OF VOLCANOES

[Music] this is a recent volcanic eruption in the state of hawaii there's enough power there to turn a forest into a wasteland enough to bury a complete village enough to change the size and shape of an entire state we'll find out more about how these islands were formed today when discovery takes a first-hand look at hawaii land of volcanoes [Music] discovery 67 the award-winning program for young people with bill owen and virginia gibson hi and welcome to discovery today we've come to hilo on the island of hawaii it's a small city not much bigger than a large town you might walk through hilo's town square and imagine that you were in a county seat in ohio or indiana it's an american town all right phil but a short walk away from this square you soon begin to realize that there's a lot here that's different from what you might see in most towns on the mainland although it's small by mainland standards hilo is the largest city in the island of hawaii and it's the county seat of the county of hawaii but its citizens come from a surprising variety of places there are filipinos here and a couple of days a week there are filipino movies playing in hilo's motion picture theaters the next night the films may be japanese because about 75 of the population on the island of hawaii is of japanese extraction there are tahitians here chinese and tongans in addition to hawaiians and people from the mainland where there are different kinds of people you find different kinds of habits and customs you can see the differences in street signs grocery stores and restaurants one of the most famous sites in hilo is right here in front of the hawaii county library this huge rectangular stone is called the naha stone and it was originally put in front of the temple of pinau as a test for chiefs to prove that they belong to the royal family if you did belong to that royal family bill you were supposed to be able to turn over this heavy stone all by yourself and according to legend king kamehameha was able to accomplish this feat and the story has endured for hundreds of years the islands that make up the state of hawaii stretch 1500 miles across the central pacific ocean they're only tiny dots on any map of the pacific and in reality they're the tops of a range of great mountains but together they make up our new estate scientists claim that the state of hawaii is built on top of the greatest mountain range on earth the lowest of the mountains which make up the hawaiian islands rise fifteen thousand feet from the ocean floor and the largest of them the mountain called mauna kea here on the island of hawaii rises almost thirty thousand feet above its base about thirteen thousand feet of it is above sea level these are the hawaiian islands eight principal islands running from north to south kauai nihihao oahu molokai lanai kaholave maui and this one where we are hawaii hawaii is called the big island but they could also call it the new island because it's the most recently formed as a matter of fact it isn't even finished yet none of us would be here not a palm tree not a fine hotel not a tourist not even the people of hawaii themselves were not for a period of violent volcanic activity which created these islands in dramatic scenes like these hawaii holds many of the secrets of her origins up here in hawaii volcanoes national park this is what a volcano looks like when it's not steaming and boiling and pushing its way through the earth's crust this crater is called kilauea it's quiet down there but that doesn't mean there's nothing going on everything around us is testimony to the power of the fiery molten mass which lies under the surface of the hawaiian islands ready at any moment to make itself felt again these are ohia trees or they were before the 1959 eruption which turned a verdant forest into a charred ruin in just a few fiery hours what lies between them isn't soil there's very little pure soil on the island of hawaii and here it isn't lava either it's ash blown out of the crater in the form of red hot cinders during violent eruptions and explosions that little hill is new too it isn't a hill at all really but a cinder heat blown up here 400 feet by the violence of the subsurface convulsions that were going on down there this is what the same crater kilauea eaton looked like on the night of november 14 1959 [Applause] that's how kilaueaiki came to look as it does at this moment but how long will the crater stay this way there could be a new eruption at any time what can we learn about future eruptions by studying the conditions created by the last one well jenny there are scientists of the us geological survey working on the floor of the lava lake right now to find out some of the answers and we'll join them down there in just a minute in order to understand more about the formation of these islands the geologists of the u.s geological survey go into the craters of hawaii's volcanoes from time to time to measure and study the changes that are constantly taking place down there today we're going with them down 400 feet into kilauea to take the temperature of the molten mass underneath the surface of the lava lake it isn't particularly difficult getting into the crater of kilaueaiki but it would be if the men had to carry all of their tools and equipment on their backs so they've devised a tram line to take the heavier pieces to the bottom one of the ways the men up top know their equipment has reached the bottom is by watching the shadow of the pack as it moves across the crater floor by the time you get halfway down you can pretty clearly make out the geological equipment which for some months now has been a visible feature of the floor of the lava lake what the men of the u.s geological survey have been doing here is very much like the work that goes on in potential oil fields before the digging of a well [Music] [Applause] [Music] the crater of kilauea ike has become a laboratory for these geologists by studying the nature of this lake of lava they can add knowledge to man's limited store of information concerning the formation and future of these islands and perhaps some information as well on how the rest of the earth was formed under this crunchy brittle crust there's a bright red vein of molten rock [Applause] if you pick up a bit of the cooled and hardened crust you'll see it resemble something that might have come out of an old-fashioned furnace this is the solidified form of the molten basalt which rose from deep within the earth's crust but the geologists would still like to know what's going on beneath the surface [Music] [Applause] [Music] [Applause] here near the center of the crater the geologists have drilled a three and a half inch hole into the hardened crust on top of this lava lake they have bored down almost to the point where the rock is molten today they're going to take the temperature of the matter 80 feet below in order to test the temperature beneath the surface the geologists like dr richard fisk use a long snake-like rod called a thermocouple the thermocouple is now on the bottom and we can read the temperature of the material near the base of the crust running through this sheathing are two wires of slightly different alloy compositions these wires are welded together just at the bottom of the thermocouple the great heat down there generates a tiny electrical voltage which passes up the wires and we measure this voltage here with the potentiometer if i measure this voltage right now we see that the temperature at the bottom of the hole is about 1 000 degrees centigrade or 1 800 degrees fahrenheit it's actually possible to see the molten lava glowing brightly 80 feet down in the drill hole from the surface it looks as if we're actually looking into the center of the earth the next part of the job is to deepen the hole and send the drill bit down for a sample of the molten material because the drill has to be water-cooled at all times to keep it from being destroyed at the high temperatures the melt turns to solidified material almost as soon as the drill bit reaches it in just a few minutes the drill bit will come out when it does it'll bring a cylinder of solidified melt with it here's a drill bit that came out just a few moments ago this must be the core sample here right dick that's right bill it's hard already oh yeah well just a few minutes ago this was uh partly molten exactly why are you geologists so concerned with these particular core samples well here in our kilauea we have the unique opportunity to study basaltic rocks in the process of forming and this has already given us a great deal of information about the origin of kilauea volcano about the origin of the hawaiian islands and furthermore about the origin of basaltic rocks all over the world there's always activity beneath the surface here because the five volcanoes which created this island of hawaii this volcano island haven't finished their work yet this is one of the best places in the world for the study of volcanoes and the tools for that study are all around us there are 12 devices called seismometers placed at various locations around hawaii volcanoes national park each of them is attached to a seismograph back in the observatory on the rim of the great crater of kilauea earth movements produce a response which is registered instantly by the pens moving across these drums of smoked paper those smoked paper drums are conventional seismographs which are still in use but even better are the new film techniques now the impulses from the seismometers are recorded on film and you can see them clearly on this viewing screen this equipment is designed to record volcanic activity and yet it will also record a passing truck or a bulldozer working in a field dick how do you know which is which well it's fairly easy if we look here at the record we see several different things at the top the traces are seen to be slightly wiggly this is just noise picked up by the seismometers all the time but here we see the trace made by the bulldozer operating about two miles away from the seismometer here at the observatory it is a con continuous jagged trace indicating that the bulldozer was operating over this period of time on the other hand here's an earthquake it arrives abruptly at a number of different seismometers scattered widely over the summit of the volcano it also produces jagged lines but these lines gradually tail out and disappear well dick we've been down in the crater we walked on the surface of a lava lake and we've seen how a seismograph works but what goes on beneath the surface well let me show you bill here's a very simplified cross-section of kilauea volcano the first thing you'll notice is that the volcano we see above sea level is only a very small part of the total mountain actually the slopes of the volcano extend down to a depth of 18 or 19 000 feet below sea level now the enormous amount of lava that builds this pile is generated at a depth of about 40 miles and if we were to draw this here on this section we would have to do it below the level of the blackboard here this lava rises up and accumulates in a shallow chamber at a depth of about two or three miles below the summit of the volcano as the lava accumulates here it causes the entire summit of the volcano to inflate well dick how do you know it's inflated well we have various methods for measuring this inflation we measure the inflation with tilt meters we measure it with a geometer that very accurately determines the amount of horizontal expansion as the inflation takes place and we also run precise level lines over the summit of the volcano and from the combination of these three methods we found that the volcano has inflated more than two feet since the last eruption pick with all your scientific information and instruments are you able to tell when the next eruption will actually take place well unfortunately the volcano does not operate on any kind of a timetable after each eruption or during each eruption there are some changes at depth some faulting movement of the structure of the volcano and so as the volcano inflates the next time we are never really sure just how much inflation will have to take place before the lava can break through to the surface now you can't tell when it will take place how about where can you tell us that well again we cannot pinpoint any spot but there the eruptions fall into two main classes the first are what we call summit eruptions the lava leaves the shallow reservoir here and moves nearly vertically to the summit of the volcano and erupts in or near the summit caldera here just outside of the observatory or another type of eruption is one in which the lava travels underground for as much as 30 miles east of the summit and erupts on the flank of the volcano this just this kind of eruption took place in 1960 and completely devastated the town of capohol so that's how a volcano erupts but what do you think it would be like if you actually lived in the path of a lava flow we'll find out in just a minute in hawaii there are two kinds of lava flows the more common of them is called pahoa hoa and it means the rather rope-like form of lava which spreads out across so much of hawaii it's baha'u'llah we're standing on right now in 1960 there was a town here a town called kapoho on january 14th of that year an eruption broke out in the crater of kilauea only one quarter mile north of kapoho village for a few hours the line of small lava fountains was half a mile long but eventually the flow concentrated and resulted in a huge double fountain at times reaching a height of 1500 feet a pahoehoe flow destroyed a papaya grove while crumbling lava advanced through a field lava poured eastward into the ocean and spread out covering an area of four square miles lava flows like these can move at the rate of 20 miles per hour most of kapoho village was destroyed the eruption which had begun on january 14 finally ended on the 19th of february [Music] a village was lost valuable agricultural land was lost but at the end of the eruption there were some 500 acres of new land land that had been created by lava pouring into the sea not too far from the village of kapoho is south point the southernmost part of the united states south point is still growing and as long as there's volcanic activity on the island of hawaii chances are it'll continue to grow because it's in the line of lava flow of hawaii's five major volcanoes three of them are still classed as active until they are termed extinct or even dormant no map of hawaii will really be permanent the story of lava and volcanoes has a violent and terrifying beginning but the end of the story is something else again it's hard to believe that much good could come from the rubble which is left on the earth after an eruption it's burned out dry and seemingly useless that's not the whole story in case the green and rich portion of the big island didn't tell us enough it's an area within volcanoes national park which gives us a happy ending to the story of volcanic eruption this is which the park department calls bird park ekipuka is an old lava flow which is decomposed but which has not been covered over by new outpourings of lava once in the past this kipuka was as barren and hopeless as the new land at the tip of south point some of the history of volcanoes is contained in the kipuka and so is some of the history of the hawaiian people this fern is called hapu'u it's young fronds before they're unfurled are curled toward the center of the parent plant they're covered with a substance called pulu this pulu is a little like a moist brown cotton soldiers took it into battle as part of their first aid kit and mothers used it to cradle the heads of their new babies inside the untroubled green lushness of the kipuka and out here where the earth steams and smells of sulfur it's all part of the volcanic time capsule which is the island of hawaii these are the alloy hotfields and they were named after the pet pig the wayward husband of the hawaiian goddess of the volcanoes the hawaiians believed that the goddess pele determined when the earth would open and pour out fire and liquid rock when will it happen again geologists say that it's overdue right now the pressures have built up to the point where by rights it ought to have happened already and a few weeks after we filmed this program it did happen kilauea began to erupt on november 5th the most active volcano in the world lived up to its name and about 20 million cubic yards of lava began spewing out events from the floor of halemaumau crater which is at the summit of kilauea volcano at one time the molten lava rose to a hundred feet in height [Music] in a traditional ceremony some hawaiians to keep pele quiet and happy go every year to the edge of kilauea and throw in offerings of pork peely grass and red fern and a tiny fish with a long hawaiian name humuhumu nukunuku apua credited to superstition or accident pele and her volcanoes are for the moment relatively quiet we'll be back in just a minute we hope you've enjoyed today's visit to volcanoes national park if you'd like to find out more about hawaii our 50th state then ask a librarian for any of these books hawaii by charles a borden hawaii naii by ruth m tabra and this book chemo and madame paley by virginia nielsen be with us next week as discovery continues to discover america bye bye bye the discovery unit's transportation and promotional consideration provided by united airlines [Music] so this has been a jewels power production in association with abc news and public affairs