ARUN RATH, HOST:
If you haven't seen the images coming out of the Big Island of Hawaii this week, well, what's happening is just incredible. Lava flowing from the Kilauea volcano is inching closer to the village of Pahoa. As of today, the lava's leading edge is stalled just a few hundred feet from the nearest home and the main road. But John Lockwood, a volcanologist who lives near Pahoa, says underneath the flow, things are moving in lava tubes, or what he calls pyroducts. We called him up on Skype.
JOHN LOCKWOOD: So, right now, even though no lava's being supplied directly to the flow front, there's plenty of what you call breakouts. Lava is breaking out from the sides of the flow further upslope and sending out new flows.
RATH: It moves so slowly. You wonder if there's anything that we can do to stop or divert the flow. It turns out scientists actually do know something about lava diversion. Lockwood was an American advisor during the 1983 volcanic eruption of Mount Etna on the east coast of Sicily.
LOCKWOOD: Mount Etna's a complex volcano. It looms above the major city of Catania on the island of Sicily. Etna is one of the world's most active volcanoes.
RATH: To save the towns below, teams scrambled to divert the lava.
LOCKWOOD: It was a massive engineering effort involving several hundred men and hundreds of pieces of equipment.
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UNIDENTIFIED WOMAN #1: Good evening. A multimillion-dollar bid to divert a stream of molten lava.
RATH: The diversion was the leading news in broadcasts as far away as New Zealand.
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UNIDENTIFIED WOMAN #1: Engineers set off dynamite charges in the walls of a channel gauged out by the lava in an attempt to change its course away from villages further down the slope.
RATH: Lockwood says workers were on the front lines. Along with explosives, they used bulldozers to build giant earthen walls to divert the flow.
LOCKWOOD: In some cases, a bulldozer was actually driven over red, incandescent lava to be able to push it up. Five minutes on the flow, and then the bulldozer - it has to be pulled away. The fire department would bring massive amounts of water to cool down the bulldozers. It was pretty heroic efforts.
RATH: While the project cost an estimated $2 million, Lockwood says they saved about $100 million worth of property from destruction, all with bulldozers and explosives. There is another technique, but it only works near the ocean - dump massive amounts of seawater to chill and solidify the molten rock. That worked once in Iceland back in 1973. But diverting lava is complicated.
LOCKWOOD: First of all, the terrain has to be amenable. The economics have to be right. What are the benefits you hope to achieve if you're successful? There is always that element of if.
RATH: Some past efforts have failed, including in Hawaii.
LOCKWOOD: Lava diversion has been attempted in Hawaii in 1955 and 1960, and they were futile. They were not well-engineered. People didn't know what they were doing, and they failed. Barriers were destroyed and towns were overrun.
RATH: Plus, politically, it's a risky decision. Lava diverted from one town could flow right into another. And even some residents in Pahoa, whose homes are in danger, don't want to divert the lava. And there are no plans to do so.
LOCKWOOD: Our volcano has deeply-held religious significance to lots of people - to the Hawaiian people, heck, to non-Hawaiian people who have lived here a long time. She - we refer to our volcano as she because we're talking about Pele, the volcano goddess. And she deserves respect.
RATH: At a public meeting held in September by Hawaii County Civil Defense and the U.S. Geological Survey, Pahoa residents spoke out against diversion.
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UNIDENTIFIED WOMAN #2: You cannot change the direction. It's Mother Nature. It's like me telling you move the moon because it's too bright.
RATH: Still, if the lava flow picks back up and continues in the same path, Lockwood says diversion might be a consideration.
LOCKWOOD: There's some very large subdivisions with over 1,000 homes that could be in jeopardy.
RATH: But any sort of diversion would be a temporary fix.
LOCKWOOD: Whatever the efforts of humans are, they'll be pretty puny compared to the long-term plans of the volcano.
RATH: Especially for the Kilauea volcano that's been erupting on Hawaii's Big Island for over 30 years.
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