Swedish iron-mining town is on the move

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For someone whose city is on its way to being swallowed up by the earth, Vice Mayor Hans Swedell is a man of unbridled optimism.

Three years ago, the Swedish mining company LKAB -- which provides the city's economic lifeblood -- informed Swedell and other local officials that a century of extracting iron ore from underground was taking a toll on the bedrock under the town's homes and offices. Cracks had developed in the mine wall that angles thousands of feet beneath the city, and if they didn't start moving the buildings in a couple of decades, key parts of the city might collapse.

The citizens of Kiruna -- who dub themselves "the No-Problem People" -- have taken on this geological challenge with gusto. Last month, the town council voted to move much of the 23,000-person city to a spot 1.25 to 2.5 miles northwest of its current location, away from the direction of the cracks.

"We have an opportunity to make a new town in the best way in the world," Swedell said in an interview.

The fate of Kiruna, a city located 90 miles above the Arctic Circle, where temperatures average below-10 degrees Fahrenheit this time of year, has been inexorably linked to the mine since both arose in 1890, when railroads made it possible for Swedish miners to transport high-phosphorus iron ore from Lapland to Stockholm and abroad. The region boasts the largest single iron ore deposit in the world, a huge slab that plunges 2.5 miles into the earth at a 60-degree angle. The slab averages 262 feet in width.

For more than 60 years, LKAB mined the ore from open pits and essentially removed a mountaintop. But in 1962 the now-state-owned company began digging underground. It now ranks as the largest underground iron ore mine in the world, with 248 miles of paved roads beneath the surface.

"We've been going deeper and deeper," explained LKAB spokesman Anders Lindberg, who added that his company is now mining 3,000 feet below the surface. "The deeper we go, the further we go under Kiruna."

And that's the problem. To extract the ore, miners blast the deposit with liquid explosives and then fill in the empty space with shattered waste rock. But the loose waste does not provide the same support to the rock above the tunnel, known as the "hanging wall," and waste rock is also falling off the wall itself. As a result, cracks are developing in the wall and expanding toward the surface.

"The subsurface strength is going to be compromised," said Kip Hodges, who directs the University of Arizona's School of Earth and Space Exploration and conducted his doctoral research not far north of Kiruna in Narvik, Norway. "I'm sure they did not set out to have this happen."

Mining towns elsewhere in the world have struggled with similar problems. The earth has started sinking underneath Pingxiang, China, due to its 1,000-year history of coal mining, prompting the Chinese government to pay for new housing, schools and hospitals for local residents. Some who live in Waihi, New Zealand, argue it's time to move their community, too, now that the closed gold mine there is causing holes to open up suddenly in the middle of town.

But in most such cases, the approach has been to prop up sinking buildings rather than move them. State officials in Ohio and West Virginia have pumped in concrete to stabilize the foundations beneath key edifices affected by local coal mining operations.

Kiruna's residents are taking a different tack. Proud of their red wooden church -- named Sweden's most beautiful building in 2001 -- and of their town hall, which features an Italian floor and handmade bricks from the Netherlands, officials want to preserve the city by moving it. They plan to move the entire town center, which includes the railroad, a highway and the city's water and sewage system, away from its current site to protect it from further harm.

"The Kiruna citizens are saying, 'We need the mine, and if we want the mine, we have to move the town,' " Lindberg said. "It's sad we have to move the town, but at the same time it's so important (that) the new town becomes as good or even better, because we want our employees to stay here."

While the city has just completed a 250-page document outlining a timetable and plan for the move, its officials have yet to pin down many specifics. They have yet to come up with an estimate for the massive project, which is likely to cost billions of dollars.

"No one actually knows what it's going to cost," said Lindberg, whose company will pay for the bulk of the move. "We don't have to move the whole town in a couple of years."

By 2013, the town plans to move the railway and the residences of 450 people; a decade later, officials hope to have relocated 1,700 to 3,000 residents, as well as the high school and hospital. The entire move is due to be complete in 2099, Swedell said.

Kiruna Mayor Kenneth Stalnacke said he and other city officials hope the relocated town can support new high-tech jobs that will attract women and young people to move back after attending university.

"Many young people leave the city to educate themselves and don't come back. That's a shame," Stalnacke said. "We have a political ambition to make this city not so dependent on the mine."

At the same time, Kiruna officials are hoping their move can become a model for communities that will be affected by climate change in the coming decades. The predicted sea level rises will eventually force many cities in the developing world to move tens of thousands of people to higher ground, and Kiruna is organizing a conference in 2008 that will examine how best to do this.

"Why not have this relocation as a good example?" asked Swedell, who has invited former U.S. Vice President Al Gore to attend but has not heard back. "We are moving because of the cracks; they are moving because of the water coming in."

source news : sfgate.com

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