Ruka ski resort’s summer piste survives soaring temperatures and midnight sun

Technically it would be possible to extend the skiing season until July, but making the snow would cost a pretty penny

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By Tapio Mainio in Kuusamo
     
      Snow scrunches under the skis when 30 alpine skiers whizz down the summer piste of the Ruka ski resort near Kuusamo in Northeastern Finland.
      “Fantastic going”, squeals Linus Ljung, who has arrived in Ruka with his family from Luoto near the city of Kokkola, over on the west coast of the country.
      The nearly 600-metre-long Saarua slope winds like a huge white scarf in an otherwise summer-green landscape.
      Sunday’s last descents down the slope mark the end of what has been an exceptionally long winter season at the popular Ruka resort.
     
Even the white nights of the northern region, just shy of the Arctic Circle, have failed to melt the thick layer of snow covering the slope.
      “In May a peak temperature of +25°C was recorded in Ruka, but even that did little damage to the slope’s snow cover”, explains resort manager Matti Parviainen.
      During the winter months, snow cannons were used to cover the slope with no less than four metres of snow, a great deal more than on the resort's thirty-odd other pistes.
      Something like 70,000 cubic metres of water, the equivalent of 35,000 tonnes of snow, were dumped on the pampered Saarua piste.
      “Basically we could extend the ski season into July, but that would mean that we would have to create a really colossal amount of snow and that would cost us a pretty penny.”
     
Anyone who has skied in the warm spring weather remembers how the skis tend to sink into the softening snow as the day progresses.
      How come the summer slope has remained in such pristine condition?
      “Different types of salts are used to harden the damp snow”, explains managing director Mikko Martikainen of the Snow Secure company.
      “The salts’ hardening effect on the melting snow is based on the fact that their dissolving is an endothermic reaction. In other words, it binds heat. This way the water residing on top of the ice crystals actually cools down and even freezes.”
     
The first time that summer skiing was experimented with at Ruka was in 2002.
      Initially highway salt or calcium chloride was used to harden the snow. Today the used chemical is a mixture of water and a formate.
      “A formate is an organic compound, which converts to carbon dioxide and water when it breaks down. Formates are used as highway salt in sensitive groundwater areas”, Martikainen continues.
      The solution is spread onto the slope each morning by using a snow-grooming machine equipped with a sprayer.
     
On the track used by competitive skiers the effectively acting salt is still being used, for the professionals need a hard surface for their runs.
      On Saturday Finland’s national freestyle team’s skiers were training in the slope.
      The majority of the used salt ends up - together with the water from the melting snow - in the Ruka resort’s artificial pond around a hundred metres away from the bottom of the slope.
      The City of Kuusamo’s environmental department keeps monitoring the pond’s salt content at regular intervals.
      “The top values of 25 milligrams per litre are recorded around Midsummer, just below the slope”, Martikainen says.
      The amount is still within the permissible limits.
     
The water of the artificial pond, in turn, drains into the Vuosselijärvi Lake below the Saarua slope. In previous years the lake’s salt content has been slightly on the elevated side.
      According to the environmental department, the values have now fallen back to nature’s normal level, in other words to a couple of milligrams per litre.
      The improvement of the salt-value situation is a result of efforts to substitute the salts with other snow-hardening agents.
     
     
Helsingin Sanomat / First published in print 13.6.2010

More on this subject:
 Helsinki's giant snow pile suffering from machine-made attrition

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TAPIO MAINIO / Helsingin Sanomat
tapio.mainio@hs.fi