Tag Archives: Ice

Spreading salt on the right roads?

by Jayne Glass

The news in late 2010 has been all about ‘the big freeze’.  Heavy snow has been falling across the UK earlier than normal, with some devastating effects. Usually, local councils work to keep the roads and pavements clear by spreading salt/grit. But despite attempts to stockpile salt ahead of this winter, some councils are already running low.  In Powys, Carmarthenshire and Caerphilly, councils have already used at least a quarter of their stock, and across Wales 15% of the salt supply has gone.

In 2008, John Thornes and Lee Chapman focussed on decision-making for salt spreading, in an article in Geography Compass.  Although the use of weather information systems for the winter maintenance of roads is now widespread, observations and predictions are often only available for a limited number of road sensor sites in a region.  Thornes and Chapman carried out a winter-long trial of the XRWIS road weather information system in Devon.  They found that up to 78 salting runs on 6 salting routes could have been prevented.  This would have saved up to £80,000 in labour and materials.  There is also scope for this system to be applied to prediction of low rail adhesion on the national rail network.

‘Road salt is disappearing fast, Welsh councils warn': BBC News, 2 December 2010

Thornes, J. and Chapman, L. (2008). The Next Generation Road Weather Information System: A New Paradigm for Road and Rail Severe Weather Prediction in the UK. Geography Compass, June 2008

Subglacial Lake Drainage Operation Commences

By Richard Gravelle

Engineers have begun an operation to drain a meltwater lake that has formed beneath a glacier in the Mont Blanc massif.

The lake, which lies underneath the Tete-Rousse glacier, threatens to flood the Saint Gervais valley with approximately 65,000 m3 of meltwater.  The valley is home to around 3,000 people, and contains the world-famous ski resort of Chamonix, so the effects of the lake draining could be catastrophic.  A previous flood in 1892 from another subglacial lake killed 175 people.

It is believed that warmer summer temperatures may have caused an increase in meltwater production which caused the lake to form, but that a period of cold temperatures may have closed a number of natural drainage routes, and preventing the water from draining away.

The engineers will have to drill a 40-50 m deep borehole in the glacier ice before they reach the lake water level.   The water can then be pumped away, making the valley safe once more.

It is thought that the drainage operation will cost around €2 (approximately £1,600,000).  However, if the project is successful, then the cost saved in human life and livelihoods will be far greater.

BBC News – France to drain lake under Mont Blanc Glacier, 25th August 2010

Spiegel – Subglacial Lake Threatens Alpine Community, 25th August 2010

Ice loss on Mount Everest

By Richard Gravelle

Several weeks ago, I wrote that Nepalese Sherpas have claimed that the effects of climate change are making Mount Everest more dangerous and difficult to climb (Is climate change making Everest more dangerous? June 5, 2010).  It is generally accepted that Everest, like other mountains worldwide, is undergoing increased rates of ice and snow melt.  However, a recent attempt by the Asian Society (AS) to take photographs of Everest from the same spot as George Mallory did in 1921 suggest that the problem may be worse than previously thought.

Comparison of the photographs revels that the main glacier on Everest, the Rongbuk glacier, has undergone a significant loss of ice mass in the last 89 years, a trend which is unfortunately unlikely to be reversed under present conditions.

Photographer David Breashears is quoted as saying “If this isn’t evidence of the glaciers in serious decline, I don’t know what is”.  These photographs act as a stark reminder of the effects of climate change, as well as allowing us to see exactly how environmental changes have occurred over the past century.

BBC News – Comparative photos of Mount Everest ‘confirm ice loss’.  16th Jul 2010