Posters Page 2 of 7 The Thermal Springs of Monetier-Les-Bains Sources Of Water The ultimate source of all natural water on Earth is rain, which is rarely used as a direct source except on islands in salt water where the rain is collected and led into cisterns to serve as the only available water supply. When rain falls, it runs off into streams in the case of heavy rain or soaks into the ground percolating through porous strata until it reaches an impervious stratum upon which it collects, forming groundwater. Groundwater is the source of wells and of the springs that feed streams and rivers and lakes. Springs A spring is any natural surface discharge of ground water. The location of most springs is controlled by a combination of surface topography and rock structure. In horizontal strata with a perched water table, springs will occur where a valley wall exposes the aquiclude. In folded and faulted strata where an aquiclude over lies an aquifer, artesian springs may occur. Many of the worlds largest springs emerge in valleys that have been eroded downward to intersect water-filled caverns in limestone. Spring discharge varies from a few drops per minute to thousands of litres per second. The worlds largest reported spring is Ras-el-Ain in Syria with an average yield of 38,7001L, (10,200gal) per second. The largest US spring is Silver Springs in Florida which averages 23000L (6,100gal) per second. Spring water temperatures vary from about the mean annual air temperature in the region of the spring to the boiling point of water (100ºC /212ºF). Most hot (geothermal) springs are heated by circulation of water to great depths. The chemical quality of spring water ranges from almost pure water to brine (saturated with salt). Springs having water containing more than about 2 grams of dissolved solids per litre (0.267 oz/ gal) are called mineral springs. Gases may be dissolved in the water, carbon dioxide for example can produce a natural soda water and hydrogen sulphide gives spring water characteristic sulphurous colour. Spring water that contains mineral salts or gases are classed as mineral waters and consequently may have an action on the human body different to that of ordinary water. As a remedial agent, mineral waters have been used from early times, popular with the ancient Greeks and Romans. Carbonic acidic waters tend to be used as table beverages and to dilute spirits or wines, compared to saline waters which are used for their medicinal effects. Case study: Le Monetier-Les-Bains Photograph to show the village of Monetier Les Bains. Monetier-Les-Bains is one of the least spoiled of the ski resort centres which form Serre Chevalier, a thriving ski resort in the heart of the Guisane Valley in the Alps, France. Le Monetier-Les-Bains is mainly limestone in geology and possesses two plentiful sources of hot mineral springs. The first spring, situated north of the village is able to reach a still temperature of 40ºC and was used in the past in bath houses for medicinal remedies. Photograph 1. The bath house on the northern side of Monetier. The second spring, situated south of Monetier is the source of Fond Chaude and is able to reach a temperature of 42ºC. Both the springs were used to supply water to the local bath houses which date back to the eighteenth century, Roman times. Photograph 2. The southern bath house in a state of disrepair. The baths were opened at the turn of this century and for a brief period of time Monetier had a small clientele of people coming to take the cure of the spring waters as remedies for diseases such as rheumatism and arthritis. The Bath Houses of Monetier have been unused and neglected for many years, although both still remain. The northern bath house appears to be in good condition and still has the traditional mosaic tiles and the iron bath rails. To the front of the bath house in an ornamental surrounding is the emerging spring water which once supplied the bath house. From this source I was able to take water samples of which I was able to analyse, the results of which can be seen in figure 1. The southern bath house, however is now in a state o disrepair, as shown in photograph 2. Analysis of the spring north of Monetier Temperature = 22.3ºC pH = 6.53 The spring water is seen to be slightly acidic. This may be due to sulphur content from the previous volcanic material which has been unable to be neutralised by the limestone. Dissolved Solutes mg.l = 950 The high level of total dissolved solutes may be due to calcium in the limestone or straight off the grounds surface. The Future The mayor of Monetier has no plans to renovate and restore either bath house to their former glory, ironic when one considers the importance these bath houses once had on the village and local people and the contribution they made to the villages history and heritage. If such bath houses were to be found in the UK for example, organisations such as English Heritage would restore the baths turning them into tourist attractions such as those found in spa towns such as Bath. Restoring the bath houses of Monetier would prove to be successful as it would expand the tourist industry on which the majority of the people rely upon and would remove dependence from the ski industry. Sarah Davenport | 1 | 2 | 3 | 4 | 5 | 6 | 7 | Page 2 of 7