Mineral and termal spring

Spa Bahia Los Delfines- termal, mineral and volcanic waters.

Mineral spas are spa resorts developed around naturally occurring mineral springs. Like seaside resorts, they are mainly used recreationally although they also figured prominently in prescientific medicine.

Spas were used for millennia for their purported healing or healthful benefits to those wealthy enough or close enough to partake of their waters. This was called a mineral cure and gave let to such phrases as taking a cure andtaking the waters. There has always been a mixture of recreational and medicinal connotations involved, from rest and relaxation, stress relief, and convalescence to more specific notions such as humorism. These phrases are still sometimes used today as a euphemism for one trying to kick a drug dependency.

In many cases, mineral spas were located in mountainous locales that gave an additional excuse to leave the drudgery of a hot house in warm weather during summer's onset and were seasonally populated by the well-to-do. They eventually became early vacation spots with the counter-Victorian work ethic 'rationale' of health as an excuse to have fun and mix with one's peers in recreation.

Subsequently, many such became the seed stock for today's modern vacation resorts. Locations such as Steamboat Springs, Vail, St Moritz, Mineral Wells first became popular for the questionable health benefits of mineral or soda-water soaks, ingestion, and clean outs during the hey-day of patent medicines and backward medical knowledge. United States President Franklin Delano Roosevelt suffered a paralytic illness, and regularly visited Warm Springs and other hot springs for restorative soaks. While his cousin Theodore Roosevelt became known as a manly-man of incredible endurance, he was a sickly child suffering from asthma and 'took cures' periodically in an attempt to gain better health.

The name "spa" comes from the Belgian town Spa


Hot or termal springs

There is no universally accepted definition of a hot spring.

For example, one can find the phrase hot spring defined as any geothermal spring

  • a spring with water temperatures above its surroundings
  • a natural spring with water temperature above body temperature – normally between 36.5 and 37.5 °C (97.7 and 99.5 °F)
  • a natural spring with warm water above body temperature
  • a thermal spring with water warmer than 36.7 °C (98 °F)
  • a natural spring of water greater than 21.1 °C (70 °F) (synonymous with thermal spring)
  • a natural discharge of groundwater with elevated temperatures
  • a type of thermal spring in which hot water is brought to the surface. The water temperature of a hot spring is usually 6.5 °C (12 °F) or more above mean air temperature. Note that by this definition, "thermal spring" is not synonymous with the term "hot spring"
  • a spring whose hot water is brought to the surface (synonymous with a thermal spring). The water temperature of the spring is usually 8.3 °C (15 °F) or more above the mean air temperature.
  • a spring with water above the core human body temperature – 36.7 °C (98 °F).
  • a spring with water above average ambient ground temperature
  • a spring with water temperatures above 50 °C (122 °F)

The related term "warm spring" is defined as a spring with water temperature less than a hot spring by many sources, although Pentecost et al. (2003) suggest that the phrase "warm spring" is not useful and should be avoided.[14] The US NOAA Geophysical Data Center defines a "warm spring" as a spring with water between 20 and 50 °C (68 and 122 °F)

Water issuing from a hot spring is heated geothermally, that is, with heat produced from the Earth's mantle. In general, the temperature of rocks within the earth increases with depth. The rate of temperature increase with depth is known as the geothermal gradient. If water percolates deeply enough into the crust, it will be heated as it comes into contact with hot rocks. The water from hot springs in non-volcanic areas is heated in this manner.

Steam Crepuscular rays atMammoth Hot Springs

In active volcanic zones such as Yellowstone National Park, water may be heated by coming into contact with magma (molten rock). The high temperature gradient near magma may cause water to be heated enough that it boils or becomes superheated. If the water becomes so hot that it builds steam pressure and erupts in a jet above the surface of the Earth, it is called a geyser. If the water only reaches the surface in the form of steam, it is called a fumarole. 

Mineral water is water from a mineral spring that contains various minerals, such as salts and sulfur compounds. Mineral water may be effervescent (i.e., "sparkling") due to contained gases.

Traditionally, mineral waters were used or consumed at their spring sources, often referred to as "taking the waters" or "taking the cure," at places such as spas, baths, or wells. The term spa was used for a place where the water was consumed and bathed in; bath where the water was used primarily for bathing, therapeutics, or recreation; and well where the water was to be consumed.

In modern times, it is far more common for mineral water to be bottled at the source for distributed consumption. Travelling to the mineral water site for direct access to the water is now uncommon, and in many cases not possible (because of exclusive commercial ownership rights). There are more than 3,000 brands of mineral water commercially available worldwide.

The more calcium and magnesium ions that are dissolved in water, the harder it is said to be; water with few dissolved calcium and magnesium ions is described as being soft.

The U.S. Food and Drug Administration classifies mineral water as water containing at least 250 parts per million total dissolved solids (TDS), originating from a geologically and physically protected underground water source. No minerals may be added to this water. In many places, however, the term "mineral water" is colloquially used to mean any bottled carbonated water or soda water, as opposed to tap water.

In the European Union, bottled water may be called mineral water when it is bottled at the source and has undergone no or minimal treatment. Permitted is the removal of iron, manganese, sulfur and arsenic through decantation,filtration or treatment with ozone-enriched air, in so far as this treatment does not alter the composition of the water as regards the essential constituents which give it its properties. No additions are permitted except for carbon dioxide, which may be added, removed or re-introduced by exclusively physical methods. No disinfection treatment is permitted, nor is the addition of any bacteriostatic agents.