[Tagging] Hot springs

[Richard Z.]

On Wed, Mar 05, 2014 at 11:01:50AM +0100, Peter Wendorff wrote:

> Aren't volcanos exactly what geothermal refers to, only near or at the
> surface instead of deep down in the earth?

apparently not, I can only direct you to the wikipedia article:
http://en.wikipedia.org/wiki/Geothermal_%28geology%29

> IMHO geothermal refers to "using the thermal energy (aka heat) of the
> earth", which of course in general is higher if you go deeper down, but
> the temperature per depth is variable, and at a volcano you just get
> high temperature even in low depths, but that's all.

yes but it is a difference. If we can do better we should not introduce 
new tags only to use them incorrectly afterwards.

* hot_spring would catch everything that is called hot_spring, I am still thinking about geysirs.
* geothermal would not apply for many south Italian hot springs, Methana (Greece) and Yellowstone
  ( http://pubs.usgs.gov/fs/2005/3024/, http://en.wikipedia.org/wiki/Grand_Prismatic_Spring ) 
  ammong others

Now consider the definitions in wikipedia

* temperature:
** wikipedia-de: above 20°C ("Gemäß den Begriffsbestimmungen werden in Deutschland Grundwässer als Thermalwasser bezeichnet, wenn ihre Temperatur am Austrittsort mehr als 20 °C beträgt")
** wikipedia-en: 
*** a spring with water temperatures above its surroundings[2]
*** a natural spring with water temperature above body temperature – normally between 36.5 and 37.5 °C (97.7 and 99.5 °F)[3]
*** a natural spring with warm water above body temperature[4]
*** a thermal spring with water warmer than 36.7 °C (98 °F)[5][6]
*** a natural spring of water greater than 21.1 °C (70 °F) (synonymous with thermal spring)[7][8][9][10]
*** a natural discharge of groundwater with elevated temperatures[11]
*** 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.[12] 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.[13]
*** a spring with water above the core human body temperature – 36.7 °C (98 °F).[14]
*** a spring with water above average ambient ground temperature,[15] a definition favored by some
*** a spring with water temperatures above 50 °C (122 °F)[16]

I would not want to go as far as fixing wikipedia before making a definitionin OSM

So my conclusion - using the locally accepted classification is the only usable
definition of hot springs.


Richard