[CZ]
Jak vznikají sirné
vody
Sirné vody na
východní Morave jsou vázány na specifické geologické podloží,
kterému se ríká karpatský flyš.
Podmínkou vzniku
jsou rozpuštené sírany hluboko pod povrchem a prítomnost
organických látek v horninách, které na východní Morave obstarávají
plynné uhlovodíky, zejména metan. Krome toho je nutná také vhodná
cirkulace podzemních vod a prítomnost desulfurikacních bakterií,
které odnímají ze síranu kyslík a produkují sirovodík
(H2S, sulfan). Mimochodem - tento typ
bakterií patrí k nejstarším bakteriím vyskytujícím se na
Zemi.
Vznik sirné vody je velmi složitý proces, do nehož
vstupuje nekolik promenných. Velký vliv má množství
srážek behem roku, aktivita bakterií závisí na teplote a
tudíž rocních obdobích. Koncentrace sirovodíku proto behem
roku casto kolísá a treba jen zdánlive nepatrné zásahy cloveka do
prírody a krajiny mohou celý složitý proces zastavit a znicit.
Jsou proto známé prípady, že z puvodne sirné vody se stala
voda prostá.
[EN]
Sulphuric Springs -
How are they formed?
Sulphuric springs in
south-eastern Moravia region are location specific. They require a
special geological sediment, so called "Carpathian
flysch."
There also need to be present dissolved sulfates in the water and
organic compounds in the sediments. The most occuring organic
compound in this region are gaseous hydrocarbons, especially
methane. There are also other conditions of sulfuric spring
formation - appropriate circulation of subterranean water and the
presence of
sulfate-reducing
bacteria, which transform sulfates into
hydrogen
sulfide. Sulfate-reducing bacteria can be traced back to 3
billion years ago and are considered to be among the oldest forms
of bacteria.
Sulphuric spring formation is a very complicated process with many
factors, that have impact on it - the total amount of precipitation
during the year, the activity of bacteria depends on temperature
(time in the year) etc. The concentration of hydrogen sulfide
varies during the year and even the smallest action of man into
above mentioned conditions may stop ar even destroy this
complicated process. There are several examples, when sulphuric
springs turned into regular potable water springs.
takhle vypada karpatsky flys / picture of a carpathian flysch
HOW TO LOG THIS EARTHCACHE
Go to the coordinates of this
cache, find the spring called SMRADAVKA.
There is a stone-concrete wall with some inscriptions in the
concrete.
1) Send me via profile answers to the following questions:
a) What year and month is mentioned on this wall
(left side of the inscription)
b) The smell of the water is caused by H2S
produced by sulfate-reducing bacteria, another bacterial strains
can reduce
sulfates into another "chemical compound" - what is it?
c) Name at least one other place, where
sulphuric spring can be seen (or smelled :-)
2) Take a photo of you and/or your GPSr in front of the spring and
stone-concrete wall. (Please no spoiler pictures with the
inscription- I would have to delete such
picture). Feel free to express your attitude towards the smell (see
Ukazkove foto picture to see the
group of people enjoying their sunday walk
:-)
3) Measure the flow in litres per minute at the time of your visit
(You can eg. use a bottle with known volume, record the time needed
to fill it and do a little maths...)
JAK NA TUHLE EARTHCACHE
Jdete na souradnice v listingu
a najdete pramen SMRADAVKA.
Pramen vyteka z kameno-betonove zidky s nekolika nápisy.
1) Skrze profil mi napište odpovedi na nekolik jednoduchých
otázek
a) Levá cást nápisu na zídce obsahuje rok a
mesíc, jaké?
b) Smradek z tehle vody zpusobuje H2S jak uz
vite, existuji ale i kmeny bakterii, ktere redukuji sirany na neco
jineho. Na co?
c) Jmenujte aspon jedno dalsi misto, kde lze
videt (citit) sirny pramen. V pripade odlovu ve skupine necht kazdy
posle
misto jine.
2) Vyfotte se (aspon vasi GPS) spolu s pramenem a zidkou .Prosim o
diskretni zamaskovani napisu (telem, pritelkyni, Photoshopem...),
ktery zjistujete, abych nemusel fotku smaznout. Budeme radi, pokud
vas pocit z nalezeneho smradku vyjadrite i na fotce - jako
inspiraci si muzete prohlednout treba fotku skupinky lidi na
nedelnim vylete - fotka Ukazkove foto :-)
3) Zmerte prutok v miste pramene v litrech za minutu (muzete napr.
pouzit lahev o znamem objemu a pomoci casu nuneho k jejimu naplneni
spocitat prutok)
Doufame, ze se vam tu libilo a hezky jste se tu prosli, tak jako
my.