Editing Hydrothermal circulation (section)

==Volcanic and magma related hydrothermal circulation==
[[File:Taal Crater Lake (39228545370).jpg|thumb|[[Taal Volcano Main Crater Lake]], where hydrothermal circulating convection cells exist]]
Hydrothermal circulation is not limited to ocean ridge environments. Hydrothermal circulating convection cells can exist in any place an anomalous source of heat, such as an intruding [[magma]] or [[volcanic]] vent, comes into contact with the [[groundwater]] system where permeability allows flow.<ref name="Cardenas-2012">{{Cite journal|last1=Bayani Cardenas|first1=M.|last2=Lagmay|first2=Alfredo Mahar F. |author-link2= Mahar Lagmay |last3=Andrews|first3=Benjamin J.|last4=Rodolfo|first4=Raymond S.|last5=Cabria|first5=Hillel B.|last6=Zamora|first6=Peter B.|last7=Lapus|first7=Mark R.|date=January 2012|title=Terrestrial smokers: Thermal springs due to hydrothermal convection of groundwater connected to surface water: SPRINGS DUE TO HYDROTHERMAL CONVECTION|journal=Geophysical Research Letters|language=en|volume=39|issue=2|pages=n/a|doi=10.1029/2011GL050475|doi-access=free}}</ref><ref>{{Cite journal|last1=Donoghue|first1=Eleanor|last2=Troll|first2=Valentin R.|last3=Harris|first3=Chris|last4=O'Halloran|first4=Aoife|last5=Walter|first5=Thomas R.|last6=Pérez Torrado|first6=Francisco J.|date=October 2008|title=Low-temperature hydrothermal alteration of intra-caldera tuffs, Miocene Tejeda caldera, Gran Canaria, Canary Islands|url=https://linkinghub.elsevier.com/retrieve/pii/S0377027308002163|journal=Journal of Volcanology and Geothermal Research|language=en|volume=176|issue=4|pages=551–564|doi=10.1016/j.jvolgeores.2008.05.002|bibcode=2008JVGR..176..551D|url-access=subscription}}</ref> This convection can manifest as [[Hydrothermal explosion|hydrothermal explosions]], [[Geyser|geysers]], and [[Hot spring|hot springs]], although this is not always the case.<ref name="Cardenas-2012" />  

Hydrothermal circulation above magma bodies has been intensively studied in the context of geothermal projects where many deep wells are drilled into the system to produce and subsequently re-inject the hydrothermal fluids.  The detailed data sets available from this work show the long term persistence of these systems, the development of fluid circulation patterns, histories that can be influenced by renewed magmatism, fault movement, or changes associated with hydrothermal brecciation and eruption sometimes followed by massive cold water invasion.  Less direct but as intensive study has focused on the minerals deposited especially in the upper parts of hydrothermal circulation systems.

Understanding volcanic and magma-related hydrothermal circulation means studying hydrothermal explosions, geysers, hot springs, and other related systems and their interactions with associated surface water and groundwater bodies.<ref name="Cardenas-2012" /> A good environment to observe this phenomenon is in [[Volcanogenic lake|volcanogenic lakes]] where hot springs and geysers are commonly present.<ref name="Cardenas-2012" /> The convection systems in these lakes work through cold lake water percolating downward through the permeable lake bed, mixing with groundwater heated by magma or residual heat, and rising to form thermal springs at discharge points.<ref name="Cardenas-2012" />

The existence of hydrothermal convection cells and hot springs or geysers in these environments depends not only on the presence of a colder water body and geothermal heat but also strongly depends on a no-flow boundary at the water table.<ref name="Cardenas-2012" />  These systems can develop their own boundaries.  For example the water level represents a fluid pressure condition that leads to gas exsolution or boiling that in turn causes intense mineralization that can seal cracks.