Editing Mount Erebus (section)

==Ice fumaroles==

Mount Erebus is notable for its numerous [[Fumarolic ice tower|ice fumaroles]] – ice towers that form around gases that escape from vents in the surface.<ref>For photographs of ice fumaroles, see [http://erebus.nmt.edu/index.php/icetowers Ice Towers] {{Webarchive|url=https://web.archive.org/web/20150101101454/http://erebus.nmt.edu/index.php/icetowers |date=2015-01-01 }} Mount Everest Volcano Observatory</ref> The ice caves associated with the fumaroles are dark, in polar alpine environments starved in organics and with oxygenated hydrothermal circulation in highly reducing host rock. The life is sparse, mainly bacteria and fungi. This makes it of special interest for studying [[oligotroph]]s – organisms that can survive on minimal amounts of resources.

The caves on Erebus are of special interest for astrobiology,<ref>{{Cite web|url=https://www.astrobio.net/alien-life/descent-frozen-underworld/|title=Descent into a Frozen Underworld|date=2017-02-17|website=Astrobiology Magazine|language=en-US|access-date=2019-07-05 |archive-url=https://web.archive.org/web/20210506181815/https://www.astrobio.net/alien-life/descent-frozen-underworld/ |archive-date=2021-05-06 |url-status=usurped}}</ref> as most surface caves are influenced by human activities, or by organics from the surface brought in by animals (e.g. bats and birds) or ground water.<ref>{{Cite web|url=https://www.anothermag.com/design-living/7522/mount-erebus-a-tale-of-ice-and-fire|title=Mount Erebus: A Tale of Ice and Fire|last=AnOther|date=2015-06-18|website=AnOther|language=en|access-date=2019-07-05}}</ref> The caves at Erebus are at high altitude, yet accessible for study. Some of the caves can reach temperatures of 25 degrees Celsius (77 degrees Fahrenheit), and with light near the cave mouths, in some caves covered by thin overlying ice, the light may reach even deeper and is sufficient to sustain an ecosystem of flora and fauna consisting of moss, algae, arthropods and nematodes.<ref>{{cite web | title=Secret Life May Thrive Under Warm Antarctic Caves | website=Geology In | date=2017-09-09 | url=https://www.geologyin.com/2017/09/secret-life-may-thrive-under-warm.html}}</ref> 

They are dynamic systems that collapse and rebuild, but persist over decades. The air inside the caves has 80 to 100% humidity, and up to 3% [[carbon dioxide]] (CO<sub>2</sub>), and some [[carbon monoxide]] (CO) and [[hydrogen]] (H<sub>2</sub>), but almost no [[methane]] (CH<sub>4</sub>) or [[hydrogen sulfide]] (H<sub>2</sub>S). Many of them are completely dark, so cannot support photosynthesis. Organics can only come from the atmosphere, or from ice algae that grow on the surface in summer, which may eventually find their way into the caves through burial and melting. As a result, most micro-organisms there are [[chemolithoautotrophic]] i.e. microbes that get all of their energy from chemical reactions with the rocks, and that do not depend on any other lifeforms to survive.  The organisms survive using CO<sub>2</sub> fixation and some may use CO oxidization for the metabolism. The main types of microbe found there are [[Chloroflexota]] and [[Acidobacteriota]].<ref name="TeboDavis2015">{{cite journal|last1=Tebo|first1=Bradley M.|last2=Davis|first2=Richard E.|last3=Anitori|first3=Roberto P.|last4=Connell|first4=Laurie B.|last5=Schiffman|first5=Peter|last6=Staudigel|first6=Hubert|title=Microbial communities in dark oligotrophic volcanic ice cave ecosystems of Mt. Erebus, Antarctica|journal=Frontiers in Microbiology|volume=6|pages=179|year=2015|issn=1664-302X|doi=10.3389/fmicb.2015.00179|pmid = 25814983|pmc=4356161|doi-access=free}}</ref><ref>{{cite web|last1=Wall|first1=Mike|title=Antarctic Cave Microbes Shed Light on Life's Diversity|url=http://www.livescience.com/17402-antarctica-mount-erebus-ice-cave-diversity.html|website=Livescience|date=9 December 2011}}</ref> In 2019, the [[Marsden grant|Marsden Fund]] granted nearly NZ$1 million to the [[University of Waikato]] and the [[University of Canterbury]] to study the micro-organisms in the geothermal fumaroles.<ref>{{Cite journal|last=Harris|first=Rosie|date=2019|title=Micro-organisms in the volcanic vents of Erebus - a key to life on other planets?|journal=Antarctic|volume=38|issue=3 & 4|pages=14–15|issn=0003-5327}}</ref>