An 8-minute talk at the Workshop on Terrestrial Analogs for Planetary Exploration, June 2021

1. Terrestrial Analogs
of Martian Ice Caves
Norbert Schörghofer
Planetary Science Institute, Hawaii & Arizona
June 2021, NASA/SSERVI/GEODES
← Image
credits: NASA,
R. Shone, L.
Denoyes
Caves preserve.

2. Present-day Mars is a Sublimation Environment
Mean annual surface
conditions
ceiling thickness >
thermal skin depth
Mars:
• sublimation environment
• absolute humidity much
lower
• caves in dry or ice-
bearing permafrost

3. Sublimation Environment → Hoarfrost
Examples of hoarfrost (sublimation crystals,
atmogenic, desublimation ice) in caves in
Greenland Moseley et al. (2020) ↑ →

4. Database & CaveXML
 Database for ice caves & volcanic caves
 Currently contains 2172 distinct caves: 524 ice caves and 1595 lava tubes
 CaveXML: Data Interchange Format
<rock-type>basalt</rock-type>
<contents>permanent ice</contents>
 borrows from the UIS Informatics Commission exchange format
recommendations (1997-2010)
 can accommodate extraterrestrial caves
 https://github.com/nschorgh/CaveXML
 user friendly, but rigorous → automated queries & processing
 database can be translated to csv, RDF-XML (KarstLink ontology), ...

5. Potential Analogs
Caves with Hoarfrost: 40 in database
• Crystal Cave (Lava Beds Natl. Monument, lava tube); hoarice with dust
• Crystal Kingdom Cave (Greenland, 80°N) Galanin (2020)
• Kungur Ice Cave (Russia, 57°N)
• Jochloch (Switzerland, 3470m a.s.l.)
• Low temperature hoarfrost caves:
Skaza and Skalolazov Caves, Eastern
Siberia, -25°C
• (very few studies of spelean hoarfrost)
• highest-lying lava tube with perennial
ice: Mauna Loa Ice Cave, Hawaii;
(Teehera et al. 2018) bacteria & archaea
• still looking for: frozen brine lakes &
ice caves in dry permafrost

6. Outlook
Open Science Questions
about Spelean Hoarfrost:
• Long-term evolution of
ice (up to Gyrs)
• Crystal habit
• Inclusions in atmogenic
ice: old air? dust?
microbes?
→ terrestrial analog studies