Habitability of lava tubes on the Moon and Mars: lessons from Earth

Author

Pascal Lee

Files

Publication Date

January 2019

Abstract

The main goal of our study was to begin to learn more about the physical and geological reality of lava tubes on Earth, specifically with respect to their habitability. Our objectives focus on two issues of central relevance to assessing the potential habitability of lava tubes on Earth, and by extension on the Moon and Mars: 1) Geotechnical characteristics: How accessible and safe are lava tubes? What makes some lava tubes experience collapse? 2) Relation to ice: Why, when and how does ice occur and evolve in lava tubes? Approach and Findings. 1) To begin surveying the geotechnical characteristics of lava tubes, we carried out a review of the published technical literature on the topic. Our finding is that while there is an abundance of archaeological and historical reports and maps documenting the access, exploration, investigation, use, and occupation of lava tubes, including many anecdotal mentions of collapse features inside lava tubes, there are essentially no published quantitative studies of the geotechnical properties of lava tubes using modern standard geotechnical metrics. 2) To begin examining the relationship between lava tubes and ice, we carried out a field investigation of the Lofthellir Lava Tube Ice Cave in Iceland in which massive ice is known to exist. Our field observations suggest that the ice inside Lofthellir is predominantly meteoric in origin (water from atmospheric precipitation or condensation) rather than from volcanic venting. In other words, the water inside the cave came mostly, if not exclusively, from “above”, not “below”. We also report two important new findings: a) Underground micro-glaciers are recognized for the first time; they form in the lave tube as a result of accumulation, slow movement, and loss of water and massive ice under the effect of gravity; b) Gelifraction, the fracturing of rocks by freezing of water trapped in joints, is an important cause of breakup and collapse inside this ice-rich lava tube.

Keywords

Lava tubes, Moon, Mars (Planet)

Document Type

Article

Language

English

Identifier

K26-05529

Recommended Citation

Lee, Pascal, "Habitability of lava tubes on the Moon and Mars: lessons from Earth" (2019). KIP Articles. 5844.
https://digitalcommons.usf.edu/kip_articles/5844