UND SpSt Graduate Student Studies Caves in the Mojave Desert
Matt Allner, Masters student in Space Studies, was recently a crew member of a caving expedition study as part of the NASA-Ames program Spaceward Bound (http://quest.nasa.gov/projects/spacewardbound/index.html). Allner spent three days in the Mojave Desert studying lava tube caves on the Pisgah Lava Flow. The expedition was lead by USGS-Southwest Biological Science Center Cave Research Scientist J. Judson Wynne of Flagstaff, Arizona, and also included Glen Cushing (the discoverer of cave-like features on Arsia Mons, Mars) and Murzy Jhabvala (Chief Engineer, NASA-Goddard).
The purpose of the mission was to: (1) collect thermal imagery over a 24 hour period to examine changes in detectability over a diurnal cycle; (2) iron out any problems with a new QWIP thermal imaging camera (developed by NASA-Goddard) before we hire an airplane to conduct overflights of caves in Hawaii; and (3) obtain a better understanding regarding sensor placement in cave entrances and how this reflects actual cave entrance temperatures. The thermal activity of caves and the surrounding surface environment changes throughout the day, which is evident in the imagery obtained by the thermal infrared (TIR) camera. Recent studies conducted in caves in the Atacama Desert in Chile have shown that the greatest thermal contrast between the cave entrance and surface is at mid-day (however, the sample size was small), while larger datasets (> 1 year) on caves in Arizona and New Mexico showed many times when contrasts were significant enough to detect in the TIR.
In the past, cave environments have provided a refuge for numerous animal species seeking shelter when the surface temperatures became less hospitable during the last glaciation. Today cave environments offer two avenues of hope to scientists: first, that life may be present in caves that exist in the sinuous rills that have been discovered on Mars; and second, that caves could offer temporary or permanent human habitats on the Moon and Mars. Therefore, further development of techniques to detect caves in the TIR may lead to the discovery and identification of similar cave environments on extraterrestrial bodies, where past or present life may exist (provided life ever evolved on Mars) and/ or caves could become the sites for permanent or temporary human habitats.
Methodology for the cave detection included the deployment of weather stations and data loggers at two caves and one shallow alcove. Protocol for sensor deployment involved placing them at three different locations: < 50 m from the cave entrance; at the cave entrance (approximately 2.5 m inside the drip line); and at the dark zone (either the back or the end of the cave, or where traversing the cave was no longer possible but where there was no visible light present). These data were collected to gain further insights into both cave thermal behavior and to improve our ability to distinguish caves from non-cave features. These data were in tandem with thermal images over a 24-hour period. Upon collecting this data, scientists working on the expedition will eventually overlap the data at various time phase points to look for similarities and patterns that further support the TIR imagery which locates the cave sites.
The Mojave Desert caving expedition served a dual purpose: one, being to achieve the scientific caving objectives and further development of the use of TIR imagery for identifying caves; and two, it provided an opportunity for a large group of teachers to join the caving crew later in the week to learn about how scientists study caves and use the TIR imagery data to identify them from a distance. Furthermore, Spaceward Bound is an educational program developed at NASA-Ames and funded by the Exploration Systems Mission Directorate (ESMD). The main purpose of Spaceward Bound is to train the next generation of space explorers by involving teachers and students in the missions while working alongside NASA scientists to learn space science in the field. Allner and Wynne had originally met and worked together in the Atacama Desert in Chile on a desert expedition in 2006. Since then they have worked together on caving projects in the Mojave Desert in 2007 and 2008, where Allner was training with Wynne to learn cave safety and how to carry out field science while in these environments. Future plans are for Allner to participate with Wynne and crew on another caving expedition in the Atacama Desert. On these future expeditions he will collect further psychology data (using the caving experience as a space analog) for his thesis work on group dynamic development in extreme environments.