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14 - Signatures of habitats and life in Earth's high-altitude lakes: clues to Noachian aqueous environments on Mars
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- By Nathalie A. Cabrol, Space Science Division, MS 245-3, NASA Ames Research Center, California, Chris P. McKay, Space Science Division, MS 245-3, NASA Ames Research Center, California, Edmond A. Grin, Space Science Division, MS 245-3, NASA Ames Research Center, California, Keve T. Kiss, Hungarian Danube Research Station, Institute of Ecology and Botany, Hungarian Academy of Sciences, Göd, Era Ács, Hungarian Danube Research Station, Institute of Ecology and Botany, Hungarian Academy of Sciences, Göd, Balint Tóth, Hungarian Danube Research Station, Institute of Ecology and Botany, Hungarian Academy of Sciences, Göd, Istran Grigorszky, Debrecen University, Botanical Department, Debrecen, K. Szabò, Eötvös L. University, Microbiological Department, Budapest, David A. Fike, Eötvös L. University, Microbiological Department, Budapest, Andrew N. Hock, University of California, Los Angeles, Cecilia Demergasso, Laboratorio de Microbiología Técnica, Avda, Lorena Escudero, Laboratorio de Microbiología Técnica, Avda, P. Galleguillos, Laboratorio de Microbiología Técnica, Avda, Guillermo Chong, Departamento de Geología, Universidad Católica del Norte, Avda, Brian H. Grigsby, Schreder Planetarium/ARISE, Redding, Jebner Zambrana Román, Servicio Nacional de Geología y Minería (SERGEOMIN), La Paz, Cristian Tambley, Department of Astrophysics, Avda
- Edited by Mary Chapman
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- Book:
- The Geology of Mars
- Published online:
- 18 September 2009
- Print publication:
- 17 May 2007, pp 349-370
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- Chapter
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Summary
Introduction
A series of astrobiological high-altitude expeditions to the South American Andean Mountains were initiated in 2002 to explore the highest perennial lakes on Earth, including several volcanic crater lakes at or above 6000 m in elevation. During the next five years, they will provide the first integrated long-term astrobiological characterization and monitoring of lacustrine environments and their biology at such an altitude. These extreme lakes are natural laboratories that provide the field data, currently missing above 4000 m, to complete our understanding of terrestrial lakes and biota. Research is being performed on the effects of UV in low-altitude lakes and models of UV flux over time have been developed (Cockell, 2000). The lakes showing a high content of dissolved organic material (DOM) shield organisms from UV effects (McKenzie et al., 1999; Rae et al., 2000). DOM acts as a natural sunscreen by influencing water transparency, and therefore is a determinant of photic zone depth (Reche et al., 2000). In sparsely vegetated alpine areas, lakes tend to be clearer and offer less protection from UV to organisms living in the water. Transparent water, combined with high UV irradiance may maximize the penetration and effect of UV radiation as shown for organisms in alpine lakes (e.g., Vincent et al., 1984; Vinebrook and Leavitt, 1996). Shallow-water benthic communities in these lakes are particularly sensitive to UV radiation. Periphyton, which defines communities of microorganisms in bodies of water, can live on various susbtrates.