FROZEN VOLCANIC TEFRA - NEW TERRESTRIAL EARTH ANALOG OF MARTIAN ECOSYSTEMS. Andrey Abramov, *Victoria Shcherbakova, Konstantin Laurinavichius, **Elizaveta Rivkina, David Gilichinsky Department of Geocryology, Moscow State University, Moscow, Russia *Institute of Biochemistry & Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia **Soil Cryology Laboratory, Institute of Physicochemical & Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino, Moscow Region, Russia Russia, 119899, Moscow, Vorobevy Gory, Moscow State University, Geology faculty, Department of Geocryology, tel.+7 (095) 439-47-06, e-mail: [email protected] Abstract. One way to have liquid water on Mars at shallow depths, according to the NASA point of view, would be through subglacial volcanism. Such volcanoice interactions are feasible nowadays beneath the polar ice caps of Mars, or even within the adjacent permafrost at the margins of the ice caps. This is why one of the Earth's models which may come close to extraterrestrial environments is represented by active volcanoes in permafrost areas. Another interesting thing is that dross-ashgaseous volcanic piles (or huge clouds), formed during volcanic eruptions, are the powerful natural “chemical reactor”, synthesizes the main biological combinations (amino acids, hydrocarbons, etc). According E. Markhinin (1977) this synthesis is abiogenic. The main question is whether volcanoes and associated environments can be ecological niche for microbial communities, and whether these bacteria can survive in permafrost. For this reason, our study was carried out on the volcano area, situated in Kamchatka a unique peninsula in the Russian Far East (pic.1). It is one of the largest modern volcanic regions with widespread glaciers and permafrost (pic.3) at high altitudes (Kotlyakov, 1997).

Pic.1. Working area. Results. We drilled a series of boreholes and pit-holes at different altitudes between 800 and 3075 m a.s.l. on the slopes of the active volcano Ploskii Tolbachik. The boreholes were placed in different landscape conditions,

and had depths ranging from 5 to 15 m (pic.3). The ground, mainly, is the young volcanic deposits (tefra, ash, basalt lava flows), which may be considered as an analog of Martian regolith (Girina, 1994). The main parameters of ground are shown on picture 4. The permafrost samples for microbiological analysis were obtained by slow rotary drilling without the use of solutions or drilling mud. The surface of the extracted cores was trimmed away with a sterile knife. Then the samples were immediately plated on a specially fitted nutrient medium. The main part of the core was divided into sections, placed in pre-sterilized aluminum cans, sealed and placed in frozen storage. Samples were taken for ice content, gas, chemical and textural composition. After completion of drilling, the boreholes were closed during a week and then borehole temperatures were measured. Based on these field measurements it is possible to suggest the following scheme of permafrost distribution on Ploskii Tolbachik slopes (see pictures below). The mean annual temperature of the frozen rocks is between 0° and 9 °С and permafrost thickness up to 350-400 m. Local taliks can be found where thermal waters exist and in the central part of the active volcano. The analysis shows that frozen samples extracted from borehole 7/02 and representing young volcanic deposits contain viable microorganisms and, among them, thermophilic anaerobic bacteria. Moreover, biogenic (?) methane (up to 1100-1900 µlCH4/kg soil) was found in these samples.

Pic.2. Methane production under the different temperatures (sample from the borehole MARS-7/02, 12.1 m depth) We have shown that various groups of anaerobic microorganisms growing on СО2 and Н2

media adapt themselves to the conditions of permafrost differently. The most part of methanogens would prefer to grow at 6 °С, with only some growing at 75 °С, while acetogens would grow at 75° and almost never at 6 °С. After 170 days of incubation the amount of newly formed methane in the enrichment culture of methanogens was 5.5% at 6 °С, 2.3% at 55° and 75 °С and it was only 0.2% under mesophilic conditions (37 °С) (pic.2). Thermophiles had never been found before in permafrost. The present study therefore demonstrates that the only way for thermophilic bacteria to appear within frozen volcanic horizon is during eruption from volcanoes or from related subsurface geological strata. The most important conclusion is that (1) thermophilic bacteria might survive in permafrost and even produce biogenic gases, and that (2) terrestrial volcanic microbial communities might serve as exobiological

models for hypotheses on existing ancient microbiocenoses, i. e., extraterrestrial habitats that may possibly be found under anoxic conditions around volcanoes on Mars or other planets. Acknowledgments. We want to say “Thank you” for: Yaroslav Muravyev for his participation, all people who help us, - for mountain equipment. References. Girina, O. A. 1994. Modern piroclastic deposites of Kamchatka volcanoes and their engineer characteristic // Ph.D. work. Moscow State University (in Russian). Kotlyakov, V. (ed.) 1997. World atlas of snow and ice resources // Moscow: Nauka (in Russian). Markhinin, E. K. 1977. The phenomenon of formation of prebiological compounds in volcanic processes // Origin of Life, #3: 225-235.

Pic 3. A schematic cross-section of the volcano Ploskii Tolbachik with the drilled boreholes. The thickness of the permafrost is estimated, but were drown not in scale.

Pic.4. The data from boreholes, drilled in summer 2002-2003.