Overview of analogue science activities at the McGill Arctic Research Station, Axel Heiberg Island, Canadian High Arctic. Planet Sp Sci

ArticleinPlanetary and Space Science 57(5-6):646-659 · May 2009with21 Reads
Impact Factor: 1.88 · DOI: 10.1016/j.pss.2009.01.008
Abstract

The Canadian High Arctic contains several of the highest fidelity Mars analogue sites in the world. Situated at nearly 80° north, Expedition Fjord on Axel Heiberg Island is located within a polar desert climate, with the surrounding landscape and conditions providing an invaluable opportunity to examine terrestrial processes in a cold, dry environment. Through the Canadian Space Agency's Analogue Research Network program, scientific activities based out of the McGill Arctic Research Station (M.A.R.S.) are extremely broad in scope, representing physical, biological, and technological investigations. Some of the most unique hydrogeologic features under investigation near M.A.R.S. are a series of cold saline springs that maintain liquid-state flow year round regardless of air temperature. Previous studies have examined their geomorphic relation to discharge-related formations, water chemistry, temperature monitoring, discharge rates, and combined flow/thermal modeling. Recent investigations have identified microbial communities and characterized biological activity within the springs and within permafrost sections, having direct relevance to astrobiological analogue research goals. Another main thrust of research activities based at M.A.R.S. pertains to the detection, mapping, and quantification of subsurface ice deposits. A long-term study is presently underway examining polygonal terrain, comparing surficial patterns found in the region with those identified on Mars, and using surface morphology to estimate ice wedge volumes through a combination of aerial photography interpretation and ground-based geophysical techniques. Other technological developments include the use of in situ microscopy for the detection of biomarkers and improved permafrost drilling techniques. This paper presents an overview of previous studies undertaken at M.A.R.S. over the past decades and will describe in detail both present and upcoming work.

    • "...S1 and S2). The geology of this site has been thoroughly described (Pollard et al., 2009). The source of these springs' waters is uncertain; ground-penetrating radar indicates the waters ascend through 400 m of..."
      S1 and S2). The geology of this site has been thoroughly described (Pollard et al., 2009). The source of these springs' waters is uncertain; ground-penetrating radar indicates the waters ascend through 400 m of Carboniferous anhydrite evaporite permafrost (Jackson and Harrison, 2006 ).
    [Show abstract] [Hide abstract] ABSTRACT: Cryopegs are subsurface hypersaline brines at sub-zero temperatures within permafrost; their global extent and distribution are unknown. The permafrost barrier to surface and groundwater advection maintains these brines as semi-isolated systems over geological time. A cryopeg 7 m below ground near Barrow, Alaska, was sampled for geochemical and microbiological analysis. Subsurface brines (in situ temperature of –6 °C, salinity of 115 ppt) and an associated sediment-infused ice wedge (melt salinity of 0.04) were sampled using sterile technique. Major ionic concentrations in the brine corresponded more closely to other (Siberian) cryopegs than to Standard seawater or the ice wedge. Ionic ratios and stable isotope analysis of water conformed to a marine or brackish origin with subsequent Rayleigh fractionation. The brine contained ∼1000X more bacteria than surrounding ice, relatively high viral numbers suggestive of infection and reproduction, and an unusually high ratio of particulate to dissolved extracellular polysaccharide substances. A viral metagenome indicated a high frequency of temperate viruses and limited viral diversity compared to surface environments, with closest similarity to low water activity environments. Interpretations of the results underscore the isolation of these under-explored microbial ecosystems from past and present oceans.
    Full-text · Article · Mar 2016 · FEMS Microbiology Ecology
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    • "...S1 and S2). The geology of this site has been thoroughly described (Pollard et al., 2009). The source of these springs' waters is uncertain; ground-penetrating radar indicates the waters ascend through 400 m of..."
      S1 and S2). The geology of this site has been thoroughly described (Pollard et al., 2009). The source of these springs' waters is uncertain; ground-penetrating radar indicates the waters ascend through 400 m of Carboniferous anhydrite evaporite permafrost (Jackson and Harrison, 2006 ).
    [Show abstract] [Hide abstract] ABSTRACT: Viruses are ubiquitous drivers of microbial ecology and evolution and contribute to biogeochemical cycling. Attention to these attributes has been more substantial for marine viruses than viruses of other environments. Microscopy-based investigation of the viral communities from two cold, hypersaline Arctic springs was undertaken to explore the effects of these conditions on microbe-viral ecology. Sediments and water samples were collected along transects from each spring, from anoxic spring outlets through oxygenated downstream channels. Viral abundance, virus-microbe ratios, and modeled virus-microbe contact rates were lower than comparable aqueous and sedimentary environments and most similar to deep subsurface sediments. No individual cell from either spring was visibly infected. Viruses in these springs appear to play a smaller role in controlling microbial populations through lytic activity than in marine water column or surface sedimentary environments. Relief from viral predation indicates the microbial communities are primarily controlled by nutrient limitation. The similarity of these springs to deep subsurface sediments suggests a biogeographic divide in viral replication strategy in marine sediments.
    Full-text · Article · Jan 2016 · Environmental Microbiology Reports
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    • "...mate, and geomorphology which mimic conditions that did once, or currently exist, on Mars (Pollard et al. 2009). For example, a gully which formed during the past decade on Mars provides compelling evidence tha..."
      Archaeal phylotypes were related to those found in hypersaline deepsea methane-seep sediments and were dominated by the ANaerobic MEthane group 1a (ANME-1a) clade of anaerobic methane oxidizing archaea indicating that the thermogenic methane exsolving from the LH spring source may act as an energy and carbon source for sustaining anaerobic oxidation of methane-based microbial metabolism under ambient hypersaline , subzero conditions (Niederberger et al. 2010). The springs on AHI are regarded as Martian analog sites due to their unique geology, climate, and geomorphology which mimic conditions that did once, or currently exist, on Mars (Pollard et al. 2009). For example, a gully which formed during the past decade on Mars provides compelling evidence that liquid water (or brine) may exist on Mars (Malin et al. 2006; McEwen et al. 2011), while the trace amounts of methane in the Mars atmosphere (Formisano et al. 2004) may originate from localized 'hot spots' or 'plumes' of methane arising from the frozen terrestrial Martian surface (Mumma et al. 2009).
    Full-text · Dataset · Oct 2013
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    • "...and sul fi de (Perreault et al., 2007Perreault et al., , 2008 Niederberger et al., 2009 ; Pollard et al., 2009 ) . A third AHI perennial spring, Lost Hammer spring, is characterized by a cone-shaped tufa structu..."
      The AHI Gypsum Hill and Color Peak springs fl ow perennially with constant discharge temperatures ranging from −0.7 to 6.9 °C and discharge waters that are moderately saline (7.5–15.8 % salts), anoxic (mean oxidoreduction potential (ORP) of −325 mV), and rich in both sulfate and sul fi de (Perreault et al., 2007Perreault et al., , 2008 Niederberger et al., 2009 ; Pollard et al., 2009 ) . A third AHI perennial spring, Lost Hammer spring, is characterized by a cone-shaped tufa structure and is the only known perennial subzero (−5 °C) and hypersaline (~24 %) terrestrial methane seep on Earth (Niederberger et al., 2010 ) .
    [Show abstract] [Hide abstract] ABSTRACT: Cryoenvironments are generally defined as environments that exist continuously and predominately at subzero temperatures. They exist primarily in polar and alpine regions and consist of large-scale geomorphological features such as permafrost, glaciers, ice caps, and sea ice. Cryoenvironments also include relatively rare subzero habitats such as cold lakes and ponds, which can be permanently ice covered, and subzero saline springs, which flow throughout the year, warmed by geothermal gradients, and maintained liquid due to their high salinity (Andersen et al., 2002; Doyle et al., 2012). The primary constraint to life in cryoenvironments is the availability of liquid water; life needs liquid water to survive, mediate biochemical reactions, provide transport of molecules, and act as a solvent. It is not necessarily subzero temperatures that constrain life in cryoenvironments but rather the conditions that are typically found associated with subzero temperatures, which include freezing, desiccation, or high osmolarity. Microorganisms in subzero environments must, however, be able to cope with the thermodynamic effects of low temperatures including lower reaction rates, increased molecule stability, and conformational changes of proteins (Bakermans, 2008). Because the presence of liquid water in cryoenvironments is often facilitated through the freezing-point depression properties of various solutes, microorganisms must also be able to tolerate osmotic stress, usually in the form of high salinity. Despite these harsh environmental conditions, there is a recent and growing body of evidence that cryophilic microorganisms (those able to reproduce at
    No preview · Chapter · Jan 2013
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    • "...of recent research (e.g., Osinski et al. 2001; Grasby et al. 2003; Grasby and Londry 2007; Pollard et al. 2009; Cloutis et al. 2010; Lacelle and Léveillé 2010). Several acid drainage sites related to weathering ..."
      The recognition of complex microbial communities in acid systems raises the potential for acid environments on Mars to also support, or have supported, life, and raises the need to understand the diversity of natural acid environments and the life they support. Canada has abundant analogue spring sites that have been the focus of recent research (e.g., Osinski et al. 2001; Grasby et al. 2003; Grasby and Londry 2007; Pollard et al. 2009; Cloutis et al. 2010; Lacelle and Léveillé 2010). Several acid drainage sites related to weathering of pyrite-rich shales have also been described in several locations in Canada (e.g., van Everdingen et al. 1985; Kwong et al. 2009; Lacelle and Léveillé 2010).
    [Show abstract] [Hide abstract] ABSTRACT: The Paint Pots are a natural Fe-SO4 acid spring system along the Kicking Horse Rim, a major geological feature that has controlled fluid flow and mineralization over geologic time. The very low pH (similar to 3) and extremely high trace metal concentrations of the springs are anomalous and greatly exceed health limits (Zn = 35.8 mg/L, Pb = 0.461 mg/L, As = 82.7 ppb). Sulphur isotopes (delta S-34 and delta O-18 in sulphate equal to +11.4 and -12.1 %, respectively) are consistent with sulphide oxidation. Mass balance calculations indicate that the springs must have derived their acidity and metal content from natural weathering of a pyrite-rich ore deposit in the vicinity. Several ore deposit types occur along the Kicking Horse Rim, with the Mississippi Valley Type (MVT) style being the most consistent with the source of the spring waters. At the spring outlet, Fe-rich waters oxidize, forming large cone features of Fe-O precipitates, predominantly goethite. A diverse microbial community has been identified in the site that is distinct from those found at acid mine drainage sites. At one site, there was a high proportion of the bacterial candidate division WPS-2, the first time that this group has been detected as the predominant phylum in a community. Compared with anthropogenically influenced acid mine drainage sites that have been studied to date as Mars analogues, the unique uncultured organisms found in the Paint Pots provide a distinct analogue site that can offer insights into the diversity of extremophilic organisms in more natural environments.
    Full-text · Article · Jan 2013 · Canadian Journal of Earth Sciences
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    • "...planet transitioned from a warmer, wetter planet to an increasingly drier and colder one (Pollard et al., 2009; Fairen et al., 2010). Ice wedges are an enticing habitat for the study of terrestrial extremophiles..."
      The characterization of terrestrial ice wedges as habitable niches with a plausibly active microbial community has been strengthened by our results. This research also lays the groundwork for future studies at the field site on Axel Heiberg, which is considered a prime analogue for the climate during Mars' second age, when the planet transitioned from a warmer, wetter planet to an increasingly drier and colder one (Pollard et al., 2009; Fairen et al., 2010). Ice wedges are an enticing habitat for the study of terrestrial extremophiles and are likely to contribute insight for developing useful criteria for searching for life in ice-rich environments.
    [Show abstract] [Hide abstract] ABSTRACT: The discovery of polygonal terrain on Mars underlain by ice heightens interest in the possibility that this water-bearing habitat may be, or may have been, a suitable habitat for extant life. The possibility is supported by the recurring detection of terrestrial microorganisms in subsurface ice environments, such as ice wedges found beneath tundra polygon features. A characterization of the microbial community of ice wedges from the high Arctic was performed to determine whether this ice environment can sustain actively respiring microorganisms and to assess the ecology of this extreme niche. We found that ice wedge samples contained a relatively abundant number of culturable cells compared to other ice habitats (∼10(5) CFU·mL(-1)). Respiration assays in which radio-labeled acetate and in situ measurement of CO(2) flux were used suggested low levels of microbial activity, though more sensitive techniques are required to confirm these findings. Based on 16S rRNA gene pyrosequencing, bacterial and archaeal ice wedge communities appeared to reflect surrounding soil communities. Two Pseudomonas sp. were the most abundant taxa in the ice wedge bacterial library (∼50%), while taxa related to ammonia-oxidizing Thaumarchaeota occupied 90% of the archaeal library. The tolerance of a variety of isolates to salinity and temperature revealed characteristics of a psychrotolerant, halotolerant community. Our findings support the hypothesis that ice wedges are capable of sustaining a diverse, plausibly active microbial community. As such, ice wedges, compared to other forms of less habitable ground ice, could serve as a reservoir for life on permanently cold, water-scarce, ice-rich extraterrestrial bodies and are therefore of interest to astrobiologists and ecologists alike. .
    Full-text · Article · Apr 2012 · Astrobiology
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