Journal articles: 'McMurdo Dry Valleys'

1

Wharton, Robert A. "McMurdo Dry Valleys of Antarctica." Eos, Transactions American Geophysical Union 74, no. 46 (1993): 540. http://dx.doi.org/10.1029/93eo00550.

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Witherow, Rebecca A., W. Berry Lyons, Nancy A. N. Bertler, Kathleen A. Welch, Paul A. Mayewski, Sharon B. Sneed, Thomas Nylen, Michael J. Handley, and Andrew Fountain. "The aeolian flux of calcium, chloride and nitrate to the McMurdo Dry Valleys landscape: evidence from snow pit analysis." Antarctic Science 18, no. 4 (November 14, 2006): 497–505. http://dx.doi.org/10.1017/s095410200600054x.

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We have determined the flux of calcium, chloride and nitrate to the McMurdo Dry Valleys region by analysing snow pits for their chemical composition and their snow accumulation using multiple records spanning up to 48 years. The fluxes demonstrate patterns related to elevation and proximity to the ocean. In general, there is a strong relationship between the nitrate flux and snow accumulation, indicating that precipitation rates may have a great influence over the nitrogen concentrations in the soils of the valleys. Aeolian dust transport plays an important role in the deposition of some elements (e.g. Ca2+) into the McMurdo Dry Valleys' soils. Because of the antiquity of some of the soil surfaces in the McMurdo Dry Valleys regions, the accumulated atmospheric flux of salts to the soils has important ecological consequences. Although precipitation may be an important mechanism of salt deposition to the McMurdo Dry Valley surfaces, it is poorly understood because of difficulties in measurement and high losses from sublimation.

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Esposito, R. M. M., S. A. Spaulding, D. M. McKnight, B. Van de Vijver, K. Kopalová, D. Lubinski, B. Hall, and T. Whittaker. "Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica." Botany 86, no. 12 (December 2008): 1378–92. http://dx.doi.org/10.1139/b08-100.

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Diatom taxa present in the inland streams and lakes of the McMurdo Dry Valleys and James Ross Island, Antarctica, are presented in this paper. A total of nine taxa are illustrated, with descriptions of four new species ( Luticola austroatlantica sp. nov., Luticola dolia sp. nov., Luticola laeta sp. nov., Muelleria supra sp. nov.). In the perennially ice-covered lakes of the McMurdo Dry Valleys, diatoms are confined to benthic mats within the photic zone. In streams, diatoms are attached to benthic surfaces and within the microbial mat matrix. One species, L. austroatlantica, is found on James Ross Island, of the southern Atlantic archipelago, and the McMurdo Dry Valleys. The McMurdo Dry Valley populations are at the lower range of the size spectrum for the species. Streams flow for 6–10 weeks during the austral summer, when temperatures and solar radiation allow glacial ice to melt. The diatom flora of the region is characterized by species assemblages favored under harsh conditions, with naviculoid taxa as the dominant group and several major diatom groups conspicuously absent.

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FOUNTAIN, ANDREW G., HASSAN J. BASAGIC, and SPENCER NIEBUHR. "Glaciers in equilibrium, McMurdo Dry Valleys, Antarctica." Journal of Glaciology 62, no. 235 (July 29, 2016): 976–89. http://dx.doi.org/10.1017/jog.2016.86.

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ABSTRACTThe McMurdo Dry Valleys are a cold, dry polar desert and the alpine glaciers therein exhibit small annual and seasonal mass balances, often <±0.06 m w.e. Typically, winter is the accumulation season, but significant snow storms can occur any time of year occasionally making summer the accumulation season. The yearly equilibrium line altitude is poorly correlated with mass balance because the elevation gradient of mass balance on each glacier can change dramatically from year to year. Most likely, winds redistribute the light snowfall disrupting the normal gradient of increasing mass balance with elevation. Reconstructed cumulative mass balance shows that the glaciers have lost <2 m w.e. over the past half century and area changes show minimal retreat. In most cases these changes are less than the uncertainty and the glaciers are considered in equilibrium. Since 2000, however, the glaciers have lost mass despite relatively stable summer air temperatures suggesting a different mechanism in play. Whether this trend is a harbinger of future changes or a temporary excursion is unclear.

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Fountain, Andrew G., Thomas H. Nylen, Andrew Monaghan, Hassan J. Basagic, and David Bromwich. "Snow in the McMurdo Dry Valleys, Antarctica." International Journal of Climatology 30, no. 5 (May 7, 2009): 633–42. http://dx.doi.org/10.1002/joc.1933.

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Doran, Peter T., Robert A. Wharton, and W. Berry Lyons. "Paleolimnology of the McMurdo Dry Valleys, Antarctica." Journal of Paleolimnology 10, no. 2 (January 1994): 85–114. http://dx.doi.org/10.1007/bf00682507.

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Putkonen, Jaakko, Daniel Morgan, and Greg Balco. "Boulder weathering in McMurdo Dry Valleys, Antarctica." Geomorphology 219 (August 2014): 192–99. http://dx.doi.org/10.1016/j.geomorph.2014.05.012.

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Welch, Kathleen A., W. Berry Lyons, Carla Whisner, Christopher B. Gardner, Michael N. Gooseff, Diane M. McKnight, and John C. Priscu. "Spatial variations in the geochemistry of glacial meltwater streams in the Taylor Valley, Antarctica." Antarctic Science 22, no. 6 (December 2010): 662–72. http://dx.doi.org/10.1017/s0954102010000702.

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AbstractStreams in the McMurdo Dry Valleys, Antarctica, flow during the summer melt season (4–12 weeks) when air temperatures are close to the freezing point of water. Because of the low precipitation rates, streams originate from glacial meltwater and flow to closed-basin lakes on the valley floor. Water samples have been collected from the streams in the Dry Valleys since the start of the McMurdo Dry Valleys Long-Term Ecological Research project in 1993 and these have been analysed for ions and nutrient chemistry. Controls such as landscape position, morphology of the channels, and biotic and abiotic processes are thought to influence the stream chemistry. Sea-salt derived ions tend to be higher in streams that are closer to the ocean and those streams that drain the Taylor Glacier in western Taylor Valley. Chemical weathering is an important process influencing stream chemistry throughout the Dry Valleys. Nutrient availability is dependent on landscape age and varies with distance from the coast. The streams in Taylor Valley span a wide range in composition and total dissolved solids and are surprisingly similar to a wide range of much larger temperate and tropical river systems.

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Hall, B. L., G. H. Denton, and B. Overturf. "Glacial Lake Wright, a high-level Antarctic lake during the LGM and early Holocene." Antarctic Science 13, no. 1 (March 2001): 53–60. http://dx.doi.org/10.1017/s0954102001000086.

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We report evidence of a large proglacial lake (Glacial Lake Wright) that existed in Wright Valley in the McMurdo Dry Valleys region of Antarctica at the last glacial maximum (LGM) and in the early Holocene. At its highstands, Glacial Lake Wright would have stretched 50 km and covered c. 210 km2. Chronology for lake-level changes comes from 30 AMS radiocarbon dates of lacustrine algae preserved in deltas, shorelines, and glaciolacustrine deposits that extend up to 480 m above present-day lakes. Emerging evidence suggests that Glacial Lake Wright was only one of a series of large lakes to occupy the McMurdo Dry Valleys and the valleys fronting the Royal Society Range at the LGM. Although the cause of such high lake levels is not well understood, it is believed to relate to cool, dry conditions which produced fewer clouds, less snowfall, and greater amounts of absorbed radiation, leading to increased meltwater production.

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Mager, Sarah, Sean Fitzsimons, Russell Frew, Denis Samyn, and Reginald Lorrain. "Composition and origin of amber ice and its influence on the behaviour of cold glaciers in the McMurdo Dry Valleys, Antarctica." Journal of Glaciology 55, no. 190 (2009): 363–72. http://dx.doi.org/10.3189/002214309788608688.

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AbstractThis paper examines the basal ice sequence of Rhone Glacier, a cold-based glacier in the McMurdo Dry Valleys, Antarctica, using isotopic and solute chemistry data. Three different ice facies are identified: englacial, amber and stratified. The englacial facies is clean, bubbly ice of meteoric origin and is underlain by an amber facies. Amber ice is a characteristic of cold alpine glaciers in the McMurdo Dry Valleys and is distinctive for its high solute concentrations and much higher strain rates compared with the overlying englacial ice and the underlying stratified ice. Analysis of the stratified facies reveals an isotopic signature indicative of melt then refreeze processes and it is most likely associated with apron entrainment at the margin. By contrast, the amber facies has a co-isotopic slope of 8 and plots on a meteoric waterline. The inclusion of impurities in the amber ice reveals prolonged contact with the bed, and its depleted isotopic signature is consistent with ice formed during a cooler period. Comparison of the basal sequence of Rhone Glacier with other cold-based glaciers in the McMurdo Dry Valleys reveals strong similarities between valley-side glaciers (e.g. Meserve and Rhone Glaciers), whereas valley-floor glacier basal sequences (e.g. Suess Glacier) are characterized by structurally complex amalgamations of ice and debris.

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11

Obryk, M. K., P. T. Doran, E. D. Waddington, and C. P. Mckay. "The influence of föhn winds on Glacial Lake Washburn and palaeotemperatures in the McMurdo Dry Valleys, Antarctica, during the Last Glacial Maximum." Antarctic Science 29, no. 5 (March 17, 2017): 457–67. http://dx.doi.org/10.1017/s0954102017000062.

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AbstractLarge glacial lakes, including Glacial Lake Washburn, were present in the McMurdo Dry Valleys, Antarctica, during the Last Glacial Maximum (LGM) despite a colder and drier climate. To address the mechanism capable of generating enough meltwater to sustain these large lakes, a conceptual model was developed based on the warming potential of infrequent contemporary föhn winds. The model suggests that föhn winds were capable of generating enough meltwater to sustain large glacial lakes during the LGM by increasing degree days above freezing (DDAF) and prolonging the melt season. A present-day relationship between infrequent summer föhn winds and DDAF was established. It is assumed that the Taylor Dome ice core record represents large-scale palaeoclimatic variations for the McMurdo Dry Valleys region. This analysis suggests that because of the warming influence of the more frequent föhn winds, summer DDAF in the McMurdo Dry Valleys during the LGM were equivalent to present-day values, but this enhanced summer signal is not preserved in the annually averaged ice core temperature record.

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12

Marinova, Margarita M., Christopher P. Mckay, Wayne H. Pollard, Jennifer L. Heldmann, Alfonso F. Davila, Dale T. Andersen, W. Andrew Jackson, Denis Lacelle, Gale Paulsen, and Kris Zacny. "Distribution of depth to ice-cemented soils in the high-elevation Quartermain Mountains, McMurdo Dry Valleys, Antarctica." Antarctic Science 25, no. 4 (February 4, 2013): 575–82. http://dx.doi.org/10.1017/s095410201200123x.

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AbstractWe report on 475 measurements of depth to ice-cemented ground in four high-elevation valleys of the Quartermain Mountains, McMurdo Dry Valleys, Antarctica. These valleys have pervasive ice-cemented ground, and the depth to ice-cemented ground and the ice composition may be indicators of climate change. In University Valley, the measured depth to ice-cemented ground ranges from 0–98 cm. There is an overall trend of increasing depth to ice-cemented ground with distance from a small glacier at the head of the valley, with a slope of 32 cm depth per kilometre along the valley floor. For Farnell Valley, the depth to ice-cemented ground is roughly constant (c. 30 cm) in the upper and central parts of the valley, but increases sharply as the valley descends into Beacon Valley. The two valleys north of University Valley also have extensive ice-cemented ground, with depths of 20–40 cm, but exhibit no clear patterns of ice depth with location. For all valleys there is a tendency for the variability in depth to ice-cemented ground at a site to increase with increasing depth to ice. Snow recurrence, solar insolation, and surface albedo may all be factors that cause site to site variations in these valleys.

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13

Courtright, Ericha M., Diana H. Wall, and Ross A. Virginia. "Determining habitat suitability for soil invertebrates in an extreme environment: the McMurdo Dry Valleys, Antarctica." Antarctic Science 13, no. 1 (March 2001): 9–17. http://dx.doi.org/10.1017/s0954102001000037.

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We sampled soils in the McMurdo Dry Valleys to determine the habitats that were suitable for extreme for soil invertebrates. Suitability was assessed by comparing nematode species diversity and abundance, and tardigrade and rotifer abundance as related to soil properties at three spatial scales: landscape (across Taylor, Wright and Victoria valleys), at three distant locations within valleys, and within small plots (1 m2). Extreme environments were characterized by the lack of nematode abundance and diversity, high salinity, low soil moisture and organic carbon, and higher elevation or a geographic location less accessible for dispersing organisms. Suitable habitats were more frequent near the coast and at lower elevations. Extreme habitats could be defined based on one environmental factor, but more typically a set of interrelated soil and environmental factors appear to determine the abundance and composition of the soil community. The three Dry Valley nematode species occupied distinct regions of a multivariate biplot relating soil chemistry and moisture. Scottnema lindsayae is unusual for its ability to live in a wide range of extreme soil habitats. Our research shows that in the McMurdo Dry Valleys, life flourishes in suitable soil habitats and that extreme habitats (“no invertebrates”) can be defined.

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Talalay, Pavel G., and Alex R. Pyne. "Geological drilling in McMurdo Dry Valleys and McMurdo Sound, Antarctica: Historical development." Cold Regions Science and Technology 141 (September 2017): 131–62. http://dx.doi.org/10.1016/j.coldregions.2017.06.007.

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15

Bockheim, J. G., and M. McLeod. "Soil distribution in the McMurdo Dry Valleys, Antarctica." Geoderma 144, no. 1-2 (March 2008): 43–49. http://dx.doi.org/10.1016/j.geoderma.2007.10.015.

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16

Fountain, Andrew G., Thomas H. Nylen, Karen L. MacClune, and Gayle L. Dana. "Glacier mass balances (1993–2001), Taylor Valley, McMurdo Dry Valleys, Antarctica." Journal of Glaciology 52, no. 178 (2006): 451–62. http://dx.doi.org/10.3189/172756506781828511.

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AbstractMass balances were measured on four glaciers in Taylor Valley, Antarctica, from 1993 to 2001. We used a piecewise linear regression, which provided an objective assessment of error, to estimate the mass balance with elevation. Missing measurements were estimated from linear regressions between points and showed a significant improvement over other methods. Unlike temperate glaciers the accumulation zone of these polar glaciers accumulates mass in summer and winter and the ablation zone loses mass in both seasons. A strong spatial trend of smaller mass-balance values with distance inland (r2 = 0.80) reflects a climatic gradient to warmer air temperatures, faster wind speeds and less precipitation. Annual and seasonal mass-balance values range only several tens of millimeters in magnitude and no temporal trend is evident. The glaciers of Taylor Valley, and probably the entire McMurdo Dry Valleys, are in equilibrium with the current climate, and contrast with glacier trends elsewhere on the Antarctic Peninsula and in temperate latitudes.

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17

Yung, Charmaine C. M., Yuki Chan, Donnabella C. Lacap, Sergio Pérez-Ortega, Asuncion de los Rios-Murillo, Charles K. Lee, S. Craig Cary, and Stephen B. Pointing. "Characterization of Chasmoendolithic Community in Miers Valley, McMurdo Dry Valleys, Antarctica." Microbial Ecology 68, no. 2 (March 27, 2014): 351–59. http://dx.doi.org/10.1007/s00248-014-0412-7.

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Seppelt, R. D., T. G. A. Green, A.-M. J. Schwarz, and A. Frost. "Extreme southern locations for moss sporophytes in Antarctica." Antarctic Science 4, no. 1 (March 1992): 37–39. http://dx.doi.org/10.1017/s0954102092000087.

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Abundant immature sporophytes of the moss Pottia heimii are reported from the Lower Taylor Valley, McMurdo Dry Valleys and from Cape Chocolate, Victoria Land. These finds extend the reported southern limit for the occurrence of abundant moss sporophytes to 77° 55′S.

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Levy, Joseph, Andrew Fountain, W. Berry Lyons, and Kathy Welch. "Experimental formation of pore fluids in McMurdo Dry Valleys soils." Antarctic Science 27, no. 2 (September 23, 2014): 163–71. http://dx.doi.org/10.1017/s0954102014000479.

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AbstractThe aim of the study was to determine if soil salt deliquescence and brine hydration can occur under laboratory conditions using natural McMurdo Dry Valleys soils. The experiment was a laboratory analogue for the formation of isolated patches of hypersaline, damp soil, referred to as ‘wet patches’. Soils were oven dried and then hydrated in one of two humidity chambers: one at 100% relative humidity and the second at 75% relative humidity. Soil hydration is highly variable, and over the course of 20 days of hydration, ranged from increases in water content by mass from 0–16% for 122 soil samples from Taylor Valley. The rate and absolute amount of soil hydration correlates well with the soluble salt content of the soils but not with grain size distribution. This suggests that the formation of bulk pore waters in these soils is a consequence of salt deliquescence and hydration of the brine from atmospheric water vapour.

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Cowan, Don A., Nuraan Khan, Stephen B. Pointing, and S. Craig Cary. "Diverse hypolithic refuge communities in the McMurdo Dry Valleys." Antarctic Science 22, no. 6 (December 2010): 714–20. http://dx.doi.org/10.1017/s0954102010000507.

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AbstractHyper-arid deserts present extreme challenges to life. The environmental buffering provided by quartz and other translucent rocks allows hypolithic microbial communities to develop on sub-soil surfaces of such rocks. These refuge communities have been reported, for many locations worldwide, to be predominantly cyanobacterial in nature. Here we report the discovery in Antarctica’s hyper-arid McMurdo Dry Valleys of three clearly distinguishable types of hypolithic community. Based on gross colonization morphology and identification of dominant taxa, we have classified hypolithic communities as Type I (cyanobacterial dominated), Type II (fungal dominated) and Type III (moss dominated). This discovery supports a growing awareness of the high biocomplexity in Antarctic deserts, emphasizes the possible importance of cryptic microbial communities in nutrient cycling and provides evidence for possible successional community processes within a cold arid landscape.

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De Los Ríos, Asunción, Jacek Wierzchos, and Carmen Ascaso. "The lithic microbial ecosystems of Antarctica’s McMurdo Dry Valleys." Antarctic Science 26, no. 5 (July 7, 2014): 459–77. http://dx.doi.org/10.1017/s0954102014000194.

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AbstractWe review the lithic microbial ecosystems of the McMurdo Dry Valleys as the main form of terrestrial colonization in this region, and assess the role of environmental controls such as temperature, solar radiation, water availability, wind, nutrient availability, salinity and the physicochemical properties of the colonized rock. Epilithic communities, especially those dominated by lichens, are able to withstand extreme environmental conditions but subsurface endolithic microhabitats provide more tolerant conditions. Endolithic microbial communities can be grouped into two main classes: eukaryotic communities (dominated by lichenized fungi and algae) and prokaryotic communities (dominated by cyanobacteria). Heterotrophic bacteria and non-lichenized algae and fungi (mainly black fungi) are also components of these communities. These lithobiontic microorganisms generally have effective mechanisms against freezing temperatures and desiccation. Extracellular polymeric substances play an important role not only in protecting microbial cells but also in community organization and in mitigating microenvironmental conditions. Antarctic lithobiontic communities are comprised of microbial consortia within which multiple interactions between the different biological and abiotic components are essential for microbial survival, whilst fossils and biomarkers provide evidence of earlier successful microbial life in Antarctic deserts. Finally, the uniqueness of the present lithobiont assemblages suggests they are the outcome of geographical isolation during the evolution of the continent and not merely the descendants of a subset of globally distributed taxa that have adapted to the extreme environmental conditions.

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Barrett, J. E., R. A. Virginia, A. N. Parsons, and D. H. Wall. "Soil carbon turnover in the McMurdo Dry Valleys, Antarctica." Soil Biology and Biochemistry 38, no. 10 (October 2006): 3065–82. http://dx.doi.org/10.1016/j.soilbio.2006.03.025.

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23

Shacat, Joseph A., William J. Green, Eric H. Decarlo, and Silvia Newell. "The Geochemistry of Lake Joyce, McMurdo Dry Valleys, Antarctica." Aquatic Geochemistry 10, no. 3 (September 2004): 325–52. http://dx.doi.org/10.1023/b:aqua.0000047184.50027.41.

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Matsumoto, Genki I., Akio Hirai, Koitsu Hirota, and Kunihiko Watanuki. "Organic geochemistry of the McMurdo Dry Valleys soil, Antarctica." Organic Geochemistry 16, no. 4-6 (January 1990): 781–91. http://dx.doi.org/10.1016/0146-6380(90)90117-i.

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Shacat, Joseph A., William J. Green, Eric H. Decarlo, and Silvia Newell. "The Geochemistry of Lake Joyce, McMurdo Dry Valleys, Antarctica." Aquatic Geochemistry 10, no. 3-4 (September 2004): 325–52. http://dx.doi.org/10.1007/s10498-004-2264-0.

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Green, William J., and W. Berry Lyons. "The Saline Lakes of the McMurdo Dry Valleys, Antarctica." Aquatic Geochemistry 15, no. 1-2 (December 2, 2008): 321–48. http://dx.doi.org/10.1007/s10498-008-9052-1.

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27

McKay, Christopher P. "Snow recurrence sets the depth of dry permafrost at high elevations in the McMurdo Dry Valleys of Antarctica." Antarctic Science 21, no. 1 (July 30, 2008): 89–94. http://dx.doi.org/10.1017/s0954102008001508.

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AbstractDry permafrost on Earth is unique to the Antarctic and is found in the upper elevations of the McMurdo Dry Valleys. Despite its widespread presence in the Dry Valleys, the factors that control the distribution of dry permafrost and the ice-cemented ground below it are poorly understood. Here I show, by a combination of theoretical analysis and field observations, that the recurrence of snow can explain the depth of dry permafrost and the location of ice-cemented ground in Antarctica. For data from Linnaeus Terrace at 1600–1650 m elevation in Upper Wright Valley a recurrence intervals of about two years explains the presence of ground ice at 25 cm depth, under 12.5 cm of dry permafrost. Snow recurrence periods longer than 10 years would create only dry permafrost at this site. The snow gradient in University Valley resulting from the windblown snow from the polar plateau creates a corresponding gradient in the depth to ice-cemented ground. On the floor of Beacon Valley, the presence of dry permafrost without underlying ice-cemented ground indicates snow recurrence intervals of more than 10 years and implies that the ancient massive ice in this valley is not stable. Snow recurrence may also set the depth to ground ice on Mars.

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Lapalme, Caitlin, Denis Lacelle, Wayne Pollard, David Fisher, Alfonso Davila, and Christopher P. Mckay. "Distribution and origin of ground ice in University Valley, McMurdo Dry Valleys, Antarctica." Antarctic Science 29, no. 2 (December 1, 2016): 183–98. http://dx.doi.org/10.1017/s0954102016000572.

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AbstractGround ice is one of the most important and dynamic geologic components of permafrost; however, few studies have investigated the distribution and origin of ground ice in the McMurdo Dry Valleys of Antarctica. In this study, ice-bearing permafrost cores were collected from 18 sites in University Valley, a small hanging glacial valley in the Quartermain Mountains. Ground ice was found to be ubiquitous in the upper 2 m of permafrost soils, with excess ice contents reaching 93%, but ground ice conditions were not homogeneous. Ground ice content was variable within polygons and along the valley floor, decreasing in the centres of polygons and increasing in the shoulders of polygons towards the mouth of the valley. Ground ice also had different origins: vapour deposition, freezing of partially evaporated snow meltwater and buried glacier ice. The variability in the distribution and origin of ground ice can be attributed to ground surface temperature and moisture conditions, which separate the valley into distinct zones. Ground ice of vapour-deposition origin was predominantly situated in perennially cryotic zones, whereas ground ice formed by the freezing of evaporated snow meltwater was predominantly found in seasonally non-cryotic zones.

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Khan, Nuraan, Marla Tuffin, William Stafford, Craig Cary, Donnabella C. Lacap, Stephen B. Pointing, and Don Cowan. "Hypolithic microbial communities of quartz rocks from Miers Valley, McMurdo Dry Valleys, Antarctica." Polar Biology 34, no. 11 (July 27, 2011): 1657–68. http://dx.doi.org/10.1007/s00300-011-1061-7.

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30

Levy, Joseph, Anne Nolin, Andrew Fountain, and James Head. "Hyperspectral measurements of wet, dry and saline soils from the McMurdo Dry Valleys: soil moisture properties from remote sensing." Antarctic Science 26, no. 5 (February 14, 2014): 565–72. http://dx.doi.org/10.1017/s0954102013000977.

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AbstractSoil moisture is a spatially heterogeneous quantity in the McMurdo Dry Valleys of Antarctica that exerts a large influence on the biological community and on the thermal state of Dry Valleys permafrost. The goal of this project was to determine whether hyperspectral remote sensing techniques could be used to determine soil moisture conditions in the Dry Valleys. We measured the spectral reflectance factors of wetted soil samples from the Dry Valleys under natural light conditions and related diagnostic spectral features to surface layer soil moisture content. Diagnostic water absorption features in the spectra at 1.4 µm and 1.9 µm were present in all samples, including samples doped with high concentrations of chloride salts. The depth of the 1.4 µm absorption is shown to increase linearly with increasing gravimetric water content. These results suggest that airborne hyperspectral imaging of the Dry Valleys could generate soil moisture maps of this environment over large spatial areas using non-invasive remote-sensing techniques.

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31

Chinn, T. J. "Recent fluctuations of the Dry Valleys glaciers, McMurdo Sound, Antarctica." Annals of Glaciology 27 (1998): 119–24. http://dx.doi.org/10.3189/1998aog27-1-119-124.

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The state of equilibrium of the frontal positions of the glaciers of the Dry Valleys area of McMurdo Sound, Antarctica, has heen a subject of speculation since the) were fu si seen. A programme to measure the changes in frontal positions of 12 ice-cliffed glaciers has been maintained since 1982-83, with a 30 year record for Mcscrve Glacier. Simple taped distances from fixed points to the fronts of the glaciers have demonstrated that, in proportion to their flow and ablation regimes which are two orders of magnitude slower than those of temperate glaciers, the glaciers are fluctuating as dynamically as do temperate glaciers. Maximum advance or recession rates have been found to be near ±1 m a−1, changes which are almost undetectable in comparative photographs. Recession was found to be the dominant change trend, with yearly variations reflecting changes in annual ablation.The total height of the ice cliff gives a ready estimation of glacier equilibrium, with cliff heights being greatest on advancing glaciers. The division between advancing and receding glaciers was found to be at a cliff height of about 25 m.

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32

Heindel, Ruth C., Angela M. Spickard, and Ross A. Virginia. "Landscape-scale soil phosphorus variability in the McMurdo Dry Valleys." Antarctic Science 29, no. 3 (February 6, 2017): 252–63. http://dx.doi.org/10.1017/s0954102016000742.

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AbstractThe predicted increase in liquid water availability in the McMurdo Dry Valleys (MDV), Antarctica, may have profound consequences for nutrient cycling in soil and aquatic ecosystems. Our ability to predict future changes relies on our understanding of current nutrient cycling processes. Multiple hypotheses exist to explain the variability in soil phosphorus content and availability found throughout the MDV region. We analysed 146 surface soil samples from the MDV to determine the relative importance of parent material, landscape age, soil chemistry and texture, and topography on two biologically relevant phosphorus pools, HCl- and NaHCO3-extractable phosphorus. While HCl-extractable phosphorus is highly predicted by parent material, NaHCO3-extractable phosphorus is unrelated to parent material but is significantly correlated with soil conductivity, soil texture and topography. Neither measure of soil phosphorus was related to landscape age across a gradient of ~20 000 to 1 500 000 years. Glacial history has played an important role in the availability of soil phosphorus by shaping patterns of soil texture and parent material. With a predicted increase in water availability, the rate of mineral weathering may increase, releasing more HCl-extractable phosphorus into soil and aquatic ecosystems.

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Doran, Peter T., G. W. Berger, W. B. Lyons, R. A. Wharton, M. L. Davisson, J. Southon, and J. E. Dibb. "Dating Quaternary lacustrine sediments in the McMurdo Dry Valleys, Antarctica." Palaeogeography, Palaeoclimatology, Palaeoecology 147, no. 3-4 (March 1999): 223–39. http://dx.doi.org/10.1016/s0031-0182(98)00159-x.

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34

Moorhead, Daryl L., Peter T. Doran, Andrew G. Fountain, W. Berry Lyons, Diane M. McKnight, John C. Priscu, Ross A. Virginia, and Diana H. Wall. "Ecological Legacies: Impacts on Ecosystems of the McMurdo Dry Valleys." BioScience 49, no. 12 (December 1999): 1009. http://dx.doi.org/10.2307/1313734.

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35

Moorhead, Daryl L., Peter T. Doran, Andrew G. Fountain, W. Berry Lyons, Diane M. Mcknight, John C. Priscu, Ross A. Virginia, and Diana H. Wall. "Ecological Legacies: Impacts on Ecosystems of the McMurdo Dry Valleys." BioScience 49, no. 12 (December 1999): 1009–19. http://dx.doi.org/10.1525/bisi.1999.49.12.1009.

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36

Putkonen, Jaakko, Daniel J. Morgan, and Greg Balco. "Regolith transport quantified by braking block, McMurdo Dry Valleys, Antarctica." Geomorphology 155-156 (June 2012): 80–87. http://dx.doi.org/10.1016/j.geomorph.2011.12.010.

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Witherow, Rebecca A., W. Berry Lyons, and Gideon M. Henderson. "Lithium isotopic composition of the McMurdo Dry Valleys aquatic systems." Chemical Geology 275, no. 3-4 (August 2010): 139–47. http://dx.doi.org/10.1016/j.chemgeo.2010.04.017.

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Berry Lyons, W. "The Geochemistry and Biogeochemistry of the McMurdo Dry Valleys, Antarctica." Aquatic Geochemistry 10, no. 3-4 (September 2004): 197–98. http://dx.doi.org/10.1007/s10498-004-2258-y.

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39

Monteiro, Maria, Mafalda S. Baptista, Joana Séneca, Luís Torgo, Charles K. Lee, S. Craig Cary, and Catarina Magalhães. "Understanding the Response of Nitrifying Communities to Disturbance in the McMurdo Dry Valleys, Antarctica." Microorganisms 8, no. 3 (March 13, 2020): 404. http://dx.doi.org/10.3390/microorganisms8030404.

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Polar ecosystems are generally limited in nitrogen (N) nutrients, and the patchy availability of N is partly determined by biological pathways, such as nitrification, which are carried out by distinctive prokaryotic functional groups. The activity and diversity of microorganisms are generally strongly influenced by environmental conditions. However, we know little of the attributes that control the distribution and activity of specific microbial functional groups, such as nitrifiers, in extreme cold environments and how they may respond to change. To ascertain relationships between soil geochemistry and the ecology of nitrifying microbial communities, we carried out a laboratory-based manipulative experiment to test the selective effect of key geochemical variables on the activity and abundance of ammonia-oxidizing communities in soils from the McMurdo Dry Valleys of Antarctica. We hypothesized that nitrifying communities, adapted to different environmental conditions within the Dry Valleys, will have distinct responses when submitted to similar geochemical disturbances. In order to test this hypothesis, soils from two geographically distant and geochemically divergent locations, Miers and Beacon Valleys, were incubated over 2 months under increased conductivity, ammonia concentration, copper concentration, and organic matter content. Amplicon sequencing of the 16S rRNA gene and transcripts allowed comparison of the response of ammonia-oxidizing Archaea (AOA) and ammonia-oxidizing Bacteria (AOB) to each treatment over time. This approach was combined with measurements of 15NH4+ oxidation rates using 15N isotopic additions. Our results showed a higher potential for nitrification in Miers Valley, where environmental conditions are milder relative to Beacon Valley. AOA exhibited better adaptability to geochemical changes compared to AOB, particularly to the increase in copper and conductivity. AOA were also the only nitrifying group found in Beacon Valley soils. This laboratorial manipulative experiment provided new knowledge on how nitrifying groups respond to changes on key geochemical variables of Antarctic desert soils, and we believe these results offer new insights on the dynamics of N cycling in these ecosystems.

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Colesie, Claudia, Burkhard Büdel, and Allan T. G. Green. "Endolithic communities in the McMurdo Dry Valleys: biomass, turnover, cyanobacteria and location – a preliminary insight." Algological Studies 151-152, no. 1 (September 1, 2016): 51–68. http://dx.doi.org/10.1127/algol_stud/2016/0254.

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41

Katurji, M., B. Khan, M. Sprenger, R. Datta, K. Joy, P. Zawar-Reza, and I. Hawes. "Meteorological Connectivity from Regions of High Biodiversity within the McMurdo Dry Valleys of Antarctica." Journal of Applied Meteorology and Climatology 58, no. 11 (November 2019): 2437–52. http://dx.doi.org/10.1175/jamc-d-18-0336.1.

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AbstractMeteorological connectivity between biological hot spots of the McMurdo Dry Valleys (MDVs) of Antarctica is thought to play a role in species distribution and abundance through the aeolian transport of bioaerosols. Understanding the potential role of such meteorological connectivity requires an understanding of near-surface wind flow within and between valley airsheds. To address this, we applied Lagrangian wind trajectory modeling to mesoscale (spatial resolution of ~1 km) weather model output to predict connectivity pathways, focusing on regions of high biodiversity. Our models produce maps of a likelihood metric of wind connectivity that demonstrate the synoptic and mesoscale dependence of connections between local, near-local, and nonlocal areas on wind transport, modulated by synoptic weather and topographic forcing. These connectivity areas can have spatial trends modulated by the synoptic weather patterns and locally induced topographically forced winds. This method is transferrable to other regions of Antarctica for broader terrestrial, coastal, and offshore ecological connectivity research. Also, our analysis and methods can inform better placement of aeolian dust and bioaerosol samplers in the McMurdo Dry Valleys, provide preliminary guidelines behind the meteorological controls of sediment transport and smaller particle distribution, and present quantifiable knowledge informing new hypotheses around the potential of wind acting as a physical driver for biological connectivity in the MDVs.

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Dugan, H. A., M. K. Obryk, and P. T. Doran. "Lake ice ablation rates from permanently ice-covered Antarctic lakes." Journal of Glaciology 59, no. 215 (2013): 491–98. http://dx.doi.org/10.3189/2013jog12j080.

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AbstractIn the McMurdo Dry Valleys of Antarctica, three large, permanently ice-covered, closed-basin lakes exist along the floor of Taylor Valley. Lake ice ablation (loss of ice mass) is calculated as the sum of sublimation and surface melt, and is the driver of ice-cover turnover in these systems. In Taylor Valley, both manual and automated lake ice ablation rates have been calculated from 2001 to 2011. Results indicate relatively consistent winter ablation of 0.07–0.21 m (0.2–0.7 mm w.e. d−1). Summer ablation of lake ice is more variable and ranges from 0.25 to 1.62 m (5–31 mm w.e. d−1) over an average 51 day period. Previous to this study, ablation rates have been cited as 0.35 m a−1in the dry valleys from sublimation modeling based on meteorological variables. We show that this value has significantly underestimated mean ablation and ice-cover turnover on the Taylor Valley lakes.

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Lyons, W. B., S. W. Tyler, R. A. Wharton, D. M. McKnight, and B. H. Vaughn. "A Late Holocene desiccation of Lake Hoare and Lake Fryxell, McMurdo Dry Valleys, Antarctica." Antarctic Science 10, no. 3 (September 1998): 247–56. http://dx.doi.org/10.1017/s0954102098000340.

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Stable isotope data from waters of lakes in the McMurdo Dry Valleys (MDV) of southern Victoria Land, Antarctica are presented in order to establish the climatic history of this region over the past two millennia. New data from Lake Fryxell and Lake Hoare in Toylor Valley, along with previously published data from Lake Vanda, Wright Valley and Lake Bonney, Taylor Valley are used to infer the recent climatic history of MDV. Lakes Vanda, Fryxell and Bonney appear to have lost their ice covers and evaporated to small, hypersaline ponds by 1000 to ~1200 yr BP. Lake Hoare either desiccated or did not exist prior to 1200 yr BP. These data indicate a major lowering of lake level prior to ~1000 yr BP, followed by a warmer and/or more humid climate since then.

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Fountain, Andrew G., Juan C. Fernandez-Diaz, Maciej Obryk, Joseph Levy, Michael Gooseff, David J. Van Horn, Paul Morin, and Ramesh Shrestha. "High-resolution elevation mapping of the McMurdo Dry Valleys, Antarctica, and surrounding regions." Earth System Science Data 9, no. 2 (July 12, 2017): 435–43. http://dx.doi.org/10.5194/essd-9-435-2017.

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Abstract. We present detailed surface elevation measurements for the McMurdo Dry Valleys, Antarctica derived from aerial lidar surveys flown in the austral summer of 2014–2015 as part of an effort to understand geomorphic changes over the past decade. Lidar return density varied from 2 to > 10 returns m−2 with an average of about 5 returns m−2. Vertical and horizontal accuracies are estimated to be 7 and 3 cm, respectively. In addition to our intended targets, other ad hoc regions were also surveyed including the Pegasus flight facility and two regions on Ross Island, McMurdo Station, Scott Base (and surroundings), and the coastal margin between Cape Royds and Cape Evans. These data are included in this report and data release. The combined data are freely available at https://doi.org/10.5069/G9D50JX3.

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Krusic, A. G., M. L. Prentice, and J. M. Licciardi. "Climatic implications of reconstructed early–mid Pliocene equilibrium-line altitudes in the McMurdo Dry Valleys, Antarctica." Annals of Glaciology 50, no. 50 (2009): 31–36. http://dx.doi.org/10.3189/172756409787769564.

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AbstractEarly–mid Pliocene moraines in the McMurdo Dry Valleys, Antarctica, are more extensive than the present alpine glaciers in this region, indicating substantial climatic differences between the early–mid Pliocene and the present. To quantify this difference in the glacier–climate regime, we estimated the equilibrium-line altitude (ELA) change since the early–mid Pliocene by calculating the modern ELA and reconstructing the ELAs of four alpine glaciers in Wright and Taylor Valleys at their early–mid Pliocene maxima. The area–altitude balance ratio method was used on modern and reconstructed early–mid Pliocene hypsometry. In Wright and Victoria Valleys, mass-balance data identify present-day ELAs of 800–1600ma.s.l. and an average balance ratio of 1.1. The estimated ELAs of the much larger early–mid Pliocene glaciers in Wright and Taylor Valleys range from 600 to 950±170ma.s.l., and thus are 250–600±170m lower than modern ELAs in these valleys. The depressed ELAs during the early–mid-Pliocene most likely indicate a wetter and therefore warmer climate in the Dry Valleys during this period than previous studies have recognized.

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Hershey, Anne E., and John C. Priscu. "Ecosystem Dynamics in a Polar Desert: The McMurdo Dry Valleys, Antarctica." Arctic, Antarctic, and Alpine Research 32, no. 3 (August 2000): 365. http://dx.doi.org/10.2307/1552540.

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47

Boudreau, Alan, and Adam Simon. "Crystallization and Degassing in the Basement Sill, McMurdo Dry Valleys, Antarctica." Journal of Petrology 48, no. 7 (May 23, 2007): 1369–86. http://dx.doi.org/10.1093/petrology/egm022.

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48

PRISCU, JOHN C. "Phytoplankton nutrient deficiency in lakes of the McMurdo dry valleys, Antarctica." Freshwater Biology 34, no. 2 (October 1995): 215–27. http://dx.doi.org/10.1111/j.1365-2427.1995.tb00882.x.

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49

de la Torre, José R., Brett M. Goebel, E. Imre Friedmann, and Norman R. Pace. "Microbial Diversity of Cryptoendolithic Communities from the McMurdo Dry Valleys, Antarctica." Applied and Environmental Microbiology 69, no. 7 (July 2003): 3858–67. http://dx.doi.org/10.1128/aem.69.7.3858-3867.2003.

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ABSTRACT In the McMurdo Dry Valleys of Antarctica, microorganisms colonize the pore spaces of exposed rocks and are thereby protected from the desiccating environmental conditions on the surface. These cryptoendolithic communities have received attention in microscopy and culture-based studies but have not been examined by molecular approaches. We surveyed the microbial biodiversity of selected cryptoendolithic communities by analyzing clone libraries of rRNA genes amplified from environmental DNA. Over 1,100 individual clones from two types of cryptoendolithic communities, cyanobacterium dominated and lichen dominated, were analyzed. Clones fell into 51 relatedness groups (phylotypes) with ≥98% rRNA sequence identity (46 bacterial and 5 eucaryal). No representatives of Archaea were detected. No phylotypes were shared between the two classes of endolithic communities studied. Clone libraries based on both types of communities were dominated by a relatively small number of phylotypes that, because of their relative abundance, presumably represent the main primary producers in these communities. In the lichen-dominated community, three rRNA sequences, from a fungus, a green alga, and a chloroplast, of the types known to be associated with lichens, accounted for over 70% of the clones. This high abundance confirms the dominance of lichens in this community. In contrast, analysis of the supposedly cyanobacterium-dominated community indicated, in addition to cyanobacteria, at least two unsuspected organisms that, because of their abundance, may play important roles in the community. These included a member of the α subdivision of the Proteobacteria that potentially is capable of aerobic anoxygenic photosynthesis and a distant relative of Deinococcus that defines, along with other Deinococcus-related sequences from Antarctica, a new clade within the Thermus-Deinococcus bacterial phylogenetic division.

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Gooseff, Michael N., Diane M. McKnight, Peter Doran, Andrew G. Fountain, and W. Berry Lyons. "Hydrological Connectivity of the Landscape of the McMurdo Dry Valleys, Antarctica." Geography Compass 5, no. 9 (September 2011): 666–81. http://dx.doi.org/10.1111/j.1749-8198.2011.00445.x.

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Journal articles on the topic 'McMurdo Dry Valleys'

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