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- Antarctica -- Ecology (1)
- Aquatic organisms -- Effect of climatic changes on (1)
- Atmospheric deposition -- Colorado (1)
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- Fossils -- Morphology (1)
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Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
The Role Of Warm, Dry Summers And Variation In Snowpack On Phytoplankton Dynamics In Mountain Lakes, Isabella A. Olesky, Whitney S. Beck, Roderick W. Lammers, Cara E. Steger, Codie Wilson, Kyle R. Christianson, Kim Vincent, Gunnar Forrest Johnson, Pieter T.J. Johnson, Jill S. Baron
The Role Of Warm, Dry Summers And Variation In Snowpack On Phytoplankton Dynamics In Mountain Lakes, Isabella A. Olesky, Whitney S. Beck, Roderick W. Lammers, Cara E. Steger, Codie Wilson, Kyle R. Christianson, Kim Vincent, Gunnar Forrest Johnson, Pieter T.J. Johnson, Jill S. Baron
Geology Faculty Publications and Presentations
Climate change is altering biogeochemical, metabolic, and ecological functions in lakes across the globe. Historically, mountain lakes in temperate regions have been unproductive because of brief ice-free seasons, a snowmelt-driven hydrograph, cold temperatures, and steep topography with low vegetation and soil cover. We tested the relative importance of winter and summer weather, watershed characteristics, and water chemistry as drivers of phytoplankton dynamics. Using boosted regression tree models for 28 mountain lakes in Colorado, we examined regional, intraseasonal, and interannual drivers of variability in chlorophyll a as a proxy for lake phytoplankton. Phytoplankton biomass was inversely related to the maximum snow …
Spring Thaw Ionic Pulses Boost Nutrient Availability And Microbial Growth In Entombed Antarctic Dry Valley Cryoconite Holes, Jon Telling, Alexandre M. Anesio, Martyn Tranter, Andrew G. Fountain, Thomas H. Nylen, Jon Hawkings, Virendra B. Singh, Preeti Kaur, Michaela Musilova, Jemma L. Wadham
Spring Thaw Ionic Pulses Boost Nutrient Availability And Microbial Growth In Entombed Antarctic Dry Valley Cryoconite Holes, Jon Telling, Alexandre M. Anesio, Martyn Tranter, Andrew G. Fountain, Thomas H. Nylen, Jon Hawkings, Virendra B. Singh, Preeti Kaur, Michaela Musilova, Jemma L. Wadham
Geology Faculty Publications and Presentations
The seasonal melting of ice entombed cryoconite holes on McMurdo Dry Valley glaciers provides oases for life in the harsh environmental conditions of the polar desert where surface air temperatures only occasionally exceed 0°C during the Austral summer. Here we follow temporal changes in cryoconite hole biogeochemistry on Canada Glacier from fully frozen conditions through the initial stages of spring thaw toward fully melted holes. The cryoconite holes had a mean isolation age from the glacial drainage system of 3.4 years, with an increasing mass of aqueous nutrients (dissolved organic carbon, total nitrogen, total phosphorus) with longer isolation age. During …
Potential Fossil Endoliths In Vesicular Pillow Basalt, Coral Patch Seamount, Eastern North Atlantic Ocean, Barbara Cavalazzi, Frances Westall, Sherry L. Cady, Roberto Barbieri, Frédéric Foucher
Potential Fossil Endoliths In Vesicular Pillow Basalt, Coral Patch Seamount, Eastern North Atlantic Ocean, Barbara Cavalazzi, Frances Westall, Sherry L. Cady, Roberto Barbieri, Frédéric Foucher
Geology Faculty Publications and Presentations
The chilled rinds of pillow basalt from the Ampere-Coral Patch Seamounts in the eastern North Atlantic were studied as a potential habitat of microbial life. A variety of putative biogenic structures, which include filamentous and spherical microfossil-like structures, were detected in K-phillipsite-filled amygdules within the chilled rinds. The filamentous structures (similar to 2.5 mu m in diameter) occur as K-phillipsite tubules surrounded by an Fe-oxyhydroxide (lepidocrocite) rich membranous structure, whereas the spherical structures (from 4 to 2 mu m in diameter) are associated with Ti oxide (anatase) and carbonaceous matter. Several lines of evidence indicate that the microfossil-like structures in …
Morphological Biosignatures And The Search For Life On Mars, Sherry L. Cady, Jack D. Farmer, John P. Grotzinger, J. William Schopf, Andrew Steele
Morphological Biosignatures And The Search For Life On Mars, Sherry L. Cady, Jack D. Farmer, John P. Grotzinger, J. William Schopf, Andrew Steele
Geology Faculty Publications and Presentations
This report provides a rationale for the advances in instrumentation and understanding needed to assess claims of ancient and extraterrestrial life made on the basis of morphological biosignatures. Morphological biosignatures consist of bona fide microbial fossils as well as microbially influenced sedimentary structures. To be recognized as evidence of life, microbial fossils must contain chemical and structural attributes uniquely indicative of microbial cells or cellular or extracellular processes. When combined with various research strategies, high-resolution instruments can reveal such attributes and elucidate how morphological fossils form and become altered, thereby improving the ability to recognize them in the geological record …