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Full-Text Articles in Physical Sciences and Mathematics

Evidence Of Variable Climate And Resources During The Late Pleistocene And Holocene At Gona, Ethiopia, Marie White Nov 2019

Evidence Of Variable Climate And Resources During The Late Pleistocene And Holocene At Gona, Ethiopia, Marie White

Steeplechase: An ORCA Student Journal

The African Humid Period (AHP) spanned a period of approximately 15 to 5 thousand years ago (ka) and resulted in Northern and Eastern Africa being wetter than today. This climate change event impacted flora, fauna, and humans to an unknown extent. Much of the work on the AHP across Eastern Africa utilizes lacustrine and marine proxies rather than river-based (fluvial). Gona, located in the Afar region of Ethiopia, is known for its extensive archaeological and fossil records in fluvial deposits. However, the paleoenvironment of the AHP at Gona has not been investigated. This study uses stratigraphy, geochronology, and paleopedology to …


Drip Water Measurements From Carlsbad Cavern: Implications Towards Paleoclimate Records Yielded From Evaporative-Zone Stalagmites, Victor J. Polyak, Jessica B.T. Rasmussen, Yemane Asmerom Jun 2018

Drip Water Measurements From Carlsbad Cavern: Implications Towards Paleoclimate Records Yielded From Evaporative-Zone Stalagmites, Victor J. Polyak, Jessica B.T. Rasmussen, Yemane Asmerom

International Journal of Speleology

Stalagmites can host numerous potential climate proxies (stable and radiogenic isotopes, trace elements, annual and non-annual banding, grayscale, growth hiatuses, mineral assemblage). Reproducibility and/or integration of proxy results between one or more stalagmites will become increasingly important, and ideally, climate records generated by multiple stalagmites from the same cave or cave room are expected to be near-identical. The reality is that stalagmites from the same cave room can yield differing results to some degree, especially in cave environment zones that are evaporative. Our drip water study in an evaporative shallow-depth cave environment in Carlsbad Cavern shows that adjacent drip sites …


Cora – A Dedicated Device For Carbon Dioxide Monitoring In Cave Environments, Marc Luetscher, Felix Ziegler Jan 2012

Cora – A Dedicated Device For Carbon Dioxide Monitoring In Cave Environments, Marc Luetscher, Felix Ziegler

International Journal of Speleology

High resolution time-series of cave CO2 fluctuations are increasingly demanded to quantify calcite precipitation processes. CORA, an energy-efficient NDIR-device, has been specifically developed for the long-term monitoring of carbon dioxide in remote cave environments. To allow comparison between different cave sites, changes in air pressure and temperature are compensated for using dedicated probes. Laboratory experiments demonstrate that CORA’s precision is adapted to the analysis of spatially and temporally variable CO2 regimes and therefore suitable for a large number of applications. Data obtained with 12 independently calibrated instruments are reproducible within 3% (1σ). The two-point calibration function is validated …