Soil distribution and soil properties in the subalpine region of Kazbegi; Greater Caucasus

Georgia Soils of the alpine ecosystem of Kazbegi region were investigated in an interdisciplinary project (founded by the Volkswagen Stiftung) from 2014 until 2017. Soils on sediment fans as well as glacial sediments, mostly Cambisols (Humic), are characterized by a low to moderate yield potential while high-yield soils, mostly Cambic Umbrisols, can be found on volcanic plateaus. A common element of all soils is the high humus content. Actually, most of them are used only for pasture, due to poor accessibility. Soils on fluvial deposits, mostly Fluvisols, show a very high range of Muencheberg Soil Quality Rating (M-SQR)-scores. Most limiting factors are climate as well as steepness, while the low nutrient supply and soil acidity can be tackled by adequate fertilization and liming practice. Inorganic or organic pollution were not detected. Altogether, the soils of the study area have the actually untapped potential to optimize the basic supply of the local population as well as tourism also by cultivation of cereals. Nevertheless, variety trials on different soil forming substrates as well as erosion control are major preconditions for successful implementation of new cropping systems in the Kazbegi region. Furthermore, particularly rare soils, e.g. Cambisols on Tephra, should be protected

Ongoing oversanding induces biological soil crust layering – A new approach for biological soil crust structure elucidation determined from high resolution penetration resistance data

© 2017 Elsevier B.V. The aim of this study was to determine the in-situ strength and microscopic characteristics of bio-physical micro-horizons in the top 40 mm of oversanded sand soils detected by depth dependent penetration resistance (PR). These micro-horizons result from the burial of biological soils crust (BSC) surfaces and contribute to soil stability. They are also important as the biotic source for seeding new surficial crusts. Ex-situ polarised optical micrograph was employed to determine the bio-physical structures associated with the fossil BSC horizons. An automated electronic micro penetrometer (EMP) determining in-situ depth dependent soil PR was used for the quantitative detection of surface and buried micro-horizons. PR data was modelled using a multi-component/soil and micro-horizon multilayer plastic shear stress model. This enabled determination of soil and sediment structure, the contribution of buried ‘fossil’ BSCs to soil strength and structural mapping. We also employed proxy (synthetic) layered soil systems to determine the effect of EMP shaft and probe tip shape upon the PR profile. This methodology represents a significant improvement over penetrometer methods that only use single-value surface breaking point information. We find that buried BSC structures can contribute over 80% of the soil strength even at ca. 20 mm depth and that the strength of a buried crust, at least in the medium term, can exceed that of (developing) surficial ones. Typical soil strengths of BSCs in the Negev desert, Israel lie between 1.5 and 3.6 MPa. Finally we discuss the effects and potential importance that buried BSC horizons may have upon heat, and the percolation and diffusion of moisture and gas through structured bio-physical, BSC capped sand soil systems

Measuring the Neutrino Cross Section Using 8 years of Upgoing Muon Neutrinos Observed with IceCube

The IceCube Neutrino Observatory detects neutrinos at energies orders of magnitude higher than those available to current accelerators. Above 40 TeV, neutrinos traveling through the Earth will be absorbed as they interact via charged current interactions with nuclei, creating a deficit of Earth-crossing neutrinos detected at IceCube. The previous published results showed the cross section to be consistent with Standard Model predictions for 1 year of IceCube data. We present a new analysis that uses 8 years of IceCube data to fit the ν$_{μ}$ absorption in the Earth, with statistics an order of magnitude better than previous analyses, and with an improved treatment of systematic uncertainties. It will measure the cross section in three energy bins that span the range 1 TeV to 100 PeV. We will present Monte Carlo studies that demonstrate its sensitivity