A Portable Membrane Contactor Sampler for Analysis of Noble Gases in Groundwater

To enable a wider use of dissolved noble gas concentrations and isotope ratios in groundwater studies, we have developed an efficient and portable sampling device using a commercially available membrane contactor. The device separates dissolved gases from a stream of water and collects them in a small copper tube (6 mm in diameter and 100 mm in length with two pinch‐off clamps) for noble gas analysis by mass spectrometry. We have examined the performance of the sampler using a tank of homogeneous water prepared in the laboratory and by field testing. We find that our sampling device can extract heavier noble gases (Ar, Kr, and Xe) more efficiently than the lighter ones (He and Ne). An extraction time of about 60 min at a flow rate of 3 L/min is sufficient for all noble gases extracted in the sampler to attain equilibrium with the dissolved phase. The extracted gas sample did not indicate fractionation of helium (³He/⁴He) isotopes or other noble gas isotopes. Field performance of the sampling device was tested using a groundwater well in Vienna and results were in excellent agreement with those obtained from the conventional copper tube sampling method.     

Geodetic grids in authoritative maps – new findings about the origin of the UTM Grid

ABSTRACT

Recent discoveries of Wehrmacht Maps in the Military Archive of the Federal Archive of Germany in Freiburg im Breisgau raised the motivation for further investigations into the history of the internationally employed Universal Transverse Mercator (UTM) projection which actually represents a prerequisite for the global use of Global Positioning System (GPS) – and thus of any type of navigation – instruments. In contrast to the frequently stated opinion that this map projection was first operationally used by U.S. Americans it turned out that presumably the first operational maps with indication of the orthogonal UTM grid were produced by German Wehrmacht officers prior to the post World War (WW) II triumph of this projection. Based on the authors´ recent discoveries this article reveals some hitherto hardly known facts concerning the history of cartography of the 1940s.     

Crystal-structure properties and the molecular nature of hydrostatically compressed realgar

The structure of realgar, As₄S₄, and its evolution with pressure have been investigated employing in situ X-ray diffraction, optical absorption and vibrational spectroscopy on single-crystal samples in diamond-anvil cells. Compression under true hydrostatic conditions up to 5.40 GPa reveals equation-of-state parameters of V ₀ = 799.4(2.4) ų and K ₀ = 10.5(0.4) GPa with \(K_0^\prime\) = 8.7. The remarkably high compressibility can be attributed to a denser packing of the As₄S₄ molecules with shortening of the intermolecular bonds of up to 12 %, while the As₄S₄ molecules remain intact showing rigid-unit behaviour. From ambient pressure to 4.5 GPa, Raman spectra exhibit a strong blue shift of the Raman bands of the lattice-phonon regime of 24 cm^–1, whereas frequencies from intramolecular As-S stretching modes show negligible or no shifts at all. On pressurisation, realgar shows a continuous and reversible colour change from bright orange over deep red to black. Optical absorption spectroscopy shows a shift of the absorption edge from 2.30 to 1.81 eV up to 4.5 GPa, and DFT calculations show a corresponding reduction in the band gap. Synchrotron-based measurements on polycrystalline samples up to 45.5 GPa are indexed according to the monoclinic structure of realgar.     

Temperature-dependent leaching of chemical elements from mineral water bottle materials

It is well established that minute amounts of chemical elements will leach from bottle materials (glass or PET – polyethylene terephthalate) to water stored in such bottles. This study investigated whether leaching increases with storage temperature. For glass bottles this is clearly the case for a long list of elements: Ag, Al, As, B, Ba, Ca, Co, Cr, Cs, Cu, Fe, Ga, Ge, K, La, Li, Mg, Mo, Na, Ni, Pb, Rb, Sb, Se, Sn, Sr, Ti, U, V, W and Zr. However, for glass bottles drinking water maximum admissible concentration values as defined by European authorities are not exceeded even after 1 week of leaching at 80 °C. The critical temperature limit where leaching substantially increases for many elements appears to be 45 °C. For PET bottles, Sb is the only element where leaching is observed at all temperatures and again leaching strongly increases at 45 °C. For PET bottles Sb concentrations observed in water after 1 week storage at 80 °C reach almost four times the maximum admissible concentration values for drinking water but do not exceed the relevant higher limit for food (including water) packaged in PET.     

Pronounced increase in slope instability linked to global warming: A case study from the eastern European Alps

In recent decades, slope instability in high-mountain regions has often been linked to increase in temperature and the associated permafrost degradation and/or the increase in frequency/intensity of rainstorm events. In this context we analyzed the spatiotemporal evolution and potential controlling mechanisms of small- to medium-sized mass movements in a high-elevation catchment of the Italian Alps (Sulden/Solda basin). We found that slope-failure events (mostly in the form of rockfalls) have increased since the 2000s, whereas the occurrence of debris flows has increased only since 2010. The current climate-warming trend registered in the study area apparently increases the elevation of rockfall-detachment areas by approximately 300 m, mostly controlled by the combined effects of frost-cracking and permafrost thawing. In contrast, the occurrence of debris flows does not exhibit such an altitudinal shift, as it is primarily driven by extreme precipitation events exceeding the 75th percentile of the intensity-duration rainfall distribution. Potential debris-flow events in this environment may additionally be influenced by the accumulation of unconsolidated debris over time, which is then released during extreme rainfall events. Overall, there is evidence that the upper Sulden/Solda basin (above ca. 2500 m above sea level [a.s.l.]), and especially the areas in the proximity of glaciers, have experienced a significant decrease in slope stability since the 2000s, and that an increase in rockfalls and debris flows during spring and summer can be inferred. Our study thus confirms that “forward-looking” hazard mapping should be undertaken in these increasingly frequented, high-elevation areas of the Alps, as environmental change has elevated the overall hazard level in these regions.     

The earthquake of Carnuntum in the fourth century a.d. – archaeological results, seismologic scenario and seismotectonic implications for the Vienna Basin fault, Austria

Excavations in the former Roman provincial capital of Pannonia Superior, Carnuntum, 40 km east of Vienna revealed damaged masonry structures from many parts of the ancient settlements. A compilation of structurally damaged buildings has formerly been given by Kandler (Acta Archaeol Acad Sci Hung, 41:313–336, 1989), who related damage to an earthquake in the middle of the fourth century a.d. This paper reviews and supplements these data, and discusses the significance of the style of damage. It is concluded that seismic damage is the only likely interpretation for the damaging mechanism. Although archaeological age dating for the individual collapsed buildings only constrains the timing of their destruction to a few decades around 350 a.d., we assume a single damaging event. In spite of the restrictions on damage assessment by the nature of the archaeological data, it is possible to give a reasonable appraisal of macroseismic intensity. The tentative seismological interpretation of damage leads to an intensity estimate of about nine of the European macroseismic scale (EMS-1998). Comparison with macroseismic data of modern earthquakes in the region, which show a rapid decrease of intensity with distance form the epicentre, indicate a near-by seismic source unless exceptionally high epicentral intensities are assumed for the fourth century event. The most likely source is an active sinistral strike-slip fault (Lassee Fault) passing about 8 km NW of the archaeological site. The fault belongs to Vienna Basin fault system with about 2 mm sinistral movement per year. The system is characterized by fault segmentation and distinct seismicity along the different segments. Moderate seismicity during the last centuries at the southern segments (e.g., Schwadorf 1927, I ₀=8) strongly contrasts from the Lassee fault segment with Carnuntum as the only known severe earthquake. The earthquake of Carnuntum provides evidence for the overall seismic style of deformation along this segment, which previously has not been regarded seismically active. Also, the fourth century earthquake is the strongest event known from the Vienna Basin fault so far.     

Thermal study of the unilluminated surface of the waning moon

A program of lunar infrared radiometry which uses large area scanning is described. Procedures for atmospheric attenuation correction and data reduction to temperature by relative radiometry are outlined. The scan data of the waning Moon taken during ten evenings in the 10- to 12-µm window are presented as isothermal contour maps of the lunar disc. More than 160 areas of anomalous thermal emission have been found in the lunar darkside data. These are tabulated and are also shown on an accompanying map. An error analysis, derived from accuracy estimates of the independent parameters, is included.