GIS Teacher Training: Empirically-Based Indicators of Effectiveness

In spite of various actions, the implementation of GIS (geographic information systems) in German schools is still very low. In the presented research, teaching experts as well as teaching novices were presented with empirically based constraints for implementation stemming from an earlier survey. In the process of various group discussions, the participants developed ideas for overcoming the constraints in the field of continuing teacher education among others. These ideas were used to create empirically based strategies for the future design of training activities in continuing education of teachers while taking these constraints into account. These strategies were later validated externally by comparing them to empirical findings on effects of training activities in continuing teacher education in general and empirical findings on GIS implementation from other studies.     

Identification and assessment of groundwater flow and storage components of the relict Schöneben Rock Glacier,Niedere Tauern Range,Eastern Alps (Austria)

More than 2,600 relict rock glaciers are known in the Austrian Alps but the knowledge of their hydraulic properties is severely limited. The relict Schöneben Rock Glacier (Niedere Tauern Range, Austria), with an extension of 0.17 km², was investigated based on spring data (2006–2014) and seismic refraction survey. Spring-discharge hydrographs and natural and artificial tracer data suggest a heterogeneous aquifer with a layered internal structure for the relict rock glacier. The discharge behavior exhibits a fast and a delayed flow component. The spring discharge responds to recharge events within a few hours but a mean residence time of several months can also be observed. The internal structure of the rock glacier (up to several tens of meters thick) consists of: an upper blocky layer with a few meters of thickness, which lacks fine-grained sediments; a main middle layer with coarse and finer-grained sediments, allowing for fast flow; and an approximately 10-m-thick basal till layer as the main aquifer body responsible for the base flow. The base-flow component is controlled by (fine) sandy to silty sediments with low hydraulic conductivity and high storage capacity, exhibiting a difference in hydraulic conductivity to the upper layer of about three orders of magnitude. The high storage capacity of relict rock glaciers has an impact on water resources management in alpine catchments and potentially regulates the risk of natural hazards such as floods and related debris flows. Thus, the results highlight the importance of such aquifer systems in alpine catchments.     

A history of violence: magma incubation,timing and tephra distribution of the Los Chocoyos supereruption (Atitlán Caldera,Guatemala)

The climactic Los Chocoyos (LCY) eruption from Atitlán caldera (Guatemala) is a key chronostratigraphic marker for the Quaternary period given the extensive distribution of its deposits that reached both the Pacific and Atlantic Oceans. Despite LCY tephra being an important marker horizon, a radioisotopic age for this eruption has remained elusive. Using zircon (U–Th)/He geochronology, we present the first radioisotopically determined eruption age for the LCY of 75 ± 2 ka. Additionally, the youngest zircon crystallization ²³⁸U–²³⁰Th rim ages in their respective samples constrain eruption age maxima for two other tephra units that erupted from Atitlán caldera, W-Fall (130 ⁺¹⁶/₋₁₄ ka) and I-Fall eruptions (56 ^+8.2/_−7.7 ka), which under- and overlie LCY tephra, respectively. Moreover, rim and interior zircon dating and glass chemistry suggest that before eruption silicic magma was stored for >80 kyr, with magma accumulation peaking within ca. 35 kyr before the LCY eruption during which the system may have developed into a vertically zoned magma chamber. Based on an updated distribution of LCY pyroclastic deposits, a new conservatively estimated volume of ~1220 ± 150 km³ is obtained (volcanic explosivity index VEI > 8), which confirms the LCY eruption as the first-ever recognized supereruption in Central America.     

Multitracer test approach to characterize reactive transport in karst aquifers

A method to estimate reactive transport parameters as well as geometric conduit parameters from a multitracer test in a karst aquifer is provided. For this purpose, a calibration strategy was developed applying the two-region nonequilibrium model CXTFIT. The ambiguity of the model calibration was reduced by first calibrating the model with respect to conservative tracer breakthrough and later transferring conservative transport parameters to the reactive model calibration. The reactive transport parameters were only allowed to be within a defined sensible range to get reasonable calibration values. This calibration strategy was applied to breakthrough curves obtained from a large-scale multitracer test, which was performed in a karst aquifer of the Swabian Alb, Germany. The multitracer test was conducted by the simultaneous injection of uranine, sulforhodamine G, and tinopal CBS-X. The model succeeds to represent the tracer breakthrough curves (TBCs) of uranine and sulforhodamine G and verifies that tracer-rock interactions preferably occur in the immobile fluid region, although the fraction of this region amounts to only 3.5% of the total water. However, the model failed to account for the long tailing observed in the TBC of tinopal CBS-X. Sensitivity analyses reveal that model results for the conservative tracer transport are most sensitive to average velocity and volume fraction of the mobile fluid region, while dispersion and mass transfer coefficients are least influential. Consequently, reactive tracer calibration allows the determination of sorption sites in the mobile and immobile fluid region at small retardation coefficients.     

Early Holocene environmental history of sunken landscapes: pollen, plant macrofossil and geochemical analyses from the Borkum Riffgrund, southern North Sea

A vibrocore from the sea floor of the southern North Sea provides a ~1,500-year record of early Holocene vegetation history and mire development in a landscape now 33 m below sea-level. Pollen, plant macrofossil and geochemical analyses of an AMS ¹⁴C dated sand–peat–marine mud sequence document the paludification on Pleistocene sands ~10,700 cal BP, the subsequent development of eutraphentic carr vegetation and the gradual inundation by the transgressing sea ~9,350 cal BP. Pinus–Corylus woodland prevailed on terrestrial grounds after hazel had immigrated ~10,700 cal BP. Salix dominated the carr vegetation throughout 1,300 years of peat formation, because Alnus did not spread in the Borkum Riffgrund area until 9,300 BP. Brackish reed vegetation with Phragmites established after inundation and siliciclastic marine sediments were being deposited. This article also examines the detection and suitability of key horizons indicative of marine influence. XRF-Scanning provides the most detailed results in the briefest possible time to pinpoint spectra best suitable for AMS ¹⁴C dating of classical key horizons such as start of peat formation and transgressive contact. The combined application of botanical and geochemical methods allows determining new key horizons indicative of marine influence, namely the earliest marine inundation and the onset of sea-level influence on coastal ground water level.     

The solar photospheric abundance of zirconium

Zirconium (Zr), together with strontium and yttrium, is an important element in the understanding of the Galactic nucleosynthesis. In fact, the triad Sr‐Y‐Zr constitutes the first peak of s‐process elements. Despite its general relevance not many studies of the solar abundance of Zr were conducted. We derive the zirconium abundance in the solar photosphere with the same CO⁵BOLD hydrodynamical model of the solar atmosphere that we previously used to investigate the abundances of C‐N‐O. We review the zirconium lines available in the observed solar spectra and select a sample of lines to determine the zirconium abundance, considering lines of neutral and singly ionised zirconium. We apply different line profile fitting strategies for a reliable analysis of Zr lines that are blended by lines of other elements. The abundance obtained from lines of neutral zirconium is very uncertain because these lines are commonly blended and weak in the solar spectrum. However, we believe that some lines of ionised zirconium are reliable abundance indicators. Restricting the set to Zr II lines, from the CO⁵BOLD 3D model atmosphere we derive A (Zr) = 2.62 ± 0.06, where the quoted error is the RMS line‐to‐line scatter (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

KGI-XGIS SUPPORTING DECISION MAKING WITH KNOWLEDGE-BASED TECHNIQUES

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On the type of spectra of S-component sources and their correlation with flare occurrence

From solar maps at 8.6 mm wavelength and total flux measurements at wavelengths of 1.7 cm to 122 cm, various spectra of the slowly varying component have been studied. The main distinction between these various types of spectra is the slope of the spectra toward wavelengths of less than 2 cm.It has been shown that the probability of flare occurrence is correlated with the type of the source spectra. It is proposed that enhanced flare production occurs from a source of SVC whose spectrum has a peak around 6–10 cm wavelength but whose slope is flatter around 8 mm, but steeper toward longer centimeter wavelengths, than in the case of normal SVC-spectra attributed to gyro resonance radiation. The implications of such spectra in terms of changes in magnetic field structure before the occurrence of a flare are discussed.     

Limnological studies of Amarga Lagoon,Chile: A saline lake in Patagonian South America

Amarga Lagoon, lat. 50°29 S and long. 73°45 S, it is located at the Torres del Paine National Park, Chile. The physical, chemical, and biological features of the lake were studied. According to salinity, the lake is mesosaline. Sodium and chloride were the dominant ions. Nitrogen was potentially limiting for phytoplankton growth. One Cyanophyceae species andArtemia were the predominant species in the plankton.Artemia provided abundant food for flamingoes.