Drought and its effects on spring discharge regimes in Poland and Germany during the 2015 drought

Areas of Western and Central Europe were severely affected by devastating droughts in 2003 and 2015. A sharp decrease in annual atmospheric precipitation led to diminished spring discharges. Analysis of the fluctuations in discharge from three groups of springs in the south of Poland, namely in the Sudetes and Carpathian mountains, and in the German province of Bavaria revealed an average discharge reduction ranging from 52 to 4%. The study proved the existence of a relationship between diminished groundwater recharge from precipitation and the type of rock forming the reservoir as well as the parameters of the rock in the drained catchment. Spring discharge regime was compared for various periods to show that a decline in the regime correlates with a decline in river flow rate; considering the continually changing weather patterns, this correlation is arguably a key factor in sustainable water management.     

New fjords,new coasts,new landscapes: The geomorphology of paraglacial coasts formed after recent glacier retreat in Brepollen (Hornsund,southern Svalbard)

Changes in the properties and dynamics of tidewater glacier systems are key indicators of the state of Arctic climate and environment. Calving of tidewater glacier fronts is currently the dominant form of ice mass loss and a major contributor to global sea-level rise. An important yet under-studied aspect of this process is transformation of Arctic landscapes, where new lands and coastal systems are revealed due to the recession of marine-terminating ice masses. The evolution of those freshly exposed paraglacial coastal environments is controlled by nearshore marine, coastal and terrestrial geomorphic processes, which rework glacial-derived sediments to create new coastal paraglacial landforms and landscapes. Here, we present the first study of the paraglacial coasts of Brepollen, one of the youngest bays of Svalbard revealed by ice retreat. We describe and classify coastal systems and the variety of landforms (deltas, cliffs, tidal flats, beaches) developed along the shores of Brepollen during the last 100 years. We further discuss the main modes of sediment supply to the coast in different parts of the new bay, highlighting the fast rate of coastal transformation as a paraglacial response to rapid deglaciation in the Arctic. This study provides an exemplar of likely coastal responses to be anticipated in similar tidewater settings under future climate change. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd     

Local‐ and regional‐scale biomorphodynamics due to tree uprooting in semi‐natural and managed montane forests of the Sudetes Mountains,Central Europe

In this work, direct and indirect geomorphic consequences of wind‐related tree uprooting are examined, using an extensive dataset from the mountain range of the Sudetes, Poland. The role of local conditions in influencing the geomorphic efficacy of tree uprooting is examined, as well as issues of upscaling individual observations from experimental sites. This problem is approached at a range of spatial and observational scales, from monitoring of root plate degradation over time through to examination of wind effects at a slope scale and region‐wide analysis. In our study area the mean root plate volume is between 0.4 and 4.2 m³ for spruce and 2.4 m³ for beech, and their degradation may last tens of years. The density of relict pit‐and‐mound microtopography varies from 2.7 up to 40 pairs per hectare and the maximum coverage of terrain is 4.7%. The volume of treethrow mounds varies from 0.5 to 3.1 m³ and mounds seem to outlive the pits formed in the same episode of disturbance. However, in specific lithological and topographic conditions, pit‐and‐mound topography does not form. The maximum biogenic transport attributable to a single windstorm event is c. 80 m³ ha^?1, while soil turnover times are calculated in the order of 1000–10 000 years. Rock fragment ‘mining’ is an important biogeomorphic process, both in terms of impact on hillslope surfaces and on soil properties. Gravel armours and small‐scale stepped topography may form instead of typical pit–mound associations in specific circumstances. Managed forests appear more prone to wind damage and associated geomorphic consequences. In the Sudetes Mountains, the variable role of tree uprooting in local and regional hillslope denudation is governed by forest stand structure, topography and regolith properties, with the former significantly influenced by human activity. Copyright © 2016 John Wiley & Sons, Ltd.     

Assessment of the Global and Regional Land Hydrosphere and Its Impact on the Balance of the Geophysical Excitation Function of Polar Motion

The impact of continental hydrological loading from land water, snow and ice on polar motion excitation, calculated as hydrological angular momentum (HAM), is difficult to estimate, and not as much is known about it as about atmospheric angular momentum (AAM) and oceanic angular momentum (OAM). In this paper, regional hydrological excitations to polar motion are investigated using monthly terrestrial water storage data derived from the Gravity Recovery and Climate Experiment (GRACE) mission and from the five models of land hydrology. The results show that the areas where the variance shows large variability are similar for the different models of land hydrology and for the GRACE data. Areas which have a small amplitude on the maps make an important contribution to the global hydrological excitation function of polar motion. The comparison of geodetic residuals and global hydrological excitation functions of polar motion shows that none of the hydrological excitation has enough energy to significantly improve the agreement between the observed geodetic excitation and geophysical ones.     

SIMS Bias on Isotope Ratios in Ca‐Mg‐Fe Carbonates (Part III): δ18O and δ13C Matrix Effects Along the Magnesite–Siderite Solid‐Solution Series

This study explores the effects of cation composition on mass bias (i.e., the matrix effect), which is a major component of instrumental mass fractionation (IMF) in the microanalyses of δ¹³C and δ¹⁸O by SIMS in carbonates of the magnesite–siderite solid‐solution series (MgCO₃–FeCO₃). A suite of twelve calibration reference materials (RMs) was developed and documented (calibrated range: Fe# = 0.002–0.997, where Fe# = molar Fe/[Mg + Fe]), along with empirical expressions for regressing calibration data (affording residuals < 0.5‰ relative to certified reference material NIST‐19). The calibration curves of both isotope systems are non‐linear and have, over a 2‐year period, fallen into one of two distinct but largely self‐consistent shape categories (data from ten measurement sessions), despite adherence to well‐established analytical protocols for carbonate δ¹³C and δ¹⁸O analyses at WiscSIMS (CAMECA IMS 1280). Mass bias was consistently most sensitive to changes in composition near the magnesite end‐member (Fe# 0–0.2), deviating by up to 4.5‰ (δ¹³C) and 14‰ (δ¹⁸O) with increasing Fe content. The cause of variability in calibration curve shapes is not well understood at present and demonstrates the importance of having available a sufficient number of well‐characterised RMs so that potential complexities of curvature can be adequately delineated and accounted for on a session‐by‐session basis.     

Earliest mordellid-like beetles from the Jurassic of Kazakhstan and China (Coleoptera: Tenebrionoidea)

Within this study the subfamily Praemordellinae is reviewed and the holotype of Praemordella martynovi Scegoleva-Barovskaja, 1929 is re-described. The genera Cretanaspis Huang and Yang, 1999, Mirimordella Liu et al., 2007, Bellimordella Liu et al., 2008 and Wuhua Wang and Zhang, 2011 is attributed to Praemordellinae. One new species, Wuhua peregrina sp. nov., is erected based on two well-preserved specimens from the Middle Jurassic Daohugou Biota (Inner Mongolia, China). The morphological characters of Praemordellinae are given and a key to genera of Praemordellinae is presented. Praemordellinae is closely related to extant Mordellidae in having humpbacked body, strongly deflexed head, filiform antennae and pectinate tarsal claws, but it is differing in that the pygidium absent and hind femora not well developed. It is also similar to Ripiphoridae in having a convex body and simple tarsi, but differs Ripiphoridae in having filiform antennae. Praemordellinae is probably a stem group including the ancestor of Mordellidae and Ripiphoridae. Also, within this paper, the fossil record of Mordellidae is summarized.     

Origin and evolution of volatiles in the Central Europe late Variscan granitoids,using the example of the Strzegom-Sobótka Massif,SW Poland

Mineralogy and Petrology - The results of the new Electron Microprobe Analysis of apatite, hornblende and biotite crystals of the hornblende-biotite variety of the Strzegom-Sobótka granite...     

Georadar studies on St. Benedict’s Church on Lasota Hill,Kraków,Poland

Georadar methodology has a considerable potential as a tool for verification of archeological hypotheses. I applied it in the present study to resolve a discussion on the importance of a Proto-Romanesque structure located on Lasota Hill. It is one of the oldest structures on the right bank of Vistula River in Kraków in Poland and some archeologists believe that it was the first seat of the rulers of Lesser Poland in the 9th century. After few decades, the prince’s castle was built on Wawel Hill, where subsequently the royal castle was constructed. On the place of the abandoned Proto-Romanesque edifice, a small St. Benedict’s Church was raised, but the importance of its predecessor was discussed. Archeological excavations suggested that it served as the prince’s residence, but this view would be much strengthened if traces of a prince’s building — palatium — could be found. With this in mind, I undertook a search for traces of palatium, employing georadar methodology. I carried out the measurements using Georadar PROEX produced by MALA Geoscience with a set of shielded antennas of frequencies 500 and 800 MHz. They permitted to construct echogram profiles, whose interpretation suggested the existence of palatium. Thus, the georadar data supported the archeological hypothesis about the important role of the Proto-Romanesque structures on Lasota Hill in the early medieval era in Poland, and at the same time demonstrated the usefulness of introducing geophysical methods to archaeology.     

Influence of a method of evaluation of the curvature of flexible vegetation elements on vertical distributions of flow velocities

Methods of computing the deflections of flexible vegetation elements under the dynamic pressure of water were presented in the paper. Two methods, based on Euler-Bernoulli beam theory, were discussed, one designed for small deflections and the other, generalized one, also for larger deflections. The choice of the method for computations of deflections was discussed from the perspective of the computation of flow velocities above flexible vegetation. Computational results were compared with laboratory experiments and it was found that the simplified, computationally less expensive method may be used in many practical situations without deterioration of the results.