Methane in Zackenberg Valley, NE Greenland: multidecadal growing season fluxes of a high-Arctic tundra

The carbon balance of high-latitude terrestrial ecosystems plays an essential role in the atmospheric concentration of trace gases, including carbon dioxide (CO2) and methane (CH4). Increasing atmospheric methane levels have contributed to ∼ 20 % of the observed global warming since the pre-industrial era. Rising temperatures in the Arctic are expected to promote the release of methane from Arctic ecosystems. Still, existing methane flux measurement efforts are sparse and highly scattered, and further attempts to assess the landscape fluxes over multiple years are needed. Here we combine multi-year July–August methane flux monitoring (2006–2019) from automated flux chambers in the central fens of Zackenberg Valley, northeast Greenland, with several flux measurement campaigns on the most common vegetation types in the valley to estimate the landscape fluxes over 14 years. Methane fluxes based on manual chamber measurements are available from campaigns in 1997, 1999–2000, and in shorter periods from 2007–2013 and were summarized in several published studies. The landscape fluxes are calculated for the entire valley floor and a smaller subsection of the valley floor, containing the productive fen area, Rylekærene. When integrated for the valley floor, the estimated July–August landscape fluxes were low compared to the single previous estimate, while the landscape fluxes for Rylekærene were comparable to previous estimates. The valley floor was a net methane source during July–August, with estimated mean methane fluxes ranging from 0.18 to 0.67 mg m−2 h−1. The mean methane fluxes in the fen-rich Rylekærene were substantially higher, with fluxes ranging from 0.98 to 3.26 mg m−2 h−1. A 2017–2018 erosion event indicates that some fen and grassland areas in the center of the valley are becoming unstable following pronounced fluvial erosion and a prolonged period of permafrost warming. Although such physical disturbance in the landscape can disrupt the current ecosystem–atmosphere flux patterns, even pronounced future erosion of ice-rich areas is unlikely to impact methane fluxes on a landscape scale significantly. Instead, projected changes in future climate in the valley play a more critical role. The results show that multi-year landscape methane fluxes are highly variable on a landscape scale and stress the need for long-term spatially distributed measurements in the Arctic.

Morpho-Tectonic Assessment of the Abu-Dabbab Area, Eastern Desert, Egypt: Insights from Remote Sensing and Geospatial Analysis

The Abu-Dabbab area, located in the central part of the Egyptian Eastern Desert, is an active seismic region where micro-earthquakes (≈ML < 2.0) are recorded regularly. Earthquake epicenters are concentrated along an ENE–WSW trending pattern. In this study, we used morphological indexes, including the valley floor width-to-valley floor height ratio (Vf), mountain front sinuosity (Smf), the asymmetry factor index (Af), the drainage basin shape index (Bs), the stream length–gradient index (SL), hypsometric integral (Hi) water drainage systems, and a digital elevation model analysis, to identify the role of tectonics. These indexes were used to define the relative tectonic activity index (RTAI), which can be utilized to distinguish low (RTAI < 1.26), moderate (RTAI = 1.26–1.73), and high (RTAI > 1.73) tectonic activity signals all over the study area. Firstly, our results indicate low to medium tectonic activity and general anomaly patterns detected along the major tectonic zones of the study area. Secondly, based on most of the low to medium tectonic activity distributed in the study area and the detected anomalies, we discuss two potential drivers of the seismicity in the Abu-Dabbab area, which are fault-controlled and deep-rooted activities.

Environmental Implications of Municipal Dump Site on Soil Nitrogen in Calabar Metropolis, Nigeria

Organic matter exhibit strong variations in nitrogen retention and transformation cycle in soil. However, nitrogen could be altered by seasonal variations, leading us to hypothesize that the open municipal waste dump site in Calabar exposed to dry and wet season could alter nitrogen dynamics in that soil. A total of sixty (60) composite soil samples were collected at different landscape positions (summit crest, shoulder slope, toe slope, interfluve slope, valley floor) of a municipal dump site and a control (no refuse area) during the dry and wet seasons in Calabar and analyzed to ascertain the effects on forms and status of soil nitrogen. The soils were loamy sand across the study location with pH values of 4.50, 7.00, 6.70, 7.30, 5.00, 7.30 (dry season) and 5.00. 7.30, 7.00, 7.40, 5.90, 7.40 (wet season) for the control, summit crest, shoulder slope, toe slope, interfluve slope and valley floor accordingly. Values obtained for total nitrogen (N) from the study site were generally low (<0.21 %), with values for dry season slightly higher than the wet season. NH4+ recorded higher content in wet than in dry season with values ranging between 12.11-14.11 mg/kg (control), 14.60 - 15.90 mg/kg (Summit crest); 18.25 - 20.05 mg/kg (Shoulder slope), 18.30 - 20.20 mg/kg (Toe slope), 12.30 - 14.00 mg/kg (Interfluve slope) and 9.24 -11.07 mg/kg (Valley floor). The Shoulder and toe slopes recorded the highest NH4+ concentration in the wet season. N02- contents documented for the control site were within the ranges of 2.78- 3.20 and 3.22-3.62 mg/kg while the dumpsite had values between 2.49-3.45 and 2.98 -3.22 mg/kg was observed for the shoulder position, the toe slope contained between 2.30-2.75 and 2.70 -2.82 mg/kg, the inter fluve slope had similar ranges of 2.32-2.90 and 2.70-3.08 mg/kg, and the valley floor 2.45-2.60 and 2.78-2.98 mg/kg. N02- values were higher for the wet than dry season. NO3- nitrogen was observed to be excessive across the dumpsite with the highest values > 80 mg/kg obtained at the valley floor. The NO3- values were higher in dry season across the all the landscape positions than in the wet season. The values were equally higher for the dumpsite than the control. It was observed that the dumpsite soils contend excessive NO3- which could be converted to nitrous oxide (N2O) thus contributing to green house (GHG) emissions. It was also noted that seasonal variation did not significantly affect the N content at the different landscape positions of the municipal dumpsite in Calabar. It is highly recommended that municipal waste be sorted and the organic materials composted to harness the rich NO3- content as observed in this research. Received: 22 September 2021 / Accepted: 25 October 2021 / Published: 5 November 2021

Is it north or west foehn? A Lagrangian analysis of PIANO IOP 1

A case study of a foehn event in the Inn Valley near Innsbruck, Austria, is investigated that occurred on 29 October 2017 in the framework of the first Intensive Observation Period (IOP) of the Penetration and Interruption of Alpine Foehn (PIANO) field campaign. Accompanied with northwesterly crest-level flow, foehn broke through at the valley floor as strong westerly winds in the moring and was terminated in the afternoon by a cold front arriving from the north. The difference between local and large-scale wind direction rises the question of whether the event should be classified as north or west foehn – a question that has not been convincingly answered in the past for similar events based on Eulerian approaches. Hence, the goal of this study is to assess the air mass origin and the mechanisms of foehn penetration to the valley floor based on a Lagrangian perspective. For this purpose a mesoscale simulation with WRF and a backward trajectory analysis with LAGRANTO are conducted. The trajectory analysis shows that the major part of the air mass arriving at Innsbruck originates six hours earlier over eastern France, crosses the two mountain ranges of the Vosges and the Black Forest and finally impinges on the Alps near Lake Constance and the Rhine Valley. Orographic precipitation over the mountains leads to a net diabatic heating of about 2.5 K and to a moisture loss of about 1 g kg−1 along the trajectories. A secondary air stream originates further south over the Swiss Plateau and contributes with about 10 to 40 % to the foehn air in Innsbruck. Corresponding trajectories are initially nearly parallel to the northern Alpine rim and get lifted above crest level in the same region as the main trajectory branch. Air parcels within this branch experience a net diabatic heating of about 2 K, and, in contrast to the ones of the main branch, an overall moisture uptake due to evaporation of precipitation formed above this air mass. Penetration into the Inn Valley mainly occurs in the lee of three local mountain ranges – the Lechtal Alps, the Wetterstein, and the Mieming Chain – and is associated with a gravity wave and a persistent atmospheric rotor. A secondary penetration takes place in the western end of the Inn Valley via the Arlberg Pass and Silvretta Pass. Changes in the upstream flow conditions cause a shift in the contributions of the associated penetration branches. From a Lagrangian perspective this shift can be interpreted on the valley scale as a gradual transition from west to northwest foehn, despite the persistent local west wind at Innsbruck. However, a clear classification in one or the other category remains subjective even with the Lagrangian approach and, given the complexity of the trajectory pattern, is nearly impossible with the traditional Eulerian view. Likewise, foehn criteria based on pure adiabatic heating due to subsidence on the leeward side, i.e., the isentropic drawdown mechanism, are not appropriate to classify such moist events.

Integrated geological and geophysical study of the Tagil river valley morphology in its middle course

Relevance. Integrated geological and geophysical studies of a bridge in the Makhnevo village area are considered in the frame of the Urals eastern slope geology. Research objective is to study the lithology of the underlying part of the valley floor, determine soil physical and mechanical characteristics, and study a complex of fluvial terraces. Results. Relief elevations across the river valley have been studied, and four main fluvial terrace levels typical of the Urals eastern slope have been identified. An unstable section of the streambed with a canyonshaped valley above the neotectonic unwarping zone has been identified. The geological section of the river’s floodplain and streambed were studied based on geological and geophysical data. A change in the physical properties of glauconite sandstones and clays of Paleogene age in the recent underlying part of the river valley has been established. Layers of sand and glauconite sandstone that can be developed have been found at the new bridge site near the existing sand and gravel deposit. Conclusions. A complex of terraces of the Tagil river valley in its middle course is typical for the Urals eastern slope. The paleovalley is cut into a Paleogene glauconite sandstone layer. In the underlying part of the valley floor, changes in sandstones and clays physical properties have been recorded, and the presence of hypogene minerals was revealed. These are the signs of possible neotectonic processes in the series of the Cenozoic and Quaternary deposits.

A STORY OF AWE AND CLAY: MOLD-MADE HIEROGLYPHS FROM ALTA VERAPAZ, GUATEMALA

The recent discovery of an ancient Late Classic ceramic production facility in a valley floor, east of the current capital of Cobán in Guatemala, reveals a new ceramic form and provides data concerning regional chronology. Among the remains are thin, mold-made fragments identified as ceramic plaques that have epigraphic information providing a Long Count date for the first time in the Alta Verapaz region. These data correlate with the preliminary ceramic sequences and assist with understanding political-economic interactions that occurred at a time of societal collapse within the southern lowland region.

Terraces of the Ohře River in Žatec Area, Czech Republic: When Models of Holocene Fluvial Development Are Not Sufficient

The development of the Ohře River near Žatec between the Late Glacial Maximum (LGM) and present time was studied to obtain its natural trajectory and thus to understand the role of human impact on floodplain development. The study was based on geomorphic research, sampling and dating fluvial sediments by optically stimulated luminescence (OSL) and anthropogenic contamination by Sn since 16th century. During the LGM and the Pleistocene/Holocene transition (P/H), the river valley was shaped by large, incising meanders creating the entire valley floor. The Holocene river, due to decreased channel forming discharges, only slowly continued the LGM and P/H trajectory by cut-offs of the large palaeomeander necks and channel belt narrowing and incision. The last Holocene incision step was likely triggered by hydrological extremes of the Little Ice Age. The LGM and P/H Ohře River consequently changed from meandering to low sinuous, incised in the valley floor; this incision was completed by river engineering in the 20th century. The Ohře River development can thus be rationalised neither by traditional terrace-step formation model nor by model of the Anthropogenic aggradation.

Does the ‘Mountain Pasture Product’ Claim Affect Local Cheese Acceptability?

This paper aims to explore the impact of “mountain pasture product” information on the acceptability of local protected designation of origin (PDO) cheese produced from the raw milk of cows grazing in mountain pastures (P) or reared in valley floor stalls (S). A total of 156 consumers (55% males, mean age 41 years) were asked to evaluate their overall liking on a 9-point hedonic scale of four samples: Cheeses P and S were presented twice with different information about the origin of the milk (cows grazing on mountain pasture or reared in a valley floor stall). Demographics, consumer habits, and opinions on mountain pasture practice (MPP), attitudes towards sustainability, and food-related behaviours (i.e., diet, food waste production, organic food, and zero food miles products purchase) were recorded and used to segment consumers. The cheeses were all considered more than acceptable, even though they were found to be significantly different in colour and texture by instrumental analyses. In the whole consumer panel, the cheese P was preferred, while in consumer segments less attentive to product characteristics, this effect was not significant. External information had a strong effect: Overall liking was significantly higher in cheeses presented as “mountain pasture product”, both in the whole panel and in consumer segments with different attitudes (except for those with a low opinion of MPP).

Geological investigation and movement analysis of the deep-seated compound rockslide Laatsch, South Tyrol

&lt;p&gt;In Alpine areas, deep-seated rockslides are relatively common. They are mostly based on geological and tectonic conditions and triggered by permafrost degradation, snowmelt or heavy rainfall events. A striking example is situated near Laatsch, South Tyrol, at the valley entrance of the M&amp;#252;nstertal at close range to the national road SS41 leading to the Swiss border. The activation of the movement occurred in the year 2000, showing a rapid expansion since the year 2012 causing a relocation of the road in 2014.&lt;/p&gt;&lt;p&gt;The U-shaped valley of the M&amp;#252;nstertal was formed by glaciers, the valley floor is filled with alluvial sediments. The Mountain ridge runs approx. 2,100 m above the Adriatic Sea, valley floor at approx. 1,000 m above Adriatic Sea. The slope gradient varies between 30 and 50&amp;#176;. The rockslide situated in this slope is approx. 400 m wide, approx. 700 m in height at its longest extension, with a slide surface ca. 50 - 100 m deep summing up to an instable rock volume of approximately 5 to 10 million m&amp;#179; and monthly average movement rates of 0.1 to 0.55&amp;#160;m.&lt;/p&gt;&lt;p&gt;Geological mapping and analysis were performed for the detailed identification of the cause of failure and occurring failure types such as sliding, falling, toppling and flow. The different gneiss bedrock types mainly consist of Quartz, Feldspar, Muscovite and Calcite, foliation is mainly caused by Muscovite layers. Muscovite-rich shearing planes could also be identified via thin section analysis. The foliation dips with a dip of ca. 10-20&amp;#176; mainly towards Northeast and therefore is orientated towards the slope. Two sets of very steep dipping joins are present deeply fragmenting the rock mass providing starting points or lines for the development of scarp surfaces. Deep weathering of the disintegrated gneiss bed rock could be observed at tectonically induced fracture surfaces. Weathering progresses along scarps and developed tension cracks further eroding and dissembling the rock mass.&lt;/p&gt;&lt;p&gt;Movement analysis of different slabs were performed twice a year using multi-temporal terrestrial laser scanning (TLS) between 2017 and 2020. Along this sliding surface, rock material is transported as individual slabs showing mainly a translational movement behavior with minor internal deformation. These slabs are visually recognizable on site as well as during the analysis of movement rates of laserscanning series measurements.&amp;#160; Main mass transport occurs from upper steep slope areas to areas of lower slope angle within and at the foot of the rockslide. General movement occurs via a basal slip surface with an average thickness of failure volume of approx. 50 to 100 Meters.&lt;/p&gt;&lt;p&gt;Volume of displaced material during accompanied processes of rock fall and rock topple events amounts to 2,000 - 5,000 m&amp;#179; depending on the size of the event. These types of rock movement mainly take place along outbreak recesses at the rockslide flanks, scarps and at the internal slab margins. These falls and topples can also be detected through several laserscanning measurement series.&lt;/p&gt;

Understanding storage and discharge behavior of a high-elevated and geologically complex karst catchment using numerical approach, Dolomites (Alps)

&lt;p&gt;Water resources from high-alpine karst aquifers are used for drinking, hydropower generation and artificial snowmaking. Therefore, understanding of their storage and flow dynamics is crucial for a sustainable water management. However, high-alpine karst areas are characterized by a great geological complexity due to the presence of mountain block fractured and karst aquifers interdigitating with the heterogeneous valley floor porous aquifers. For that reason, hydrogeological characterization and model prediction remains a big challenge. In this work, we investigated a geologically complex alpine catchment in the Dolomites (Italian Alps) by using experimental data and a reservoir numerical model to simulate three years of stream discharge. The structure of the model is based on experimental knowledge of the catchment and on previous studies and investigations. It (1) includes snow dynamics and accounts for hydrogeological heterogeneities, (2) separately considers karstic conduit and matrix flow in a dolomitic aquifer and flow through the porous deposits accumulating on the slopes and at the valley floor in an unconsolidated aquifer (non-karst), and (3) takes into account the groundwater transfer between the two aquifers. In the frame of a multi-step model evaluation, we used a Regional Sensitivity Analysis with three performance measures including observations of catchment discharge, karst spring discharge and unconsolidated aquifer spring discharge to assess the realism of model simulations. We show that the newly developed model reliably reproduces the hydrogeological variability of the catchment, even during strongly different hydroclimatic conditions. Analyzing its simulated storage dynamics, we can show that despite its moderate storage, the porous aquifer contributes most to catchment discharge, while the largest storage of the system is the matrix of the dolomite aquifer that recharges the unconsolidated aquifer together with discharge from the karstic conduits. A clear seasonality of groundwater storage in the karst matrix and of unconsolidated aquifer discharge indicates a strong sensitivity of this complex aquifer system to climatic variability.&lt;/p&gt;