Suspended sediment and discharge dynamics in a glacierized alpine environment: Identifying crucial areas and time periods on several spatial and temporal scales in the Ötztal, Austria

Climatic changes are expected to fundamentally alter discharge and sediment dynamics in glaciated high alpine areas, e.g. through glacier retreat, prolonged snow-free periods and more frequent intense rainfall events in summer. However, how exactly these hydrological changes will affect sediment dynamics is not yet known. In the present study, we aim to pinpoint areas and processes most relevant to recent sediment and discharge dynamics on different spatial and temporal scales in the Ötztal Alpine Region in Tyrol, Austria. Therefore, we analyze observed discharge and relatively long suspended sediment time series of up to 15 years from three gauges in a nested catchment setup. The catchments range from 100 to almost 800 km2 in size with 10 to 30 % glacier cover and span an elevation range of 930 to 3772 m a.s.l.. The investigation of satellite-based snow cover maps, glacier inventories, mass balances and precipitation data complement the analysis. Our results indicate that mean annual specific discharge and suspended sediment fluxes are highest in the most glaciated sub-catchment and both fluxes correlate significantly with annual glacier mass balances. Furthermore, both discharge and suspended sediment loads show a distinct seasonality with low values during winter and high values during summer. However, the spring onset of sediment transport is almost synchronous at the three gauges, contrary to the spring rise in discharge, which occurs earlier further downstream. A spatio-temporal analysis of snow cover evolution indicates that the spring increase in sediment fluxes at all gauges coincides with the onset of snow melt above 2500 m elevation. Zones above this elevation include glacier tongues and recently deglaciated areas, which seem to be crucial for the sediment dynamics in the catchment. Precipitation events in summer were associated with peak sediment concentrations and fluxes, but on average accounted for only 21 % of the annual sediment yields of the years 2011 to 2020. We conclude that glaciers and the areas above 2500 m elevation play a dominant role for discharge and sediment dynamics in the Ötztal area, while precipitation events play a secondary role. Our study extends the scientific knowledge on current hydro-sedimentological changes in glaciated high alpine areas and provides a baseline for investigations on projected future changes in hydro-sedimentological system dynamics.

A worldwide meta-analysis (1977–2020) of sediment core dating using fallout radionuclides including ¹³⁷Cs and ²¹⁰Pb_xs

Dating recent sediment archives (< 150 years) constitutes a prerequisite for environmental and climatic reconstructions. Radiocaesium (137Cs) emitted during thermonuclear bomb testing (∼ 1950–1980) and nuclear accidents and the decrease in excess lead-210 (210Pbxs) with depth are often combined to establish sediment core chronology. Although these methods have been widely used during the last several decades, there is a lack of structured and comprehensive worldwide synthesis of fallout radionuclide analyses used for dating sediment cores in environmental and Earth sciences. The current literature overview was based on the compilation of 573 articles published between 1977 and 2020, reporting the collection of 1351 individual dating sediment cores (the dataset can be accessed at https://doi.org/10.1594/PANGAEA.931493; Foucher et al., 2021). This review was conducted in order to map the locations where 137Cs fallout events were detected. These included the thermonuclear bomb testing peak in 1963, the Chernobyl accident in 1986, the Fukushima accident in 2011, and 24 additional events identified at 112 sites that led to local or regional radioactive releases (e.g., Sellafield accidents, Chinese nuclear tests). When 210Pbxs records were used along with 137Cs data, detailed information on the 210Pbxs age–depth models were also synthesized. With the current growing number of studies analyzing sediment cores and the increasing interest in the deployment of sediment fingerprinting techniques including radionuclides as potential discriminant properties, this spatialized synthesis provides a unique worldwide compilation for characterizing fallout radionuclide sources and levels at the global scale. This synthesis provides in particular a reference of 137Cs peak attribution for improving the sediment core dating, and it outlines the main questions that deserve attention in future research as well as the regions where additional 137Cs fallout investigations should be conducted in priority.

Sculpture and New Technologies in Scientific Educational Outreach: 3D Foraminiferal Models as a Referent of Ocean Acidification and Climate Change

The Foraminifera Project is a collaboration between researchers of the Faculty of Fine Arts and the Faculty of Geological Sciences at the Complutense University (UCM, Madrid, Spain). The work, based on scientific dissemination through art, is framed in the theme “Climate change and Ocean Acidification'' as part of the course “Art, Science and Nature” of the Master's Degree in Research in Art and Creation (Faculty of Fine Arts, UCM). The team used recent sediment samples from Indian Ocean and Red Sea that contained healthy and unhealthy foraminifera specimens to create 3D specimen models. These models were made using traditional sculpture techniques, photogrammetry, and 3D printing to show different states of foraminifera dissolution and corrosion from ocean acidification. The end result of this project resulted in nine interactive pieces which were part of the exhibition “Drift & Migrate'' open to the public during the month of November 2019 in the exhibition hall of the Faculty of Fine Arts (UCM). The 3D models of foraminifera were displayed with educational graphics and blind-accesible explanatory signage (Braille) to share the scientific facts of foraminifera and their role in the ocean ecosystem. The main objective of the collaboration is to raise awareness of anthropogenic effects on foraminifera and the marine ecosystems in general and to expand research opportunities between the arts and sciences at the university.

A worldwide meta-analysis (1977–2020) of sediment core dating using fallout radionuclides including ¹³⁷Cs and ²¹⁰Pb_xs

Dating recent sediment archives (< 150 years) constitutes a prerequisite for environmental and climatic reconstructions. Radiocaesium (137Cs) emitted during thermonuclear bomb testing (~1950 ̶ 1980) and nuclear accidents, as well as the decrease of excess lead-210 (210Pbxs) with depth are often combined to establish sediment core chronology. Although these methods have been widely used during the last several decades, there is a lack of structured and comprehensive worldwide synthesis of fallout radionuclide analyses used for dating sediment cores in environmental and Earth sciences. The current literature overview was based on the compilation of 573 articles published between 1977 and 2020, reporting the collection of 1351 individual dating sediment cores (the dataset can be accessed at https://doi.pangaea.de/10.1594/PANGAEA.931493). This review was conducted in order to map the locations where 137Cs fallout events were detected. These included the thermonuclear bomb testing peak in 1963, the Chernobyl accident in 1986, the Fukushima accident in 2011, and 24 additional events identified in 112 sites that led to local radioactive releases (e.g. Sellafield accidents, Chinese nuclear tests). When 210Pbxs records were used along with 137Cs data, detailed information on the 210Pbxs age depth models were also synthesized. Multiple information including the core collection method, sediment properties, radionuclide analysis techniques and catchment characteristics were also compiled. With the current growing number of studies analyzing sediment cores and the increasing interest in the deployment of sediment fingerprinting techniques including radionuclides as potential discriminant properties, this spatialized synthesis provides a unique worldwide compilation for characterizing fallout radionuclide sources and levels at the global scale. This synthesis provides in particular a referential of 137Cs peak attribution for improving the sediment core dating and it outlines the main questions that deserve attention in future research as well as the regions where additional 137Cs fallout investigations should be conducted in priority.

Assessing Soil-Related Terroir Factors in Sunnyslope District Vineyards of Southwest Idaho

Terroir is the set of factors including climate, soil, and management practices that influence the character of a wine. Of these factors, soil texture and chemistry is a major determinant in wine grape quality (van Leeuwen et al., 2009). Understanding the characteristics of the soil is key to making decisions that support the production of the highest possible quality grapes from the resources available. Few studies have been conducted in the Snake River Valley AVA (SRVAVA). This study seeks to build upon the data already available and provide analysis of vineyard-scale terroir in a leading grape growing district of the SRVAVA. Nine vineyards from the Sunnyslope wine grape growing district of southwestern Idaho were selected for their diversity of geographic location and growing environment. Soil pit locations in each vineyard were determined using a stratified-random sampling technique and normalized difference vegetation indices (NDVI) calculated from aerial imagery. This study combines field collection, sampling and analyses of soil texture and chemistry to characterize the soils in the selected vineyards. The results show the majority of vineyards contain aeolian or colluvium-derived soils composed of coarse silts and fine sands. Only two vineyards, those located closest to the Snake River, contain basalt gravels and lithic sands not observed in the other vineyards. Geochemical data show an increase in Ca with elevation and a decrease in Fe and Mn with elevation, which may be the result of varying soil parent materials or recent deposition of sediments. The results of my study support the presence of vineyard-scale terroir and the assertion that intra- and inter-vineyard heterogeneity is inherent. Further, my results show recent sediment deposition and agricultural practices have overprinted the original soil profiles. Understanding vineyard-specific soil characteristics like those investigated in this study will allow vineyard owners to manage for specific soil traits and promote the unique terroir of their product. Management of vineyards in this way can support the growth of high-quality grapes and the production of desirable wines that reflect the unique conditions under which they were grown, their terroir.

External and internal forcing of African Humid Periods from MIS 6 to MIS 1

&lt;p&gt;During the last million years, northern Africa has alternated between arid and humid conditions, as recorded by different kinds of climate archives, including fossil pollen, lake sediments, marine sediments and archaeological remains. Variations occur at millennial scale, with dry phases being similar to the current desert state in the region, and with wet phases, known as African Humid Periods (AHPs), characterised by a strong summer monsoon which can carry enough moisture inland to support rivers, lakes and lush vegetation further north than seen today. Recent sediment records from the Mediterranean Sea revealed that the previous five AHPs had different intensities, in relation to rainfall and vegetation extent. Motivated by these findings, our work focuses on explaining what caused such differences in intensity. To this end, we use the CLIMBER-2 climate model to study the AHP response to changes in three drivers of atmospheric dynamics: Earth's orbit variations, atmospheric concentration of CO&lt;sub&gt;2&lt;/sub&gt; and inland ice extent. Global transient simulations of the last 190,000 years are used in new factorisation analyses, which allow us to separate the individual contributions of the forcings to the AHP intensity, as well as those of their synergies. We confirm the predominant role of the orbital forcing in the strength of the last five AHPs, and our simulations agree with previous estimates of a threshold in orbital forcing above which an AHP develops. Moreover, we show that atmospheric CO&lt;sub&gt;2&lt;/sub&gt; and the extent of ice sheets can also add up to be as important as the orbital parameters. High values of CO&lt;sub&gt;2&lt;/sub&gt;, past a 205 ppm threshold, and low values of ice sheets extent, below an 8 % of global land surface threshold, yield the AHPs with the most precipitation and vegetation. Additionally, our results show that AHPs differ not only in amplitude, but also in their speed of change, and we find that the non-linear vegetation response of AHPs does not correlate with a single forcing and that the vegetation growth response is faster than its subsequent decline. In regards to future change, an extension of the simulations until the next 50,000 years, shows CO&lt;sub&gt;2&lt;/sub&gt; to be the main driver of AHPs, with orbital forcing only setting the pace and their intensities being scenario-dependent.&lt;/p&gt;

A review of worldwide sediment core dating research including fallout radiocaesium (137Cs)

&lt;p&gt;Dating recent sediment archives (&lt;150 years) constitutes are need for environmental and climatic reconstructions. Radiocaesium (&lt;sup&gt;137&lt;/sup&gt;Cs) emitted during thermonuclear bombs testing (~1950 - ~1980) and nuclear accidents (1986 and 2011) was generally used for identifying sediment sources or for establishing sediment core chronology based on discrete time markers. Although this method was widely used during the last several decades, there is a lack of structured and comprehensive worldwide synthesis of radiocaesium fallouts. The current literature overview was based on 573 articles published between 1977 and 2020, reporting the collection of 1351 individual dated sediment cores. This synthesis led to the identification of the worldwide distribution of discrete time markers associated with the thermonuclear bomb testing peak in 1963, the Chernobyl fallout, the Fukushima fallout, as well as the identification of at least 25 events induced by local accidents or nuclear tests (e.g. Sellafield, la Hague accidents, Chinese nuclear tests).&lt;/p&gt;&lt;p&gt;With a growing number of studies focusing on the analysis of recent sediment cores and the increasing interest in sediment fingerprinting techniques, this spatialized synthesis provides a unique worldwide referential for identifying the distribution of the &lt;sup&gt;137&lt;/sup&gt;Cs sources at global scale. It also outlines the main questions that would deserve attention in future research perspectives and the regions where &lt;sup&gt;137&lt;/sup&gt;Cs fallouts investigations should be conducted in priority.&lt;/p&gt;

Active back-arc thrust in North West Java, Indonesia

&lt;p&gt;The Baribis-Kendeng Fault System crosscuts the northern part of Java Island (Indonesia). It seems that the fault systems is the continuation westward from the active Flores thrust in the northern offshore of the Lesser Sunda Islands. While the Flores thrust in the east is well documented as an active fault in the back-arc platform (e.g., source of the 2018 Lombok 6.9 Mw earthquake), the nature, timing, and activity of the Baribis-Kendeng Fault Systems, particularly the Baribis Fault Zone (BFZ) in the westernmost part of the system remain elusive. Yet, understanding the geological risk associated with the BFZ is crucial, as it crosscuts densely-populated regions, possibly up to 30 million inhabitants in the megalopolis of Jakarta. Previous studies mostly identified the BFZ by first-order morphotectonic observations, as well as large-scale geodetic and seismotectonic investigations, and assigned historical earthquakes (estimated up to 8.5 Mw in 1780) in northern Java to the BFZ. Ground-truthing the structure and activity of the BFZ from geological arguments is a cornerstone to evaluate associated geohazards.&lt;/p&gt;&lt;p&gt;We first focus on the Cikamurang Ridge, nearly at the eastern part of the BFZ, where uplifted Pliocene-Recent sediment sequences outcrop. Morphotectonic data include an 8-m resolution digital elevation model that we used to map fault lineaments and calculate the channel steepness index of the rivers crossing the mapped fault segments. Field data, including paleoseismological trenching at the central part of Cikamurang Ridge and sediment dating (OSL and radiocarbon) provide temporal constraints on the BFZ activity. Subsurface geophysical data include seismic reflection and resistivity imaging provide better image of the fault geometry in the sub-surface.&lt;/p&gt;&lt;p&gt;Our results suggest that the BFZ has been active in the Cikamurang Ridge during the late-Pleistocene to Holocene times, with deformed sediment sequences dated between 55 and 7 ka. Eastward, the BFZ crosses the Cisanggarung River where the fault deformed ~13-ka old sediments. Westward of the Cikamurang Ridge, both fault lineament interpretation and channel steepness index indicates that the fault continues from Subang regency to Jatiluhur and reaches the area between Jakarta and Bogor. Even though in the area between Jakarta and Bogor the surficial trace of the BFZ is not as clear as the Cikamurang and Subang, the seismic reflection data reveal the blind fault propagation fold. We conclude that the BFZ has a high seismic hazard that requires a careful risk evaluation along its trace, as it threats the numerous infrastructures of the extremely densely-populated West Java.&amp;#160; Comparing to the Flores back-arc thrust, the existence of the BFZ indicate the whole island of Java affected with the back-arc compressive regime as well as the existence of the Kendeng Fault Zone, in the easternmost of the Baribis-Kendeng Fault Systems.&lt;/p&gt;

Plastics and microplastics – A future marker to reconstruct floodplain chronology (Opinion)

&lt;p&gt;After approximately two decades of plastic research in freshwater environments, plastics and especially microplastics (d&amp;#160;&lt;&amp;#160;5&amp;#160;mm) have entered the scientific consciousness as an anthropogenic pollutant. Even if this pollutant shows certain comparability with heavy metal pollution in soils and sediments, it should be seen as a purely anthropogenic material without geochemical or natural background loads, which leads to the assumption that it might also be a potential marker of the Anthropocene. Regarding the global plastic cycle within the environment, rivers act as main transport paths from land-to-sea. As rivers are embedded into landscapes, accumulation of plastics within riverine (e.g. sediment temporary sink) and accompanied terrestrial environments (e.g., floodplain storage for deposited plastics) has been proven in initial studies.&lt;/p&gt;&lt;p&gt;In contrast to other natural or anthropogenic pollutants, the approximate time since plastics and microplastic can be introduced into the environment starts in the 1950's with increasing global plastic production and consumption. A steady increase of possible plastic loads with the rising plastic production, probably decreasing with beginning environmental responsibility (approx. 2010 or beyond) leads to the fact, that plastic contents mainly occur in sediments and soils over a period of the last 70 years. This circumstance in connection with the general known sink function of soils and sediments, especially floodplains, nutrients as well as pollutants, allows the consideration of plastic deposits for dating purposes. As different dating methods reach their limits regarding comparatively young sediments, the connection between plastic deposition depth and temporal entry provides a basis for dating recent sediment layers. Possible detailed age differentiations in dependence on the identification of polymer types and additives, particle surface appearance (e.g., fresh/weathered) or spectroscopic criteria (e.g., surface weathering determination) are thinkable.&lt;/p&gt;&lt;p&gt;The opinion presented here, aims to address this new opportunity on the basis of own research findings within floodplains as well as other studies and highlights two main requirements: The first requirement for a sufficient dating implementation of plastic particles is the particle size: Detection and application for dating purposes is relatively easy to apply for macro- and mesoplastic particles (&amp;#707;5 mm), due to size and less mobility in soils or sediments (e.g., plastic films embedded in sediment structure). In contrast for particles in the microplastic size class (&amp;#706; 5mm down to 1 &amp;#181;m) we recommend only the consideration of coarse microplastics (&amp;#707; 2mm) as smaller particles could easily shift in soils and sediments (e.g., bioturbation, preferential flow).&amp;#160; Additionally, the selection of a suitable sampling site as a second requirement depends on the appropriate localization within the floodplain area and surface morphology, sampling depth, flood history and anthropogenic influences.&lt;/p&gt;&lt;p&gt;Apart from the numerous potential environmental risks of plastics, their purely anthropogenic production and their respectively features, can turn them into a useful dating tool in river and floodplain sediments and thus enabling, besides the detection alone, a further application. This approach could also be transferred to marine or lacustrine sediments in future.&lt;/p&gt;