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114 results for “grain size”
North Carolina Outer Banks, USA Coastal Foredune Sediment Cores - Grain Size Data & Core Log Descriptions
<p>This repository includes sediment core data collected at seven sites along the northern Outer Banks, North Carolina, USA. From north to south, the sites include Pine Island, Corolla Reserve, Duck, the US Army Corps of Engineers Field Research Facility (FRF) North, FRF South, Southern Shores (i.e., Hillcrest Beach Access), and Nags Head (Bonnett St. Beach Access).</p><p>At each site, internal dune sedimentology and stratigraphy were characterized using sediment vibracores, each 1.5–2.2 m long, collected along a cross-shore transect from the dune toe to the dune heel. Coring locations were selected based on dune morphology to capture the stratigraphy of the dune toe, stoss slope, primary dune crest, lee slope, swale, and secondary dune crest, as applicable. Sediment core locations were documented using RTK-GPS and are included in the .kmz file.</p><p>All sediment cores were split, photographed, described for sedimentary structures, texture (as compared to standards), mineralogy, and color (Munsell, 2012). Sediment cores were described using the Modified Burmister System in 10-cm intervals, with additional intervals added as needed to capture stratigraphic units with thicknesses less than 10 cm but greater than 1 cm. Sediment core log descriptions are included in the NOAA_NCDunes_Vibracore_CoreLogs.xlsx data file.</p><p>Sediment size and shape were analyzed from oven-dried samples using a CAMSIZERX2Ⓡ. These data are included in the Dune_Grain_Size_camsizer_outputs.csv data file. Metrics reported for each sample include the following: Site, Core ID, Sample Number, Depth (cm below ground surface), Elevation (m, NAVD88), D2 (mm), D5 (mm), D10 (mm), D16 (mm), D25 (mm), D50 (mm), D75 (mm), D84 (mm), D90 (mm), D95 (mm), D98 (mm), average grain symmetry, average grain sphericity, average grain aspect ratio, percent pebble, percent granule, percent very coarse sand, percent coarse sand, percent medium sand, percent fine sand, percent very fine sand, and percent silt.</p><p><strong>More details regarding these measurements can be found in the following manuscript:</strong></p><p>Davis, E.H., Hein, C.J., Cohn, N., White, A.E., Zinnert, J.C. Differences in internal sedimentologic and biotic structure between natural, managed, and constructed coastal foredunes (in review).</p>
Bulk, biomarker and mineralogy data of grain size fractions along a land-sea transect offshore the Atchafalaya river, northern Gulf of Mexico
<p>This dataset comprises the bulk, biomarker and mineralogy data of partitioned surface sediments along a land-sea transect offshore the Atchafalaya River, northern Gulf of Mexico. It includes the total concentrations of the biomarkers and proxies as presented in the accompanied publication, as well as concentrations of single isomers. Supplement to: Yedema et al., (2024); Influence of Organo-mineral Associations on Terrestrial Particulate Organic Matter Dispersal in the northern Gulf of Mexico (doi.)</p> <p> </p> <p><strong>This research has been supported by the Netherlands Earth System Science Centre (grant no. 024.002.001)</strong></p> <p> </p>
Sediment grain size in the Virginia coastal bays, 2022
This dataset contains sediment grain size distributions from benthic sediment cores collected from shallow sites across coastal bays of Virginia, USA. The samples were collected in July 2022 at 50 long-term sampling sites. Most sites were sampled in seagrass meadows (eelgrass Zostera marina), but some sites are unvegetated (bare substrate).
Organic Matter, Geochemical, Visible Spectrocolorimetric Properties, Radiocesium Properties, and Grain Size of Potential Source Material, Target Sediment Core Layers and Laboratory Mixtures for Conducting Sediment Fingerprinting Approaches in the Mano Dam Reservoir (Hayama Lake) Catchment, Fukushima Prefecture, Japan
<p>The current dataset was compiled to study sediment fingerprintings practices, i.e tracer selection and contribution modelling. Organic matter, elemental geochemistry, visible difuse spectrocolorimetric properties, radiocesium properties, and grain size were analysed were analysed in potential source material that may supply sediment to coastal rivers, here the upper part of the Mano river, draining the main Fukushima radioactive pollution plume (Japan). Four potential soil source materials (<em>n</em> = 68) were considered: undecontaminated cropland (<em>n</em> = 24), as non-decontaminated soil before the application of local decontamination policies, remediated cropland (<em>n</em> = 10), as decontaminated soil after the application of local decontamination policies, forest soils (n = 24) and subsurface material originating from channel bank collapse or landslides (<em>n</em> = 10; referred to as subsoil). A sediment core was collected in the Mano Dam lake (Hayama lake) on the 6th June 2021 and was sectionned into 1-cm layers (<em>n</em> = 38). Laboratory mixtures (<em>n</em> = 27) were made to assess different contribution levels from the sources.</p> <p>The current dataset comprises four .csv files including data and metadata information and their respective descriptions of variables. The data set is composed of soil samples, sediment core layer and laboratory mixtures. Laboratory mixtures were prepared to provide a dataset to calibrate/validate un-mixing models implemented to address this research question and analysed in the same conditions and using the same equipment as the source/target material.</p> <p>Recommended encoding format: <strong>latin1</strong></p>
Grain-size data from the loess profiles Ostrau and Gleina in Saxony (Germany)
<p><strong>Grain-size data from the loess profiles Ostrau and Gleina in Saxony (Germany)</strong></p> <p>The samples were taken between 2009 and 2010 in the framework of the DFG project <a href="https://gepris.dfg.de/gepris/projekt/46526743"><em>"Rekonstruktion der Umweltbedingungen des Spätpleistozäns in Mittelsachsen anhand von Löss-Paläobodensequenze</em>n" (DFG FU 417/7-1 and FA 239/13-1</a>) from the loess records Ostrau and Gleina. Both located in the Saxonian-Loess-Region in Germany. For further details on the project profiles (with further references therein), we refer to Meszner et al. (2011,2013), Kreutzer et al. (2012), Meszner (2015) and Zech et al. (2017). </p> <p>Samples for the data reported here were selected in 2015. 212 samples were taken from the loess profile Ostrau and 269 samples from the loess profile Gleina. Full details on sampling and sample preparation can be found in the Grassl (2016) (unpublished master thesis in Germany, available upon request). The most relevant details are extracted below. </p> <p><strong>Preparation and measurements</strong></p> <p>Sample preparation and measurements were carried out at the GFZ in Potsdam (Germany). Thirty-nine samples from the profile Ostrau were separated into eight equal parts to obtain representative samples. The samples were labeled with "G" for Gleina and "O" for Ostrau. All other samples were sampled without applying this separation method. <br> For samples from the profile Ostrau, the suffix "mT" (with separation) and "oT" (without separation) indicates whether this <br> separation method was used. </p> <p>The samples were treated with HCl (10 %, 12 h to 20 h) and rinsed in the demineralized water. To suspend the samples, NO<sub>3</sub>P0<sub>4</sub> was used on twelve pars of H<sub>2</sub>O<sub>2</sub>. </p> <p>A <em>Retch Laser Scattering Particle Size Distribution Analyzer (HORIBA LA- 950)</em> was used for the grain-size measurements. Details <br> on the settings are reported separately in each file.</p> <p><br> <strong>The data in the repository </strong></p> <p>Grainsize_data.zip This folder contains 4,853 ASCII TXT-files with the raw granulometric data. Filenames are unique timestamps (measurement date and time in the format <em>YYYYMMDDHHMMSS</em> CET). Each file comes with a header with relevant metadata and the measurement data. The metadata also contains the sample name, e.g., <em>O_55_oT</em> reads "O" for Ostrau, "55" sampling depth in cm, and "oT" for "ohne Teiler" (without separator, while "mT", "mit Teiler" would stand for with separator). For files for the profile Gleina, a "G" is used followed by the sampling depth range (two numbers, e.g., <em>G_380_382</em>) in cm. </p> <p>The files <em>Gleina_depth.txt</em>, <em>Ostrau02_depth.txt</em>, and <em>Ostrau03_depth.txt</em> allow a correlation with the profiles graphs published in Meszner (2015). </p> <p><br> <strong>References</strong></p> <p>Grassl, W., 2016. End-Member-Modellierungsanalyse an hochauflösenden Korngrößen der Lössprofile Ostrau und Gleina, Lommatzscher Pflege, Sachsen. unpublished Master thesis, TU Dresden.</p> <p>Kreutzer, S., Fuchs, M., Meszner, S., Faust, D., 2012. OSL chronostratigraphy of a loess-palaeosol sequence in Saxony/Germany using quartz of different grain sizes. Quaternary Geochronology 10, 102–109. doi:10.1016/j.quageo.2012.01.004</p> <p>Meszner, S., Fuchs, M., Faust, D., 2011. Loess-Paleosol-Sequences from the loess area of Saxony (Germany). E & G, Quaternary Science Journal 60, 47–65.</p> <p>Meszner, S., 2015. Loess from Saxony. A reconstruction of the Late Pleistocene landscape evolution and palaeoenvironment based on loess-palaeosol sequences from Saxony (Germany). Dresden. PhD thesis. TU Dresden. </p> <p>Meszner, S., Kreutzer, S., Fuchs, M., Faust, D., 2013. Late Pleistocene landscape dynamics in Saxony, Germany: Paleoenvironmental reconstruction using loess-paleosol sequences. Quaternary International 296, 95–107. doi:10.1016/j.quaint.2012.12.040</p> <p>Zech, M., Kreutzer, S., Zech, R., Goslar, T., Meszner, S., McIntyre, C., Häggi, C., Eglinton, T., Faust, D., Fuchs, M., 2017. Comparative 14C and OSL dating of loess-paleosol sequences to evaluate post-depositional contamination of n-alkane biomarkers. Quaternary Research 87, 180–189. doi:10.1017/qua.2016.7</p>
Tables of results for lower mantle grain size and viscosity estimates
<p>Data on diffusivity, grain size, and viscosity calculations are shown in Figs. 7-10 and Figs. S4-S5 in Okamoto and Hiraga's "A Common Diffusional Mechanism for Creep and Grain Growth in Polycrystalline Rocks: Application to Lower Mantle Viscosity Estimates".</p>
The Water-ice Feature in Near-infrared Disk-scattered Light around HD 142527: Micron-sized Icy Grains Lifted up to the Disk Surface?
<p>This is a reproduction package for the paper "The Water-ice Feature in Near-infrared Disk-scattered Light around HD 142527: Micron-sized Icy Grains Lifted up to the Disk Surface?" by Tazaki et al. (2021). In this repository, you will find the data files used to make figures in the paper. Source codes and scripts are included as well.</p>
Preliminary Coastal Grain Size Portal (C-GRASP) dataset. Version 1, January 2022
<p>Provisional database: The data you have secured from the U.S. Geological Survey (USGS) database identified as <em>Preliminary Coastal Grain Size Portal (C-GRASP) dataset. Version 1, January 2022</em> have not received USGS approval and as such are provisional and subject to revision. The data are released on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use.</p> <p>Version 1 (January 2022) of the the Coastal Grain Size Portal (C-GRASP) database. This is a preliminary internal deliverable for the National Oceanography Partnership Program (NOPP) Task 1 / USGS Gesch team and project partners only.</p> <p>The primary purpose of this Provisional data release is to provide National Oceanography Partnership Program (NOPP) project partners with programmatic access to this preliminary version of the Coastal Grain Size Portal (C-GRASP) database for internal project use. These data are preliminary or provisional and are subject to revision. They are being provided to meet the need for timely best science. The data have not received final approval by the U.S. Geological Survey (USGS) and are provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the data.</p> <p>This preliminary data release contains various files that list grain size information collated from secondary data already in the public domain, in the form of public datasets, or in published literature.</p> <p>Where possible, we have indicated the source, location, and sampling methods used to obtain these data. Where not possible to establish these facts, those fields have been left empty.</p> <p>More information on our methods, data sources, and data processing and analysis codes are found on our <a href="https://github.com/C-GRASP">github page </a></p> <p>The dataset consists of one zipped file, Source_Files.zip, and 4 comma separated value (csv) files</p> <ol> <li>dataset_10kmcoast.csv- This is all data that is found to be within 10km of the Natural Earth coastline polyline</li> <li>Data_EstimatedOnshore.csv- This is all the data from dataset_10kmcoast.csv that lies within the Natural Earth United States Polygon</li> <li>Data_VerifiedOnshore.csv- This is all data that was able to be verified onshore from either sampling method, note, or location type data</li> <li>Data_Post2012_VerifiedOnshore.csv- This is all the data from Data_VerifiedOnshore.csv that is after 2012</li> </ol> <p>The files each have the following fields (no data is blank):</p> <p>'ID': row ID integer</p> <p>'Sample_ID': identifier to raw data source</p> <p>'Sample_Type_Code': code of sample id</p> <p>'Project': raw datasource project identifier</p> <p>'dataset': raw dataset major identifier</p> <p>'Date': date, where specified, and to whatever precision that is specified</p> <p>'Location_Type': where specified, code indicating type of location information</p> <p>'latitude': latitude in decimal degrees</p> <p>'longitude': longitude in decimal degrees</p> <p>'Contact': where specified, raw data originator</p> <p>'num_orig_dists': number of unique grain size distributions</p> <p>'Measured_Distributions': number iof measured grain size distributions</p> <p>'Grainsize': grain size is sometimes reported without specification</p> <p>'Mean', mean grain size in mm</p> <p>'Median', median grain size in mm</p> <p>'Wentworth', wentworth name (one of ['Clay', 'CoarseSand', 'CoarseSilt', 'Cobble', 'FineSand', 'FineSilt', 'Granule', 'MediumSand', 'MediumSilt', 'Pebble', 'VeryCoarseSand', 'VeryFineSand', 'VeryFineSilt'])</p> <p>'Kurtosis', kurtosis value (non-dim)</p> <p>'Kurtosis_Class', kurtosis category</p> <p>'Skewness', skewness value (non-dim)</p> <p>'Skewness_Class', skewness category</p> <p>'Std', standard deviation of grain sizes </p> <p>'Sorting', sorting category</p> <p>'d5', grain size distribution 5th percentile</p> <p>'d10', grain size distribution 10th percentile</p> <p>'d16', grain size distribution 16th percentile</p> <p>'d25', grain size distribution 25th percentile</p> <p>'d30', grain size distribution 30th percentile</p> <p>'d50', grain size distribution 50th percentile</p> <p>'d65', grain size distribution 65th percentile</p> <p>'d75', grain size distribution 75th percentile</p> <p>'d84',grain size distribution 84th percentile</p> <p>'d90', grain size distribution 90th percentile</p> <p>'d95', grain size distribution 95th percentile</p> <p>'Notes': notes - these can be informative and substantial, do not disregard</p> <p> </p> <p>Source_Files.zip contains 11 comma separated value files, namely bicms.csv boem.csv clark.csv dbseabed.csv ecstdb.csv mass.csv mcfall.csv rossi.csv sandsnap.csv sbell.csv ussb.csv, which contain raw datasets that have been collated and extracted from their native formats into csv format</p>
Core log descriptions and sediment grain size data for Hurricane Ian sediment cores collected in Lee County, Florida, USA
<p>These data represent qualitative and quantitative measurements of sediment cores collected from various environments following the landfall of Hurricane Ian. These sediment cores were collected using pound coring techniques up to 2m into the subsurface to characterize the sedimentological signature of storm deposits resulting from Hurricane Ian. More details regarding these measurements and interpretations of storm deposits can be found in the folllowing manuscript:</p> <p>McCormick, W.M., Briggs, T.R., Hauptman, L.H., Wang, P., Morphologic and sedimentological signatures resulting from Hurricane Ian, southwest Florida, USA: Insight into intra-storm bidirectional sediment transport processes (In Review). </p>
Standardized reference grids for spatial analyses at various grain sizes
<p><strong>Description:</strong><br> These Reference grids have been created for the <a href="https://naturaconnect.eu/">NaturaConnect project</a> and are based on an intersection of the<a href="https://www.eea.europa.eu/data-and-maps/data/eea-coastline-for-analysis-1/gis-data/europe-coastline-shapefile"> European Coastline delineation</a> and the <a href="https://gadm.org/">GADM database</a>.<br> Thee reference grids have been created in a way so that they are fully consistent with the EEA reference grid (https://www.eea.europa.eu/data-and-maps/data/eea-reference-grids-2), meaning that for example two 5km gridded cells fully match a 10km grid cell in width.</p> <p><strong>Filestructure:</strong><br> ReferenceGrid_Europe_{format}_{grain}</p> <ul> <li> format is either "frac" for fractional data (which has been multiplied with 10000 to save in integer format) or binary (0,1).</li> <li> grain is provided as layers in 100m, 1000m, 5000m, 10000m, 50000m spatial resolution. Alternative aggregations can be provided on request.</li> </ul> <p><strong>File format:</strong><br> The layers are gridded geoTiff files and can be loaded in any conventional Graphical Information System (GIS) or specific analytical programming languages (e.g. R or python). In addition external pyramids (.tfw) have been precreated to enable faster rendering.</p> <p><strong>Geographic projection:</strong><br> We use the <a href="https://epsg.io/3035">Lamberts-Equal-Area Projection</a> by default for all layers in NaturaConnect. This is an equal-area (but distorted shape) projection and commonly used by European institution with a focus on the European continent. For global layers the <a href="https://epsg.io/54009">equal-area World Mollweide projection</a> is used.<br> <br> <strong>Sourcecode:</strong><br> The code to reproduce the layers has been made available in the "code" file.<br> </p>
Interpolation of the median grain size of the first 2 cm sediment layer in the former saltworks of Salin de Giraud in 2017
<p>Sediment samples were collected in the summer of 2017 over the entire study area at 500 m spacing and in the channels. Grain size analysis of the collected sediment samples was conducted using a Malvern Mastersizer 2000© laser beam grain sizer. The median grain size (d50 in µm) at each sample location was then interpolated over the entire study area. Interpolation was made with the SAGA-GIS software (version 7.9.0). According to the cross-validation error, the best method for the D50mm interpolation was the Modified Quadratic Shepard. The 10-fold validation provided an R² of 0.93, an NMRSE of 24.5, an RMSE of 83.9, an MRE of 7039 with the fit set to “node”, the quadratic neighbours and weighting neighbours set to 50 and the spatial resolution was set to 10 m. The resultant interpolation map was then categorized following the nomenclature of Blott and Pye (2001) provided in the file style_sediment_map.qml.</p>
Gini index mean score grain size estimates for Murray formation rocks (Gale crater, Mars) from ChemCam LIBS data (sols 766-1804)
<p>This repository includes main research results from the Journal of Geophysical Research: Planets manuscript entitled <em>"Grain Size Variations in the Murray Formation: Stratigraphic Evidence for Changing Depositional Environments in Gale Crater, Mars"</em>. These datasets were also included as Supplementary tables with the manuscript. Please find the plain language summary of the manuscript and the captions for these datasets below:</p> <p><strong><em>Plain language summary:</em></strong> The lowest exposed rocks of the Murray formation in Gale crater, Mars are interpreted as ancient lake deposits based on <em>Curiosity </em>rover data. However, the duration and temporal variability of this ancient lake is still an open question. Here we characterize the vertical distribution of deposits within the entire Murray formation using new grain size information. Characterizing grain size in rocks provides information about the speed of past fluid flows, which is crucial for interpreting depositional environments. However, measuring grain size in images is rarely possible for martian rocks. Thus, we estimate grain sizes with the Gini Index Mean Score (GIMS), a grain-size proxy that uses ChemCam Laser Induced Breakdown Spectroscopy data. GIMS results indicate that the Murray formation is dominated by rocks with mud-sized grains (i.e., mudstones), suggesting mud-sized grain settled in a low energy lake environment. Mud cracks occur in some of the mudstones, indicating drying periods in a lake. Rocks with sand-sized grains (i.e., sandstones) and cross bedding occur at specific intervals, suggesting episodes with stream channels and wind-blown sand dunes. The dominance of lake deposits interspersed with stream deposits suggests that liquid water was present in Gale crater for tens of thousands to millions of years.</p> <p><strong>Table captions:</strong></p> <p><em>Table S3. </em>All Murray formation targets used in the Gini mean index score (GIMS) analysis (sols 766-1804) with summary information, general grain size estimates from MAHLI and RMI images if known, and G<sub>MEAN </sub>values with associated standard deviation errors. For targets with N/A grain sizes, grains could not be resolved in any of the images, or images were not available. Protrusions in the rocks that are not grains are likely diagenetic nodules or concretions. Targets with G<sub>MEAN</sub>=0.07 have transitional GSRs, indicated by GSR1/GSR2. Targets names are merged in the same cell for those analyses that were taken on the same rock exposure. Next to the target names, the symbol * denotes that the ChemCam target was imaged by the MAHLI, the symbol ** denotes that the dust removal tool was used before the MAHLI image was taken, and ~ signifies that a location close to the ChemCam target was imaged by the MAHLI.</p> <p><em>Table S4</em>. The mean, median, minimum and maximum G<sub>MEAN</sub> and the minimum and maximum grain size regime (GSR) for each locality in the Murray formation.</p>
Data from "Multi-wavelength continuum sizes of protoplanetary discs: scaling relations and implications for grain growth and radial drift"
<p>Table 1, Table 2, and Table 3 from Tazzari et al., 2021, "Multi-wavelength continuum sizes of protoplanetary discs: scaling relations and implications for grain growth and radial drift", Monthly Notices of the Royal Astronomical Society, arXiv:2010.02249</p> <p>Both tables are available in IPAC format, which is in human- and machine-readable:</p> <pre><code class="language-python">from astropy.io import ascii tb = ascii.read('Table1.txt', format='ipac')</code></pre> <p>Table comments (stored at the beginning of the ASCII file as lines starting with "/") can be read as:</p> <pre><code class="language-python">tb.meta['comments'] </code></pre>
A Novel Laboratory Technique for Measuring Grain Size Specific Transport Characteristics of Bed Load Pulses
<p>We present a novel, time-efficient and non-destructive laboratory technique to investigate grain size specific transport characteristics of bed load pulses. The method consists of a through-water, high-resolution image acquisition followed by the application of a supervised color classification algorithm (Gaussian Maximum Likelihood Classification). Quality assessment based on a confusion matrix approach and basic random sampling showed a high classification performance. By statistically analyzing the temporal and spatial color distribution of the experimental reach, characteristic parameters to describe the propagation behavior were determined. The analyzed bed load pulse consisted of five different grain size classes of dyed quartz sand and gravel, each having a unique color. The initial experimental bed was uni-colored and contained the same size fractions as the augmented pulse.</p>
Data from: Promoting success in thin layer sediment placement: effects of sediment grain size and amendments on salt marsh plant growth and greenhouse gas exchange
<p>Thin layer sediment placement (TLP) is a method to mitigate factors resulting in loss of elevation and severe alteration of hydrology, such as sea level rise and anthropogenic modifications, and prolong the lifespan of drowning salt marshes. However, TLP success may vary due to plant stress associated with reductions in nutrient availability and hydrologic flushing or through the creation of acid sulfate soils. This study examined the influence of sediment grain size and soil amendments on plant growth, soil and porewater characteristics, and greenhouse gas exchange for three key US salt marsh plants: <em>Spartina alterniflora, Spartina patens, </em>and <em>Salicornia pacifica. </em>We found that bioavailable nitrogen concentrations (measured as extractable NH<sub>4</sub><sup>+</sup>-N) and porewater pH and salinity were found to have an inverse relationship with grain size, while soil redox was more reducing in finer sediments. This suggests that utilizing finer sediments in TLP projects will result in a more reduced environment with higher nutrient availability, while larger grain-sized sediments will be better flushed and oxidized. We further found that grain size had a significant effect on vegetation biomass allocation and rates of gas exchange, although these effects were species-specific. We found that soil amendments (biochar and compost) did not subsidize plant growth but were associated with increases in soil respiration and methane emissions. Biochar amendments were additionally ineffective in ameliorating acid sulfate conditions. This study uncovers complex interactions between sediment type and vegetation, emphasizing limitations of soil amendments. The findings aid restoration project managers in making informed decisions regarding sediment type, target vegetation, and soil amendments for successful TLP projects.</p>
Data and code for: Grain size of fluvial gravel bars from close-range UAV imagery – uncertainty in segmentation-based data
<p>UAV images used for SfM model generation and all images (both SI and OM), in which we measured grain sizes. The code used for image processing and uncertainty estimation of grain size distributions as python files and executable jupyter notebooks, where the latter also serve as documentation.</p>
ChRM and grain-size data of deep-sea sediments in the Central Philippine Sea
<p>The Philippine Sea is a typical region of eolian dust reposition and is located within the Western Pacific Warm Pool. Here, we use the paleo-magnetic stratigraphy and the grain-size distributions of Quaternary abyssal deposits in the Central Philippine Sea to investigate the factors controlling regional sedimentary and paleoenvironmental changes. Our principal results are as follows: (1) A reliable geochronologic framework for Quaternary sediments in the Central Philippine Sea is established. (2) An eastward expansion of the regional depocenter in the Middle Pleistocene is observed. (3) The mean grain size of the abyssal sediments is 7–8 μm, and there are only minor differences between the sites. Comparison of the geochronological framework with various paleoenvironmental events during the Mid-Pleistocene Transition shows that sedimentary processes can be correlated to a major transition in global climate which affected regions from the Asian interior to the tropical Pacific, and that changes in aeolian sedimentation are likely the predominant factor responsible. A derived grain-size proxy of the sedimentary dynamics and its comparison with various paleoenvironmental proxies show that the relative contributions are roughly estimated as 23%, 9%, and 68% for aeolian inputs, oceanic circulation, and the tropical Pacific zonal SST gradient, respectively in the studied region. The relative importance of tropical processes in abyssal sedimentary dynamics highlights the possibility of the long-term influence of (sub)mesoscale eddies in the upper ocean, via regional upwelling and unique submarine topography, on the deepest part (>5000 m) of the Central Philippine Sea, from meteorological to geological timescales.</p>
Additional files for manuscript titled 'The double round-robin population unravels the genetic architecture of grain size in barley'
<p>Additional file 1: Parental allele for barley orthologs of genes controlling grain size in rice</p> <p>Additional file 2: Cross-validation of quantitative trait loci (QTLs) detected for grain size characters in rice</p> <p>Additional file 3: Adjusted entry means of recombinant inbred lines of 45 HvDRR sub-populations</p>
Influence of sand supply and grain size on upper regime bedforms
<p>Notwithstanding the large number of studies on bedforms such as dunes and antidunes, performing quantitative predictions of bedform type and geometry remains an open problem. Here we present the results of laboratory experiments specifically designed to study how sediment supply and caliber may impact equilibrium bedform type and geometry in the upper regime. Experiments were performed in a sediment feed flume with flow rates varying between 5 l/s and 30 l/s, sand supply rates varying between 0.6 kg/min and 20 kg/min, and uniform and non-uniform sediment grain sizes with geometric mean diameter varying between 0.22 mm and 0.87 mm. The analysis of the experimental data and the comparison with datasets available in the literature revealed that the ratio of the volume transport of sediment to the volume transport of water Q<sub>s</sub>/Q<sub>w</sub> plays a prime control on the equilibrium bed configuration. The equilibrium bed configuration transitions from washed out dunes, to downstream migrating antidunes for Q<sub>s</sub>/Q<sub>w</sub> between 0.0003 and 0.0007. For values of Q<sub>s</sub>/Q<sub>w</sub> greater than those typical of the downstream migrating antidunes, the bedform wavelength increases. Equilibrium bed configuration for fine sands is characterized by upstream migrating antidunes or cyclic steps, and significant suspended sand. At these high values of Q<sub>s</sub>/Q<sub>w</sub> the equilibrium bed for coarse sands is plane with bedload transport in sheet flow mode. Standing waves form at the transition between downstream migrating antidunes and bed configurations with upstream migrating bedforms or bedload transport in sheet flow mode. </p>
Frictional Properties of Opalinus Clay: Influence of Humidity, Normal Stress and Grain-size on Frictional Stability
<p>We designed frictional experiments to characterize the effect exerted by humidity, grain size and normal stress on frictional behaviour of the Opalinus clay fault gouge. We explored a wide range of normal stresses, ranging from 5 to 70 MPa performing velocity up-steps from 1 to 300 μm/s and slide-hold-slide from 1 to 3000s. Our experiments confirms that the OPA clay is weak, with friction coefficients at steady-state of ~0.35 and ~0.41, for 100% RH and 25% RH experiments, respectively. The OPA clay is velocity strengthening over the entire range of applied normal stress. We observe a direct relationship between frictional parameter <em>(a-b)</em> and slip velocity up to 35 MPa where, from there on, <em>(a-b)</em> parameter seems to be velocity independent. As evidenced by the microstructural analysis, we suggest that this behaviour is due to the progressive transition with normal stress, from strain localization and grain size reduction to distributed deformation on well-developed phyllosilicate networks. The amount of relative humidity does not affect deformation mechanisms (i.e. localized or distributed), whereas decreases fault strength and increases fault stability. We hypothesize that this is due to a possible interplay of OPA clay swelling and lubrication, caused by the weakening of chemical bonds between phyllosilicate foliae. Notably, the initial grain size (< 63 µm or 63 < g.s. < 125 µm) does not affect either the frictional strength or stability, with similar values of dilation upon velocity up-step. Collectively, our mechanical and microstructural observations have allowed us to build a conceptual model that summarizes the main mechanical features of the OPA clay fault gouge. In the context of deep geological repositories (DGR), our results confirm that slow aseismic slip is the most likely slip behaviour for a fault gouge hosted in the OPA clay, with similar mineralogical composition and clay fabric as our samples. Beyond the context of deep geological repositories, this study has also implications for carbon capture and geological storage in the deep subsurface. Indeed, OPA has the characteristics of a low permeability caprock, but faulted, and the integrity of a sealing caprock overlying a storage reservoir can evolve after fault reactivation, potentially generating undesired seismicity and new hydraulic pathways.</p> <p>The data are uploaded are structured as follow:</p> <p>1) A .txt file of the datafile that is recorded from the machine (raw data)</p> <p>2) A file in .txt format containing the elaborated data (data_rp) </p> <p>The data are analyzed using rawPy that can be found at <a href="https://github.com/marcoscuderi/rawPy">https://github.com/marcoscuderi/rawPy</a></p> <p>For any additional information please do not hesitate to contact the corresponding author Nico Bigaroni at nico.bigaroni@uniroma1.it</p> <p> </p>
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.