scholarly journals Cyclostratigraphy of a type-Maastrichtian chalk record, based on high-resolution geochemical analysis of the Gulpen Formation, NE Belgium 

2021 ◽  
Author(s):  
Jarno Huygh ◽  
Johan Vellekoop ◽  
Matthias Sinnesael ◽  
Pim Kaskes ◽  
John Jagt ◽  
...  
Keyword(s):  
High Resolution ◽  
Geochemical Data ◽  
Composition Analysis ◽  
Data Sets ◽  
Data Set ◽  
Age Model ◽  
Cyclic Variations ◽  
Elemental Data ◽  
Isotope Stratigraphy ◽  
Palaeoenvironmental Conditions

<p>Cyclostratigraphic studies on carbonate successions have proved invaluable for understanding palaeoclimate and for constructing improved, high-resolution age models of the Late Cretaceous. Whereas carbonate strata from the type-Maastrichtian from the Netherlands and Belgium have provided a wealth of palaeontological data, so far, dating of these deposits has relied mainly on biostratigraphy and preliminary attempts at cyclostratigraphy. The existing basic cyclostratigraphic framework is based principally on apparent cyclic variations in bioclast composition and suggested Milankovitch-paced flint cycles. Until now, these strata have not yet been examined using a cyclostratigraphic approach based on high-resolution multi-proxy geochemical data sets. Within the scope of the Maastrichtian Geoheritage Project, we attempt to construct an improved astrochronological age model for Maastrichtian chalk deposits of the Gulpen Formation.</p><p>We have carried out a high-resolution elemental composition analysis of the Lower to Middle Maastrichtian chalk succession exposed at the Hallembaye (Kreco) quarry, NE Belgium. Approximately 460 chalk samples were collected every 5 cm over a 23-metre-thick stratigraphic interval and analysed as homogenised powders using micro X-ray fluorescence. This extensive elemental data set is used to evaluate (regular) changes in palaeoenvironmental conditions over time. Additionally, stratigraphic comparison of variations in elemental concentrations in the chalk with the occurrence of flint layers provides insights into potential diagenetic alterations. </p><p>Preliminary results display promising trends with potential for the development of a cyclostratigraphic age model for the Gulpen Formation. Significant correlation between the main matrix elements calcium and silica might suggest a relationship between silica-depleted chalk and occurring flint layers throughout the chalk succession. Additionally, observed rhythmic variations in elements including - but not limited to - titanium, aluminium and potassium might exemplify changing palaeoenvironmental conditions. This improved astrochronological age model can be compared with age-equivalent astrochronologies and will, in combination with ongoing carbon isotope stratigraphy work, enable a better dating of the geological and biological records from the type-Maastrichtian. </p>

scholarly journals Global whole-rock geochemical database compilation

2019 ◽  
Author(s):  
Matthew Gard ◽  
Derrick Hasterok ◽  
Jacqueline Halpin
Keyword(s):  
Database Management ◽  
Temporal Trends ◽  
Physical Property ◽  
Database Management System ◽  
Geochemical Data ◽  
Data Sets ◽  
Unique Contribution ◽  
Data Set ◽  
Wide Range ◽  
Geochemical Indices

Abstract. Dissemination and collation of geochemical data are critical to promote rapid, creative and accurate research and place new results in an appropriate global context. To this end, we have assembled a global whole-rock geochemical database, with other associated sample information and properties, sourced from various existing databases and supplemented with numerous individual publications and corrections. Currently the database stands at 1,023,490 samples with varying amounts of associated information including major and trace element concentrations, isotopic ratios, and location data. The distribution both spatially and temporally is quite heterogeneous, however temporal distributions are enhanced over some previous database compilations, particularly in terms of ages older than ~ 1000 Ma. Also included are a wide range of computed geochemical indices, physical property estimates and naming schema on a major element normalized version of the geochemical data for quick reference. This compilation will be useful for geochemical studies requiring extensive data sets, in particular those wishing to investigate secular temporal trends. The addition of physical properties, estimated by sample chemistry, represents a unique contribution to otherwise similar geochemical databases. The data is published in .csv format for the purposes of simple distribution but exists in a format acceptable for database management systems (e.g. SQL). One can either manipulate this data using conventional analysis tools such as MATLAB®, Microsoft® Excel, or R, or upload to a relational database management system for easy querying and management of the data as unique keys already exist. This data set will continue to grow, and we encourage readers to contact us or other database compilations contained within about any data that is yet to be included. The data files described in this paper are available at https://doi.org/10.5281/zenodo.2592823 (Gard et al., 2019).

scholarly journals Reconstruction of Axial Tomographic High Resolution Data from Confocal Fluorescence Microscopy: A Method for Improving 3D FISH Images

2000 ◽  
Vol 20 (1) ◽  
pp. 7-15 ◽  
Author(s):  
R. Heintzmann ◽  
G. Kreth ◽  
C. Cremer
Keyword(s):  
High Resolution ◽  
Laser Scanning ◽  
Axial Direction ◽  
Laser Scanning Microscopy ◽  
Three Dimensions ◽  
Confocal Laser ◽  
Data Sets ◽  
Data Set ◽  
High Resolution Data ◽  
3D Data

Fluorescent confocal laser scanning microscopy allows an improved imaging of microscopic objects in three dimensions. However, the resolution along the axial direction is three times worse than the resolution in lateral directions. A method to overcome this axial limitation is tilting the object under the microscope, in a way that the direction of the optical axis points into different directions relative to the sample. A new technique for a simultaneous reconstruction from a number of such axial tomographic confocal data sets was developed and used for high resolution reconstruction of 3D‐data both from experimental and virtual microscopic data sets. The reconstructed images have a highly improved 3D resolution, which is comparable to the lateral resolution of a single deconvolved data set. Axial tomographic imaging in combination with simultaneous data reconstruction also opens the possibility for a more precise quantification of 3D data. The color images of this publication can be accessed from http://www.esacp.org/acp/2000/20‐1/heintzmann.htm. At this web address an interactive 3D viewer is additionally provided for browsing the 3D data. This java applet displays three orthogonal slices of the data set which are dynamically updated by user mouse clicks or keystrokes.

scholarly journals Fennec dust forecast intercomparison over the Sahara in June 2011

2016 ◽  
Vol 16 (11) ◽  
pp. 6977-6995 ◽  
Author(s):  
Jean-Pierre Chaboureau ◽  
Cyrille Flamant ◽  
Thibaut Dauhut ◽  
Cécile Kocha ◽  
Jean-Philippe Lafore ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Wind ◽  
Dust Emission ◽  
Airborne Lidar ◽  
Data Sets ◽  
Density Currents ◽  
Data Set ◽  
Near Surface ◽  
Western Sahara ◽  
Deep Well

Abstract. In the framework of the Fennec international programme, a field campaign was conducted in June 2011 over the western Sahara. It led to the first observational data set ever obtained that documents the dynamics, thermodynamics and composition of the Saharan atmospheric boundary layer (SABL) under the influence of the heat low. In support to the aircraft operation, four dust forecasts were run daily at low and high resolutions with convection-parameterizing and convection-permitting models, respectively. The unique airborne and ground-based data sets allowed the first ever intercomparison of dust forecasts over the western Sahara. At monthly scale, large aerosol optical depths (AODs) were forecast over the Sahara, a feature observed by satellite retrievals but with different magnitudes. The AOD intensity was correctly predicted by the high-resolution models, while it was underestimated by the low-resolution models. This was partly because of the generation of strong near-surface wind associated with thunderstorm-related density currents that could only be reproduced by models representing convection explicitly. Such models yield emissions mainly in the afternoon that dominate the total emission over the western fringes of the Adrar des Iforas and the Aïr Mountains in the high-resolution forecasts. Over the western Sahara, where the harmattan contributes up to 80 % of dust emission, all the models were successful in forecasting the deep well-mixed SABL. Some of them, however, missed the large near-surface dust concentration generated by density currents and low-level winds. This feature, observed repeatedly by the airborne lidar, was partly forecast by one high-resolution model only.

scholarly journals High-resolution numerical modeling of mesoscale island wakes and sensitivity to static topographic relief data

2015 ◽  
Vol 8 (8) ◽  
pp. 2645-2653 ◽  
Author(s):  
C. G. Nunalee ◽  
Á. Horváth ◽  
S. Basu
Keyword(s):  
High Resolution ◽  
Vortex Shedding ◽  
Weather Prediction ◽  
Surface Wind ◽  
Wrf Model ◽  
Data Sets ◽  
Data Set ◽  
Near Surface ◽  
Nwp Model ◽  
Height Data

Abstract. Recent decades have witnessed a drastic increase in the fidelity of numerical weather prediction (NWP) modeling. Currently, both research-grade and operational NWP models regularly perform simulations with horizontal grid spacings as fine as 1 km. This migration towards higher resolution potentially improves NWP model solutions by increasing the resolvability of mesoscale processes and reducing dependency on empirical physics parameterizations. However, at the same time, the accuracy of high-resolution simulations, particularly in the atmospheric boundary layer (ABL), is also sensitive to orographic forcing which can have significant variability on the same spatial scale as, or smaller than, NWP model grids. Despite this sensitivity, many high-resolution atmospheric simulations do not consider uncertainty with respect to selection of static terrain height data set. In this paper, we use the Weather Research and Forecasting (WRF) model to simulate realistic cases of lower tropospheric flow over and downstream of mountainous islands using the default global 30 s United States Geographic Survey terrain height data set (GTOPO30), the Shuttle Radar Topography Mission (SRTM), and the Global Multi-resolution Terrain Elevation Data set (GMTED2010) terrain height data sets. While the differences between the SRTM-based and GMTED2010-based simulations are extremely small, the GTOPO30-based simulations differ significantly. Our results demonstrate cases where the differences between the source terrain data sets are significant enough to produce entirely different orographic wake mechanics, such as vortex shedding vs. no vortex shedding. These results are also compared to MODIS visible satellite imagery and ASCAT near-surface wind retrievals. Collectively, these results highlight the importance of utilizing accurate static orographic boundary conditions when running high-resolution mesoscale models.

scholarly journals A 20-year record (1998–2017) of permafrost, active layer, and meteorological conditions at a High Arctic permafrost research site (Bayelva, Spitsbergen): an opportunity to validate remote sensing data and land surface, snow, and permafrost models

2017 ◽  
Author(s):  
Julia Boike ◽  
Inge Juszak ◽  
Stephan Lange ◽  
Sarah Chadburn ◽  
Eleanor Burke ◽  
...  
Keyword(s):  
Energy Balance ◽  
High Resolution ◽  
Observational Data ◽  
Digital Elevation Model ◽  
Positive Feedback ◽  
The Arctic ◽  
Data Sets ◽  
Data Set ◽  
Digital Elevation ◽  
Elevation Model

Abstract. Most permafrost is located in the Arctic, where frozen organic carbon makes it an important component of the global climate system. Despite the fact that the Arctic climate changes more rapidly than the rest of the globe, observational data density in the region is low. Permafrost thaw and carbon release to the atmosphere are a positive feedback mechanism that can exacerbate climate warming. This positive feedback functions via changing land-atmosphere energy and mass exchanges. There is thus a great need to understand links between the energy balance, which can vary rapidly over hourly to annual time scales, and permafrost, which changes slowly over long time periods. This understanding thus mandates long-term observational data sets. Such a data set is available from the Bayelva Site at Ny-Ålesund, Svalbard, where meteorology, energy balance components and subsurface observations have been made for the last 20 years. Additional data include a high resolution digital elevation model and a panchromatic image. This paper presents the data set produced so far, explains instrumentation, calibration, processing and data quality control, as well as the sources for various resulting data sets. The resulting data set is unique in the Arctic and serves a baseline for future studies. Since the data provide observations of temporally variable parameters that mitigate energy fluxes between permafrost and atmosphere, such as snow depth and soil moisture content, they are suitable for use in integrating, calibrating and testing permafrost as a component in Earth System Models. The data set also includes a high resolution digital elevation model that can be used together with the snow physical information for snow pack modeling. The presented data are available in the supplementary material for this paper and through the PANGAEA website ( https://doi.pangaea.de/10.1594/PANGAEA.880120).

Cyclostratigraphic calibration of the Eifelian Stage (Middle Devonian, Appalachian Basin, Western New York, USA)

2020 ◽  
Vol 133 (1-2) ◽  
pp. 277-286 ◽  
Author(s):  
Damien Pas ◽  
Anne-Christine Da Silva ◽  
D. Jeffrey Over ◽  
Carlton E. Brett ◽  
Lauren Brandt ◽  
...  
Keyword(s):  
New York ◽  
High Resolution ◽  
Time Scale ◽  
Middle Devonian ◽  
Accurate Determination ◽  
Total Duration ◽  
Appalachian Basin ◽  
Geochemical Data ◽  
Ionization Mass ◽  
Data Set

Abstract Over the past decade the integration of astrochronology and U/Pb thermal ionization mass spectrometry dating has resulted in major improvements in the Devonian time scale, which allowed for accurate determination of ages and rates of change in this critical interval of Earth history. However, widely different durations have been published for the Middle Devonian Eifelian stage. Here we aim to solve this discrepancy by building an astronomically calibrated time scale using a high-resolution geochemical data set collected in the early to late Eifelian outer-ramp and deep-shelf deposits of the Seneca section (Appalachian Basin, Western New York, USA). The Middle Devonian Eifelian Stage (GTS2012; base at 393.3 ± 1.2 m.y. and duration estimate of 5.6 ± 1.9 m.y.), is bracketed by two major bioevents, respectively the Choteč event at its base and the Kačák event just prior to the Eifelian–Givetian boundary. To capture the record of Milankovitch-scale climatic cycles and to develop a model of the climatic and oceanographic variations that affected the Appalachian Basin during the Eifelian, 750 samples were collected at typically 2.5 cm intervals across the Seneca section. Major and trace elements were measured on each sample with an inductively coupled plasma–optical emission spectrometer. To estimate the duration of the Seneca section sampled, we applied multiple spectral techniques such as harmonic analysis, the multi-taper, and evolutionary spectral analysis, and we tuned the Log10Ti series using the short orbital eccentricity ∼100 k.y. cycle. Then, to assess the reliability of our cyclostratigraphic interpretation we ran the Average Spectral Misfit method on selected proxies for detrital input variation. The estimated duration derived using this method falls in the range of durations estimated with the tuning method. Using the approximate position of the Emsian–Eifelian and Eifelian–Givetian boundaries, constrained within <1 m, the proposed estimation of the total duration of the Eifelian age is ∼5 m.y. Interpolated from the high-resolution U-Pb radiometric age available for the Tioga F Bentonite, the numerical ages of the Emsian–Eifelian and the Eifelian–Givetian were respectively recalibrated at 393.39 Ma and 388.24 Ma. The uncertainty from the radiometric date is respectively ± 0.86 Ma and ± 0.86 Ma.

Efficiency of HLA-A, -B, -C, -DRB1 High-Resolution Typings of Newly Recruited Potential Stem Cell Donors.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5415-5415 ◽  
Author(s):  
Alexander H. Schmidt ◽  
Andrea Stahr ◽  
Daniel Baier ◽  
Gerhard Ehninger ◽  
Claudia Rutt
Keyword(s):  
Stem Cell ◽  
High Resolution ◽  
Final Decision ◽  
Data Sets ◽  
Donor Group ◽  
Donor Center ◽  
Full Data ◽  
Data Set ◽  
Group A ◽  
Group B

Abstract In strategic stem cell donor registry planning, it is of special importance to decide how to type newly registered donors. This question refers to both the selection of HLA loci and the resolution (low, intermediate, or high) of HLA typings. In principle, high-resolution typings of all transplant-relevant loci are preferable. However, cost considerations generally lead to incomplete typings (only selected HLA loci with low or intermediate typing resolution) in practice. Here, we present results of a project in which newly recruited donors are typed for the HLA-A, -B, -C, and -DRB1 loci with high resolution by sequencing. Efficiency of these typings is measured by subsequent requests for confirmatory typings (CTs) and stem cell donations. Results for donors who were included in the project (Donor Group A) are compared to requests for donors with other, less complete typing levels: HLA-A and HLA-B at intermediate resolution, HLA-DRB1 at high resolution (Group B); HLA-A, -B, -C, and -DRB1 at intermediate resolution (Group C); HLA-A, -B, and -DRB1 at intermediate resolution (Group D). All data are taken from the donor file of DKMS German Bone Marrow Donor Center. Since the four groups differ considerably regarding their age and sex distributions, calculations are also carried through for restricted data sets that include only male donors up to age 25. Results are shown in Table 1. Donors of Groups A and B have similar CT request frequencies of 5.90 and 5.92 requests per 100 donors per year in the resctricted data sets, respectively. These frequencies significantly exceed the corresponding frequencies of the other groups with less complete typing levels. For donation requests, the frequency is signifcantly higher for Group A than for Group B (restricted data sets): 1.45 vs 1.02 requests per donor per year (p<0.05). Obviously, the additional HLA information for Group A donors leads to a higher ratio between donations and CT requests. Again, figures are much lower for Groups C and D. These results are based on a high number of requests even for the restricted data sets, namely between 44 and 90 donation requests and between 227 and 619 CT requests per group. Our results show that full (HLA-A, -B, -C, and -DRB1) high-resolution typings at donor recruitment lead to significantly higher probabilities for donation requests. Donor centers and registries should carefully take into account these higher probabilities when they consider full high-resolution typings for newly recruited donors. However, the final decision regarding the typing strategy at recruitment must also depend on the individual cost structure of a donor center or registry. The presented results are based on a donor file that consists mainly (≈99%) of Caucasian donors. It should be subject to further analyses if these results also apply to other, more heterogeneous donor pools. Table 1: Requests per 100 donors per year by donor group CT requests Donation requests Donor Group Full data set Only male donors≤ 25 Full data set Only male donors≤ 25 A 5.14 5.90 1.45 1.45 B 4.60 5.92 0.84 1.02 C 2.50 3.03 0.58 0.67 D 2.36 2.80 0.38 0.48

scholarly journals Fennec dust forecast intercomparison over the Sahara in June 2011

2016 ◽  
Author(s):  
J.-P. Chaboureau ◽  
C. Flamant ◽  
T. Dauhut ◽  
C. Kocha ◽  
J.-P. Lafore ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Wind ◽  
Dust Emission ◽  
Airborne Lidar ◽  
Data Sets ◽  
Density Currents ◽  
Data Set ◽  
Near Surface ◽  
Western Sahara ◽  
Deep Well

Abstract. In the framework of the Fennec international programme, a field campaign was conducted in June 2011 over the western Sahara. It led to the first observational data set ever obtained that documents the dynamics, thermodynamics and composition of the Saharan atmospheric boundary layer (SABL) under the influence of the heat low. In support to the aircraft operation, four dust forecasts were run daily at low and high resolutions with convection-parameterizing and convection- permitting models, respectively. The unique airborne and ground-based data sets allowed the first ever intercomparison of dust forecasts over the western Sahara. At monthly scale, large Aerosol Optical Depths (AODs) were forecast over the Sahara, a feature observed by some satellite retrievals but mislocated by others over the Sahel. The AOD intensity was correctly predicted by the highresolution models while being underestimated by the low-resolution models. This was partly because of the generation of strong near-surface wind associated with thunderstorm-related density currents that could only be reproduced by models representing convection explicitly. Such models yield to emissions mainly in the afternoon that dominate the total emission over the western fringes of the Adrar des Iforas and Aïr Mountains in the high-resolution forecasts. Over the western Sahara, where the harmattan contributes up to 80 % of dust emission, all the models were successful in forecasting the deep well-mixed SABL. Some of them, however, missed the large near-surface dust extinction generated by density currents and low-level winds. This feature, observed repeatedly by the airborne lidar, was partly forecast by one high-resolution model only.

scholarly journals ULTRA-HIGH RESOLUTION IMAGING OF FACADES AND VERTICAL INFRASTRUCTURE BY CARBORNE SAR AND AIRBORNE CSAR

2019 ◽  
Vol IV-2/W7 ◽  
pp. 129-136 ◽  
Author(s):  
S. Palm ◽  
R. Sommer ◽  
A. Tessmann ◽  
U. Stilla
Keyword(s):  
High Resolution ◽  
Single Channel ◽  
Theoretical Background ◽  
Data Sets ◽  
Radar Sensor ◽  
Data Set ◽  
High Bandwidth ◽  
Airborne Sar ◽  
High Level ◽  
Very High

<p><strong>Abstract.</strong> In this paper we propose a strategy to focus ultra-high resolution single channel carborne SAR and airborne circular SAR (CSAR) data to image facades and vertical infrastructure. We illustrate the related theoretical background and the design of an optimal focusing geometry for carborne SAR applications while using backprojection focusing techniques. Of particular interest is thereby the determination of the minimum distance and orientation of the facade to the radar sensor. Potential image distortions due to a wrong choice of these parameters are illustrated. Effects on the final resolution of the data due to the rotation of the focusing geometry compared to typical airborne SAR are discussed. We validated the strategy by driving on conventional roads illuminating facades with an experimental mobile radar mapping (MRM) sensor operating at 300 GHz. We further present an adapted version of the proposed strategy to focus vertical infrastructure in CSAR data sets. By extracting the center coordinate and the principal orientation of an object from GiS data, the focusing plane is designed arbitrarily in the 3D space. For the CSAR data set, a radar sensor particularly designed for circular flight trajectories operating at 94 GHz was evaluated. An electrical pylon was chosen as potential target. In both applications, the final images show a high level of detail. The combination of proposed strategy and radar sensor with very high bandwidth is capable of subcentimeter imaging of facades. The height, shape and dimensions of objects can be extracted directly from the image geometry at very high accuracy.</p>

scholarly journals EcoDes-DK15: High-resolution ecological descriptors of vegetation and terrain derived from Denmark's national airborne laser scanning data set

2021 ◽  
Author(s):  
Jakob J. Assmann ◽  
Jesper E. Moeslund ◽  
Urs A. Treier ◽  
Signe Normand
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Airborne Laser Scanning ◽  
Data Sets ◽  
Ecosystem Structure ◽  
Data Set ◽  
Vegetation Height ◽  
Airborne Laser

Abstract. Biodiversity studies could strongly benefit from three-dimensional data on ecosystem structure derived from contemporary remote sensing technologies, such as Light Detection and Ranging (LiDAR). Despite the increasing availability of such data at regional and national scales, the average ecologist has been limited in accessing them due to high requirements on computing power and remote-sensing knowledge. We processed Denmark's publicly available national Airborne Laser Scanning (ALS) data set acquired in 2014/15 together with the accompanying elevation model to compute 70 rasterized descriptors of interest for ecological studies. With a grain size of 10 m, these data products provide a snapshot of high-resolution measures including vegetation height, structure and density, as well as topographic descriptors including elevation, aspect, slope and wetness across more than forty thousand square kilometres covering almost all of Denmark's terrestrial surface. The resulting data set is comparatively small (~ 87 GB, compressed 16.4 GB) and the raster data can be readily integrated into analytical workflows in software familiar to many ecologists (GIS software, R, Python). Source code and documentation for the processing workflow are openly available via a code repository, allowing for transfer to other ALS data sets, as well as modification or re-calculation of future instances of Denmark’s national ALS data set. We hope that our high-resolution ecological vegetation and terrain descriptors (EcoDes-DK15) will serve as an inspiration for the publication of further such data sets covering other countries and regions and that our rasterized data set will provide a baseline of the ecosystem structure for current and future studies of biodiversity, within Denmark and beyond.

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