High-resolution Reconstruction of a Holocene Coastal Sequence (NW Germany) Using Inorganic Geochemical Data and Diatom Inventories

1999 ◽  
Vol 48 (6) ◽  
pp. 617-633 ◽  
Author(s):  
O. Dellwig ◽  
F. Watermann ◽  
H.-J. Brumsack ◽  
G. Gerdes
Keyword(s):  
High Resolution ◽  
Geochemical Data ◽  
Nw Germany ◽  
High Resolution Reconstruction

High-resolution reconstruction in off-axis digital holographic imaging by using aliasing-spectrum filtering

2021 ◽  
Author(s):  
Yiwei Liu ◽  
Yibo Wang ◽  
Qiuya Sun ◽  
Hao Chen ◽  
Hongpeng Qin ◽  
...  
Keyword(s):  
High Resolution ◽  
Holographic Imaging ◽  
High Resolution Reconstruction

Optimizing High Resolution Reconstruction in Digital Breast Tomosynthesis Using Filtered Back Projection

2014 ◽  
pp. 520-527 ◽  
Author(s):  
Shiras Abdurahman ◽  
Frank Dennerlein ◽  
Anna Jerebko ◽  
Andreas Fieselmann ◽  
Thomas Mertelmeier
Keyword(s):  
High Resolution ◽  
Digital Breast Tomosynthesis ◽  
Back Projection ◽  
Filtered Back Projection ◽  
Breast Tomosynthesis ◽  
High Resolution Reconstruction

A 2200-yr record of hydrologic variability from Foy Lake, Montana, USA, inferred from diatom and geochemical data

2006 ◽  
Vol 65 (02) ◽  
pp. 264-274 ◽  
Author(s):  
Lora R. Stevens ◽  
Jeffery R. Stone ◽  
Josh Campbell ◽  
Sherilyn C. Fritz
Keyword(s):  
Spectral Analysis ◽  
High Resolution ◽  
High Frequency ◽  
Lake Level ◽  
Low Frequency ◽  
Seasonal Distribution ◽  
Geochemical Data ◽  
Hydrologic Variability ◽  
Moisture Balance ◽  
Hydrologic Balance

AbstractA 2200-yr long, high-resolution (∼5 yr) record of drought variability in northwest Montana is inferred from diatoms and δ18O values of bio-induced carbonate preserved in a varved lacustrine core from Foy Lake. A previously developed model of the diatom response to lake-level fluctuations is used to constrain estimates of paleolake levels derived from the diatom data. High-frequency (decadal) fluctuations in the de-trended δ18O record mirror variations in wet/dry cycles inferred from Banff tree-rings, demonstrating the sensitivity of the oxygen-isotope values to changes in regional moisture balance. Low frequency (multi-centennial) isotopic changes may be associated with shifts in the seasonal distribution of precipitation. From 200 B.C. to A.D. 800, both diatom and isotope records indicate that climate was dry and lake level low, with poor diatom preservation and high organic carbon: nitrogen ratios. Subsequently, lake level rose slightly, although the climate was drier and more stable than modern conditions. At A.D. 1200, lake level increased to approximately 6 m below present elevation, after which the lake fluctuated between this elevation and full stage, with particularly cool and/or wetter conditions after 1700. The hydrologic balance of the lake shifted abruptly at 1894 because of the establishment of a lumber mill at the lake's outlet. Spectral analysis of the δ18O data indicates that severe droughts occurred with multi-decadal (50 to 70 yr) frequency.

Stratigraphy and sedimentary process in a closed-basin lake in Central Italy during the Anthropocene

2021 ◽  
Author(s):  
Paola Gravina ◽  
Beatrice Moroni ◽  
Riccardo Vivani ◽  
Alessandro Ludovisi ◽  
Roberta Selvaggi ◽  
...  
Keyword(s):  
High Resolution ◽  
Water Level ◽  
Lake Sediments ◽  
Biological Effects ◽  
Central Italy ◽  
Geochemical Data ◽  
Climate Variations ◽  
Sedimentary Process ◽  
Climatic Fluctuations ◽  
Precipitation Processes

<p>Shallow and closed lakes are affected by meteorological and climate variations and are especially sensitive to the change in their hydrological balance. In central Italy, there is the fourth-largest lake of the country, the Trasimeno Lake, whose water level has undergone various fluctuations over the centuries with alternation of flood and drought periods because of its shallow depth and the absence of natural outflows [1].</p><p>Sediment archives are used as information records to study chemical, physical, and biological environmental variations and changes in the hydrological budget driven by climatic fluctuations, but this is particularly complicated in shallow lakes due to the multiple perturbative phenomena. A robust study depends on the ability to obtain valid high-resolution geochemical data from lake sediments.</p><p>We conducted high-resolution geochemical analysis on three sediment cores about 1 meter long each, collected in Lake Trasimeno. We sectioned at 1  or 2 cm interval, which provided a detailed characterization of the significant changes in lacustrine processes that occurred in the basin during the Anthropocene (~last 150 years) [2], combining quantitative chemical (ICP-OES) and semi-quantitative (XRD and SEM) investigations. Geochemical variables are used as paleolimnological proxies to reconstruct past lake events that occurred within the water column. In particular, we report the study of the endogenic precipitates characteristic of the Trasimeno sediments, whose precipitation processes have been influenced by water fluctuations and anthropogenic impacts.</p><p>Given the strong presence of water fluctuations, the investigation period was divided into three distinct phases related to the lake's hydrometric state and characterized by sedimentary compounds of different nature. The endogenic carbonate compounds of calcite (commonly present in the Trasimeno sediments) contain a different Mg percentage during the different hydrometric phases. The lake sediments are particularly rich in Mg-calcite due to both water level changes and biological effects. Moreover, co-precipitation of non-crystalline Ca-P compounds (e.g., apatite type) has been detected during a hydrometric phase characterized by high microorganisms activity. Precipitation processes were triggered in Trasimeno by the growth of nutrient discharge into the lake (since the 1970s) and are currently studied for their importance in controlling eutrophication phenomena.</p><p>In conclusion, our findings show that rapid lake responses to water fluctuations and climate variations were transcribed within the sedimentary stratigraphic archives, which underlines their value and high quality in paleoenvironmental and paleohydrological reconstruction.</p><p>References:</p><p>[1] Frondini, Dragoni, Morgantini, Donnini, Cardellini, Caliro, Melillo, and Chiodini (2019). An En-dorheic Lake in a Changing Climate: Geochemical Investigations at Lake Trasimeno (Italy).Water, 11(7):1319.</p><p> [2] Gaino, E., Scoccia, F., Piersanti, S., Rebora, M., Bellucci, L. G., and Ludovisi, A. (2012). Spiculerecords of Ephydatia fluviatilis as a proxy for hydrological and environmental changes inthe shallow Lake Trasimeno (Umbria, Italy). Hydrobiologia, 679(1):139–153.</p>

Petrological microscopy data workflow – an example from Cap de Creus, NE Spain

2021 ◽  
Author(s):  
Richard Wessels ◽  
Thijmen Kok ◽  
Hans van Melick ◽  
Martyn Drury
Keyword(s):  
High Resolution ◽  
Shear Zones ◽  
Research Data ◽  
Image Correlation ◽  
Geochemical Data ◽  
Rock Composition ◽  
Meta Data ◽  
Sample Number ◽  
Thin Sections ◽  
The Impact

<p>Publishing research data in a Findable, Accessible, Interoperable, and Reusable (FAIR) manner is increasingly valued and nowadays often required by publishers and funders. Because experimental research data provide the backbone for scientific publications, it is important to publish this data as FAIRly as possible to enable reuse and citation of the data, thereby increasing the impact of research.</p><p>The structural geology group at Utrecht University is collaborating with the EarthCube-funded StraboSpot initiative to develop (meta)data schemas, templates and workflows, to support researchers in collecting and publishing petrological and microstructural data. This data will be made available in a FAIR manner through the EPOS (European Plate Observing System) data publication chain <span xml:lang="EN-GB"><span>(https://epos-msl.uu.nl/</span></span><span xml:lang="EN-GB"><span>)</span></span><span xml:lang="EN-GB"><span>.</span></span></p><p>The data workflow under development currently includes: a) collecting structural field (meta)data compliant with the StraboSpot protocols, b) creating thin sections oriented in three dimensions by applying a notch system (Tikoff et al., 2019), c) scanning and digitizing thin sections using a high-resolution scanner, d) automated mineralogy through EDS on a SEM, and e) high-resolution geochemistry using a microprobe. The purpose of this workflow is to be able to track geochemical and structural measurements and observations throughout the analytical process.</p><p>This workflow is applied to samples from the Cap de Creus region in northeast Spain. Located in the axial zone of the Pyrenees, the pre-Cambrian metasediments underwent HT-LP greenschist- to amphibolite-facies metamorphism, are intruded by pegmatitic bodies, and transected by greenschist-facies shear zones. Cap de Creus is a natural laboratory for studying the deformation history of the Pyrenees, and samples from the region are ideal to test and refine the data workflow. In particular, the geochemical data collected under this workflow is used as input for modelling the bulk rock composition using Perple_X.    </p><p>In the near future the workflow will be complimented by adding unique identifiers to the collected samples using IGSN (International Geo Sample Number), and by incorporating a StraboSpot-developed application for microscopy-based image correlation. This workflow will be refined and included in the broader correlative microscopy workflow that will be applied in the upcoming EXCITE project, an H2020-funded European collaboration of electron and x-ray microscopy facilities and researchers aimed at structural and chemical imaging of earth materials. </p>

scholarly journals High resolution reconstruction of modern charcoal production kilns: An integrated approach combining dendrochronology, micromorphology and anthracology in the French Pyrenees

2020 ◽  
Author(s):  
Léonel Fouédjeu ◽  
Mélanie Saulnier ◽  
Mathieu Lejay ◽  
Martin Dušátko ◽  
Vincent Labbas ◽  
...  
Keyword(s):  
High Resolution ◽  
Integrated Approach ◽  
Charcoal Production ◽  
High Resolution Reconstruction

Depth texture synthesis for high-resolution reconstruction of large scenes

2019 ◽  
Vol 30 (4) ◽  
pp. 795-806
Author(s):  
Félix Labrie-Larrivée ◽  
Denis Laurendeau ◽  
Jean-François Lalonde
Keyword(s):  
High Resolution ◽  
Texture Synthesis ◽  
High Resolution Reconstruction

Zero-crossing approach to high-resolution reconstruction in frequency-domain optical-coherence tomography

2012 ◽  
Vol 29 (10) ◽  
pp. 2080 ◽  
Author(s):  
Sunder Ram Krishnan ◽  
Chandra Sekhar Seelamantula ◽  
Arno Bouwens ◽  
Marcel Leutenegger ◽  
Theo Lasser
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Frequency Domain ◽  
Optical Coherence ◽  
Zero Crossing ◽  
High Resolution Reconstruction
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