Glaciotectonics and tunnel valleys in the southeastern North Sea imaged by high-resolution multi-channel seismics

2020 ◽  
Author(s):  
Arne Lohrberg ◽  
Sebastian Krastel ◽  
Daniel Unverricht ◽  
Klaus Schwarzer
Keyword(s):  
High Resolution ◽  
North Sea ◽  
Cross Sections ◽  
Forward Direction ◽  
Subsequent Formation ◽  
Reflection Seismic ◽  
Dense Grid ◽  
Thrust Sheets ◽  
Multiple Deformation ◽  
East West

<p>Glaciotectonic disturbance of sediments and tunnel valleys are often found near the margin of former ice sheets. Hence, these landforms can be used to reconstruct the dynamics of former ice sheet margins. The direction of thrusts usually points perpendicular to the ice front. Considering heterogeneity due to local ice advances, this relation can be used to infer the regional forward direction of large ice lobes. Here, we present a dense grid of high-resolution 2D multi-channel reflection seismic data from the German sector of the southeastern North Sea imaging a buried glaciotectonic complex and tunnel valleys in unprecedented detail.</p><p>We have identified individual thrust sheets in an area of approx. 650 km² (combined with recent results of Winsemann et al. (2020)). All thrust sheets are buried and partly eroded at their top. Two major phases of thrusting with two corresponding detachment surfaces have been identified in the subsurface, of which the younger phase led to the deformation of sediments several kilometers further into the foreland. The thickness of individual thrust sheets differs between 180 and 240 m. Some thrust sheets have been cut by the subsequent formation of tunnel valleys with an overall incision direction ranging from east-west to northeast-southwest. The glaciotectonic complex is limited to its southeast by an updipping reflector, which represents the margin of a source depression.</p><p>The restauration of cross-sections shows that the thrust sheets transported sediments over more than a kilometer towards the northwest to west, which relates the formation of the thrust sheets and the source depression. The landforms are very similar to a hill-hole pair that led to the foreland thrust sheets, probably as a result of combined bulldozing and gravity spreading in the foreland of the ice margin. Their occurrence and the adjacent tunnel valleys leads us to assume that we identified the marginal position of an Elsterian ice lobe in the southeastern North Sea.</p><p>Reference:<br>Winsemann, J., Koopmann, H., Tanner, D.C., Lutz, R., Lang, J., Brandes, C., Gaedicke, C., 2020. Seismic interpretation and structural restoration of the Heligoland glaciotectonic thrust-fault complex: Implications for multiple deformation during (pre-)Elsterian to Warthian ice advances into the southern North Sea Basin. Quat. Sci. Rev. 227, 1–15. https://doi.org/10.1016/j.quascirev.2019.106068</p>

3-D high‐resolution reflection seismic imaging of unconsolidated glacial and glaciolacustrine sediments: processing and interpretation

Geophysics ◽  
2000 ◽  
Vol 65 (1) ◽  
pp. 18-34 ◽  
Author(s):  
Frank Büker ◽  
Alan G. Green ◽  
Heinrich Horstmeyer
Keyword(s):  
High Resolution ◽  
Cross Sections ◽  
Guided Waves ◽  
Three Dimensional ◽  
High Amplitude ◽  
Seismic Facies ◽  
Small Scale ◽  
Shallow Subsurface ◽  
Reflection Seismic ◽  
Reflecting Boundaries

Shallow 3-D seismic reflection techniques have been used to map glacial deposits in a Swiss mountain valley. A dense distribution of source and receiver positions resulted in a small subsurface sampling of 1.5 m × 1.5 m and a high fold of >40. Common processing operations that included pseudotrue amplitude scaling, deconvolution, and band‐pass filtering successfully enhanced shallow reflections relative to source‐generated noise. Careful top muting helped avoid erroneous stacking of direct and guided waves. Azimuth‐dependent velocity analyses proved to be unnecessary. Three‐dimensional (3-D) migration of the stacked data yielded the final high‐resolution images of the shallow subsurface (15–170 m). Because most reflections and diffractions were migrated to their correct subsurface locations, confident interpretations of 3-D structures were possible. Time slices and cross‐sections along arbitrary directions proved to be powerful analysis tools. Even small‐scale features (<20 m wide), such as subglacial channels and troughs, could be mapped. Five major lithologic units separated by four principal reflecting boundaries were distinguished on the basis of their characteristic seismic facies. The principal reflecting boundaries were semiautomatically tracked through the 3-D data volume. Borehole information allowed the uppermost boundary at 15–27 m to be identified as the top of a 68–80-m-thick sequence of basal and reworked tills characterized by high‐amplitude discontinuous to quasi‐continuous reflections. Low reflectivity of seismic units above and below the till units was associated with finely layered or massive glaciolacustrine clay/silt deposited during and after two principal phases of glaciation (Würm at 28 000 to 10 000 and Riss at 200 000 to 100 000 years before the present). Top of Tertiary Molasse basement was delineated by prominent east‐dipping reflections at variable depths of 85–170 m.

An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 486-487
Author(s):  
Mihir Parikh
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Sections ◽  
Resolving Power ◽  
Peak Intensity ◽  
Molecular Film ◽  
Resolution Electron ◽  
Dissociation Cross Section ◽  
High Resolution Electron Microscope ◽  
The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

Comparison of ultra high resolution immersion lens CFESEM and TEM for imaging of semiconductor devices

1990 ◽  
Vol 48 (4) ◽  
pp. 622-623
Author(s):  
Terrence Reilly ◽  
Al Pelillo ◽  
Barbara Miner
Keyword(s):  
High Resolution ◽  
Sample Preparation ◽  
Cross Sections ◽  
Semiconductor Devices ◽  
Ion Milling ◽  
Observation Area ◽  
Transmission Electron ◽  
Milling Machines ◽  
Resolution Imaging ◽  
Electron Microscopes

The use of transmission electron microscopes (TEM) has proven to be very valuable in the observation of semiconductor devices. The need for high resolution imaging becomes more important as the devices become smaller and more complex. However, the sample preparation for TEM observation of semiconductor devices have generally proven to be complex and time consuming. The use of ion milling machines usually require a certain degree of expertise and allow a very limited viewing area. Recently, the use of an ultra high resolution "immersion lens" cold cathode field emission scanning electron microscope (CFESEM) has proven to be very useful in the observation of semiconductor devices. Particularly at low accelerating voltages where compositional contrast is increased. The Hitachi S-900 has provided comparable resolution to a 300kV TEM on semiconductor cross sections. Using the CFESEM to supplement work currently being done with high voltage TEMs provides many advantages: sample preparation time is greatly reduced and the observation area has also been increased to 7mm. The larger viewing area provides the operator a much greater area to search for a particular feature of interest. More samples can be imaged on the CFESEM, leaving the TEM for analyses requiring diffraction work and/or detecting the nature of the crystallinity.

FIB Enhancement of Mechanically Polished Cross-sections

2019 ◽  
Author(s):  
Becky Holdford
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Cross Sections ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Resolution Imaging ◽  
Chemical Attack ◽  
Resolution Imaging ◽  
Scanning Electron

Abstract On mechanically polished cross-sections, getting a surface adequate for high-resolution imaging is sometimes beyond the analyst’s ability, due to material smearing, chipping, polishing media chemical attack, etc.. A method has been developed to enable the focused ion beam (FIB) to re-face the section block and achieve a surface that can be imaged at high resolution in the scanning electron microscope (SEM).

Cross Section Analysis of Cu Filled TSVs Based on High Throughput Plasma-FIB Milling

2012 ◽  
Author(s):  
Frank Altmann ◽  
Jens Beyersdorfer ◽  
Jan Schischka ◽  
Michael Krause ◽  
German Franz ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Section ◽  
High Throughput ◽  
Cross Sections ◽  
Electron Backscatter Diffraction ◽  
Grain Structure ◽  
Electron Backscatter ◽  
Section Surface ◽  
Backscatter Diffraction ◽  
Section Analysis

Abstract In this paper the new Vion™ Plasma-FIB system, developed by FEI, is evaluated for cross sectioning of Cu filled Through Silicon Via (TSV) interconnects. The aim of the study presented in this paper is to evaluate and optimise different Plasma-FIB (P-FIB) milling strategies in terms of performance and cross section surface quality. The sufficient preservation of microstructures within cross sections is crucial for subsequent Electron Backscatter Diffraction (EBSD) grain structure analyses and a high resolution interface characterisation by TEM.

scholarly journals LEvEL: Low-Energy Neutrino Experiment at the LHC

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Kevin J. Kelly ◽  
Pedro A. N. Machado ◽  
Alberto Marchionni ◽  
Yuber F. Perez-Gonzalez
Keyword(s):  
Cross Sections ◽  
Hadron Collider ◽  
Neutrino Flux ◽  
Coherent Scattering ◽  
Forward Direction ◽  
Low Energy ◽  
Neutrino Experiment ◽  
Beam Dump ◽  
Neutrino Production ◽  
Energy Neutrino

Abstract We propose the operation of LEvEL, the Low-Energy Neutrino Experiment at the LHC, a neutrino detector near the Large Hadron Collider Beam Dump. Such a detector is capable of exploring an intense, low-energy neutrino flux and can measure neutrino cross sections that have previously never been observed. These cross sections can inform other future neutrino experiments, such as those aiming to observe neutrinos from supernovae, allowing such measurements to accomplish their fundamental physics goals. We perform detailed simulations to determine neutrino production at the LHC beam dump, as well as neutron and muon backgrounds. Measurements at a few to ten percent precision of neutrino-argon charged current and neutrino-nucleus coherent scattering cross sections are attainable with 100 ton-year and 1 ton-year exposures at LEvEL, respectively, concurrent with the operation of the High Luminosity LHC. We also estimate signal and backgrounds for an experiment exploiting the forward direction of the LHC beam dump, which could measure neutrinos above 100 GeV.

scholarly journals High-resolution 2D Raman mapping of mono- and bicomponent filament cross-sections

Polymer ◽  
2021 ◽  
pp. 124011 ◽  
Author(s):  
E. Perret ◽  
O. Braun ◽  
K. Sharma ◽  
S. Tritsch ◽  
R. Muff ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Sections ◽  
Raman Mapping

scholarly journals Photoionization Cross-Sections of Carbon-Like N+ Near the K-Edge (390–440 eV)

Atoms ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 27
Author(s):  
Jean-Paul Mosnier ◽  
Eugene T. Kennedy ◽  
Jean-Marc Bizau ◽  
Denis Cubaynes ◽  
Ségolène Guilbaud ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Section ◽  
Cross Sections ◽  
Experimental Studies ◽  
Photoionization Cross Section ◽  
Theoretical Work ◽  
Rydberg Series ◽  
R Matrix ◽  
Resonance Strengths ◽  
Nitrogen Ion

High-resolution K-shell photoionization cross-sections for the C-like atomic nitrogen ion (N+) are reported in the 398 eV (31.15 Å) to 450 eV (27.55 Å) energy (wavelength) range. The results were obtained from absolute ion-yield measurements using the SOLEIL synchrotron radiation facility for spectral bandpasses of 65 meV or 250 meV. In the photon energy region 398–403 eV, 1s⟶2p autoionizing resonance states dominated the cross section spectrum. Analyses of the experimental profiles yielded resonance strengths and Auger widths. In the 415–440 eV photon region 1s⟶(1s2s22p2 4P)np and 1s⟶(1s2s22p2 2P)np resonances forming well-developed Rydberg series up n=7 and n=8 , respectively, were identified in both the single and double ionization spectra. Theoretical photoionization cross-section calculations, performed using the R-matrix plus pseudo-states (RMPS) method and the multiconfiguration Dirac-Fock (MCDF) approach were bench marked against these high-resolution experimental results. Comparison of the state-of-the-art theoretical work with the experimental studies allowed the identification of new resonance features. Resonance strengths, energies and Auger widths (where available) are compared quantitatively with the theoretical values. Contributions from excited metastable states of the N+ ions were carefully considered throughout.

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