Anisotropic velocity models for (3D) seismic imaging ofthe Lower Seve Nappe in Jämtland, Sweden

Strong anisotropy of seismic velocity in the Earth’scrust poses serious challenges for seismic imaging. Where in situ seismic properties are not available the anisotropy can be determined from velocity analysis of surface and borehole seismic profiles. This is well established for dense, long-offset reflection seismic data. However, it is unknown how applicable this approach is for sparse seismic reflection data with low fold and short offsets in anisotropic metamorphic rocks. Here we show that anisotropy parameters can be determined from a sparse 3D data set at the COSC-1 borehole site in the Swedish Caledonides and that the results agree well with the seismic anisotropy parameters determined from seismic laboratory measurements on core samples. Applying these anisotropy parameters during 3D seismic imaging improves the seismic image of the high amplitude reflections especially in the vicinity of the lower part of the borehole. Strong reflections in the resulting seismic data show good correlation with the borehole-derived lithology. Our results aid the interpretation and extrapolation of the seismic stratigraphy of the Lower Seve Nappe in Jämtland and other parts in the Caledonides

Die Wirkungen von MINT-Vorkursen - ein systematischer Literaturreview

In den MINT-Fächern sind Vorkurse weit verbreitet. Umso erstaunlicher erscheint der Umstand, dass bisher wenige (Wirkungs-)Evaluationen der MINT-Vorkurse durchgeführt wurden und in der Konsequenz kaum Befunde zu dieser Intervention vorliegen. Um der Frage der kurz-, mittel- und langfristigen Wirkungen von MINT-Vorkursen auf studienrelevante Aspekte nachzugehen, wurde ein systematischer Literaturreview in 21 elektronischen Datenbanken durchgeführt. Die 29 einbezogenen Studien verweisen auf eher kurzfristige Wirkungen der MINT-Vorkurse auf fachlicher Ebene. Darüber hinaus lassen sich jedoch auch mittelfristige und nicht fachliche Effekte aufzeigen

Core-log-seismic integration in metamorphic rocks and its implication for the regional geology: A case study for the ICDP drilling project COSC-1, Sweden

Continental collision causes deformation in the crust along shear zones. However, the physical and chemical conditions at which these zones operate and the deformation processes that enable up to hundreds of km of tectonic transport are still unclear because of the depth at which they occur and the challenges in imaging them. Ancient exhumed collision zones allow us to investigate these processes much better, for example at the COSC‐1 borehole in the central Scandinavian Caledonides. This study combines data from the COSC‐1 borehole with different seismic measurements to provide constraints on the spatial lithological and textural configuration of the Seve Nappe Complex. This is one of the few studies that shows that core‐log‐seismic integration in metamorphic rocks allows to identify the spatial distribution of major lithological units. Especially gamma ray logs in combination with density data are powerful tools to distinguish between mafic and felsic lithologies in log‐core correlation. Our results indicate that reflections along the borehole are primarily caused by compositional rather than textural changes. Reflections in the Seve Nappe Complex are not as distinct as in greater depths but continuous and several of them can be linked to magmatic intrusions, which have been metamorphically overprinted. Their setting indicates that the Seve Nappe Complex consists of the remnants of a volcanic continental margin. Our results suggest that ductile‐deformed middle crustal reflectivity is primarily a function of pre‐orogenic lithological variations which has to be considered when deciphering mountain building processes

Single azopyridine-substituted porphyrin molecules for configurational and electronic switching

A new azopyridine functionalized Ni–porphyrin was synthesized as a model compound for deposition and switch on surfaces. Two geometrically and electronically different states of single molecules on Au(111) were found by scanning tunneling microscopy/ spectroscopy and analyzed with density functional calculations

Electronic and vibrational states of single tin-phthalocyanine molecules in double layers on Ag(111)

Electronic and vibrational properties of the two stable molecular configurations of Sn-phthalocyanine adsorbed on an ultrathin Sn-phthalocyanine buffer film on Ag(111) have been investigated with scanning tunneling microscopy and density functional calculations. Complex submolecular patterns are experimentally observed in unoccupied states images. The calculations show that they result from a superposition of Sn p orbitals. Furthermore, the characteristic features in spectra of the differential conductance are reproduced by the calculations together with a remarkable difference between the two configurations. First-principles calculations show that rather than a single vibrational mode and its higher harmonics the excitations of different molecular vibrational quanta induce replica of orbital spectroscopic signatures. The replicated orbital features appear for the configuration with a low molecule-surface coupling. To model spectra of molecules with a larger coupling to the surface it is sufficient to consider elastic tunneling to orbital resonances alone

Chronology of the Fram Slide Complex offshore NW Svalbard and its implications for local and regional slope stability

Highlights • The Fram Slide Complex has been active from late Miocene to late Pleistocene. • Local processes were critical for slope stability in the Fram Strait area. • Toe erosion caused by normal faulting may have led to retrogressive failure. • Low gradient contourite drifts might smooth and stabilize submarine slopes. • Low tsunami potential from the Fram Slide Complex could increase in the future. Abstract The best known submarine landslides on the glaciated NW European continental margins are those at the front of cross-shelf troughs, where the alternation of rapidly deposited glycogenic and hemi pelagic material generates sedimentary overpressure. Here, we investigate landslides in two areas built of contourite drifts bounded seaward by a ridge-transform junction. Seismic and bathymetric data from the Fram Slide Complex are compared with the tectonically similar Vastness area ~ 120 km to the south, to analyze the influence of local and regional processes on slope stability. These processes include tectonic activity, changes of climate and oceanography, gas hydrates and fluid migration systems, slope gradient, toe erosion and style of contourite deposition. Two areas within the Fram Slide Complex underwent different phases of slope failures, whereas there is no evidence at all for major slope failures in the Vastness area. The comparison cannot reveal the distinct reason for slope failure but demonstrates the strong impact of variation in the local controls on slope stability. The different failure chronologies suggest that toe erosion, which is dependent on the throw of normal faults, and the different thickness and geometry of contourite deposits can result in a critical slope morphology and exert pronounced effects on slope stability. These results highlight the limitations of regional hazard assessments and the need for multi-disciplinary investigations, as small differences in local controlling factors led to substantially different slope failure histories