Context.
Cosmic rays (CRs) propagating through dense molecular clouds (MCs) produce
γ
-rays, which carry direct information about the CR distribution throughout the Galaxy. Observations of
γ
-rays in ...different energy bands allow for the exploration of the average CR density in the Galactic disk, the so-called level of the “CR sea”. Observations with the
Fermi
-Large Area Telescope (LAT) demonstrated the method’s feasibility based on two dozen MCs in our Galaxy. However, the potential of
Fermi
-LAT is limited to the exploration of the most massive and relatively nearby MCs; thus, the current observations cover only a tiny fraction of the Milky Way.
Aims.
In this work, we aim to study the prospects of expanding the CR measurements to very and ultra-high energies and remote parts of the Galaxy with the current and next-generation detectors.
Methods.
Based on calculations of fluxes expected from MCs, we formulated the requirements to the sensitivity of the post-
Fermi
-LAT detectors in order to map GeV-TeV CRs in the Galactic disk. We also explored the potential of the current and future air-shower and atmospheric Cherenkov telescope arrays for the extension of CR studies to multi-TeV and PeV energy bands.
Results.
We demonstrated that the improvement of the
Fermi
-LAT sensitivity by a factor of a few would allow a dramatic increase in the number of detectable MCs, covering almost the entire Galaxy. The recently completed Large High altitude air Shower Observatory should be able to take the first CR probes at PeV energies in the coming five years or so.
The large‐magnitude faults that control crustal thinning and excision at rifted margins combine into laterally persistent structural boundaries that separate margin domains of contrasting morphology ...and structure. We term them breakaway complexes. At the Mid‐Norwegian margin, we identify five principal breakaway complexes that separate the proximal, necking, distal, and outer margin domains. Downdip and lateral interactions between the faults that constitute breakaway complexes became fundamental to the evolution of the 3‐D margin architecture. Different types of fault interaction are observed along and between these faults, but simple models for fault growth will not fully describe their evolution. These structures operate on the crustal scale, cut large thicknesses of heterogeneously layered lithosphere, and facilitate fundamental margin processes such as deformation coupling and exhumation. Variations in large‐magnitude fault geometry, erosional footwall incision, and subsequent differential subsidence along the main breakaway complexes likely record the variable efficiency of these processes.
Plain Language Summary
Faults that cut large parts of or the entire crust behave differently than the ones that only affect the brittle upper crust. Also, they are much more fundamental in the process of thinning continental crust, which eventually leads to the separation of continents. We now have access to seismic reflection data that are much better than before. Thus, for some margins we are now able to map the lateral extent and evolution of the very large, fundamental structures responsible for margin formation. We have mapped such structures offshore Norway and propose a mapping approach and a new classification of the structures that form rifted margins. Furthermore, the lateral and downdip behavior of these very large structures offers enticing insights into the processes that accompany faulting at this enormous scale. We propose that faults that do the same fundamental job on the margin link up in margin‐wide complexes that eventually separate domains of differing internal structure and morphology. Our approach aims to link margin deformation at different scales and will thus be useful for workers in academics and industry.
Key Points
Rift margin domains are separated by structural boundaries termed here breakaway complexes that form through the linkage of large‐magnitude normal faults with tens of kilometers displacement
Geometrical variations along the breakaway complexes reflect this interaction and the structural response to variations in crustal thickness, rheology, and inherited structure
The concepts outlined here link rift margin domains to individual faults and basins and, likely, to lateral variability in coupling efficiency and the efficiency of other margin‐forming processes
Observations of rift and rifted margin architecture suggest that significant spatial and temporal structural heterogeneity develops during the multiphase evolution of continental rifting. Inheritance ...is often invoked to explain this heterogeneity, such as preexisting anisotropies in rock composition, rheology, and deformation. Here, we use high‐resolution 3‐D thermal‐mechanical numerical models of continental extension to demonstrate that rift‐parallel heterogeneity may develop solely through fault network evolution during the transition from distributed to localized deformation. In our models, the initial phase of distributed normal faulting is seeded through randomized initial strength perturbations in an otherwise laterally homogeneous lithosphere extending at a constant rate. Continued extension localizes deformation onto lithosphere‐scale faults, which are laterally offset by tens of km and discontinuous along‐strike. These results demonstrate that rift‐ and margin‐parallel heterogeneity of large‐scale fault patterns may in‐part be a natural byproduct of fault network coalescence.
Key Points
Distributed normal fault networks develop from randomized initial strength perturbations
Rifted margin heterogeneity develops through fault network localization
Detachment fault systems typically record displacements in the order of 10s of kilometers. The principles that control the growth of smaller magnitude normal faults are not fully applicable to the ...evolution of detachment fault systems. We use interpretation of 2D and 3D seismic reflection data from the mid‐Norwegian rifted margin to investigate how the structural evolution of a detachment fault interacted with the effects of isostatic footwall rollback to produce complex 3D geometries and control the configuration of associated supradetachment basins. We further investigate the effects of lateral interaction and linkage of extensional detachment faults on the necking domain configuration. In our study area, the domain‐bounding Klakk Fault Complex demonstrates how successive incision may induce a complex structural relief in response to faulting and fault plane folding. We interpret the previously proposed metamorphic core complex within its footwall as an extension‐parallel turtleback‐structure. The now eroded turtleback is flanked by a major supradetachment basin, connecting two main basin segments. We attribute footwall‐ and turtleback exhumation to Middle Jurassic‐Early Cretaceous rifting. The study area further demonstrates how detachment fault geometries can change during rifting and lead to the formation of younger, successively incising fault splays. Lateral linkage between the original detachment fault plane and these fault splays enables displacement along a detachment fault system consisting of fault segments generated at different stages in time. Implicitly, detachment faults are complex 3D systems that change configuration during their evolution, perpetually controlling associated basin formation, footwall configuration, subsidence and uplift patterns.
Key Points
Central parts of the Frøya High in the necking domain of the mid‐Norwegian rifted margin represent an eroded turtleback structure
Evolution of increasingly sinusoidal detachment fault geometries may lead to successive incision, and complex lateral linkage
Increasingly sinusoidal detachment fault geometries control the spatio‐temporal distribution of depocenters throughout fault evolution
Aims. We investigate the nature of the accelerated particles responsible for the production of the gamma-ray emission observed from the middle-aged supernova remnant (SNR) HB 21. Methods. We present ...the analysis of more than nine years of Fermi LAT data from the SNR HB 21. We performed morphological and spectral analysis of the SNR by means of a three-dimensional binned likelihood analysis. To assess the intrinsic properties of the parent particle models, we fit the obtained gamma-ray spectral energy distribution of the SNR by both hadronic- and leptonic-induced gamma-ray spectrum. Results. We observe an extended emission positionally in agreement with the SNR HB 21. The bulk of this gamma-ray emission is detected from the remnant; photons up to ~10 GeV show clear evidence of curvature at the lower energies. The remnant is characterized by an extension of 0°.83, that is, 30% smaller than claimed in previous studies. The increased statistics allowed us also to resolve a point-like source at the edge of the remnant, in proximity to a molecular cloud of the Cyg OB7 complex. In the southern part of the remnant, a hint of an additional gamma-ray excess in correspondence to shocked molecular clouds is observed. Conclusions. The spectral energy distribution of the SNR shows evidence of a break around 400 MeV, which can be properly fitted within both the hadronic and leptonic scenario. The pion-decay mechanism reproduces well the gamma rays, postulating a proton spectrum with a slope ~2.5 and with a steepening around tens of GeV, which could be explained by the energy-dependent escape of particles from the remnant. In the leptonic scenario the electron spectrum within the SNR matches closely the locally measured spectrum. This remarkable and novel result shows that SNR HB 21 could be a direct contributor to the population of Galactic electrons. In the leptonic scenario, we find that the local electron spectrum with a break around 2 GeV, closely evokes the best-fitting parental spectrum within this SNR. If such a scenario is confirmed, this would indicate that the SNR might be a source of Galactic background electrons.
In this contribution we evaluated the effect of synthesis procedure (complexing molecule, calcination temperature) and doping on the properties and catalytic performance of SrTiO
3
. Focusing on ...preparation we compared two complexants: citric acid and glycine calcinating the catalysts at 700 and 850 °C. Moreover, we doped the perovskite substituting Sr with K and Ti with Mn. The obtained catalysts have been characterized by X-Ray diffraction, X-Ray photoelectron spectroscopy, BET, scanning electron microscopy, energy dispersive X-Ray analysis, temperature programmed reduction. To evaluate the effect of upon mentioned aspects on the catalytic activity, the following reactions have been considered: CO oxidation, CO assisted NO reduction, soot oxidation. The obtained results underline the deep effect of dopants, with particular reference to Mn, on the catalytic performance.
We re-evaluate the structure and spreading evolution of the southeastern Norway Basin (NB) based on a new high resolution aeromagnetic survey (NB-07). The survey covers a complete oceanic spreading ...segment from the continental–oceanic transition of the Møre margin, off Norway to the aborted Aegir Ridge. The new survey documents a transform margin, an orthogonally rifted segment and an oblique-sheared volcanic margin formed during the onset of breakup, observed from the East Jan Mayen Fracture Zone to the Faroe Platform. The detailed fabric of the NB revealed by the new data indicates that two distinct tectonic phases have reshaped the basin before the cessation of seafloor spreading and abortion of the Aegir Ridge in the Late Oligocene. After continental breakup, Phase I (from C24 to C21r, ∼52 to 49 Ma) marks the earliest phase of spreading, probably initiated in the central and outer part of the Møre Basin. During this period, competing oceanic segments led to the formation of overlapping systems and pseudo-fault development. We observe a significant change in the NB's oceanic spreading system in the late Early Eocene and, based on observations from surrounding areas, we suggest that this is a record of a major tectonic event in the Norwegian–Greenland Sea around C21r (49–47.9 Ma). During Phase II (from C21r to C10?, 48 to 28 Ma) of NB's development, spreading rates decreased, spreading direction changed, and the number of faulting with large displacement increased leading to the formation of unexpected N–S oriented oceanic fracture zones. The fan-shaped development of the spreading system initiated around C21r (∼49–47.9 Ma) instead of C18–C17 (∼40–38 Ma) or C24 (53.3–52.3 Ma) as previously proposed. These new observations were used to re-evaluate the tectonic evolution of the Norwegian–Greenland Sea and discuss some implications on the syn- and post-breakup development of the surrounding continental margins and the evolution of the Jan Mayen microcontinent.
► We re-evaluate the spreading evolution of the Norway Basin, Norway. ► A new high resolution aeromagnetic survey. ► A major event in the Norwegian–Greenland Sea around (49–47.9 Ma). ► Implications on the syn- and post-breakup development of the surrounding continental margins. ► Evolution of the Jan Mayen microcontinent updated.
Paracoccidioides brasiliensis and P. lutzii are fungi that cause paracoccidioidomycosis (PCM), the most prevalent systemic mycosis in South America. For serological diagnosis, although 43-kDa ...glycoprotein (gp43) is regarded as highly specific for PCM, the occurrence of false negative reactions in sera from patients infected with P. lutzii suggests that preparation with only one antigen is not recommended. Heat shock proteins are feasible alternatives as a second antigen because they are often highly immunogenic. In this study, we evaluated the usefulness of recombinant 60-kDa heat shock protein from P. brasiliensis (rPbHsp60) for the serological diagnosis of PCM. Using western blotting assay, we observed that 77.3% of the sera from PCM patients were positive to rPbHsp60, with 90.9% positivity to recombinant gp43 (rgp43). More importantly, sera from healthy subjects had 27% positivity to rPbHsp60 and none to rgp43. When rPbHsp60 was used in ELISA, we did not observe significant differences between the reactions with sera from PCM patients and healthy subjects, while the difference was clearly evident when the antigen was rgp43. Furthermore, rPbHsp60 was recognized by sera from patients with histoplasmosis, aspergillosis, sporotrichosis or tuberculosis in an ELISA test. These results show that rPbHsp60 is not a good antigen for PCM diagnosis.
Most rifts and rifted margins around the world developed on former orogens. This implies that the pre-rift lithospheric configuration is heterogeneous in most cases. Here we investigate how collision ...inheritance in the form of inherited weak thrusts, long-term thermal weakening, compositional changes, and orogenic collapse, could have played into the spatio-temporal evolution and final architecture of rifted margins. We present interpretations of dynamic numerical experiments, including constraints representative of the North Atlantic Mid-Norwegian rift system phases of continental collision, orogenic collapse, and extension, and compare these to interpretations of seismic reflection profiles.
The experiments form rifted margins characterized by basement structures and sedimentary geometries very similar to the Møre and Vøring rifted margins - with onshore collapse-related basins, extensively deformed continental crust with detachments, shear zones, core complexes, rotated thrusts and an offshore succession of distinct structural domains (proximal, necking, hyperextension, exhumation, and outer).
Although extensional models developed on homogeneous lithosphere are a good approximation of rifted margin architecture, our results suggest that models that consider pre-rift orogenic inheritance tend to reproduce more accurately the geometries observed in our natural example.
•We examine how orogenic inheritance plays into the architecture of rifted margins.•We present numerical experiments of lithospheric extension including inheritance.•The Norwegian margins are reproduced with unprecedented correct geometrical details.
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