Seismic model and geological interpretation of the basement beneath the Doupovské Hory Volcanic Complex (NW Czech Republic)

The Doupovské Hory Volcanic Complex (DHVC) is the best-preserved large volcanic suite of the Cenozoic intraplate volcanism in the Bohemian Massif. However, many uncertainties remain in the geological setting of its basement. In summer 2008, two seismic refraction profiles ran across this area to reveal the depth of the volcanic rocks and the underlying geological structure.     

Tracing metamorphism,exhumation and topographic evolution in orogenic belts by multiple thermochronology: a case study from the Nízke Tatry Mts., Western Carpathians

A combination of four thermochronometers [zircon fission track (ZFT), zircon (U–Th)/He (ZHe), apatite fission track (AFT) and apatite (U–Th–[Sm])/He (AHe) dating methods] applied to a valley to ridge transect is used to resolve the issues of metamorphic, exhumation and topographic evolution of the Nízke Tatry Mts. in the Western Carpathians. The ZFT ages of 132.1 ± 8.3, 155.1 ± 12.9, 146.8 ± 8.6 and 144.9 ± 11.0 Ma show that Variscan crystalline basement of the Nízke Tatry Mts. was heated to temperatures >210°C during the Mesozoic and experienced a low-grade Alpine metamorphic overprint. ZHe and AFT ages, clustering at ~55–40 and ~45–40 Ma, respectively, revealed a rapid Eocene cooling event, documenting erosional and/or tectonic exhumation related to the collapse of the Carpathian orogenic wedge. This is the first evidence that exhumation of crystalline cores in the Western Carpathians took place in the Eocene and not in the Cretaceous as traditionally believed. Bimodal AFT length distributions, Early Miocene AHe ages and thermal modelling results suggest that the samples were heated to temperatures of ~55–90°C during Oligocene–Miocene times. This thermal event may be related either to the Oligocene/Miocene sedimentary burial, or Miocene magmatic activity and increased heat flow. This finding supports the concept of thermal instability of the Carpathian crystalline bodies during the post-Eocene period.     

Spatio-temporal regression kriging model of mean daily temperature for Croatia

High resolution gridded mean daily temperature datasets are valuable for research and applications in agronomy, meteorology, hydrology, ecology, and many other disciplines depending on weather or climate. The gridded datasets and the models used for their estimation are being constantly improved as there is always a need for more accurate datasets as well as for datasets with a higher spatial and temporal resolution. We developed a spatio-temporal regression kriging model for Croatia at 1 km spatial resolution by adapting the spatio-temporal regression kriging model developed for global land areas. A geometrical temperature trend, digital elevation model, and topographic wetness index were used as covariates together with measurements from the Croatian national meteorological network for the year 2008. This model performed better than the global model and previously developed models for Croatia, based on MODIS land surface temperature images. The R2 was 97.8% and RMSE was 1.2 °C for leave-one-out and 5-fold cross-validation. The proposed national model still has a high level of uncertainty at higher altitudes leaving it suitable for agricultural areas that are dominant in lower and medium altitudes.     

Galactic gradients, postbiological evolution and the apparent failure of SETI

Motivated by recent developments impacting our view of Fermi’s Paradox (the absence of extraterrestrials and their manifestations from our past light cone), we suggest a reassessment of the problem itself, as well as of strategies employed by the various SETI projects so far. The need for such reassessment is fueled not only by the failure of SETI thus far, but also by great advances recently made in astrophysics, astrobiology, computer science and future studies. As a result, we consider the effects of the observed metallicity and temperature gradients in the Milky Way galaxy on the spatial distribution of hypothetical advanced extraterrestrial intelligent communities. While properties of such communities and their sociological and technological preferences are, obviously, unknown at present, we assume that (1) they operate in agreement with the known laws of physics and (2) at some point in their history they typically become motivated by a meta-principle embodying the central role of information-processing; a prototype of the latter is the recently suggested Intelligence Principle of Steven J. Dick. There are specific conclusions of practical interest to astrobiological and SETI endeavors to be drawn from the coupling of these reasonable assumptions with the astrophysical and astrochemical structure of the spiral disk of our galaxy. In particular, we suggest that the outer regions of the Galactic disk are the most likely locations for advanced SETI targets, and that sophisticated intelligent communities will tend to migrate outward through the Galaxy as their capacities of information-processing increase, for both thermodynamical and astrochemical reasons. However, the outward movement is limited by the decrease in matter density in the outer Milky Way. This can also be regarded as a possible generalization of the galactic habitable zone (GHZ), concept currently being investigated in astrobiology.     

SCR Distribution Function in the Radial IMF Approximation

The transport of cosmic rays in the interplanetary medium is considered in terms of the kinetic equation describing the energetic particle scattering by magnetic irregularities and their focusing by the regular interplanetary magnetic field. The analytical expression for solar cosmic ray distribution function in the approximation of radial regular magnetic field is obtained and the evolution of energetic particle angular distribution is analyzed. The obtained results can be used for the analysis of ground-level enhancements of cosmic ray intensity.     

Tracking an upper limit of the “Carnian Crisis” and/or Carnian stage in the Western Carpathians (Slovakia)

International Journal of Earth Sciences - The Late Triassic timescale, especially the Carnian–Norian boundary, is poorly constrained mainly due to a paucity of high-precision radio-isotopic...     

Reconstruction of missing data in remote sensing images using conditional stochastic optimization with global geometric constraints

This paper addresses the issue of missing data reconstruction for partially sampled, two-dimensional, rectangular grid images of differentiable random fields. We introduce a stochastic gradient–curvature (GC) reconstruction method, which is based on the concept of a random field model defined by means of local interactions (constraints). The GC reconstruction method aims to match the gradient and curvature constraints for the entire grid with those of the sample using conditional Monte Carlo simulations that honor the sample values. The GC reconstruction method does not assume a parametric form for the underlying probability distribution of the data. It is also computationally efficient and requires minimal user input, properties that make it suitable for automated processing of large data sets (e.g. remotely sensed images). The GC reconstruction performance is compared with established classification and interpolation methods for both synthetic and real world data. The impact of various factors such as domain size, degree of thinning, discretization, initialization, correlation properties, and noise on GC reconstruction performance are investigated by means of simulated random field realizations. An assessment of GC reconstruction performance on real data is conducted by removing randomly selected and contiguous groups of points from satellite rainfall data and an image of the lunar surface.     

Methodological Advances in the Spatial Analysis of Land Fragmentation

This article evaluates the effect of moving window (MW) size on observed fragmentation spatial patterns and proposes a method to identify an effective MW size using Simpson's diversity index. To test the robustness of the proposed method, we demonstrate its use in six cities in the Phoenix metropolitan area that have substantial variation in land composition and configuration. Next we explore the effects of gradient observation scale and the role of scale in removing noise. We compare and discuss two popular approaches to measuring urban-to-rural fragmentation gradients—concentric ring- and transect-based approaches—highlighting the usefulness of each approach in an extensive and rapidly urbanizing region. This study provides a new method for selecting window size, offers insights on scale effects, and provides guidance on gradient scale selection to achieve the best representation of land fragmentation patterns for urban analysis.