Basic research

TOMAŠOVÝCH, Adam - GALIMETZER, Ivo - HASELMAIR, Alexandra - KAUFMAN, D. S. - VIDOVIĆ, Jelena - ZUSCHIN, Martin. Stratigraphic unmixing reveals repeated hypoxia events over the past 500 yr in the northern Adriatic Sea. In Geology, 2017, vol. 45, no. 4, p. 363-366. (4.635 - IF2016). (2017 - Current Contents). ISSN 0091-7613.

TOMAŠOVÝCH, Adam - KIDWELL, Susan M. Nineteenth-century collapse of a benthic marine ecosystem on the open continental shelf. In Proceedings of  the Royal Society : B - Biological Sciences, 2017, vol. 284, no. 1856. (4.940 - IF2016). (2017 - Current Contents). ISSN 0962-8452.

TOMAŠOVÝCH, Adam - JABLONSKI, David. Decoupling of latitudinal gradients in species and genus geographic range size: a signature of clade range expansion. In Global Ecology and Biogeography, 2017, vol. 26, no. 3, p. 288-303. (6.045 - IF2016). (2017 - Current Contents). ISSN 1466-822X.

Climatic and ecological history of marine environments archived in sediment cores can be traced on the basis of stratigraphic analyses. However, such analyses are compromised by bioturbational mixing. Bioturbation frequently mixes dead shells of different age into the same stratigraphic increments. On the basis of extensive radiometric dating of molluscan and brachiopod shells, we have developed methods that allowed us to unmix the effects of bioturbation on stratigraphic distributions of dead shells. We have applied these methods to marine ecosystems in the northern Adriatic Sea and on the southern California shelf. We have found that outbreaks of hypoxia-tolerant bivalves represent long-term phenomena in the northern Adriatic Sea rather than novel states characteristic of the 20th century eutrophication. These outbreaks positively correlate with fluctuations in sea-surface temperature, suggesting that the hypoxia events were coupled with water-column stratification. We have also found that benthic ecosystems dominated by epifaunal suspension-feeders on the southern California shelf effectively collapsed at the end of the 19th century, and were replaced by deposit- and detritus-feeding infaunal benthic species.

KRISTEK, Jozef - MOCZO, Peter - CHALJUB, Emmanuel - KRISTEKOVÁ, Miriam. An orthorhombic representation of a heterogeneous medium for the finite-difference modelling of seismic wave propagation. In Geophysical Journal International, 2017, vol. 208, issue 2, p. 1250-1264. (2.414 - IF2016). (2017 - Current Contents). ISSN 0956-540X.

The possibility of applying one explicit finite-difference scheme to all interior grid points (points not lying on a grid border) no matter what their positions are with respect to the material interface is one of the key factors of the computational efficiency of the finite-difference modelling. Smooth or discontinuous heterogeneity of the medium is accounted for only by values of the effective grid moduli and densities. Accuracy of modelling thus very much depends on how these effective grid parameters are evaluated. We have developed a new orthorhombic representation of a heterogeneous medium for the finite-difference modelling. We numerically demonstrate its superior accuracy. Compared to the harmonic-averaging representation the orthorhombic representation is more accurate mainly in the case of strong surface waves that are especially important in local surface sedimentary basins. The orthorhombic representation is applicable to modelling seismic wave propagation and earthquake motion in isotropic models with material interfaces and smooth heterogeneities using velocity-stress, displacement-stress and displacement FD schemes on staggered, partly-staggered, Lebedev and collocated grids.

KOPÁČEK, Jiří - KAŇA, Jiří - BIČÁROVÁ, Svetlana - FERNANDEZ, Ivan J. - HEJZLAR, Josef - KAHOUNOVÁ, Marie - NORTON, Stephen A. - STUCHLÍK, E. Climate change increasing calcium and magnesium leaching from granitic Alpine catchments. In Environmental Science and Technology, 2017, vol. 51, no. 1, p. 159-166. (6.198 - IF2016). (2017 - Current Contents). ISSN 0013-936X.

Climate change can increase calcium and magnesium [Ca+Mg] leaching from granitic alpines catchment in the High Tatra Mts. In these catchments, reverse trend of the average [Ca+Mg] concentration over the period of recovery from acidification was found. It is in contrary with unchanged trends of strong acid anions concentration (SAAs), pH and acid neutralising capacity (ANC) since the early 1990s. It is assumed that increasing [Ca+Mg] leaching is associated with elevated terrestrial export of [Ca+Mg] resulted from extensive weathering and accelerated physical erosion of rocks due to climate-related mechanical forces. This assumption is supported by the fact that frequency of days with high precipitation amounts and air temperatures around 0 °C increased during the last 2−3 decades.

Applied research

HURAI, Vratislav - PAQUETTE, Jean-Louis - HURAIOVÁ, Monika - SLOBODNÍK, Marek - HVOŽĎARA, Pavel - SIEGFRIED, Peter - GAJDOŠOVÁ, Michaela - MILOVSKÁ, Stanislava. New insights into the origin of the Evate apatite-iron oxide-carbonate deposit, Northeastern Mozambique, constrained by mineralogy, textures, thermochronometry, and fluid inclusions. In Ore Geology Reviews, 2017, vol. 80, p. 1072-1091. (3.095 - IF2016). (2017 - Current Contents). ISSN 0169-1368.

Ložisko Evate v Mozambiku je najväčšia akumulácia apatitu v juhovýchodnej Afrike viazaná na magnetitové horizonty v karbonátoch. Genéza ložiska nie je jednoznačná. Náš výskum preukázal, že magnetitovo-apatitové rudy sa sformovali v intervale 590-450 mil. rokov. Vysokoteplotné štádium (> 800 °C) reprezentované zirkónom, baddeleyitom a molybdenitom časovo koreluje s intrúziami mafických a alkalických hornín, ktoré intrudovali do metamorfovaného komplexu v termálnom vrchole granulitovej metamorfózy. Hydrotermálne štádium reprezentované sulfidmi, anhydritom, monazitom a zeolitmi vzniklo zo sulfátových roztokov medzi kambriom a ordovikom pri teplotách <300 °C.

KARCOL, Roland - PAŠTEKA, Roman. Density function evaluation from borehole gravity meter data – regularized spectral domain deconvolution approach. In Geophysical Prospecting, 2017, vol. 65, no. 1., p.365-378. (1.846 - IF2016). (2017 - Current Contents). ISSN 0016-8025.

Comparison of solution from MacQueen and Mann (2007) (grey line) and regularized solution (black line)

Vyvinuli sme novú metódu transformácie gravimetrických dát z vrtov na hodnoty hustôt vo vertikálnom profile vrtu na základe regularizovanej spektrálnej dekonvolúcie hustotných funkcií. Táto metóda predstavuje novú alternatívu ku klasickému prístupu.

ZAHOREC, Pavol - MARUŠIAK, Ivan - MIKUŠKA, Ján - PAŠTEKA, Roman - PAPČO, Juraj. Numerical calculation of terrain correction within the bourguer anomaly evaluation (Program Toposl). Chapter 5. In PAŠTEKA, Roman - MIKUŠKA, Ján - MEURERS, Bruno. Understanding the bouguer anomaly. A gravimetry puzzle. - Amsterdam : Elsevier Science Publishing, 2017, p. 79-92. ISBN 978-012-812913-5.

ZAHOREC, Pavol - PAŠTEKA, Roman - MIKUŠKA, Ján - SZALAIOVÁ, Viktória - PAPČO, Juraj - KUŠNIRÁK, Dávid - PÁNISOVÁ, Jaroslava - KRAJŇÁK, Martin - VAJDA, Peter - BIELIK, Miroslav - MARUŠIAK, Ivan. National gravimetric database of the Slovak Republic. Chapter 7. In PAŠTEKA, Roman - MIKUŠKA, Ján - MEURERS, Bruno. Understanding the bouguer anomaly. A gravimetry puzzle. - Amsterdam : Elsevier Science Publishing, 2017, p. 113-125. ISBN 978-012-812913-5.

The current Bouguer anomaly map of Slovakia is compiled from approx. 320 000 observation points collected during more than 50 years which represent a very heterogeneous dataset. Quality control process and complete recalculation of the Bouguer anomalies is presented in Chapter 7 of the monograph. Primary focus was on a proper recalculation of the terrain corrections. The new software Toposk was developed for this purpose (Chapter 5). The most important attribute of the new software is the correct calculation for arbitrary point location with regard to the real Earth surface. The use of the program is worldwide, not limited to the territory of Slovakia.

Research related to international collaboration

FASSMER, Kathrin - KLONOWSKA, I. - WALCZAK, Katarzyna - ANDERSSON, B. - FROITZHEIM, Nikolaus - MAJKA, Jarosław - FONSECA, Raúl O. C. - MÜNKER, Carsten - JANÁK, Marian - WHITEHOUSE, Martin. Middle Ordovician subduction of continental crust in the Scandinavian Caledonides: an example from Tjeliken, Seve Nappe Complex, Sweden. In Contributions to Mineralogy and Petrology, 2017, vol. 172, no. 11-12, article Number 103. (2.913 - IF2016). (2017 - Current Contents). ISSN 0010-7999.

KLONOWSKA, I. - JANÁK, Marian - MAJKA, Jarosław - PETRÍK, Igor - FROITZHEIM, Nikolaus - GEE, David G. - SASINKOVÁ, Vlasta. Microdiamond on Åreskutan confirms regional UHP metamorphism in the Seve Nappe Complex of the Scandinavian Caledonides. In Journal of Metamorphic Geology, 2017, vol. 35, no. 5, p. 541-564. (3.594 - IF2016). (2017 - Current Contents). ISSN 0263-4929.

New finds of diamond in the Scandinavian Caledonides, in metasedimentary crustal rocks of the Seve Nappe Complex in Sweden (Jämtland, Vesterbotten) were reported. Diamond was identified by Raman spectroscopy. Occurence of diamond is evidence of ultrahigh-pressure (4.2 GPa, 150 km) metamorphism due to deep subduction of  Baltica continent in Ordovician (ca. 460-450 Ma) time. Timing of UHPM was recorded by Th-U-Pb dating of monazite (Klonowska et al. 2017), Lu-Hf dating of garnet and U-Pb dating of zircon (Fassmer et al. 2017). Possible geodynamic setting was collision  of Baltica with an Island arc during closure of the Iapetus ocean.

NEJEDLÍK, Pavol - DALEZIOS, Nicolas R. Hazards information management and services. In Environmental hazards methodologiest for risk assesment and management. - London : Iwa Publishing, 2017, p. 504-528. ISBN 1780407122, 9781780407128.

JORGENSEN, A. - HEILIG, Balázs - VELLANTE, Massimo - LICHTENBERGER, János - REDA, Jan - VALACH, Fridrich - MANDIC, Igor. Comparing the dynamic global core plasma model with ground-based plasma mass density observations. In Journal of Geophysical Research : Space Physics, 2017, vol. 122, no. 8, p. 7997-8013. (2.733 - IF2016). (2017 - Current Contents, WOS, SCOPUS). ISSN 2169-9380.

The DGCPM is a dynamical model of the flux-tube content in the plasmasphere which is widely used in space physics. The comparison of this model with the results of the observations of the plasma mass density made by means of the field-line resonance technique yielded relatively large disagreement. On the basis of data from the European quasi-meridional magnetometer array (EMMA), three of the parameters of the DGCPM were changed: characteristic time for depletion of the flux-tube, maximum flux from the ionosphere to the flux-tube, and saturation value of the plasma density. The functional form of the equations in the DGCPM as well as the other parameters of the model were preserved. For changing the parameters, only the data observed at the McIlwain L-value equal at 3.24 were used. Nonetheless, it turned out that the modified model well agrees also with the observations at other L-values.