Potential collapse of the upper slope and tsunami generation on the Great Barrier Reef margin, north-eastern Australia     

Ángel Puga-Bernabéu  Jody M. Webster  Robin J. Beaman 《Natural Hazards》2013,66(2):557-575

Analysis of high-resolution multibeam bathymetry and seismic profiles in the Noggin Passage region, north-eastern Australia, has identified a small area (Noggin block) in the upper-slope offshore Cairns that may potentially collapse and generate a tsunami wave. The Noggin block extends from 340 to 470 m depth covering a roughly circular (2.4 km long and 3.7 km wide) area of about 5.3 km². The well-defined margins of the block correspond to different bounding seabed features. These features include steep headscarps, small landslides and a group of aligned circular pockforms up to 500 m wide and 20 m deep. Slope stability simulations indicate that the Noggin block is stable under normal present-day gravitational conditions on the upper slope. However, block failure may result under external loads, such as those produced by earthquakes. Failure modelling shows that critical peak horizontal accelerations of 0.2–0.4 g could lead to the collapse of the Noggin block. In north-eastern Australia, these acceleration values would involve earthquakes generated at short hypocentral distances and short periods. The collapse of the potential sediment slide mass of about 0.86 km³ (162 m average thickness) may lead to the formation of a landslide-generated tsunami wave. Semi-empirical equations indicate the collapse of this mass would yield a 7–11-m high three-dimensional tsunami wave. These waves could reach an estimated run-up height at the coast of 5–7 m. Our first-order approach highlights the potential consequences for nearby coastal communities, the need for better sediment characterisation in the study area, and the systematic identification of other areas prone to slope failures along the Great Barrier Reef margin.  相似文献   

Combined U/Pb and (U–Th)/He geochronometry of basalt maars in Western Carpathians: implications for age of intraplate volcanism and origin of zircon metasomatism     

Vratislav Hurai  Martin Danišík  Monika Huraiová  Jean-Louis Paquette  Alexander Ádám 《Contributions to Mineralogy and Petrology》2013,166(4):1235-1251

The age of intraplate volcanism in northern Pannonian Basin of Carpathians is revisited using a combination of zircon U/Pb, zircon (U–Th)/He and apatite (U–Th)/He dating techniques, complemented by electron microprobe (EMP) characterisation of dated minerals. A total of six maar structures and diatremes in the South-Slovakian Volcanic Field (SSVF) were dated and the obtained new ages yielded the following key findings: Two isolated maars in SE part indirectly dated by geomorphologic constraints to Late Pleistocene are actually of Pliocene (2.8 ± 0.2 Ma) and Late Miocene (5.5 ± 0.6 Ma) ages. In contrast, two maars in NW part of the study area are of Late Pliocene age (4.1 ± 0.4 and 5.2–5.4 Ma), younger than the Late Miocene age (~6.5 Ma) inferred previously from K/Ar data on the proximal basaltic lava flows. These maars therefore belong to the second volcanic phase that was previously identified only in SE part of the SSVF. In the light of the new geochronologic data, it seems likely that the Pliocene phreatomagmatic eruptions may have occurred along extension-related, NW- and NE-trending orthogonal faults. EMP analyses and imaging revealed an extensive syn- and post-growth metasomatic replacement by dissolution-reprecipitation in the majority of zircons. Abundant silicate melt inclusions in porous metasomatised parts of the zircons are diagnostic of magmatic rather than hydrothermal metasomatism. Consistent ages of the metasomatised and non-metasomatised zones do not indicate disturbance of the U–Pb system during the metasomatism. Enrichment in U and Th loss in the metasomatised zircons are diagnostic of an increasing oxygen fugacity triggered by degassing of the volatile residual melt during the final stages of alkali basalt fractionation. Rare zircon-to-baddeleyite transformation was probably connected with lowered silica activity in carbonated basaltic magmas in south-eastern part of the study area.  相似文献   

Filter design for GOCE gravity gradients     

Zs. Polgár  L. Sujbert  P. Asbóth  J. Ádám 《国际地球制图》2013,28(1):28-36

The GOCE satellite observes gravity gradients with unprecedented accuracy and resolution. The GOCE observations are reliable within a well-defined measurement bandwidth. In this study, different finite and infinite impulse response filters have been designed to obtain the demanded pass. Exhaustive time and frequency domain investigations prove that the proposed infinite impulse response filter can be a real competitor of the existing solution of the filtering problem.  相似文献   

Feasibility of Solid‐State Fermentation Using Spent Fungi‐Substrate in the Biodegradation of PAHs     

Emilio Rosales  Marta Pazos  M. Ángeles Sanromán 《洁净——土壤、空气、水》2013,41(6):610-615

The ability of Trametes versicolor and Pleurotus ostreatus to grow on agroindustrial wastes, such as orange peels, and to degrade model polycyclic aromatic hydrocarbons (PAHs) in solid‐state fermentation (SSF) was evaluated. Best results in laccase production were obtained with T. versicolor cultures (3000 U L^?1), however, P. ostreatus (2700 U L^?1) showed higher ability to degrade the tested PAHs phenanthrene (PHE) and pyrene (PYR). Moreover, orange peels can be used as biofertilizer and the oxidative ability of the spent fungus and substrate obtained in SSF can be used in the remediation of polluted soil. The results obtained confirm this hypothesis. Thus, the decontamination achieved in soils polluted with PYR was around 43% (after 30 days) by addition of spent fungus and substrate from SSF.  相似文献   

On the Asynchronous Rotation of Accretors in Interacting Binaries     

Augustin Skopal  Richard KomžÍk  MÁria CsatÁryová 《Astrophysics and Space Science》2005,296(1-4):427-430

We show that the gaining component in interacting binaries can rotate faster than its orbital revolution as a consequence of the accretion process. We derive an approximative analytical formula for the Roche lobe radius of asynchronously rotating accretors. We present the case of the semi-detached interacting binary TX UMa, for which we measured directly asynchronous rotation of its accretor. We suggest a method to detect indirectly a fast spinning of accretors in symbiotic binaries based on the the X-ray luminosity of the boundary layer. We demonstrate this possibility for the case of EG And.  相似文献   

Computation of X-Ray Blazar Light Curves Using RHD Simulations     

Petar Mimica  Miguel-Ángel Aloy  Ewald Müller  Wolfgang Brinkmann 《Astrophysics and Space Science》2004,293(1-2):165-172

We present the results of a two-dimensional relativistic hydrodynamic simulation of collisions of dense shells of matter moving within a uniform jet. The non-thermal synchrotron radiation produced by the relativistic electrons injected at shocks is computed following their temporal and spatial evolution. We test different parameterizations of the shock acceleration process and compute the corresponding X-ray light curves. A time lag between hard and soft X-ray radiation is found. The collision has an efficiency of few times 10^?3 in converting kinetic energy into radiation.  相似文献   

JOINT LIGHTCURVE OBSERVATIONS OF 10 NEAR-EARTH ASTEROIDS FROM MODRA AND ONDŘEJOV     

A. GALÁD  P. PRAVEC  P. KUŠNIRÁK  Š. GAJDOŠ  L. KORNOŠ  J. VILÁGI 《Earth, Moon, and Planets》2005,97(1-2):147-163

The effort in photometry of near-Earth asteroids (NEAs) at Modra Observatory has been enhanced following a recent collaboration with Ondřejov Observatory. We present a part of our collaborative work on measuring rotation lightcurve data for 10 NEAs. We derived following synodic periods P and amplitudes of their composite lightcurves: (3553), 3.1944 h, 0.08 mag; (22753), 10.24 h, 0.11 mag; (31669), 5.807 h, 0.07–0.27 mag; (40267), 4.9568 h, 1.01–1.11 mag; (66146), 2.3774 h, 0.12–0.15 mag; (88188), 2.6906 h, 0.06 mag; (103067), 9.489 h, 0.49 mag; 2001 CB₂₁, 3.302 h, 0.19 mag; 2004 LJ₁, 2.7247 h, 0.17–0.59 mag; 2004 XO₁₄, 8.417 h, 0.19–0.25 mag. While the derived periods are unique (the reliability code U=3) for most of the objects, those of (3553), (22753) and 2001 CB₂₁ are somewhat less reliable (U=2). We checked all the U=3 data for deviations from strict periodicity, but found no significant attenuation that would indicate the presence of a satellite. Absolute magnitudes in Cousins R band (H _R ) were derived for (3553), 16.05; (40267), 15.59; (88188), 16.04; 2004 XO₁₄, 15.84; errors of the first three H _R estimates are 0.20 mag, but that of 2004 XO₁₄ is <0.10 mag.  相似文献   

Effects of climate change on wind energy production in Iran     

Roshan  Gholamreza  Najafei  Mohammad Saeed  Costa  Ángel M.  Orosa  José A. 《Arabian Journal of Geosciences》2015,8(4):2359-2370

Arabian Journal of Geosciences - This study explores the effect of future climate change on wind energy conversion in Iran, based on data from existing wind farms. In an effort to estimate and...  相似文献   

The gamma-ray blazar quest: new optical spectra,state of art and future perspectives     

F. Massaro  N. Álvarez Crespo  R. D’Abrusco  M. Landoni  N. Masetti  F. Ricci  D. Milisavljevic  A. Paggi  V. Chavushyan  E. Jiménez-Bailón  V. Patiño-Álvarez  J. Strader  L. Chomiuk  F. La Franca  Howard A. Smith  G. Tosti 《Astrophysics and Space Science》2016,361(10):337

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Mesoscale eddy variability in the Caribbean Sea     

López-Álzate  Margarita E.  Sayol  Juan-Manuel  Hernández-Carrasco  Ismael  Osorio  Andrés F.  Mason  Evan  Orfila  Alejandro 《Ocean Dynamics》2022,72(9-10):679-693

Ocean Dynamics - The spatial distribution, and the monthly and seasonal variability of mesoscale eddy observations derived from the AVISO eddy atlas are assessed in the Caribbean Sea during...  相似文献