Multi-Meteotsunami Event in the Adriatic Sea Generated by Atmospheric Disturbances of 25–26 June 2014     

Jadranka Šepić  Iva Međugorac  Ivica Janeković  Natalija Dunić  Ivica Vilibić 《Pure and Applied Geophysics》2016,173(12):4117-4138

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Climate induced changes of Lithuanian rivers runoff in 1960–2009     

E. Stonevičius  G. Valiuškevičius  E. Rimkus  J. Kažys 《Water Resources》2014,41(5):592-603

The primary objective of this study was the evaluation of runoff regime changes over the last 50 years in Lithuanian rivers. These changes were compared with the Neman river runoff regime changes in 1812–2009. On the basis of daily water discharge data, trends in the annual, maximum and minimum runoff characteristics as well as changes in the seasonal pattern of runoff were estimated. Regression analysis and the Mann-Kendall test were used to determine changes in the long-term hydrological regime. The magnitude of changes was estimated using Theil-Sen estimator. 1960–2009 runoff changes in Lithuanian rivers can be related to climatic changes. Sharp increases of January and February runoff during 1960–2009 were the largest changes throughout the observation period 1812–2009. The rate off runoff decrease in April was also among the largest decreases recorded. Spring flood and cold season minimum flow dates have become earlier than used to be.  相似文献   

Kamchatka subduction zone,May 2013: the Mw 8.3 deep earthquake,preceding shallow swarm and numerous deep aftershocks     

Aleš Špičák  Jiří Vaněk 《Studia Geophysica et Geodaetica》2014,58(1):76-83

A sequence of 98 teleseismically recorded earthquakes occurred off the east coast of Kamchatka at depths between 10-90 km around latitude 52.5°N and longitude 160°E on May 16–23, 2013. The swarm occurred along the northern limit of the rupture area of the 1952 M_w 9.0 great Kamchatka earthquake, the fifth largest earthquake in the history of seismic observations. On May 24, 2013 the strongest deep earthquake ever recorded of M_w 8.3 occurred beneath the Sea of Okhotsk at a depth of 610 km in the Pacific slab of the Kamchatka subduction zone, becoming the northernmost deep earthquake in the region. The deep M_w 8.3 earthquake occurred down-dip of the shallow swarm in a transition zone between the southern deep and northern shallow segments of the Pacific slab. Several deep aftershocks followed, covering a large, laterally elongated part of the slab. We suppose that the two described earthquake sequences, the May 16–23 shallow earthquake swarm and the May 24–28 deep mainshock-aftershock series, represent a single tectonic event in the Pacific slab having distinct properties at different depth levels. A low-angle underthrusting of the shallow part of the slab recorded by the shallow earthquake swarm activated the deep part; this process induced the deep mainshock-aftershock series only three days after the swarm. The domain of the subducting slab activated by the May 2013 earthquake occurrence was extraordinarily large both down-dip and along-strike.  相似文献   

Dynamic response analysis of solitary flexible rocking bodies: modeling and behavior under pulse‐like ground excitation          下载免费PDF全文

Michalis F. Vassiliou  Kevin R. Mackie  Božidar Stojadinović 《地震工程与结构动力学》2014,43(10):1463-1481

Results obtained for rigid structures suggest that rocking can be used as seismic response modification strategy. However, actual structures are not rigid: structural elements where rocking is expected to occur are often slender and flexible. Modeling of the rocking motion and impact of flexible bodies is a challenging task. A non‐linear elastic viscously damped zero‐length spring rocking model, directly usable in conventional finite element software, is presented in this paper. The flexible rocking body is modeled using a conventional beam‐column element with distributed masses. This model is verified by comparing its pulse excitation response to the corresponding analytical solution and validated by overturning analysis of rocking blocks subjected to a recorded ground motion excitation. The rigid rocking block model provides a good approximation of the seismic response of solitary flexible columns designed to uplift when excited by pulse‐like ground motions. Guidance for development of rocking column models in ordinary finite element software is provided. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Motion of dust in mean motion resonances with planets     

Pavol Pástor  Jozef Klačka  Ladislav Kómar 《Celestial Mechanics and Dynamical Astronomy》2009,103(4):343-364

Effect of stellar electromagnetic radiation on the motion of spherical dust particle in mean motion orbital resonances with a planet is investigated. Planar circular restricted three-body problem with the Poynting–Robertson (P–R) effect yields monotonic secular evolution of eccentricity when the particle is trapped in the resonance. Planar elliptic restricted three-body problem with the P–R effect enables nonmonotonous secular evolution of eccentricity and the evolution of eccentricity is qualitatively consistent with the published results for the complicated case of interaction of electromagnetic radiation with nonspherical dust grain. Thus, it is sufficient to allow either nonzero eccentricity of the planet or nonsphericity of the grain and the orbital evolutions in the resonances are qualitatively equal for the two cases. This holds both for exterior and interior mean motion orbital resonances. Evolutions of argument of perihelion in the planar circular and elliptical restricted three-body problems are shown. Numerical integrations show that an analytic expression for the secular time derivative of the particle’s argument of perihelion does not exist, if only dependence on semimajor axis, eccentricity and argument of perihelion is admitted. Connection between the shift of perihelion and oscillations in secular eccentricity is presented for the planar elliptic restricted three-body problem with the P–R effect. Period of the oscillations corresponds to the period of one revolution of perihelion. Change of optical properties of the spherical grain with the heliocentric distance is also considered. The change of the optical properties: (i) does not have any significant influence on the secular evolution of eccentricity, (ii) causes that the shift of perihelion is mainly in the same direction/orientation as the particle motion around the Sun. The statements hold both for circular and noncircular planetary orbits.  相似文献   

Photographic observations of fireballs in Tajikistan     

P. B. Babadzhanov  G. I. Kokhirova  J. Borovička  P. Spurny 《Solar System Research》2009,43(4):353-363

Since 2006, systematic double-station photographic observations of fireballs using all-sky cameras equipped with Zeiss Distagon “fisheye” objectives (f/3.5, f = 30 mm) with a 180° field of view have been carried out at two observatories, Gissar (GisAO) and Sanglokh (IAOS), of the Institute of Astrophysics of the Tajik Academy of Sciences. In the method of astrometric reduction of fireball photographs, the empirical formulae for converting the measured coordinates to horizontal celestial coordinates are used. These formulae contain 12 unknown constants to be determined by the least-squares method and the iteration method. Such an approach enables the determination of the coordinates of an object at any point of the celestial hemisphere with a precision close to the theoretical limit whose value is quite comparable with the measurement errors. In the photometric reduction, the dependence of the measured width of the diurnal star trails on their magnitudes was used. As a result of astrometric and photometric reduction of the double-station photographs of five fireballs, the data on atmospheric trajectories, the coordinates of radiants, orbits in interplanetary space, light curves, and photometric masses of meteoroids which produced fireballs were obtained, and the belonging of fireballs to the known meteor showers was determined as well.  相似文献   

Deficit and surplus of precipitation as a continuous function of time     

D. Radinović  M. Ćurić 《Theoretical and Applied Climatology》2009,98(1-2):197-200

The quantitative measure of drought is a complex problem. A common factor in all types of drought is that they originate from a deficiency of precipitation. The difference between the real and potentially expected daily precipitation amount is what we have used to define the continuous function of daily deficit and surplus of precipitation (DSP). We have also defined the monthly and yearly DSP. We tested the precipitation data series for the normal climatic period 1961–1990 observed at the Meteorological Observatory of Belgrade. The DSP considers that the intensity of drought during the current period is dependent upon the current precipitation plus the cumulative precipitation of the previous period. When applied to longer periods, this function denotes dry and wet periods.  相似文献   

The variability of European floods since AD 1500     

Rüdiger Glaser  Dirk Riemann  Johannes Schönbein  Mariano Barriendos  Rudolf Brázdil  Chiara Bertolin  Dario Camuffo  Mathias Deutsch  Petr Dobrovolný  Aryan van Engelen  Silvia Enzi  Monika Halíčková  Sebastian J. Koenig  Oldřich Kotyza  Danuta Limanówka  Jarmila Macková  Mirca Sghedoni  Brice Martin  Iso Himmelsbach 《Climatic change》2010,101(1-2):235-256

The paper presents a qualitative and quantitative analysis of flood variability and forcing of major European rivers since AD 1500. We compile and investigate flood reconstructions which are based on documentary evidence for twelve Central European rivers and for eight Mediterranean rivers. Flood variability and underlying climatological causes are reconstructed by using hermeneutic approaches including critical source analysis and by applying a semi-quantitative classification scheme. The paper describes the driving climatic causes, seasonality and variability of observed flood events within the different river catchments covering the European mainland. Historical flood data are presented and recent research in the field of historical flood reconstructions is highlighted. Additionally, the character of the different flood series is discussed. A comparison of the historical flood seasonality in relation to modern distribution is given and aspects of the spatial coherence are presented. The comparative analysis points to the fact that the number of flood events is predominately triggered by regional climatic forcing, with at most only minor influence on neighbouring catchments. The only exceptions are extreme, supra-regional climatic events and conditions such as anomalous cold winters, similar to that of 1784, which affected large parts of Europe and triggered flood events in several catchments as a result of ice-break at the beginning of the annual thaw. Four periods of increased occurrence of flooding, mostly affecting Central European Rivers, have been identified; 1540–1600, 1640–1700, 1730–1790, 1790–1840. The reconstruction, compilation and analysis of European-wide flood data over the last five centuries reveal the complexity of the underlying climatological causes and the high variability of flood events in temporal and spatial dimension.  相似文献   

A cross-border regional earthquake early warning system: PRESTo@CE<Superscript>3</Superscript>RN     

Damiano Pesaresi  Matteo Picozzi  Mladen Živčić  Wolfgang Lenhardt  Marco Mucciarelli  Luca Elia  Aldo Zollo  Andrej Gosar 《Natural Hazards》2017,86(2):431-440

Since 2002 the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Udine (Italy), the Agencija Republike Slovenije za Okolje (ARSO) in Ljubljana (Slovenia) and the Zentralanstalt für Meteorologie und Geodynamik (ZAMG) in Vienna (Austria), are collecting, analyzing, archiving and exchanging seismic data in real time, initially in the framework of the EU Interreg IIIa Italia-Austria project “Trans-national seismological networks in the South-Eastern Alps”. As outcome of the successful cooperation, in the 2013 OGS, ARSO and ZAMG decided to officially merge their seismic monitoring efforts into the “Central and Eastern European Earthquake Research Network—CE³RN”. This work reports the results of a nine-month real-time test of the earthquake early warning (EEW) algorithm probabilistic and evolutionary early warning system carried out at the CE³RN. The study allowed identifying the actions to be implemented in order to let the CE³RN become in the next future an efficient cross-border EEW system.  相似文献   

Absolute Sea Level Surface Modeling for the Mediterranean from Satellite Altimeter and Tide Gauge Measurements     

Marijan Grgić  Robert Steven Nerem  Tomislav Bašić 《Marine Geodesy》2017,40(4):239-258

Changes in the height of the ocean can be described through the relative and absolute sea level changes depending on the geodetic reference the sea level records are related to. Satellite altimetry provides absolute sea level (ASL) measurements related to the global geodetic reference, whereas tide gauges provide relative sea level (RSL) measurements related to the adjacent land. This study aims at computing the ASL surfaces for different time epochs from combined satellite altimeter and tide gauge records. A method of sea level data fusion is proposed to enable modeling of the impact of present and future sea level changes on the coast. Sea surface modeling was investigated for ten different gridding methods commonly used for the interpolation of altimeter data over the open ocean and extrapolation over the coastal zones. The performance of gridding methods was assessed based on the comparison of the gridded altimeter data and corrected tide gauge measurements. Finally, the sea level surfaces related to the GRS80 global reference ellipsoid were computed for the Mediterranean Sea over the altimeter period. In addition, the current sea level trends were estimated from both sea level measurements.  相似文献