Integrated Reservoir Management for the Long Term-The Carpinteria Offshore Field     

E. M. Whitney  R. P. Kendall  M. R. Brickey  S. E. Coombs  C. A. Duda  V. K. Duda 《Marine Georesources & Geotechnology》2013,31(2-3):103-116

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Magnification of undamped seismographs and the analysis of the 1906 San Francisco earthquake record obtained on the Vicentini seismograph in Zagreb (Croatia)     

Marijan Herak  Ivo Allegretti  Seweryn J. Duda 《地学学报》1996,8(3):286-292

A method to estimate the dynamic magnification of nonlinear seismographs is presented. The method was tested by applying it to the record of the 1906 San Francisco earthquake seismogram obtained on the Vicentini seismograph in Zagreb, in order to reconstruct the ground motion amplitudes. The magnitudes inferred from the corrected Vicentini recording of P- and surface waves are internally consistent ( m _b= 7.74, M _s= 8.48) and agree with the values published in various catalogues, within the error limits of magnitude determination for individual events. The corrected P-waveform is compatible with a rupture slip profile exhibiting several distinct maxima along the 300 km-long section of the San Andreas fault, in accordance with recent studies and contemporary geodetic measurements.  相似文献   

Verification and refinement of spectral magnitude calibrating functions for P-waves     

E. L. Lyskova  Yu. V. Roslov  T. B. Yanovskaya  S. J. Duda 《Journal of Seismology》1998,2(2):117-124

Calibrating functions for determination of P-wave spectral magnitudes calculated by Duda and Yanovskaya (1994) on the basis of the IASP91 velocity model and the PREM Q-model are verified empirically. For this purpose IRIS broadband records for 120 earthquakes are used, each earthquake having been recorded at about 100 stations. The discrepancies indicate that anelastic absorption assumed in PREM is too high. New calibrating functions are calculated on the basis of the AK135 velocity and anelasticity models (Kennet et al., 1995; Montagner and Kennet, 1996), in which Q in the mantle is higher than in PREM. The verification of the new calibrating functions based on the same observations yields magnitude figures less depending on the epicentral distance. In addition the parameter ₂in the Liu-Anderson Q(T) model is estimated, proceeding from the assumption that on the average the radiated spectra comply with the ²-model. The value of ₂ was assumed to be 0.1 s in the analysis and its use resulted in the verification of the ²-model for the source spectrum.  相似文献   

The amplitude spectra of P- and S-waves and the body-wave magnitude of earthquakes     

R Nortmann  S.J Duda 《Tectonophysics》1982,84(1):17-32

Synthetic calibration functions for body-wave magnitudes are presented. They have been obtained from computations made under the assumption that the variation of amplitude spectra along the earth's surface is due to radial velocity heterogeneity and radial changes of the dissipation factor Q inside the earth only. The new calibration functions depend on the epicentral distance and the focal depth of the earthquake, as well as on the period of the body-wave under consideration.No single calibration function exists which would produce magnitude figures identical for all Fourier components of a body-wave. Observations on several hundreds of strong earthquakes in recent years show that the P-wave magnitudes vary systematically with the period of the wave. With the application of the synthetic calibration function a general increase of the teleseismically determined P-wave magnitudes with frequency is observed. This fact reconciles acceleration response spectra from narrowband strong-motion analyzers in the near-field of an earthquake and spectral magnitudes determined from far-field observations by sensitive narrow-band seismographs. The strength of high-frequent spectral components generally exceeds the strength of low-frequent components determined in both cases.  相似文献   

Effects of antifouling biocides to the germination and growth of the marine macroalga, Hormosira banksii (Turner) Desicaine     

Myers JH  Gunthorpe L  Allinson G  Duda S 《Marine pollution bulletin》2006,52(9):1048-1055

The International Maritime Organisation's (IMO) ban on the use of tributyltin in antifouling paints has inevitability increased the use of old fashioned antifoulants and/or the development of new paints containing 'booster biocides'. These newer paints are intended to be environmentally less harmful, however the broader environmental effects of these 'booster biocides' are poorly known. Germination and growth inhibition tests using the marine macroalga, Hormosira banksii (Turner) Desicaine were conducted to evaluate the toxicity of four new antifouling biocides in relation to tributyltin-oxide (TBTO). Each of the biocides significantly inhibited germination and growth of Hormosira banksii spores. Toxicity was in increasing order: diuron < zineb < seanine 211< zinc pyrithione < TBTO. However, the lack of knowledge on partitioning in the environment makes it difficult to make a full assessment on whether the four biocides tested offer an advantage over organotin paints in terms of environmental impact.  相似文献   

Frequency analysis of the 2004 Sumatra-Andaman earthquake using spectral seismograms     

Monika Wilde-Piórko  Seweryn J. Duda  Marek Grad 《Acta Geophysica》2011,59(3):483-501

Frequency analysis of the Sumatra-Andaman earthquake of 2004, one of the most significant and best-recorded earthquakes, is based on spectral seismograms obtained from their broadband seismograms. The Sumatra-Andaman earthquake is found to have a wide-range frequency content of P-wave radiation during the rupturing process. On the basis of stacking spectral seismograms we distinguished four time events of the rupturing process of a total length of about 540 s. The frequency, f _max, is the highest for the first event (0.163 Hz in time interval 0–88 s), lowest for the second — which is the strongest (0.075 Hz in time interval 88–204 s). For third and fourth events frequencies are similar (0.089 and 0.082 Hz in time intervals 204–452 and 452–537 s, respectively). The frequency also shows an azimuthal dependence (±0.02 Hz). Azimuths for which the frequency, f _max, has maximum and minimum values are 203–222° and 23–42°, respectively. These observations are discussed in relation to previously published papers on this topic.  相似文献   

Palaeomagnetism of some late Mesozoic dolerite dykes of South Spitsbergen     

S. A. Vincenz  D. Cossack  S. J. Duda †  K. Birkenmajer  M. Jele&#;ska  M. K&#;dzia&#;ko-Hofmokl  J. Kruczyk 《Geophysical Journal International》1981,67(3):599-614

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The Stress around a Fault according to a Photoelastic Model Experiment     

Seweryn J. Duda 《Geophysical Journal International》1965,9(4):399-410

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PROSPECTOR—A computer-based consultation system for mineral exploration     

P. E. Hart  R. O. Duda  M. T. Einaudi 《Mathematical Geosciences》1978,10(5):589-610

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Earthquake magnitude scales     

Seweryn J. Duda  Otto W. Nuttli 《Surveys in Geophysics》1974,1(4):429-458

The earthquake magnitude was introduced into seismology nearly 40 yr ago, as a purely empirical concept. After an unparalleled success in scientific and practical applications the magnitude is developing into a concept with a clearer physical meaning and a more solid theoretical foundation. The magnitude determined from the maximum particle amplitude or velocity reflects the maximum radiation power of the seismic source in the frequency band recorded on a particular seismograph. Recently developed models for seismic sources assist in classifying earthquakes according to size and spectral character. From corresponding scaling laws the relations between various magnitude scales can be established. The magnitude aims at enabling one to compare the sizes of seismic sources ranging in character from nearly aseismic events to explosions. While the former are characterized by a relatively long-peroidic radiation maximum, the latter radiate primarily short-periodic seismic energy. Tectonic earthquakes are likely to range in character between the two extreme spectral cases. A comparison of earthquake magnitude with stellar magnitude leads to analogies in spectral character between earthquakes and stars, whereby seismic sources seem to follow a distribution similar to the Hertzsprung-Russell diagram for stars. Before seismological practice can catch up with the new cognitions, improvements in the definition of the earthquake magnitude are in need.  相似文献