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First, we investigated some aspects of tsunami–tide interactions based on idealized numerical experiments. Theoretically, by changing total ocean depth, tidal elevations influence the speed and magnitude of tsunami waves in shallow regions with dominating tidal signals. We tested this assumption by employing a simple 1-D model that describes propagation of tidal waves in a channel with gradually increasing depth and the interaction of the tidal waves with tsunamis generated at the channel's open boundary. Important conclusions from these studies are that computed elevations by simulating the tsunami and the tide together differ significantly from linear superposing of the sea surface heights obtained when simulating the tide and the tsunami separately, and that maximum tsunami–tide interaction depends on tidal amplitude and phase. The major cause of this tsunami–tide interaction is tidally induced ocean depth that changes the conditions of tsunami propagation, amplification, and dissipation. Interactions occur by means of momentum advection, bottom friction, and variable water flux due to changing total depth and velocity. We found the major cause of tsunami–tide interactions to be changing depth. Secondly, we investigate tsunami–tide interactions in Cook Inlet, Alaska, employing a high-resolution 2-D numerical model. Cook Inlet has high tides and a history of strong tsunamis and is a potential candidate for tsunami impacts in the future. In agreement with previous findings, we find that the impacts of tsunamis depend on basin bathymetries and coastline configurations, and they can, in particular, depend on tsunami–tide interactions. In regions with strong tides and tsunamis, these interactions can result in either intensification or damping of cumulative tsunami and tide impacts, depending on mean basin depth, which is regulated by tides. Thus, it is not possible to predict the effect of tsunami–tide interaction in regions with strong tides without making preliminary investigations of the area. One approach to reduce uncertainties in tsunami impact in regions with high tides is to simulate tsunamis together with tidal forcing. 相似文献
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The influence of industrial immissions on the magnetic susceptibility of soils in upper Silesia 总被引：4，自引：0，他引：4
Zygmunt Strzyszcz Tadeusz Magiera Friedrich Heller 《Studia Geophysica et Geodaetica》1996,40(3):276-286
Summary Samples of metallurgical dusts and fly ashes from coal power plants and iron works in Upper Silesia as well as soil profiles
in the close vicinity of these plants and in Ojcow National Park (ca. 25 km east of the industrial area) have been studied
magnetically and mineralogically. The metallurgical dusts and fly ashes are highly enriched in ferromagnetic minerals. The
topsoils from profiles collected near the plants have very high values of magnetic susceptibility while susceptibility in
the fermentation and humic subhorizons in soil profiles from Ojcow National Park is considerably increased. The magnetic properties
of the metallurgical dusts and fly ashes such as frequency dependence of susceptibility, saturation remanence or coercivity
are similar to those observed in the top horizons of the soils. They are mostly related to the occurrence of large (multidomain)
grains of non-stoichiometric magnetite ranging from 1 to 20 μm. The similarity of the magnetic particles in the soils is taken
as evidence of an anthropogenic origin. They are responsible for the high soil susceptibilities in Upper Silesia and in adjacent
areas. Some of the magnetic particles carry substantial quantitities of trace elements such as Pb, Ni, Zn and Cu. Field and
laboratory susceptibility measurements can therefore be used as a simple and costeffective method of detecting the presence
of heavy metals in the soils of this area. 相似文献
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Zygmunt Kowalik William Knight Tom Logan Paul Whitmore 《Pure and Applied Geophysics》2007,164(2-3):379-393
A numerical model for the global tsunamis computation constructed by Kowalik et al. (2005), is applied to the tsunami of 26 December, 2004 in the World Ocean from 80°S to 69°N with spatial resolution of one
minute. Because the computational domain includes close to 200 million grid points, a parallel version of the code was developed
and run on a Cray X1 supercomputer. An energy flux function is used to investigate energy transfer from the tsunami source
to the Atlantic and Pacific Oceans. Although the first energy input into the Pacific Ocean was the primary (direct) wave,
reflections from the Sri Lankan and eastern shores of Maldives were a larger source. The tsunami traveled from Indonesia,
around New Zealand, and into the Pacific Ocean by various routes. The direct path through the deep ocean to North America
carried miniscule energy, while the stronger signal traveled a considerably longer distance via South Pacific ridges as these
bathymetric features amplified the energy flux vectors. Travel times for these amplified energy fluxes are much longer than
the arrival of the first wave. These large fluxes are organized in the wave-like form when propagating between Australia and
Antarctica. The sources for the larger fluxes are multiple reflections from the Seychelles, Maldives and a slower direct signal
from the Bay of Bengal. The energy flux into the Atlantic Ocean shows a different pattern since the energy is pumped into
this domain through the directional properties of the source function. The energy flow into the Pacific Ocean is approximately
75% of the total flow to the Atlantic Ocean. In many locations along the Pacific and Atlantic coasts, the first arriving signal,
or forerunner, has lower amplitude than the main signal which often is much delayed. Understanding this temporal distribution
is important for an application to tsunami warning and prediction. 相似文献
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Study of litter influence on magnetic susceptibility measurements of urban forest topsoils using the MS2D sensor 总被引：1，自引：1，他引：0
Jarosław Zawadzki Piotr Fabijańczyk Tadeusz Magiera Zygmunt Strzyszcz 《Environmental Earth Sciences》2010,61(2):223-230
Field magnetometry is fast and convenient method used to detect areas contaminated by technogenic magnetic particles and potentially
polluted with heavy metals. Frequently, measurements of soil magnetic susceptibility (κ) are carried out with MS2D Bartington
sensor, which penetration range equals 10 cm, although 90% of the total signal is detected from a depth of up to 6 cm. Thick
uppermost organic soil layers may significantly influence on the measured κ because the penetration range may be not large
enough to cover the layers where the most of anthropogenic contaminants are cumulated. The aim of the study was to investigate
on how the removal of the litter improves the MS2D measurements of soil pollution. Accordingly, the correlations between κ
values measured on the successively removed overlying soil sub-horizons were investigated. Measurements were performed at
15 sites located in different forest in the Upper Silesian Industrial Area, Poland. The results showed that the litter removal
enabled the MS2D to measure the κ more related to the anthropogenic pollution, and did not affect the measuring variance. 相似文献
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Zygmunt Meyer 《Acta Geophysica》2009,57(3):743-759
In this paper, a modified tachoida is applied to the estimation of sediment transport in a river. Eddy viscosity coefficient
at the bottom which satisfied hydrodynamics stability of the flow is related to the sediment concentration. On this basis
it was possible to determine the sediment stream in the river based on the bottom sediment composition. 相似文献