Comparison between three-dimensional linear and nonlinear tsunami generation models

The modeling of tsunami generation is an essential phase in understanding tsunamis. For tsunamis generated by underwater earthquakes, it involves the modeling of the sea bottom motion as well as the resulting motion of the water above it. A comparison between various models for three-dimensional water motion, ranging from linear theory to fully nonlinear theory, is performed. It is found that for most events the linear theory is sufficient. However, in some cases, more sophisticated theories are needed. Moreover, it is shown that the passive approach in which the seafloor deformation is simply translated to the ocean surface is not always equivalent to the active approach in which the bottom motion is taken into account, even if the deformation is supposed to be instantaneous.Comment: 39 pages, 16 figures; Accepted to Theoretical and Computational Fluid Dynamics. Several references have been adde

Water waves generated by a moving bottom

Tsunamis are often generated by a moving sea bottom. This paper deals with the case where the tsunami source is an earthquake. The linearized water-wave equations are solved analytically for various sea bottom motions. Numerical results based on the analytical solutions are shown for the free-surface profiles, the horizontal and vertical velocities as well as the bottom pressure.Comment: 41 pages, 13 figures. Accepted for publication in a book: "Tsunami and Nonlinear Waves", Kundu, Anjan (Editor), Springer 2007, Approx. 325 p., 170 illus., Hardcover, ISBN: 978-3-540-71255-8, available: May 200

Ventilatory lung function in workers in the tobacco industry

U cilju odgovora na pitanje u kojoj su meri profesionalne nokse registrovane u duvanskoj industriji mogle uticati na stanje ventilacije pluća eksponiranih radnika sprovedena su ispitivanja u radnoj sredini i na radnicima. U radnoj sredini je izvršena analiza tehnološkog procesa rada, rezultata mikroklimatskih merenja, hemijskih štetnosti i zaprašenosti. Ispitivanje ventilacije pluća sprovedeno je na 95 radnika eksponirane grupe i 129 radnika kontrolne grupe. Rezultati analize radne sredine ukazuju na prisustvo duvanske prašine iznad maksimalno dopuštenih koncentracija. lspitivanja ventilacije pluća eksponiranih radnika su pokazala statistički značajno sniženje vrednosti nekih primenjenih testova kod nepušača ove grupe u odnosu na nepušače kontrolne grupe, što objašnjavamo delovanjem navedenih noksi na radnom mestu.A study was carried out to determine respiratory hazards to workers in tobacco manufacture. The investigations at the workplace included analysis of the work technology and measurements of chemical pollutants and dust concentrations in the work rooms. Ventilatory lung function tests were performed in 95 workers exposed to tobacco dust and in 129 control workers. Results of workplace analysis showed the presence of tobacco dust levels exceeding the maximum permissible concentrations. The values of some lung function tests for exposed workers non-smokers were significantly lower than for control workers non-smokers. They could be attributed to the effect of occupational noxae on the respiratory system

Finite Fault Analysis and Near Field Dynamic Strains and Rotations due to the 11/05/2011 (Mw5.2) Lorca Earthquake, South-Eastern Spain

The 11/5/2011 Lorca, Spain earthquake (Mw5.2) and related seismicity produced extensive damage in the town of Lorca and vicinity. During these earthquakes, evidence of rotations and permanent deformations in structures were observed. To analyze these aspects and study the source properties from the near field, the displacement time histories were obtained including the static component at Lorca station. Displacement time histories were computed by an appropriate double time integration procedure of accelerograms. Using these data, the foreshock and mainshock slip distributions were calculated by means of a complete waveform kinematic inversion. To study the dynamic deformations, the 3D tensor of displacement gradients at Lorca station was first estimated by a single station method. Using the finite fault inversion results and by means of a first order finite difference approach, the dynamic deformations tensor at surface was calculated at the recording site. In order to estimate the distribution of the peak dynamic deformations, the calculation was extended to the close neighboring area of the town. The possible influence of the near-field deformations on the surface structures was analyzed.Comment: 29 pages, 8 figure

Recording and interpreting earthquake response of fullscale structures

Earthquake resistant design (or retrofit) of structures requires realistic and accurate physical and theoretical models. Validation and further improvement of these models can be done only by comparison with full-scale, in situ measurements of the response to earthquake excitation. This paper presents (a) a review of the principles this validation process is based on, (b) discussion of selected examples of past contributions to modeling of structures, and (c) an outline of some of the current research needs. It is concluded that, in the education of future engineers, the art of modeling full-scale structures, and breadth of knowledge in classical mechanics have been neglected, and that this trend should be reversed. 1