4. Conclusions
In this study, the process of tsunami generation and propagation was investigated over a realistic tsunami source model in the form of a
curvilinear stochastic slump and slide model of two independent Gaussian white noise processes in the x- and y-directions. We
demonstrated the waveform amplification resulting from curvilinear stochastic source spreading in the x-direction and wave focusing in
the near-field under the effect of the various factors such as the noise intensities, propagated uplift length and the water depth. We
studied the effect of moving submarine block slide on the tsunami generation waveforms and the tsunami propagation waveform after the
block slide stops moving. Through our analysis, the following understandings and conclusions were obtained:
(1) Near the source, the tsunami waveforms has two large peaks of comparable amplitudes, one in the front of the block due to sliding of
the block forward, and the other one behind the block due to spreading of the depletion zone. The waves build up progressively as
time increases and the focusing and the amplification of tsunami amplitudes occur above the spreading edge of the stochastic
depletion and accumulation zones.
(2) As the normalized noise intensities increases, the peak amplitude of the waveforms increases, in addition to an increase in oscillations
of the free surface elevation due to the random deformation of slump and slide bottom during faulting.
(3) As the length and width in the random slump and slide source model increase, the amplitude of the tsunami wave increases as the
volume of the displaced water increases which depend on the characteristic size of the source region. This explains why the
amplification is larger for wider area of uplift source, than for small source area.
(4) As the water depth of the ocean increases, the amplitude of tsunami waveforms decreases. This phenomenon happens because the
change in the total energy of the tsunami remains constant which is proportional to the wave's velocity and height. The speed of the
tsunami is related to the water depth, so as the water depth increases, the speed increases and hence the height decreases and
vise verse.
(5) In case of moving block slide, the propagated leading waves were faster than in the case of stationary block slide. The motion of the
landslide allowed energy to be fed into the wave field above the landslide so that the trapped trough continued to grow with time as a
forced wave.
(6) The tsunami peak amplitude of the leading wave resulting from the variable movement of the submarine block slide is smaller than
the tsunami wave resulting from constant movement of the submarine block slide as a result of longer wavelength and faster speed.
(7) In the far field, as the tsunami wave further departed away from the source, the leading wave amplitudes decay, due to of geometric
spreading and dispersion.
(8) During the propagation process, increase in noise intensity leads to more oscillations in the propagated free surface elevation and a
slight difference in the peak amplitude of the leading propagated waveforms.