Geoscience Reference
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Fig. 2.28 Comparison of experimental and theoretical dependences of amplitudes of excited pro-
gressive wave versus frequency of bottom oscillations
The strikingly clear orientation of the Chilean tsunami of May 22, 1960, when
the amplitude of the wave travelling in a direction, perpendicular to the South
American coast, was several times larger than the amplitudes of waves prop-
agating in other directions, initiated the appearance of a series of publications
[Voit et al. (1980), (1981), (1982); Lebedev, Sebekin (1982)], in which the role was
estimated of a horizontal motion of the ocean bottom in forming an oriented tsunami
wave. In these works, the influence of a horizontal motion on the ocean was sim-
ulated by applying an effective mass force in the vicinity of the source, and, then,
the properties of waves at a large distance from the generation area were studied.
Thus, for example, it was established that a wave caused by a vertically directed
mass force exhibits axial symmetry at long distances from the source, in spite of
the perturbating force not being axially symmetric, while at the same time the wave
front of a tsunami caused by a transfer of horizontal momentum remains anisotropic.
Numerical models of tsunamis that gained well-known popularity as
powerful means for investigations [Chubarov et al. (1992); Kato, Tsuji (1995);
Satake (1995); Satake, Imamura (1995); Tanioka, Satake (1996); Titov (1999);
Myers, Baptista (1995); Suleimani et al. (2003); Zaitsev et al. (2005); Kowalik et
al. (2005); Titov et al. (2005); Horrillo et al. (2006); Rivera (2006); Gisler (2008)],
seem to have achieved a certain limit in their perfection, in the sense that for their
