Geoscience Reference
In-Depth Information
Fig. 3.21 Profile of wave formed by the non-linear mechanism in an incompressible ocean. The
calculation is performed for consecutive moments of time
t
= 2, 4, 6, 8, 10, 12 (curves 1-6) for
the case of
η
1
and
a
= 5,
τ
= 3
Fig. 3.22 Amplitude of long
wave versus the duration of
the source action. Curves 1-3
are calculated for the space
distribution of
1
for
a
= 5,
10 and 20, curves 4 and 5
for
η
2
and
b
= 2,
c
=3(4)
and
b
= 1,
c
= 9(5)
η
max
(the height of the hump) as a func-
tion of the duration of ocean bottom oscillations for different shapes of the space
distribution of the oscillation amplitude. The quantity
Figure 3.22 presents the wave amplitude
ξ
ξ
max
increases monotonously
with the duration of oscillations, but this increase is not without limit: the ampli-
tude cannot exceed a certain value, which is practically independent of the shape
of the space distribution of
η
i
(
x
). The horizontal extension of the oscillating area of
the ocean bottom noticeably affects the value of
, at which the maximum amplitude
is achieved: when the extension in space of the source is greater, the formation of
a wave of maximum amplitude will require prolonged action of the source.
The non-linear effect considered can be briefly presented as follows. When
oscillations of the basin bottom occur, the liquid is 'pushed out' of the region
of most intense movements (the source), which is precisely what causes the
τ
