Geoscience Reference
In-Depth Information
.
.
(a)
.
.
.
.
(b)
.
.
Fig. 2.13 Maximum amplitude of first crest (a) and first trough (b) of wave, excited by membrane-
like displacement of seabed, versus displacement duration for various distances from the generation
area. Curves 1-3 correspond to values of parameter
a
/
H
= 1
,
3
,
9. The broken line represents
linear theory of long waves (
a
/
H
1)
a membrane-like displacement the corresponding dependence is not monotonous:
as the duration of the displacement increases, the energy starts to increase and, then,
drops. The maximum corresponds to
τ
∗
= 4.
As to the wave periods and lengths, these quantities increase monotonously with
the displacement duration, in accordance with formulae (2.82) and (2.83). Actually,
τ
∗
1, therefore both the period and length of a tsunami wave mostly depend on
the horizontal dimension of the area of seabed deformation.
