Geoscience Reference
In-Depth Information
(mm)
(
8
C)
(m
2
s
−2
)
(m
2
s
−2
)
(m
2
s
−2
)
(m)
(m)
(m)
Fig. 7.9 Range of parameters
β
0
τ
and
L
, for which turbulence energy pumping during a time
τ
(the values are indicated in the figure) results in (1) an increase (+), a decrease (-) of the maximum
temperature gradient by a quantity, exceeding 10% of the initial value; (2) a change of the surface
temperature and (3) a change of the centre-of-mass position. The figures at the isolines indicate
the change in the surface temperature in degrees Celsius and in the centre-of-mass position in
millimeters. Calculations are carried out for
h
1
= 45 m and
H
= 100 m
(7.8), it is not difficult to demonstrate that a change in the centre-of-mass position
by 1 mm approximately corresponds to an energy of 1 kJ m
−
2
.
As to changes in the surface temperature, they are primarily determined by
the depth of the thermocline: the closer the cold layers are to the surface, the more
noticeable are the changes in the
T
s
value, given all other conditions being equal.
This assertion is demonstrated in Fig. 7.10. Here, we no longer present diagrams for
the centre-of-mass position, since calculations were performed for various depths
H
.
In each case the depth
H
was chosen to be the minimum possible one, but so that
variations in the temperature profile did not reach the bottom.
Now, we shall estimate the power (energy), which can be provided by a seismic
source. Estimations will be based on the known correlative relationship between an
earthquake energy
E
[J] and its magnitude
M
[Puzyrev (1997)]:
lg
E
= 1
.
8M+ 4
.
(7.9)
