Geoscience Reference
In-Depth Information
8
e
C
Fig. 7.3 Change of vertical temperature profile after earthquake of December 4, 1972, with epi-
centre to the south of Honshu Island (Japan)
event—December 6, 1972. From Fig. 7.3 the temperature in the upper 20-m layer is
seen to be reduced, on the average, by 4-6
◦
C.
Without presenting illustrations, we shall briefly describe two more events. The
second case was observed during the November 5, 1938 earthquake of magnitude
M
= 7
.
7 at the eastern coast of Honshu Island (Japan). In the upper 50-m layer, a re-
duction of temperature by 2
◦
C was noted, while on the 250 m horizon it amounted
to approximately 4
◦
C.
The third case was noted during the earthquake of magnitude
M
= 7
.
5 that oc-
curred at the point with coordinates 8.5
◦
S and 123.5
◦
E on the Indonesian Island
of Flores on March 22, 1944. The sites of temperature profile measurements before
and after the event were situated next to each other within a radius of 5-10 km and at
a distance of 40-50 km from the epicentre. The temperature at the surface decreased
from 29
◦
C down to 26.5
◦
C.
We note that the prospects of making use of instrumental observations of sea-
quakes may be related not only to improvement of the quality and volume of infor-
mation (for instance, enhancement of the spatial resolution of satellite images, an
increase of the number of buoy stations, etc.). An analysis of oceanographic mea-
surements, made in the past, but performed at a qualitatively new level, may still
yield new interesting results.
