Geoscience Reference
In-Depth Information
The captain of one of the ships said he was surprised to see, several miles from
Cape Corso, a great number of currents running rapidly with a frightening force in
different directions (i.e. he observed maelstrom).
After the January 27 powerful underground shock.
...
the weather was quiet and
fine, but at the time of the shock the sea was very stormy
...
and after the earthquake
'most high' waves rose. According to other data, a hurricane south-western wind
accompanied by rain started to blow just before the earthquake.
On January 27 the sea boiled with such fury and rage, that its noise was like
the roar of an enormous cannon.
11.
1766, May 22, 5 h 30 min. Zone of the Sea of Marmara, Strait of Bosphorus.
40
◦
8
N, 29
◦
0
E, I = IX.
An underground boom passed through Istanbul from south to north, after which
strong underground shocks immediately followed in the same direction; they lasted
for 2 min without interruption. The town was destroyed. The sea was unusually
turbulent.
12.
1783, February 5, 12 h
30
min. Calabrian Arc.
38
◦
25
N, 15
◦
50
E.
The catastrophic Calabrian earthquake, which started the long period of seismic
activity in the south-west of Italy that lasted for several years.
Unusual phenomena in the sea have been described, which could be considered
short-term precursors of the earthquake. First, the deep-water small fish cicirella,
which usually does not leave the sea bottom and buries itsels in the silt, began to
appear in abundance near the sea surface not far from Messina and in other places in
the first days of February. Second, on February 5 the sea was calm in the immediate
vicinity of the coast in the region of Monteleone di Calabria, but it was stormy and it
'boiled up' in windless weather far off the coast, according to fishermen's accounts.
According to words of the officer, who was commander of the Messina Citadel
and stayed inside it during the events, the sea 'swelled' in an absolutely unusual
manner, within a quarter of a mile from the fortress, during the earthquake and three
subsequent days, and it boiled with an incredibly gloomy and terrible roar, inspiring
indescribable fear, while at the same time the sea on the other side of the light-house
was calm.
13.
1846, August. Ligurian Sea, Italy, France.
43
◦
30
N, 10
◦
30
E.
A hollow underground rumble started to be heard from the sea near a light-house
in Livorno since July 25, and it grew louder on August 12 and 13. The rumble was
accompanied by an unusual choppiness of the sea water, which could not be ex-
plained by the character and force of the winds, that blew at the time. Thus, on
August 11, at 12 h, in the vicinity of the Fancale di Livorno the sea level signifi-
cantly and quite instantaneously rose, and, where the bottom was silty and covered
with seaweed, the water become turbid.
...
The underground rumble and change in
sea level increased by 10 h 30 min on August 14, and the main earthquake broke out
at 12 h 52 min.
A strong choppiness occurred throughout lake Massaciuccoli, where the water
was covered with ripples and became turbid.
14.
1846, September-November. Ligurian Sea, Italy, Tuscany district, Livorno.
September 12. A rumble and movements of the sea water resumed under
a clear sky.
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