The Encyclopedia of Geography [pp. 307-313]

The Encyclopedia of Geography.
the district of Plaisano, a rent, of nearly a mile in
length, one hundred and five feet broad, and thirty
feet deep opened; and in the same district two
gulfs arose, one at Cerzulli, three quarters of a
mile long, one hundred and fifty feet broad, and
about one hundred feet deep; and another, nearly
a quarter of a mile long, about thirty feet broad,
and two hundred and twenty-five feet deep. Ulloa
relates that in the earthquake of 1746, in Peru, a
rent took place, which was two miles and a half
long, and four or five feet wide. These rents
sometimes close again; thus, in the year 1692, in
the island of Jamaica, during an earthquake, the
ground heaved like a boiling sea, and was traversed
by numerous rents, two or three hundred of which
were often seen at a time opening and closing rapidly again.
"6. Elevation and subsidence of land during
earthquakes. It is evident that, if the land is fractured and then traversed with vast rents by earthquakes, that portion of the land will in some places
sink and in others rise, and this not once but several
times in the same place. In the year 1772, during
an eruption of one of the loftiest mountains in Java,
the ground began to sink, and a great part of the
volcano, and part of the neighboring country, estimated to be fifteen miles long and six miles broad,
was swallowed up. During the earthquake at Lisbon in 1755. a new quay entirely disappeared;
thousands of the inhabitants had taken shelter on
its, to b e ou t of the reach of the tottering and falling
buildings, when suddenly the quay sunk down with
its thousands of human beings, and not one of their
dead bodies ever floated to the surface. In the
year 1692, during an earthquake in Jamaica, a
tract of land about a thousand acres in extent sank
down in less than a minute, and the sea immediately
took its place. On the north side of the island
several large tracts with their whole population
were swallowed up, and a lake appeared in their
place covering above a thousand acres. Numerous
examples of the upraising of the land by earth quakes might be given; we shall enumerate a few
of them. On the 19th of November, 1822, a most
dreadful earthquake visited the coast of Chili; the
shock was felt at the same time throughout a space
of one thousand two hundred miles from north to
south. When the country around Valparaiso was
examined on the morning of the shock, it was found
that thle entire line of coast, for the distance of
more than a hundred miles, was raised above its
former level. T~he area over which this upraising
took place was estimated at one hundred thousand
square miles: the rise upon thle coast was fromn
two to four feet; at the distance of a mile inland,
it was estimated from five to seven feet. On the
18th of March in the year 1790, at St. Maria di
N~iscomi, some miles from Terranuovo, near the
south coast of Sicily, a loud subterranean noise was
heard under the town just mentioned, and the day
after earthquakes were felt; then the ground gradually sunk down for a circumference of three Italian
mile s, during seven shocks, and in one place to a
depth of thirty feet; as the subsiden ce w as unequal,
rents were formed, some of which wer e so wide
that they could not be leaped over: this gradual
sinking continued to the end o f the month. About
the mi ddle of thi s perio d an opening took place in
the subsiding land, about three feet in diameter;
through these, continued to flow, for three hours, a
s tr e am of m ud, which covered a space sixt y feet
long and thir ty f eet br oad; the mud was saltish
and composed of chalky marl and a viscid clay,
with fragments of crystalline limestone; it smelt
of sulphur and petroleum. On the 16th Jun e
1819, at Cutvel, in Bombay, a v iolent e arthquake
took place, during which, independent of other
changes, the eastern and almost aband os aned channel
of the Indus was much altered: th is estuary was,
before th e earthquake, fordable at Luckput, being
only a foot deep when the ti de was at ebb, at flood
tide never more than six feet; but it was deepened
at the fort of Luckput, after the eart hquake, to
more than eighteen feet at low wat er, showing t hat
a co nsiderable depression had ta ken place. The
channel of the river Runn, was so much sunk that,
instead of being d ry as before, d uri ng tha t period
o f the year, it was no longer fordable except at
one place; and it is remarked by Captain Macmur doch,-and the observation is of high geological
import, as connected with the formation of valleys,
of river districts, &c. —' should the water continue
throughout the year, we may perhaps see an in land navigation along the northern shore of Cutch;
which, from stone anchors, &e. still to be seen,
and the tradition of the count r y, I be lieve t o have
existed at some former period.' Sindree, a small
mud fort and village belonging to the Cutch go vernment, situated where the Runn joins the Indus,
was overflowed at the time of the shock. The
people escaped with difficulty, and the tops of the
houses and walls are now alone seen above water.
In the year 1790, in the Caraccas, during an earth quake, a portion of granite soil sunk, and left a
lake 800 yards in diameter, and from eighty to an
hundred feet deep; it was a part of the forest of
Aripao which sunk, and the trees remained green
for several months under water.
"7. Agitations of the sea. We have already
noticed, in a general way, the agitations observed
in the sea during earthquakes; we shall now add
some particu lars illustrative of these motions. Du ring the Lisbon earthquake of 1755, the sea rose
along the coast of Spain; and at Cadiz it advanced
in the form of vast waves sixty feet high. At Lis bon about sixty thousand persons perished. The
sea first retired, and laid the bar dry; it then rush ed in, rising upwards of fifty feet above its ordi nary level. At Kinsale, in Ireland, the sea rushed
into the harbor, and invaded the land. At Tangier,
1843.]
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