Young Folks' Library: Wonders of Earth, Sea and Sky HTML version

The Greatest Sea-Wave Ever Known
(From Light Science in Leisure Hours.)
August 13th, 1868, one of the most terrible calamities which has ever visited a people
befell the unfortunate inhabitants of Peru. In that land earthquakes are nearly as common
as rain storms are with us; and shocks by which whole cities are changed into a heap of
ruins are by no means infrequent. Yet even in Peru, "the land of earthquakes," as
Humboldt has termed it, no such catastrophe as that of August, 1868, had occurred within
the memory of man. It was not one city which was laid in ruins, but a whole empire.
Those who perished were counted by tens of thousands, while the property destroyed by
the earthquake was valued at millions of pounds sterling.
Although so many months have passed since this terrible calamity took place, scientific
men have been busily engaged, until quite recently, in endeavoring to [pg 212] ascertain the real
significance of the various events which were observed during and after the occurrence of
the earthquake. The geographers of Germany have taken a special interest in interpreting
the evidence afforded by this great manifestation of Nature's powers. Two papers have
been written recently on the great earthquake of August 13th, 1868—one by Professor
von Hochsteter, the other by Herr von Tschudi, which present an interesting account of
the various effects, by land and by sea, which resulted from the tremendous upheaving
force to which the western flanks of the Peruvian Andes were subjected on that day. The
effects on land, although surprising and terrible, only differ in degree from those which
have been observed in other earthquakes. But the progress of the great sea-wave which
was generated by the upheaval of the Peruvian shores and propagated over the whole of
the Pacific Ocean differs altogether from any earthquake phenomena before observed.
Other earthquakes have indeed been followed by oceanic disturbances; but these have
been accompanied by terrestrial motions, so as to suggest the idea that they had been
caused by the motion of the sea-bottom or of the neighboring land. In no instance has it
ever before been known that a well-marked wave of enormous proportions should have
been propagated over the largest ocean tract on our globe by an earth-shock whose direct
action was limited to a relatively small region, and that region not situated in the centre,
but on one side of the wide area traversed by the wave.
We propose to give a brief sketch of the history of this enormous sea-wave. In the first
place, however, [pg 213] it may be well to remind the reader of a few of the more prominent
features of the great shock to which this wave owed its origin.
It was at Arequipa, at the foot of the lofty volcanic mountain Misti, that the most terrible
effects of the great earthquake were experienced. Within historic times Misti has poured
forth no lava streams, but that the volcano is not extinct is clearly evidenced by the fact
that in 1542 an enormous mass of dust and ashes was vomited forth from its crater. On
August 13th. 1868, Misti showed no signs of being disturbed. So far as the volcanic
neighbor was concerned, the forty-four thousand inhabitants of Arequipa had no reason
to anticipate the catastrophe which presently befell them. At five minutes past five an
earthquake shock was experienced, which, though severe, seems to have worked little
mischief. Half a minute later, however, a terrible noise was heard beneath the earth; a
second shock more violent than the first was felt, and then began a swaying motion,
gradually increasing in intensity. In the-course of the first minute this motion had become