PREDICTION OF EARTHQUAKES.
General nature of predictions—Prediction by the observation of
unusual phenomena (alteration in the appearance and taste of
springs; underground noises; preliminary tremors; earthquake
prophets—warnings furnished by animals, &c.)—Earthquake warning.
_General nature of predictions._—Ever since seismology has been
studied, one of the chief aims of its students has been to discover
some means which would enable them to foretell the coming of an
earthquake, and the attempts which have been made by workers in various
countries to correlate these occurrences with other well-marked
phenomena may be regarded as attempts in this direction.
Ability to herald the approach of these calamities would unquestionably
be an inestimable boon to all who dwell in earthquake-shaken countries,
and the attempts which have been made both here and in other places are
extremely praiseworthy. In almost all countries where earthquakes are
of common occurrence these movements of the earth have been more or
less connected with certain phenomena which, in the popular mind, are
supposed to be associated with an approach of an earthquake.
If predictions were given in general terms, and they only referred
to time, inasmuch as on the average there are in the world several
shakings per day, we should always find that predictions were
verified. We might even go further and predict that on certain days
earthquakes would occur in certain countries, and still find that in
many instances our supposed power of foresight had not deceived us.
Thus, for instance, in Japan, where on the average there are probably
one or two shakings every day, if prognostications were never correct
there would be a violation of the laws of chance.
What is required from those who undertake to forewarn us of an
earthquake is an indication not only of the time at which the
disturbance will happen, but also an indication of the area in which
it is to occur. Those who dwell in an area where there are certain
well-defined periods during which seismic activity is at a maximum—if
ten or fourteen days should have passed without a shock—might, in many
instances, find that a prophecy that there would be an earthquake
within the next few days would prove itself correct. Also, if a severe
shock had taken place, a prophecy that there would be a second or
third smaller disturbance within a short period would also meet with
verification.
Certain persons with whom I am intimate appear to have persuaded
themselves that they can foretell the coming of an earthquake by the
sultry state of the atmosphere or a certain oppressiveness they feel,
and an instinctive feeling arises that an earthquake is at hand.
It is said that a few minutes before many of the shocks which shook
New England between 1827 and 1847 people could foretell the coming
disturbance by an alteration in their stomach.[132] No doubt many who
dwell in earthquake countries, and have been alarmed by earthquakes,
are at times subject to nervous expectancy.
The author has had such sensations himself, due, perhaps, to a
knowledge that it was the earthquake season, that there had been no
disturbance for some weeks, and a consequent increasing state of
nervous presentments. In consequence of this, not only has he carefully
prepared his instruments for the coming shock, but he has written and
telegraphed to friends to do the same.
Sometimes these guesses have proved correct. One remarkable instance
was a few hours prior to the severe shock of February 22, 1880, when
he communicated with his friends in Yokohama and asked them to see
that their instruments were in good order. Oftener, however, his
prognostications have been incorrect. The point in connection with
this subject which he wishes to be remarked is, that the instances
where earthquakes occurred shortly after the receipt of his letters
are carefully remembered, and often mentioned, but the instances in
which earthquakes did not occur appear to be entirely forgotten. He is
led to mention these facts because they appear to be an experimental
proof of what has taken place in bygone times, and what still takes
place, especially amongst savages—namely, that the record of that which
is remarkable survives, whilst that which is of every-day occurrence
quickly dies. Had the records of all prognostications been preserved,
the probability is that we should find that they had, in the majority
of cases, been incorrect, whilst it would have been but in very few
instances they had been fulfilled.
_Prediction by the observation of natural phenomena._—The above remarks
may perhaps help us to understand the prognostications of the ancient
philosophers about which Professor Antonio Favaro, of Padua, has
written.[133] Cicero in the ‘De Divinatione,’ speaking on this subject,
says that ‘God has not predicted so much as the divine intelligence of
man.’—‘Non Deus prævidet tantum, sed et divini in genii viri.’ Favaro
regards these predictions, however, as the result of observations of
nature which show it is possible that indications of coming earthquakes
had been announced by variations in the gas given out from subterranean
sources, the change in colour, taste, level, temperature of the water
in springs, &c.
In 1843 a bishop of Ischia forewarned his people of a conning
earthquake, and thus was instrumental in the saving of many lives.
Naturally, in an age of superstition, the bishop would be regarded as
a prophet, but Favaro considers that the prognostication was probably
due to a knowledge of premonitory signs as exhibited in changes in the
characters of mineral waters.
The shock of 1851, at Melfi, was in this way predicted by the Capuchin
fathers, who observed that a lake near their door became frothy and
turbulent.
Underground noises have led persons to the belief that an earthquake
was at hand. It was in this way that Viduari, a prisoner at Lima,
predicted the destruction of that city.
Before the earthquake of 1868, so severely felt at Iquique, the
inhabitants were terrified by loud subterranean noises.
That underground noises have preceded earthquakes by considerable
intervals appears to be a fact, but, at the same time, it must
be remembered that similar noises have often occurred without an
earthquake having taken place.
Farmers predicted the earthquake of St. Remo, in 1831, by underground
noises.
On the day before the earthquake which, in 1873, shook Mount Baldo,
the inhabitants of Puos, a village north of Lake Santa Croce, heard
underground noises.
Before the earthquakes which, in 1783, shook Calabria and Sicily, fish
are said to have appeared in great numbers on the coast of Sicily, and
the whirlpool of Charybdis assumed an unusual excited state.
It is said that Pherecydes predicted the earthquakes of Lacedemon and
Helm out, by the taste of the water in the very deep well at the castle
of Lovain.[134]
The writer of an article on the Lisbon earthquake says that ‘after the
24th I felt apprehensive, as I observed the same prognostics as on the
afternoon of October 31, that is, the weather was severe, the wind
northerly, a fog came from the sea, the water in a fountain ran of a
yellow clay colour, and’ he adds, ‘from midnight to the morning of the
25th I felt five shocks.’[135]
At the present time Rudolf Falb, following a theory based upon the
attractive influences of the sun and moon, tells us the time at which
we are to expect earthquakes.
That occasionally there are signs attendant on earthquakes, although
we cannot give them a physical explanation, we cannot doubt. Also we
know that in certain areas earthquakes are more likely to occur at
one season than at another. Should earthquakes be foretold with the
assistance of knowledge of this description, the predictions at once
become the result of the application of certain natural laws, and are
not to be regarded as predictions in the popularly accepted sense of
that term, any more than the arrival of a friend is predicted by the
previous receipt of a telegram announcing his coming.
Rather than accredit the ancients and those of more modern times who,
in consequence of their feelings, have recorded the coming of an
earthquake, with a knowledge of premonitory signs, we might in many
instances regard the records of those prognostications as the survival
of accidental guesses, and, as such, examples of the survival of the
useless.
The effect of accidental occurrences of this description upon an
uneducated mind, in engendering superstition, is a subject which has
often been dwelt upon, and the difficulty of eradicating the same—as
may be judged of by the following accident which came under the
observation of Mr. T. B. Lloyd and the author, in 1873, when travelling
in Newfoundland—will be easily appreciated.
At the time to which I refer, my companion was bringing a canoe down
the rapids below the Grand Pond in a country which is practically
uninhabited, and where an Indian trapper would perhaps be the only
person met with, and this not more than once a year. Whilst shooting
the rapids one of the Indians, Reuben Soulian, shot at a deer passing
up one bank of the river. That the deer had been hit was testified by a
trail of blood which bespattered the rocks. Subsequently several more
shots were fired, and it was believed by all that the deer was killed.
Soulian quickly followed the animal to the spot where it was supposed
to have fallen. Some time after he returned, having failed to find any
trace of the animal. He was greatly agitated, but eventually became
melancholy, saying that the sudden disappearance of the animal was a
sure sign that some of his relations had suddenly died. About two hours
afterwards Mr. Lloyd’s party met with a party of Indians coming up
the river, the first they had seen for four weeks, who told them that
Soulian’s sister had just died on the coast.
In the northern part of South America certain shocks are anticipated by
preliminary vibrations which cause a little bell attached to a T-shaped
frame (cruz sonante) to ring. There are, however, persons (trembloron)
who are supposed to be endowed with seismic foresight, whose verdicts
are much relied upon.
In Caraccas it is said that nearly every street in the river suburb has
an earthquake Cassandra or two. Some of these go so far not only as
to predict the coming seisms, but also the vicissitudes of particular
streets.[136] Earthquake prophets are, however, by no means confined to
the new world, and many examples of them may be found in the histories
of countries where earthquakes have been felt.
The story of the crazy lifeguardsman who prophesied an earthquake to
take place in London on April 4, 1691, is an example. The Rev. Sig.
Pasquel E. Perdini, writing on the earthquakes at Leghorn in 1742,
says that ‘a Milanese astrologer predicted this earthquake for January
27, by which “misfortune” the faith and credit given to the astrologer
gained him more reverence and honour than the prophets and holy
gospel.’ Before the time at which he predicted a second shock, people
removed away from Leghorn.
_Warnings furnished by animals._—A study of the warnings furnished by
animals is also interesting. Several of the natives in Caraccas possess
oracular quadrupeds, such as dogs, cats, and jerboas, which anticipate
coming dangers by their restlessness.
Before the catastrophe of 1812, at Caraccas, a Spanish stallion broke
out from its stable and escaped to the highlands, which was regarded
as the result of the prescience of a coming calamity. Before the
disturbances of 1822 and 1835, which shook Chili, immense flocks of sea
birds flew inland, as if they had been alarmed by the commencement of
some suboceanic disturbance. Before this last shock it is also related
that all the dogs escaped from the city of Talcahuano.
_Earthquake warning._—What has here been said respecting the prediction
of earthquakes is necessarily imperfect—many of the signs which are
popularly supposed to enable persons to foretell the coming of an
earthquake having already been mentioned in previous chapters. That
we shall yet be able to prepare ourselves against the coming of
earthquakes, by the applications of laws governing these disturbances,
is not an unreasonable hope.
With an electric circuit which is closed by a movement of the ground,
we are already in a position to warn the dwellers in surrounding
districts that a movement is approaching.
An earthquake which travelled at the rate of four seconds to the
mile might, if it were allowed to close a circuit which fired a gun
at a station fifteen miles distant, give the inhabitants at that
place a minute’s warning to leave their houses. The inhabitants of
Australia and the western shores of the Pacific might, by telegraphic
communication, receive eighteen to twenty-five hours’ warning of the
coming of destructive sea waves resulting from earthquakes in South
America.
Although warnings like these might have their value, that which is
chiefly required is to warn the dwellers at and near an earthquake
centre of coming disturbances.
What the results of the observations on earth tremors will lead to is
problematical.
Should microseismic observation enable us to say when and where the
minute movements of the soil will reach a head, a valuable contribution
to the insurance of human safety in earthquake regions will have been
attained.
As to whether the movements of tromometers are destined to become
barometric-like warnings of increased activity beneath the earth
crust, or whether they are only due to vibrations of the earth
crust produced by variations in atmospheric pressure, has yet to be
investigated.
Other phenomena which may probably forewarn us of the coming of an
earthquake are phenomena resultant on the stresses brought to bear upon
the rocky crust previous to its fracture, or phenomena due to changes
in the position and condition of heated materials beneath the earth’s
surface. Amongst these may be mentioned electrical disturbances, which
appear to be so closely related to seismic phenomena.
At the time of earthquakes telegraph lines have been disturbed, but
as to what may happen before an earthquake we have as yet but little
information. The subject of earthquake warning is of importance to many
countries, and is deserving of attention.
As our knowledge of earth movements, and their attendant phenomena,
increases, there is but little doubt that laws will gradually be
formulated, and in the future, as telluric disturbances increase, a
large black ball gradually ascending a staff may warn the inhabitants
on the land of a coming earthquake, with as much certainty as the ball
upon a pole at many seaports warns the mariner of coming storms.