SOME FAMOUS EARTHQUAKES
Of all earthquakes perhaps the best known and remembered is that of
Lisbon on November 1st, 1755, and volumes have been written about it.
The first shocks of this earthquake came without other warning than a
deep sound resembling thunder, which appeared to proceed from beneath
the ground, and it was immediately followed by a quaking which threw
down the entire city of Lisbon. In six minutes sixty thousand persons
perished. The day was almost immediately turned into night, owing
to the thickness of the dust from the ruined city. A few minutes
afterwards fire sprang up among the ruins. The new Lisbon quay, which
had been built entirely of marble, suddenly sank down into the bay
with an immense crowd of people, who thronged to it for safety, and
it is said that none of the bodies of the drowned were ever seen
again. Following hard on the first shocks the sea retired from the
land, carrying boats and other craft with it, only to return in a
great wave, which completed the destruction in and about the city.
This great sea wave, the mightiest that has ever been described in
connection with an earthquake, is said to have washed not only the
coasts of Portugal and Spain, but to have extended with destructive
violence to other countries. At Kinsale, in Ireland, it was strong
enough to whirl vessels about in the harbour and to pour into the
market-place, and it was of great violence also at the island of
Madeira. Portions of the sea-coast between Cape-da-Roca and Cape
Carvociro fell away into the sea, and the damage was very great along
the coast between Cape St. Vincent and the mouth of the Guadiana. The
great Sierra da Estrella, on the west of the Tagus valley, was split
and rent in a most remarkable manner, and threw down avalanches of
rock into the valley.
The great earthquake which shook Calabria and North-Eastern Sicily
in the year 1783 stands out in rather striking contrast with other
disturbances of history, because it was carefully studied by a
great number of skilled observers. Among them were Vivenzio, the
court physician of the King of Naples, who has supplied us with a
narrative of the events; Grimaldi, the Minister of War, who at the
King's command visited the region and has left accurate measurements
of the greater and lesser fissures associated with the earthquake;
Pignaturo, a physician, who kept a record of the long-continuing
shocks, together with an estimate of their intensities; the French
geologist Dolomieu; and Sir William Hamilton, who was the British
Ambassador at Naples. The Academy of Naples sent a special commission
to the scene of the earthquake's destruction, and prepared a bulky
report of great scientific value. Calabria is a country which has
many times been racked with earthquakes; the disturbances being
almost as conspicuous for number as in Japan. The areas shaken have
not usually been great in extent, but as regards the geological
changes and the loss to life by which they have been accompanied,
they rank among the greatest in history.
The shocks of 1783, which cost thirty thousand lives, came without
warning on February 5th, and in two minutes threw down the structures
in hundreds of cities and villages scattered through Calabria
and North-Eastern Sicily. The great central granite formation of
Calabria, which was but slightly disturbed by the first shock, was
more heavily shaken by those which followed; and it was noted by the
early writers on this earthquake that the mountains had been a little
raised in comparison with the neighbouring plains at their bases.
The fact of the elevation of mountains by earthquakes or some other
underground disturbance has been elsewhere noted. On November 19th,
1822, a great earthquake shook the Chilian coast for a distance of
twelve hundred miles north and south. The greatest energy was shown
about one hundred miles north of Valparaiso, where the coast was
found to have risen suddenly from three to five feet for a distance
which has never been accurately ascertained, but which is known
to have exceeded thirty-five miles. In 1835 and in 1837 similar
elevations of the coast were caused by earthquakes at Concepcion,
about three hundred miles south of Valparaiso, and at Valdivia,
about two hundred miles south of Concepcion. Charles Darwin, in the
_Voyage of the "Beagle,"_ says: "I have convincing proofs that this
part of the continent of South America has been elevated near the
coast at least from four to five hundred feet, and in some parts from
one thousand to thirteen hundred feet, since the epoch of living
shells." Darwin finds his evidence in the raised beaches near the
coast on which these shells abound. That this uplift has been going
on by small and sudden movements, from a foot to ten feet at each
shock, for more than two centuries is attested by good evidence.
The coast in many places is proven to be from twenty to thirty feet
higher to-day than it was in the middle of the seventeenth century.
Sir Charles Lyell, in his _Principles of Geology_, gives a most
interesting account of the sudden upheaval of a portion of a mountain
range, with the accompaniment of a great earthquake, near Wellington,
in New Zealand, in January, 1855. Both the North and South Islands of
that colony have been affected by upliftings during the nineteenth
century, and these movements have been attended by powerful and
far-reaching earthquakes. The changes wrought by these movements on
the shores and farther inland as well have been remarkable during the
last hundred years.
Another example of the same kind of activity is seen in the
occasional rise of islands from the sea; but to this we shall refer
again, and for the present we may return to the Calabrian earthquake,
which presented many curious and many characteristic features.
During the earthquake the surface of the country heaved in great
undulations, which were productive of a feeling of sea-sickness, and
which, according to some observers, made the clouds appear to stand
still, as they will sometimes seem to do from the deck of a tossing
ship. The fissures which appeared in the ground were numbered by
thousands, and sometimes the displacements of the earth amounted to
as much as ten feet. Houses were lifted high up; in other places the
land or the sea-floor sank several feet. Many of the fissures opened,
spurted out sand or water, and then closed again; and some of the
Calabrian plains after the earthquake were found to be dotted with
circular hollows, on the average about the size of carriage wheels,
which were like wells, but were sometimes filled with sand instead
of water. These were afterwards found to be =V=-shaped. In addition
to these hundreds of small cone-shaped hollows or wells there were
other water basins more deserving the name of ponds or lakes. One of
these in the neighbourhood of Seminara, to which the name of Lago di
Tolfilo was given, was about a third of a mile in length, and was so
copiously fed by the springs ranged in a fissure in its bottom that
all attempts to drain it proved useless. Near Sitizam a valley was
completely choked up by the landslip from opposite sides, and behind
this new dam a lake was formed which was about two miles in length
and one mile in breadth. Vivenzio states that fifty lakes arose
at the time of the earthquake, and the Government surveyors, who
included ponds, counted no fewer than 215. The first effect of the
more violent shocks was generally to dry up the rivers. Immediately
afterwards many of their beds were so blocked up over them that the
rivers overflowed. From the rock of Scylla opposite to Charybdis, in
the Straits of Messina, large sections of cliff were broken off,
in one instance for a whole mile's length of coast. The sea and the
neighbourhood was greatly disturbed; and soon after the fall of the
cliffs of Scylla the sea rose to a height of twenty feet, and the
wave rolling over the coast-line drowned 1500 people.
Japan is perhaps as unstable an area as anywhere exists on the
earth, and the records of its earthquakes are more complete than in
any other country. The number of destructive earthquakes recorded
there in the last fifteen hundred years is 223. Since the beginning
of the seventeenth century the records are fairly perfect, and it
is found that since then a destructive earthquake has occurred
somewhere in the Japanese islands nearly every two and a half years.
For the lighter shocks systematic observation has become necessary,
and the Japanese, with that development of the scientific spirit
which is so remarkable an accompaniment of their progress during the
last generation, have organised an Earthquake Recording Service--a
Seismological Bureau--at which such conspicuous meteorologists as Mr.
John Milne and Dr. Knott have worked, and which has produced great
seismologists among the Japanese themselves. As many of our readers
are aware, the earth is hardly ever still; it trembles continually
like a boiling kettle, though not for the same reasons; and the
delicate instruments for measuring earthquakes, which are called
seismometers, show continual earth tremors or earth shivers. Since
1888 the earthquakes of all intensities recorded in Japan give a
yearly average of 1447 shocks, or a daily average of four. Until the
great earthquake of 1891, the greatest shocks within the memory of
living men were those of 1854-5.
The earthquake of October 28th, 1891, shook an area of 243,000
square miles, or more than three-fifths of the entire area of Japan,
though the greatest damage was done on the Mino-Owari Plain, a
broad expanse of country occupied by rice fields and surrounded by
mountains. Without the least warning the blow came, and in the first
shock 20,000 buildings fell, 7000 people were killed and 17,000 were
injured. Innumerable fissures great and small appeared all over the
plain, and the houses in the thickly packed villages fell like packs
of cards. The plain is one of Japan's great gardens, and supported
almost 1000 people to the square mile. Villages were thereabout
continuous, and a narrow lane of unusual destruction could be traced
through them for twenty miles. After the first shock there were
numerous smaller ones, and during the next five months no fewer than
256 shocks were recorded in all. Among the more remarkable effects
of the earthquake was the actual shifting of the country. Along a
crack many miles in length the plain after the earthquake was some
feet lower on one side than on the other. Reservoirs and swamps were
formed, as well as sand pits and mud craters. The most conspicuous
effect, however, from a geological standpoint was the shifting and
distortion of the strata.
[Illustration:
_Photo, G. C. Niven_
The Curious Eruption of Mount Asama, Japan
Mount Asama is nearly 8000 feet high, and the crater is nearly a
mile across, and has a depth of about 1000 feet. Steam is being
continually discharged. The above display was photographed from about
8 miles distance. The discharge was about 1-1/2 miles high, and shot
up to that height in some ninety seconds. The evident inference
is either that water is being forced out of the rocks by volcanic
action, or that the eruptions are of the nature of steam explosions
caused by water which comes in contact with molten rock.]
A few years later, on the 26th and 27th August, 1896, occurred
the remarkable Icelandic earthquake, which affected a triangular
plateau, bordered by high mountains, including Mount Hecla and other
well-known volcanoes, in the south-western portion of the island.
During the shocks the earth's surface was thrown into waves, so that
neither man nor cattle could stand. Persons who were lying on the
ground near a cliff were by the shock thrown bodily over the edge. A
high hill in the plain is described as shaken "like a dog coming out
of the water," and a thick mantle of loose soil which had covered it
was afterwards found distributed in heaps about its base. The surface
of the plain was scarred by open fissures or by rock walls which had
been caused by the earth's rising on one side of a fissure. One of
the fissures was nine miles and another seven miles in length. The
mountains round the plains were riven by clefts, and many landslips
occurred. As we have mentioned elsewhere, a new geyser was formed,
throwing up water to an enormous height, but soon spending its early
force; and many geysers and springs were violently disturbed.
An earthquake of a very different kind occurred the next year in the
province of Assam, India (June 12th, 1897). Unlike the Icelandic
earthquake, almost the whole damage was here the result of the first
shock. Everything was destroyed within the first fifteen seconds of
the earthquake, and the heavy shocks had all passed before two and
a half minutes had elapsed. In this brief space of time an area of
1,750,000 square miles had been shaken and 150,000 square miles laid
in ruins. A member of the Geological Survey of India, who was in
the town of Shillong, says that a rumbling sound like near thunder
preceded the shocks by a second or so and increased in loudness,
so that when masonry began to fall the noise and rattle of the
falling stones were hardly to be perceived. Unable to stand on his
feet, this observer sat down on the ground, and not only felt but
saw the ground thrown into violent waves as if "composed of soft
jelly." These waves seemed to run along the ground. When the shocks
had passed all the masonry houses in Shillong had been levelled to
the ground, and over each hung a cloud of pink plaster particles
and dust. Some of the shocks seem to have occurred with a kind of
twist, and stone monuments were given the appearance of corkscrews.
There were left many fissures and depressions in the ground, and
the rivers and lakes and streams were greatly affected. Thirty new
lakes were formed; along the great Brahmaputra River rolled a great
wave ten feet high. One great rent in the geological strata at the
earth's surface was twelve miles long. Important changes of level
of great blocks of country were clearly shown by the alterations in
the aspect of the landscape. Ranges of hills which before had not
been visible from certain points now came into view for the first
time, while others had disappeared. Though the most destructive shock
was that felt during the first few seconds, there were others which
followed, lasting for nearly a week afterwards. This earthquake is of
special interest, because it was the first one which was registered
on the earthquake instruments set up in Europe. Since that date
these instruments have been set up all over the world, and, as we
say elsewhere, a great earthquake is now usually recorded on the
seismometers and seismographic instruments set up in observatories
stationed thousands of miles away.
All of our readers will recollect the Jamaica earthquake which
occurred comparatively recently. Port Kingston, in Jamaica, has had
its share of earthquake disasters. In the year 1692 Port Royal, the
then chief city, was destroyed, and in rebuilding it the Jamaicans
moved it across the harbour, because the old town site was largely
submerged beneath the sea. It was a recurrence of the settlement
of the ground which in part produced the earthquake of January
14th, 1907. There were slight shocks preceding the earthquake, and
subterranean rumblings. The chief damage was done before thirty-five
seconds had gone by, and of course the catastrophe was greater
because the shocks were felt in the neighbourhood of a city.
Considered by itself the earthquake was not of the order of "great"
earthquakes, but many of the effects were most curious. A statue of
Queen Victoria on a pedestal was partly turned round; a series of
steep terraces was formed by the side of the harbour; a small spring
was converted into a stream eight feet wide; and, as we all know,
very great destruction was inflicted on life and property. Soundings
which have since then been made in the harbour show that its depth
has greatly increased in some parts, in one instance by not less
than twenty-seven feet. The greatest depression occurred near Port
Royal (the old city), where a hundred yards or more of the ground was
submerged by water varying from eight to twenty-five feet in depth.
Proceeding northwards from the Antilles to North America, we come
to other famous areas of earthquake disturbance. In 1811 and 1812
there were earthquakes along the lower lands of the great Mississippi
River, which were felt throughout the whole of the eastern portion
of the United States and as far west as exploration had gone. At
New Madrid, which appears to have been near the centre of the
disturbance, "subterranean thunder" appears to have been heard
frequently for many years preceding the earthquake, though it had
ceased for nearly a year. About two o'clock in the morning of
December 16th, 1811, there came a severe shock accompanied by a noise
which was like near thunder, and a few minutes afterwards the air was
filled with sulphurous vapour. People thought that the end of the
world had come. Light shocks were felt till sunrise; and then one
more violent than the first occurred. But this was not the end. For
three months the shocks went on, and in that time no fewer than 1874
shocks were recorded, eight of them great ones. The shock of January
23rd, though as violent as any that preceded it, was surpassed by
the so-called "hard shock," which came at about four o'clock in the
afternoon of February 7th. It was accompanied by a discharge of
sulphurous vapour in the atmosphere, and an unusual darkness which
added greatly to the terror of the people.
[Illustration:
_Stereo Copyright, Underwood & U._ _London and New York_
A House destroyed by an Earthquake
This was Senator Stanford's house at Palo Alto, about 25 miles from
San Francisco, which is situated on a fault or ancient fracture of
the earth's surface.]
The Mississippi seemed to recede from its banks, and its waters
gathered up like mountains, leaving boats high up on the sands. "The
waters then moved inwards with a front wall fifteen to twenty feet
in height, tearing the boats from their moorings and carrying them
closely packed up a creek for a quarter of a mile. The river fell
as rapidly as it had risen, and receded from its banks with such
violence that it took with it a grove of cotton-woods which hedged
its borders. These trees were broken off with such regularity that
it was hard to persuade people who had not witnessed the catastrophe
that it had not been brought about by human agency." During all the
greater shocks the earth's surface was reported to have been raised
in great crumplings, the crests of which opened into fissures. Some
of these were six hundred to seven hundred feet long and twenty
to thirty feet wide, and water and sand and even coal[13] were
spouted out of them to a height of forty feet. Many craters and
holes in the ground were formed, surrounded by rings of sand; and
traces of them remain to this day, a century-old monument of the
destruction wrought. Notable changes in the level of the country were
effected; new lakes and new islands came into existence; some lakes
disappeared; some of the lakes then formed remain to this day. On
the eastern bank of the Mississippi a lake a hundred miles long, six
miles wide, and ten to fifty feet in depth was formed; and another
lake, known now as Reelfoot Lake, which came then into existence,
is twenty miles long, seven miles broad--larger than Windermere,
and deeper. The fishermen's boats to-day float over the top of
eighteenth-century cypress trees. In addition to sections of country
which were depressed and submerged, an area of some twenty miles in
diameter was elevated into a low dune twenty to twenty-five feet
above the level of the plain of the Mississippi. Many years after the
great shocks, smaller ones were felt; and even now scarcely a year
passes without slight tremors in this region, and small fissures are
still formed in the ground.
[Footnote 13: Or "lignite," a form of hard pitch.]
It must be repeated that the great earthquakes are not those of
which most is heard. The earthquake of San Francisco which did such
widespread damage because it took place in the neighbourhood of a
thickly populated city was, after all, less in magnitude than the
Sonora earthquake of 1887, which took place in a great expanse of
desert country in which few people lived and few towns had been
built. But this earthquake was felt all over the countries of Mexico
and the State of Arizona; and a range of mountains, the Sierra Teras,
was uplifted between faults which opened upon either side. Millions
of cubic feet of rock were thrown down from the slopes of the
mountains into the deep cañons and water-courses, and cliffs of hard
rock were shattered and split as though by a charge of giant powder.
The Yakutat Bay earthquake in Alaska changed the whole face of the
country over thousands of square miles during September, 1899; and
along the shore of the bay the shore showed that in some cases it had
been lifted from five to thirty and in some cases even fifty feet.
New reefs and islands were formed; and a study of the country and the
coast-line seems to show that from time to time this neighbourhood,
like the beaches south of Valparaiso, is being lifted by some agency,
perhaps the gradual elevation of a continent, perhaps by continuous
earthquake action.
[Illustration:
_Stereo Copyright, Underwood & U._ _London and New York_
The Ruins of the Magnificent City Hall of San Francisco
The great earthquake of 1906 caused this destruction. Some of the
distortive effects of an earthquake movement can be perceived.]
But if the San Francisco earthquake of April 18th, 1906, was not of
itself a very great earthquake, it brought about an enormous amount
of damage. The heavy shocks came without warning at about five
o'clock in the morning of April 18th. They lasted about a minute, and
then went off into lighter quakes, which were felt till evening, and
for many days after, gradually growing smaller and smaller. The loss
of life, though great, was but a tenth of what it would have been had
the worst shocks come at a later hour when men were at their places
of business and the children in school. As it was, the greatest loss
was due to the fire which was started by the earthquake, and which
was soon beyond control, because the water-main had been snapped by
the earth movement. The cause of the earthquake has been generally
assigned to the slipping of the strata of California. Athwart the
whole state runs a straight furrow, like an ancient earthquake crack
of primeval times, which is about four hundred miles long, and the
rocks about which are still liable to slip. As we have said, however,
the Californian earthquake, though accompanied by great destruction
of property, and by the characteristic accompaniments of fissures in
the ground, and slight elevations and depressions of the country over
a line sixty miles long, was not a very profound earthquake.
Rather a curious coincidence may be here noted. We have spoken of
submarine earthquakes and volcanoes and of islands which are raised
by something akin to volcanic action or earthquake action underneath
the sea.
Some weeks after the Californian earthquake the officers and crew
of the U.S. Fish Commission steamer _Albatross_, while on their way
to investigate, with Professor Charles H. Gilbert, the fisheries of
Japan, passed the group of islands known as the Bogoslofs, and to
their astonishment perceived that a third island had been added to
the other two. Professor Gilbert, in a letter concerning the first
sight of the island, on May 28th, wrote: "When I saw the Bogoslofs
in 1890 there were really two small islands about 1-1/2 miles apart,
one of them steaming and the other cooled off. This has been the
condition for a number of years, so the hot one had received the name
of Fire Island, the cold one, Castle Island. When they came in sight
yesterday, we were astonished to find that Fire Island was no longer
smoking, and that a very large third island had arisen half-way
between the other two. It was made of jagged, rugged lava, and was
giving off clouds of steam and smoke from any number of little
craters scattered all over it. Around these craters the rocks were
all crusted with yellow sulphur. The new cone, occupying much of the
space between the two older ones, was somewhat higher than either,
but was certainly far from 900 feet high--300 feet would be an
extreme figure. There was no evidence of a central crater. The steam
and fumes were given off most abundantly from cracks and fumaroles
on the slopes. About these were heavy incrustations of sulphur. We
saw no indications of boiling water, nor did we believe that landing
would be impossible."
All three of these Bogoslof islands, which are about 120 miles
south of the Pribyloff Islands, belonging to Russia in the Behring
Sea, have risen above the waters hot and steaming in the last 150
years. The oldest Bogoslof, now called Castle Island, rose from the
sea in 1796; and Kotzebue describes the first glimpse of it, as
seen by a trader, named Krinkof, who had been forced to seek refuge
from a storm on a neighbouring island. The birth of the volcanic
islet was accompanied by an earthquake which shook the island
where the trader had taken refuge, and by an outburst of fire with
thunderous explosions. The island was said to emit fire for months
afterwards, and for eight years afterwards the water round it was
warm and its ashes unbearably hot. The eruption of 1883, in which
the second Bogoslof, called Fire Island, was born, had no witnesses;
but in September of that year great volumes of steam and smoke,
accompanied by showers of ashes, were thrown out from the summit
and through fissures in the sides and base, the bright reflections
from the heated interior being visible at night. At the time of this
eruption a severe earthquake was felt in the sea off Cape Mendocino,
apparently in the line of the Californian furrow or rift.
The islands were visited in 1884 by the officers of the U.S. revenue
cutter _Corwin_, and Lieutenant J. C. Cantwell and Surgeon H. W.
Yemans made the ascent of New Bogoslof. Lieutenant Cantwell thus
describes his experience in the _Cruise of the Corwin_:--
"The sides of New Bogoslof rise with a gentle slope to the crater.
The ascent at first appears easy, but a thin layer of ashes, formed
into a crust by the action of rain and moisture, is not strong enough
to sustain a man's weight. At every step my feet crushed through the
outer covering and I sank at first ankle deep, and later on knee
deep, into a soft, almost impalpable dust, which arose in clouds and
nearly suffocated me. As the summit was reached the heat of the ashes
became unbearable.... On all sides of the cone there are openings
through which steam escaped with more or less energy."
Seven years after that Drs. Merriam and Mendenhall, of the Behring
Sea Seal Commission, found the newer island still smoking, steaming,
and occasionally roaring like a giant steam escape. The older island
had quite cooled, and had become a sheer cliff or hill of cold ashes,
and was, and is, the home of countless sea birds, as well as of a
small herd of sea lions. Captain Cook, in the eighteenth century, had
passed by the neighbourhood of this island. This was eighteen years,
however, before it was born, and he named a pillar of ash or rock
which he found there Ship Rock. Ship Rock fell in ruins five years
after the birth of Fire Island.
Since that time the new island has again sunk beneath the waves.
But it will probably rise again, or another island somewhere in its
neighbourhood will take its place, for a great new submarine ridge of
volcanic rocks is forming in this neighbourhood and has been forming
for many hundreds of years. The Pribyloff Islands are known to be
volcanic from the materials of which they are composed, and sprang up
above the waves in the same way.