San Francisco's great disaster; a full account of the recent terrible destruction of life and property by earthquake, fire and volcano in California and at Vesuvius .. online

San Francisco from Nob Hill 246

Panorama of Nob Hill, After the Fire 255

Panorama of San Francisco, from Telegraph Hill 256

San Francisco After the Fire, Corner Folsom and East Streets. . 265

View in Market Street, San Francisco 266

A Church Tower Demolished by the Earthquake 275

Frame Residence Demolished by the Earthquake 276

High Skyscrapers Threatened by Flames on April 19th 285

Up Broadway to Telegraph Hill After the Fire 286

Park in San Francisco, Wednesday Morning, After the Earthquake 295

Children's Playground in Golden Gate Park, San Francisco 296

Dupont Street, the Main Street of Chinatown 305

A Rag-Picker's Alley in Chinatown, San Francisco 306

View in San Francisco Looking up California Street 315

The New Chinatown at Fort Mason 316

The Chicago Fire— The Rush for Life Over Randolph St. Bridge.. 357

The Baltimore Fire— The Shopping District 358

The Earthquake in Charleston, September, 1886 3^

Market Street, San Francisco, After the Fire 3(8

Scene in Pompeii Showing Excavated Street 3^3

The Terror of Vesuvius — People of Ottaiano Fleeing 3^

Eruption of Vesuvius— Panic Stricken Refugees 403

Ruins of the City of St. Pierre, Martinique, After the Eruption.. 404



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EARTHQUAKES AND THEIR CAUSES.



BY PROFESSOR' RALPH S. TARR, OF CORNELL UNIVERSITY.



It is a human characteristic to look for coincidences and
to allow one coincidence to counterbalance many exceptions,
for while these do not attract the attention, the coincidences
fix themselves firmly in the mind. This tendency is well
illustrated in the widespread but fallacious belief in the
influence of the moon on the weather, and of the occur-
rence of the equinoctial storm. It is now finding expression
in the widespread belief that because Vesuvius is in the
same general latitude as the earthquake stricken Caucasus
and San Francisco regions, there must be some relation.
In proof of this assumption, other coincidences are called
to mind; but all failures to show sympathy of earth dis-
turbances are overlooked. It is the duty of the scientific
men to take into account all facts, weigh them,, study their
relation to one another, and draw conclusions from all
and not from a portion of the facts.

VESUVIUS AND THE EARTHQUAKE.

By such methods of study and comparison geologists
have so far been unable to detect any definite relation be-
tween the eruption of volcanoes and the shaking of the
earth's crust in remotely separated parts of the earth ; con-
sequently it is all but universally held by students of the
subject that the 'recent eruption of Vesuvius is in no known
way related to the recent earthquakes. As a matter of
fact, the eruption of Vesuvius does not appear to have
been one of great vigor; it is certainly not to be compared

17



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l8 SAN FRANCISCO'S GREAT DISASTER.

in violence with a number of eruptions which have occurred
in other parts of the earth in the last score of years ; it was
unusually vigorous for the present day Vesuvius, and it
occurred in the midst of a densely populated land, conse-
quently it attracted widespread notice. Had it been in
Central America and several times more violent, it mifht
have received a passing notice in the papers, but hardly
more. In the same way the San Francisco earthquake
shock is certainly not the most violent one which has been
noticed in recent times. It was undoubtedly, one of great
vigor, but its destructiveness is entirely out of proportion
to its violence, because of the accidental circumstance that
the center of greatest disturbance passed near or through a
large city.

LOCATION OF EARTH0UAKE8 AND VOLCANOES.

The great majority of volcanoes and the recorded
earthquakes lie in two well defined belts or great circles
on the earth. Vesuvius lies in one of these belts, California
in the other. The Vesuvian belt extends from Central
America through the West Indies, the Azores and Canary
Islands, the Mediterranean region, the Caucasus, Hima-
layas, Philippine Islands, and a number of volcanic islands
in the Pacific, including the Hawaiian Islands. Fifty-three
per cent, of all recorded earthquake shocks have occurred
in this zone. The second belt nearly encircles the Pacific.
It includes the entire Andenn chain, and the mountains of
Western North America from Southern Mexico to the Aleu-
tian Islands : thence it extends down the archipelago of the
Kurile and Japanese Islands to the East Indies, New Guinea
and New Zealand. In this belt, forty-one per cent, of all
recorded earthquake shocks have occurred. It is to be noted



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ftAK FRANCISCO'S GREAT DISASTER. M

tfiat the two belts cross at two points, one in the Philippines
and East Indies, the other in Central America. These two
crossing places are the seats of the most destructively ac-
tive volcanoes and of the most violent earthquakes on the
$arth.

Outside of these two zones there are only a very few
active volcanoes, and although the rest of the earth far ex-
ceeds in area that included in the two belts, only six per
cent, of all recorded earthquakes have occurred in it

While this is true of the present day it has not always
been the case. Geological evidence definitely proves that
in past ages vokanic activity has been prominent in parts
of the earth where active volcanoes are now entirely ab-
sent. Northern Europe and Eastern United States, for ex-
ample, now possessing no active volcanoes, were in earlier
geological periods the seats of stupendous volcanic activity
and with it, without doubt, of numerous and violent earth-
quake shocks.

THE GROWTH OF MOUNTAINS.

The reason for the present distribution of volcanoes
and earthquakes, and for their presence in past time where
now they are absent, is definitely related to the growth of
mountains. The two zones mentioned are the two portions
of the earth's surface where mountains are at present in
the most active state of formation. Likewise, in earlier
geological times, when volcanoes were present in Northern
Europe and Eastern America, motmtain growth was then
in progfress in those parts of the earth. With the cessation
of mountaia growth both volcanoes and fr^equent earth-
quake shocks cease. Until mountain growth is at an end
in the two belts mentioned, volcanic action and earthquakes



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^ SAN FkANCISCO*S GREAt DISASTER.

may be expected to occur throughout these zones. Just
where or when they will occur in these zones cannot now
be predicted; but certain sections are especially liable to
their occurrence, and that part of California near San
Francisco is one of the places in which earthquake shocks
iriay be expected.

DISTRIBUTION OF EARTHQUAKES.

To niake clear the difference between the conditions
in a part of these zones of earthquake frequency and what
by contrast may be called non-earthquake zones, we will
compare briefly the State of California with the entire
United States east of the looth meridian. For many years
a record has been kept of the earthquake shocks which have
visited the State of California. Between 1892 and 1898,
these records were published by the United States Geolog-
ical Survey, and from these lists we find that from one to
two score of noticeable earthquake shocks have been re-
corded each year in the State of California. Some of these
have been of sufficient violence to have caused much de-
struction of property and life had the center of disturbance
been in or close by a large city. Between the years 1727
and 1906, the number of noticeable earthquake shocks
which visited California would undoubtedly be several thou-
sand.

In the same period, while there have been numerous
slight tremors and a few earthquake shocks that have at-
tracted attention, only four earthquake shocks of importance
are known to have affected that part of the United States
which lies east of the looth meridian. The first of these,
called the Newburyport earthquake occurred in 1727, in and
near Newburyport in eastern Massachusetts. The Aak-



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SAN FRANaSCO'S GREAT DISASTER 2$

iag lasted for a long time but did little damage, attention
being called especially to it because of the peculiarity of
acccmipanying sounds which were compared to wild bellow-
ing. In 1755 occurred the greatest shock ever felt in
New England. It was strongest and most violent in and
near Boston, but the destruction caused was slight, in large
part, no doubt, because of the fact that most of the build-
ings were new, small, and built of wood. The third earth-
quake affected the country of the lower Mississippi, with
the center of greatest disturbance in and near New Madrid,
in Southern Missouri. Since this occurred in 1812, at a
time when that country was occupied only by trappers, the
destruction was slight ; but the reports make it clear that the
earthquake was of great violence, and that the shaking lasted
for fully three months. Even at the present time its ef-
fects are visible, notably in the area known as the "sunk
country," where the surface of the land was lowered and
transformed to lake and swamp for a distance of seventy
or eighty miles in a north-south direction, and thirty miles
from east to west. The fourth and last notable earthquake
of Eastern United States is known as the Charleston earth-
quake of August 31, 1886. This was a vigorous earth-
quake, but not one of first violence ; and, although the center
of disturbance was near Charleston, the destruction in that
city was mot at all comparable to that of the San Francisco
shock.

The lesson to be learned from these facts is that while
an earthquake shock may visit any part of eastern United
States, the liabilty to earth shaking of any particular section
is exceedingly slight. Earth movements are still in pro-
gress there, but only locally and of moderate intensity. In
California, on the other hand, earth movements are still
vigorous and occurring every here and there at frequent



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14 SAN FRANCISCO'S GREAT DISASTER.

intervals, sometimes with moderate effect, sometimes, as
on April i8th, with sufficient violence, and suffidently
near centers of population, to cause great destruction. What
is said of California applies to other portions of the two
great zones of earthquake frequency; and what was said
of Eastern United States applies to most other parts of the
earth than those included in the zones of growing moun-
tains.

CAUSE OF MOUNTAIN GROWTH.

The reason for the conditions which have given rise
to the recent eruption of Vesuvius and the San Francisco
earthquake is a subject on which geologists and geophysi-
cists are now at work. The immediate cause for individual
shocks and eruptions is fairly well understood, but the
fundamental cause for the distribution of mountains, vol-
canoes and earthquakes is still an obscure subject upon
which only hypotheses can be offered. Without question
it relates to the interior condition of the earth, and this con-
dition is believed, upon numerous lines of evidence, to be
that of a heated interior with a cold, rigid, outer crust of
rock. The hypothesis best supported by the facts so far
discovered is that of contraction. The heated interior is
believed to be steadily losing its heat, and consequently
shrinking. The cold outer crust is settling upon this shrink-
ing interior, and as it settles the rocks move and break
along planes which are known as fault-planes. The greatest
areas of settling are the ocean basins, and as the crust
settles in them a lateral thrust is exerted upon the margins
which causes the crust to rise locally along lines of weak-
ness whose original cause is not understood Thus the
settling in the great area of the Pacific is believed to be



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FAULT LINES IN YAKUTAT BAY, SHOWING HOW THE
ROCKS ARE FRACTURED AT THE SURFACE. THE CLIFF
ON THE LEFT WAS RAISED THREE FEET.



ELEVATED BEACH AND WAVE CUT BEACH, IN YAKUTAT
BAY, HOISTED DURING THE EARTHQUAKE TO A HBIQHT
•r It FUT. BARNACLBS STILL CLINB TB THE RMKB.



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SAN FRANaSCO S GREAT mSASTER, 2J

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exerting a thrust upon the shores of the continents and
islands which border it. Settling elsewhere is affecting
the s.econd belt of weakness and consequent mountain
growth which extends east and west around the earth.

EARTH CRU8T BEINQ BROKEN.

So much is h)rpothesis ; for the rest of the explanation
we are able to speak with more certainty. With the
thrust, whatever its source, the rigid crust is being folded
and brcJcen along certain lines, especially in the two great
zones previously described. At numerous points lava is
squeezed out to the surface through the cracks in the grow-
ing mountains. In some cases, as in the Hawaiian Islands,
this lava wells out without great disturbance or destruction.
In others, where the vent has been temporarily closed or
clogged, the lava is expelled with sufficient violence to
blow it into fragments ; it then rises high in the air in the
form of volcanic ash, which, falling back upon the earth,
settles near the vent, building up the cone, and, as in the
case of the recent eruption of Vesuvius, settling in smaller
quantities on the surrounding country. The expelling
force, whether in the case of quietly flowing lava or violent
ash explosions, is in all cases steam. The melted rocks
contain a vast amount of water imprisoned in them under
great pressure and at high temperature. When finally the
force becomes sufficient, the expansive action of the steam
expells the lava.

The history of Vesuvius clearly illustrates this point.
Before the year '79 of the Christian era, the volcano was
dormant and was not even mentioned as a volcano in
Pliny's list, in his natural history. Its flanks were occupied



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28 SAN Francisco's great disaster.

by villages and farms ; and, as now, a fringe of towns en-
circled its base. Sixteen years before its outbreak, the
renewal of activity was indicated by vigorous shaking of
the earth. The pent-up lava was slowly forcing its way
upward as premonition of the violent outbreak with which
it would finally clear the closed-up vent by expelling the
solidified lava that had accumulated there in the centuries
of quiescence. An earthquake shock in the year 63 did
so much damage to the buildings of Pompeii, that it had
not been completely repaired when the final outburst of
the volcano occurred. From the year 63 until 79, earth-
quakes were frequent, increasing in intensity and violence
in the summer and fall of the year 79 ; then came the ter-
rific outbreak, without question, the greatest that Vesuvius
has experienced in historic times, which buried the city of
Pompeii under a heavy burden of volcanic ash.

Since then Vesuvius has been almost continuously
active, though with some periods of quiet which were al-
ways followed by violent eruptions, whose intensity was
proportional to the length of the interval of quickening.
Sometimes the vent is kept fairly clear and open for long
periods, and then the eruptions have been of moderate in-
tensity. At such times, the eruptions have Been those of
liquid bva, while in the periods of greatest violence ash
eruptions have predominated. The eruption in 1906 in-
cluded both ash and lava and is to be redkoned as one of
the more moderate eruptions of Vesuvius's history, rather
than as one of its most intense outbursts. Compared with
one of the great eruptions of modem times, for example
the volcano of Krakaton in the Straits of Sunda, in 1883,
the last outburst of Vesuvius is really insignificant. /



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SAN FRANCISCO^S GREAT DISASTER. 29

VOLCANOES AND EARTHQUAKE SHOCKS.

From what has already been said, it is evident that
volcanic eruptions form one of the prime causes for earth-
quake shocks, and by people in general an earthquake is
naturally supposed to be, of necessity, an indication of vol-
canic action. This, however, is far from the case; for,
while earthquakes are common and necessary associates
with vigorous volcanic eruptions, such shocks are local
in the area which they disturb and are not ordinarily of
the first magnitude. Earthquake shocks of this sort both
precede and accompany volcanic eruptions, as is the case
of Vesuvius, prior to the year 79 ; but their center of dis-
turbance is always close by the volcano with which they
are associated. It is true, of course, that the outbreak of
a new volcano would give rise to earthquake shocks prior
to the birth of the volcano. Such phenomena have been
observed, but always in regions of already existing vol-
canic activity. Therefore, while it is not possible to state
with absolute certainty that a volcanic cone is not about
to be formed in or near San Francisco, there is every rea-
son to doubt this. The nearest large volcanoes to the city
are Lassen Peak and Mtount Shasta in the northern part
of the State, and these are, so far as we can tell, volcanoes
whose life is ended.

Other volcanoes in Western United States have been
in activity much more recently than Shasta, and, without
question, some have been in eruption since the settlement
of America. Mount St. Helens, in Washington, is reported
on fairly good authority to have been in eruption before
the middle of the last century; and even in Califomia,



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30 SAN Francisco's great disaster.

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near Lassen Peak, there is a small volcano which has
erupted in very recent times, probably not more than a
century and a half ago. Trees which this eruption killed,
and otliers which were flooded in a lake fomied by the pas-
sage of a htva-flow across a small stream, are still stand-
ing. Therefore, this eruption cannot be of very ancient
date. It need surprise no one to hear at any time of the
renewal of volcanic activity in one or more of the cones in
the mountains of Western United States. They have
ceased eruptbn too recently to warrant the assumption that
they are extinct. The evidence of Vesuvius, with its period
of centuries of quiet, warns us not to believe that, because
activity has ceased for the time, it is forever ended. At the
same time, the absence of even dormant or extinct cones
near San Francisco leaves us little reason to expect an out-
break of volcanic activity there, or any association what-
soever of the earthquake of April i8th, with volcanic con-
ditions.

SLIPPING ROCKS ALONG FAULT-PLAN E8.

The second great cause for earthquake shocks is that
of slipping of the rocks along planes of breaking, or fault-
planes, when the strain to which the g^rowing mountains
are subjected becomes so great that the rocks must either
break and slide over one another or slip along lines of
previous fracture. This may be illustrated by reference
to a specific instance, one which the writer had the good
fortune to study in the summer of 1905. This instance is
m Alaska, north of Sitka, and almost at the very base of
Mount St. Elias. At this point a jfrreat inlet, known as



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SAN FRANCISCO S GREAT DISASTER. 3 1

Yakutat Bay, extends into the very heart of the Mount St.
Elias range, its total length being about seventy-five miles,
and its walls being made of mountams rising from 3000
to 16,000 feet above sea-level. This part of Alaska has
long been known to be a region of growing mountains,
and earthquake shocks have been frequent along various
points on the coast, in this respect resembling the condi-
tion in the Coast Ranges of California.

In September, 1899, ^^ui earthquake shock of great
violence occurred in this inlet. A party of prospectors
were camped at a point on the shores, and their account of
the shaking of the ground is exceedingly vivid. They re-
port that great masses of rock fell from the mountains;
the neighboring glacier front was greatly fractured and
fell into the fjord; and a huge water wave rushed up the
inlet, washing high on its shores. The earthquake began
on the 3rd of September and there were frequent shocks
until the 20th, the two most violent occurring on the loth
and 15th of the month. On the former day, between 9
A. M. and 3 P. M., more than fifty distinct shocks culmi-
nated in one of exceptional vigor, during which the ground
was so shaken that it was impossible to stand up.

Thirty-five miles from this point is an Indian village
in which a number of white men also live. Durir^ the
same period, and in the same succession of violence, shocks
occurred of such alarming severity as to drive the inhabitants
from their small wooden houses to tents on neighboring
hills. During this same month, a violent earthquake vis-
ited Muir inlet and shook the earth so violently that the
front of the Muir Glacier was broken into pieces and thrown
into the inlet, forming such a mass of icebergs, that for



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32 SAN FRANCISCO S GREAT DISASTER.

three or four years it was impossible for the steamer to
take parties of tourists up to the glacier, as had been the
custom each summer.

While studying the geology and physical geography
of the Yakutat Bay inlet in the summer of 1905, my party
had the opportunity of studying not only the effects of
this earthquake, but also its cause. Owing to the fact
that the region of greatest disturbance is not inhabited
there was no destruction of life or property, but the moun-
tain faces are scarred by huge avalanches which the violent
shaking of the ground threw down. The effect of the
great water wave is plainly visible along and near the shore
line, especially where it is forest-covered. In sudi places up
to an elevation of forty feet, the forest is completely de-
stroyed and a mass of torn, twisted, overturned trees lit-
ters the surface in such a state of utter confusion as only
a violent rush of water could produce.

We found that during this earthquake the mountain
rocks enclosing the inlet had been bodily uplifted, in one
place to an elevation of forty-seven feet. The evidence of
this is of the clearest kind. Beaches, wave-cut cliffs and
sea-caves now stand where they were hoisted high above
the reach of the highest waves. On these elevated strands
various marine animals are still clinging to the rocks,
among them barnacles and mussel shells which, i^i 1899,
were growing in the sea at levels varying from five to
forty-seven feet below their present positions. Annual
plants and young alder and willow bushes have since taken
root on the elevated shores and there exists the anomaly of
land plants growing where six years before the salt water
stood.



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SAN FRANaSCO's GREAT DISASTER. 33

A study of these elevated strands shows that they
were not all upraised to the same elevation. In one part
of the inlet the uplifted beaches stand five feet above the
water^ in another part seven to nine feet, and still another
eight to ten feet; at one point seventeen to nineteen feet,
and along a stretch of coast line three or four miles in
length, at an elevation of from thirty-three to forty-seven
feet above present high tide mark. These differences in
elevation are the result of the fact that the upward move-
ment of the mountains was along a series of fractures or
fault-planes. The mountain, as a whole, was bodily up-
lifted in this section, but the mountain mass was moved
higher in some parts than in others, being broken and
raised as a series of tilted blocks bounded by fault-planes.
In certain parts of the fjord we were able to actually see
the fractured surface, but in other parts it was hidden be-
neath the waters of the inlet. Where the faulting crossed
the land the surface is fissured and upraised in a series of
little steps or terraces. In some instances these minor
faults show a vertical movement of not less than three feet.

Such fracturing of the rocks must of necessity have
sent a series of violent jars through the crust as the solid
rocks slipped and ground over one another; and there can
be no question but that the earthquake of 1899 was the di-