The Idaho Springs siftings-news., 1906-05-12
SEES SEISMIC PERIL.
PROF. GoODF OF CHICAGO UNI
vERSITY ON EARTHQUAKE
rremors in Region of the Garden
City as SymptomS-Record OF
Earthquakes in San
Francisco.

tions that Chicago may experience
an earthquake within few years,
according to Professor ]. Paul Goode,
OF the University of Chicago geology
faculty. The presence of certain
species of rock in the earth inside
or near the city limits, he believes.
is an indication of a condition that
might result in the dismantling of a
portion Of the city.
There is no absolutely geological
proof that Chicago may have an
earthquake in the next few years.
Professor Goode declared. "One can
detect slight symptoms, however.
Certain formations of certain kinds
of rock underneath Chicago might
be taken as an indication. An earth
quake is as simple as the breaking
Of q timber.
Il bsliSve that the seat of the
disturbance at San Francisco was
| about seven miles below the surface
of the earth 1t was quite probable
slipping of the crust of the earth.
| Generally one block of the crust
| slips up while the other slips down.
The focus of the disturbance may be
noted by the direction of the cracks
| in the Sierra Madra Mountains are
the wrecked buildings.
The Sierra Madra Mountains are
young and are growing slowly. and
no doubt their growing was the
cause of the earthquake"
According to Rollin ID. Salisbury,
| of the university. California has ex-
perienced close to 1000 earthquakes.
of which number All have occurred
| in San Francisco.
Previous to 1887, 94S earthquake
| shocks have been recorded in Cali
fornia," he stated. of these AIT
have taken place in San Fransicc'.
| Since that date the earthquake leG-
ord of California. so far as available,
as follows: 1888, SO; 1889, 40; 1890,
30; 1891. 21; 1892, AZ; 1893, Al; 1894.
SO; 1895, SO; 1896, 4o 1898, &c.
THE majority of this large num-
ber of earthquakes were the merest
tremors. Many of them would have
| passed unnoticed but for the exist
ence at various points of seismo-
graphs which record movements
much too slight to be sensible.
Practically half of the earthquakes
recorded in California have been felt
in the vicinity of San Francisco.
| Only a few, however. were severe
enough to be destructive. The most
severe was April Is 1902. Others
| severe enough to be destructive oc-
Cured April 81, 1892, and March 30,
1898. A careful record of earth
quakes and of earth tremors has
been made at Lick Observatory and
on Mount Hamilton"
According to Professor Ulysses S.
Grant, head of the geology depart
ment of Northwestern University,
there is no city in the country in
| which a great earthquake could be
more destructive than in San Fran
cisco, because the western city is
built on solid foundation of rock.
| IF a shock of equal severity had
| occurred in Chicago" said he, "it is
probable few buildings would have
| been destroyed, because Of the clay
and gravel foundation of the city. 1t
is probable there may be smaller
shocks in the Western States for a
| few days, and there may be consid-
cradle danger from tidal waves, for
these things are likely to come at
once.
In fact it may be that SO severe
shock as the recent cne in San Fran
cisco may bring Oh tidal wave that
| will be large enough to extinguish
| the flames along the water front.
Il cannot say that l think there is
any connection between the eruption
of Vesuvius and the earthquake in
California, because the two phe-
nomena are of different origin. The
latter is of the sort that is caused
by sliding or slipping in the rocky
crust from cooling. Besides this, the
line Of volcanic sympathy which
causes a chain of earthquakes to oc-
cur at about the same time, runs
from north to SOUTH