The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1910-05-23
DR.. Fred ]. Pack, of the University of
Utah, Gives His Opinion as to
the Cause of the Dis
turbanCes
CENTER OF THE TROUBLE is WITHIN
STONES THROW OF BIG INSTITUTION
Charles johnson, Weil-Known Photographer and
Deep Student of Seismic Phenomena,
Also Gives Information.


seismograph at the University of Utah.
stated Sunday afternoon that the three
earthquake shocks travelled from the
northwest to the southeast and were
entirely local in their nature. From
the record Of the sersmograph it is evil
dent that the center of the seismic dis
turbance was within a stone s throw
of the university declared DIR. Pack.
HThe record shows that there were no
preliminary tremors such as character
ize an earthquake which occurs at a
distance. The recording point swung
over fully three inches when the first
shock struck, and was kept IN thas
position for number of seconds by
repeated earth tremors from the north
west and was not permitted to swing
back to the other side, as is usually the
case when tremors come from dis
tance'
In discussing the cause and the origin
Of Sundays earthquake shocks, DIR.
Pack said that most of the earthquakes
oririnate some distance from the sur
face, at point known as the centrum.
Directly above tho centrum ut the sur
face is the epiccntrum. He declared
that the tTemors which travelled from
the epicentrum along the surface were
far more intense than those which came
from the centrum to the surface at
right angles. 1--WE know that the cen,
trum was directly beneath us SAID
he. "because of the violence of the
first vibrations, without any prelimi.
nary tremors. Just at the cpicentrum
there is always violent vibration, but
as the earth wave gets further away it
becomes undulatory in character.
"Ncver in the history of the city,
or at least since the. seismogr,aph was
installed, has there been such dis
tinctly local shock, though such shocks
have been experienced elsewhere.
Cause of the Tremors.
"Of tho Two conditions. volcanic az
tivity and lapd mass rcadjustmcnt
which are generally responsible for
earthquakes. the latter was response
bic for the shocks of Sunday forenoon.
The same condition was responsible for
the San Francisco earthquake. This
section of the west has the advantage,
however, over that part of the earth on
which San Francisco is located, in that
it passed through the worst stages Of
land mass readlustment several thou
sand years ago, The coast line is sub
ject at any time to serious crGstal
slips
''Other shocks in this section will
undoubtedly follow In the future,
though | am not appreheusive OF any
extreme danger from the land mass
readiustments.
"Oftentimes one of tho Two condi-
Eiops / mentioned may be entirely re-
sponsible, but not infrcquently disturb
aDces may be traced back to combl-
nation of the two. The terrible disas-
ter of lttlc over year ago. in Gala
brla and Sicily, appears to have been
tho result Of sudden readiustment Of
tho earth block separating tho two,
which was undoubtedly influenced by
the presence OF Vcsuvius. Aetna and
the Laparian volcanoes, Immediately to
the northward The almost complete
destruction Of Charleston several years
ago seems to have been the result of
teetopic activity alone, The Japanese
islands hayo suffered largely from earth
quakes, generated largely by Il combi-
nation of the two causes. The lesser
Antilles arc frequently disturbed by
earthquakes originating solely through
vulcanism
s'The Salt Lake valley was formed
not BY crosional activity, but by cruStal
movement, which brought the Wasatch
mountains TO the eastward TO their pres
ent elevation.
Clarence Kings View.
"CIarence King. Mt ono time director
of the United States geological survey,
has estimated that the great throw Mt
the western face Of the Wasatch noun
tains aggregated 10000 feet This dis
placement, III Will DC ICHltlllpeISu, Is
not the result of single slip, but in
all probability the result Of many, many
smaller ones. And again erosional ac-
tlvity acted contcmporaneously with
the reformation and faulting processes;
so that now many of tho Basin range
mountains have lost the true external
evidence of their block nature. The
city Of Salt Lake is situated imme
diatcly west of this great plane and
directly upon one Of the down thrown
blocks which is now covered by allu.
vium washed from the surrounding hills
The old escarpment. or face, left
through faulting IN many places, still
stands out precipitously, such as, for
instance, directly cast OF Provo, and
cast of Willard City, while at other
places this great fault scarp has been
much eroded and occasionally almost
effaccd. Movement along this great
fracture has continued up to tho pres
cnt.
Evidence of Slipping.
"Evidcnco of recent slipping along
this old Wasatch fracture may he seen
at almost every point from Collmston
on the north to Ncphi on the south. In !