The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1902-11-24
Lester H. Murdoch, Sec
ton Director of Wealth
er Bureau, Writes on
Conditions.
PRECIPITATION CYCLES
Dry Period to Be Succeeded by
Wet Era and High
Water.

Is our climate changing? If this
question were asked 100 men of mature
years, at least ninety of them would
answer in the affirmative.
In Utah. a cycle of unusually heavy
precipitation began in 1866 and con-
tinued until 1886 During that period.
the old settler confidently asserted
that the climate had changed to wet
ter. and even men OF scientific train
ing tried to explain the increased pre-
cipitatiOn as due to human agencies.
IT was stated that the humidity had
been greatly increased by breaking up
the land, irrigation. increased vegeta-
ton. etc. Since 1887 the precipitation
has been deficient. and nothing is now
heardsOn the subject of human agencies
increasing the humidity. Most men who
spent their youth between 1866 and
1886 will now tell you that our climate
has changed to drier.
Great Change in the Past.
It is, therefore, evident that the per-
son who forms the opinion that climate
is changing. based upon his own per-
sonal experience, is very likely to be
mistaken. And yet no one who has
stood near Salt Lake City and OBJ
served on the mountain sides the shore
lines of the ancient Lake Bonneville,
can doubt for a minute that the eli
mate Of the Great Basin has under
gone very decided change. The max
imum height of the old fresh water
lake was about 1000 feet above it's
remnant, Great Salt lake and it's depth
at the point where Salt Lake City now
stands was something like 900 feet.
Lake Bonneville covered the western
half of Utah and small portions of
eastern Nevada and southern Idaho.
It's waters were discharged through
Red Rock pass. in southern Idaho, and
finally reached the Pacific ocean
through the Columbia river. During
the existence of the lake, it's outlet
was lowered 3T5 feet by erosion, pro-
ducing corresponding fall in the lake
itself
The lake existed as long as precipita-
ton was in excess of the evaporation,
and this was for thousands of years.
Finally a change in climate caused the
evaporation to exceed the precipita-
stion, with the result that the lake
dropped below its outlet The fall has
continued until there now remains only
a comparative small body of nearly
saturated brine-Great Salt lake-or,
indeed, il may be that all water dis
appeared from the basin and that the
present lake is the result of a swing
ing back to more humid conditions
The mere fact that lake has disap-
peaTed does not necessarily demon
strate that this change is due to in
creased evaporation or diminished rain
fall, but after careful investigation OF
the subject. Gilbert concludes that the
disappearance of Lake Bonneville can
be accounted for only by a change in
climate.
Era of Transformation Long.
Gilbert calculates that it would take
$4,000 years for Great Salt lake to ac-
cumulate its present supply of chlorine
E7rfVr lot H. l.
tanned of the centuries that have
. elapsed since the time of Lake Bonnie
Vile. His studies of this region aIsC
show that preceding the epoch of high
water was a period during which the
basin was nearly or quite dry. This
period exceeds in length the time tha
has elapsed since the Lake Bonnevill,
epoch. And still preceding that period
of drouth was another humid epocl
during which the water rose to with
in ninety feet of the Lake Bonneville
stage and continued five times as long
Biologists generally agree that ther'
were two periods of glaciation on tn
northern hemisphere. An epoch o
much warmer weather separates tn
two during which most Of the ic
disappeared. 1t seems probable tina
the GwO great lakes which have covered
thin basin were produced by the sam
conditions which caused the two peri
DDS of glaciation and were, therefore
coexlstent with them.
Many theories have been advance,
to explain these great vicissitudes o
climate. but the question is far from
settled
Precipitation Goes in Cycles.
The changes in climate which &c
OlOgy shows have taken place are s
slow that they probably would not b
appreciable in the most carefully. KEEP
record in a thousand years, but a stud
of the precipitation record o
any locality will show tina
there are extended periods o
comparatively dry weather fol
lowed by a number of years with ex
cessive precipitation, and these in tur
by cycle of dry years. During tn
twenty-one years from 1866 to 1886. tn
average annual precipitation at Sal
Lake City was 1919 inches, or 1.S4 in
ches more than the average for tn
entire record, and, during the first thir
teen years of this wet cycle the aver
age precipitation was zoos inches, @
y = = y y = = \ = = = = \ = = = = 4