/l//-Sl2 STATE OF CALIFOlil:NIA-THE RESOURCES AGENCY
DEPARTMENT OF CONSERVATION
DIVISION OF MINES AND GEOLOGY DIVISION HEADQUARTERS RESOURCES BUILDING, ROOM 13'1 1416 NINTH STREET SJICRAMENTO, CA 95814
Dl1trlct Off1iei!11: LOS ANGELES Junip•ro S.rra Bldg., Rm. 1065 107 South lrogdway 9001'
Mr. John D. Conlin
SJICRAMENTO Re1ource1 Bldg., Rm. 118 1416 Ninth StJ"Mt 95814
CI ty of Desert Hot Springs 11711 West Drive Desert Hot Springs, CA 9224o
Dear Hr, Conlin:
SAN FRANCISCO Ferr~ Building 94111
(415) 557-0413
November 10, 1977
l:DMUND G. BROWN JM., GciY•rJJCllr
We are placing on open file the following reports, reviewed and approved by the City of Desert Hot Springs In compliance with the Alquist-Priolo Special Studies Zones Act:
Subsurface engineering geology investigation, San Diego Federal Savings and Loan Branch Office, Desert Hot Springs, California; by G. S. Rasmussen; 4/24/7'{,
Subsurface engineering geology Investigation, Assembly of God Church, Desert Hot Springs, CA; by G.S. Rasmussen; 4/30/75.
Engineering geology investigation, Temple N'Vey Shalom addition, Desert Hot Springs, CA; by G,S. Rasmussen; 12/10/75.
Engineering geology investigation, Retirement Center, NW Corner Second Street and Ocotillo Road, Desert Hot Springs, California; by G.S. Rasmussen; 1/29/76.
Engineering geology investigation, proposed commercial building for Robert W. Dye, Desert Hot Springs, California; by G.S. Rasmussen; 3/31/77. ·
In the future, it would be appreciated If these reports were submitted within 30 days of acceptance as required.
EWH/mkr
cc: A-P fl 1 e.,-' J.D. Fett
/
Sincerely yours,
EARL W. HART Office of the State Geologist CEG 935
I
GEOLOGY GrorHYSICS S~tSMOLOGV
Earth Science S Engineering f)P-572 27595 Sanla Fe Street
Hemet, California 92343
(7H) 658-7509
CHy of Desert Hot Springs 11711 West Drive Desert Hot Springs, CA 92240
Attention John D. Conlin
Gentlemen:
September 8, 1977
At your request we have reviewed the roport by G. Rassmussen dated March 31, l !)77 and entitled:
Engineering Geology Investigation, Proposed Commercial Building, Robert W. Dye, Desert Hot Springs, California
The property is located at the northwest corner of Palm Drive and Desert View Avenue.
ENfilNEE.RING OLE.ANOGRAi'HY HYDROl,O(;y
It is our opinion that the investigation and report have been performed according to the present state-of-the-art and complies with the requirements of the Alquist-Prlolo geologic hazards zono act.
Respectfully, Earth Science & Engineering, Inc.
--ef ~ D Y:.£ <~
John D. Fett, President Cert. Engineering Geologist 858
JF:jl Copy: G. Rasmussen
GEOLOGY GEOPHYSICS SEISMOJ,.OGY
Earth Science fi Engineering 27595 Santa Fe StrE!el
Hemet, California 92343
(714) 653·7509
City of Desert Hot Springs 11711 West Drive Desert Hot Springs, CA 92240
Attention John D. Conlin
STATEMENT
September 8, 1977
ENGINEERING
OCfANOGR,\PHV HYDROLOGY
Review Rasmusson & Associates report dated March 31, 1977 entitled Engineering Geology Investigation, Proposed Commercial Building Robert W. Dye.
Located at the Northwest corner of Palm Drive and Desert View Ave.
3/4 Hour @ $40.00 Report reproduction, clerical and postage
$30.00 9.17
$39.17
I I I I I I I I I I I I I I I I I I I
GARY S. RASMUSSEN & ASSOCIATES /ENGINEERING GEOLOGY
POST OFFICE BOX N • IS6!5 NORTI-! WILL.OW AVENUE • RIAL'l'O, CAl...IF'ORNIA 92876 • (714) 87!1-0906
ENGINEERING GEOLOGY INVESTIGATION PROPOSED COMMERCIAL BUILDING
ROBERT W. DYE DESERT HOT SPRINGS, CALIFORNIA
March 31, 1977
Project No. 1186
r;:-:~-
Prepared for
Robert W. Dye 1146 Olancha Drive
Los Angeles, California 90065
I I I I I I I I I I I I I I I I I I I
GARY S. RASMUSSEN & ASSOCIATES / ENGINERlllNG GEOLOGY
POST OFFICE SOX N • 186" NORTH WILLOW AV'°NUE • RIAL.TO. Cl\LIFORNIA 923'71:5 • 1714) ~!,.'l~~O~Oti
March 31, 1977
Robert W. Dye Project No. 1186 1146 Olancha Drive Los Angeles, California 90065
Subject: Engineering Geology Investigation, Proposed Commercial Building, NW Corner of Palm Drive and Desert View Avenue, Desert Hot Springs, California.
A subsurface geologic investigation of the SS' x 140' parcel was con
ducted at your request. The purpose of our investigation was to determine
if any active faults pass through the proposed building location. We
understand a single-story, commercial structure will be built at the
location shown on the enclosed 20-scale map. A single,backhoe trench was
excavated across the proposed building area to determine the presence
or absence of active faulting in the upper 10 feet of sediments. The
area covered by our investigation is limited to the northwest trending zone
shown on the enclosed 20-scale map (the southwest portion of the site
outside of the zone covered by trenching, has not been proven free of
active faulting). The location of the site is shown on the index map
on page 2 and on the 400-scale topographic map enclosed with this report.
The site was free of man-made structures and vegetation at the time of
our investigation. The location of the proposed structure was deter
mined in the field by measuring from existing curbs with a steel tape.
The field location was based on measurements provided by the builder,
Oscar Aiken. A parking area is to be provided west of the proposed
structure.
The site lies within a zone of known active faults as determined by the
Alquist-Priolo Special Studies Zone Act. The approximate limits of the
Special Studies Zone are shown on the index map on page 2. The active,
Mission Creek fault lies approximately 400 feet northeast of the north
east corner of the site, based on an obvious lineation that appears on
older aerial photographs.
/
._., ...
-·· . ' .. . ' . . .... . · ...
... - .. ·-1· . :·.:~- ,:. ' . - :-....... : . ~ ' \ :'!:· ',f'- ·- •. ·. . . - . -"'. .. ":; ~ ... -,.; . '
··1-- ~
·' _-_ ·-,.. ~ ~ : ' . :, _
..
. ,_ ..
I ., :1
~
I
.• .-
...... ::~ ·. :... -·.., . ..,-_ .. .:.. ·~·.~ ·-.
& ...... .
· ..
·:..:-
• .. "':· • • - "'f"'. { -..
·--
INDEX MAP Robert W. Dye
Desert Hot Springs, California -······ Fault, Dashed where
dotted where approx. buried
Base Map--USGS 1"~2000•
Project No. 1186
r·.,
Gacy S." Rasmussen Ii Associates, Inc.
.. ' '
I I I I I I I I I I I I I I I I I I I
Robert Dye-Commercial Building-Desert Hot Springs March 31, 1977
SITE INVESTIGATION
Project No. 1186
The backhoe trench was excavated at the location shown on the enclosed
20-scale map. The trench was placed so that any active, northwest
trending faults, such as are known to exist in the area, would have to
pass through the trench if the fault exists under the proposed building
site. Our subsurface investigation only includes the area within the
limits shown on the enclosed 20-scale map and does not apply to any
active faults that may exist just beyond those limits.
In addition to the subsurface exploration trench, our investigation
included a geologic field reconnaissance of the site and surrounding
area; review of stereoscopic aerial photographs flown in 1939; review
of infra-red stereoscopic aerial photographs flown in 1971; review of
pertinent geological literature and maps; and review of significant
seismic data. A list of references is enclosed.
SITE GEOLOGY
The proposed structure will be located on Recent alluvium approximately
one mile southwest of the southwest flank of the Little San Bernardino
Mountai,ns. The sediments observed in the trench were probably deposited
by alluvial streams emanating from the mouth of Blind Canyon, approximately
one mile to the north. The coarse-grained sediments observed in the trench
walls are typical alluvial fan deposits commonly found near the base
of mountain ranges in desert areas.
The ground surface slopes downward toward the south at a rate of approxi
mately 3 per cent. The backhoe trench was entered and logged in detail.
The log of the materials observed in the trench walls is enclosed with
this report. The trench was flooded and the backfill material placed in
shallow lifts during the flooding operation. Approximately 10,300
gallons of water were used during flooding and backfilling of the trench.
-3-
I I I I I I I I I I I I I I I I I I I
Robert Dye-Commercial Building-Desert Hot Springs March 31, 1977
Project No. 1186
The full depth of the trench was carefully examined for evidence of Recent
faulting, and none was observed. Nearly horizontal to south sloping bedding
and laminae could be observed throughout the trench. Any disruptions or
offsets due to faulting should have been observable in the bedded
portions of the units. Although the exact age of the sediments at a
depth of 10 feet is not known, they are estimated to be at least
several thousand years old.
SEISMIC SETTING
The location of the Mission Creek fault (a branch of the San Andreas
fault zone) has been plotted at approximately 400 feet northeast of the
proposed northeast building corner by Richard Proctor, 1968. Our
observation of the 1939 aerial photographs, taken prior to development
of the area, indicates the Mission Creek fault lies at the location plotted
by Proctor and as shown on the Special Studies Zone map. No clear evidence
of the fault's location in this area has been documented other than the
vegetational lineation on the older aerial photographs. This lineation
does line up with a possible southwest-facing fault scarp just west of
Northwest Drive and Eighth Street.
The Miracle Hill fault, a branch of the Mission Creek-San Andreas fault
zone, is shown northeast of the Mission Creek fault on the Special
Studies Zone map. Observation of the 1939 photos, suggests that the
Miracle Hill fault trends more westerly than shown on the Special Studies
Zone map and probably merges with the Mission Creek fault due east of the
site.· The Miracle Hill fault does not appear to rupture Recent alluvium,
as does the Mission Creek fault, based on observation of the photos.
The Mission Creek fault is considered to be an active fault in this area
and has had historic earthquakes along it.
Other faults in the area include the northwest-west trending Banning
fault, approximately 4 miles to the southwest, and the north-northwest
-4-0.A.RY S. l't.A.Sl><tUSSl!lN & ASS=:r.AT:WS
I I I I I I I I I I I I I I I I I I I
Robert Dye-Col!lillercial Building-Desert Hot Springs March 31, 1977
Project No. 1186
trending Blind Canyon fault, approximately one mile to the northeast. The
Banning and Mission Creek faults are considered to be the two main
branches of the San Andreas fault zone in the upper Coachella Valley
area (Desert Hot Springs area).
Additional active faults are located within the general region, such as
the Pinto Mountain fault to the north and northeast, but because of
their much greater distance from the site and lower or equal maximum
probable earthquakes expected, they are not considered significant when
compared to the nearby traces of the San Andreas fault zone (Mission
Creek fault).
SEISMIC HISTORY
Numerous earthquakes up to Richter magnitude 5.8 have occurred along the
San Andreas and Pinto Mountain fault zones in the general region.
Probably the most significant historic earthquake in the area was the
Richter magnitude 6.5, Desert Hot Springs earthquake of December 4, 1948.
The epicenter of this earthquake was located approximately 6 miles south
east of the site. Although the epicenter of this earthquake was located
in the foothills of the Little San Bernardino Mountains, the subsurface
movement or origin of the earthquake is believed to have occurred along
the Mission Creek fault at depth (Richter, et • .!.!_., 1958; Proctor, 1968).
Therefore, the effective point of energy release at the surface may have
been considerably closer to the site.
Earthquakes of magnitude 6,Q and greater commonly result in surface
rupture along faults in California. However, no surface rupture along
the Mission Creek or related faults was reported after the 1948 earth
quake (Proctor, 1968).
The Imperial Valley earthquake of 1940 has been reported with Richter
magnitudes ranging from 6.7 to 7.1. This earthquake also originated
along the San Andreas fault zone. Therefore, at least two earthquakes
-5-
0-.A.:A.Y S. RASMUSSlDN .!I:; .ASSOCIATB:B
I I I I I I I I I I I I I I I I I I I
Robert Dye~Commercial Building-Desert Hot Springs March 31, 1977
Project No. 1186
of Richter magnitude 6.5 to 7.1 have occurred along the San Andreas fault
zone in this region in the last 35 years.
SEISMIC ANALYSIS
The nearby Mission Creek fault is considered to be an active fault, based
on both surficial evidence and seismic history. The Banning fault is
also considered to be active, as historic earthquakes up to Richter
magnitude 5.5 have occurred along it. Because of the abundant evidence
of activity along these two faults and the two large historic earthquakes
along the San.Andreas fault zone previously mentioned, the probability
of a large earthquake in the area w.ithin the next 100 years seems quite
high.
Recurrence intervals for maximum probable earthquakes cannot yet be
precisely determined from a statistical standpoint, as recorded
information on siesmic activity does not encompass a sufficient span
of time. However, based on information available at this time, it is
our opinion that a Richter magnitude 7.5 earthquake, originating along
one or more branches of the San Andreas fault zone in this area (Mission
Creek, Banning, and related faults) should be expected within the next
100 years (at least SO percent chance of occurence). An earthquake of
this magnitude and distance from the site can be expected to produce
maximum ground accelerations in bedrock under the site of approximately
0.7g. This acceleration should not necessarily be used as a design value
as it is a peak acceleration and is estimated for bedrock (estimated to
be more than 1,000 feet deep under the site).
FLOODING
The older photographs indicate the area has been subject to flooding
during historic times. The large grain size of the subsurface materials
including small boulders, indicate the site has been subject to periods
of flooding in the Recent geologic past. The flood control channel north
-6-
I I I I I I I I I I I I • . , I I I I I I
Robert Dye-Commercial Building-Desert Hot Springs March 31, 1977
Project No. 1186
of town and existing man-made improvements should help to mitigate the
flood hazard on the site.
CONCLUSIONS
Ground rupture due to faulting is not expected through the proposed building
site as no evidence of Recent faulting through the area trenched was
found during our investigation.
No active faults pass through the proposed building area that have dis~
rupted the upper 10 feet of alluvium on the site, as determined by
trenching.
Severe seismic shaking of the site should be expected in the next
100 years.
Earthquake induced flooding of the site is not likely as no large bodies
of water exist above the site, other than water in the Colorado River
Aqueduct.
Liquefaction and other shallow ground water hazards are not expected
as the ground water table is at least 100 feet deep .
Earthquake induced landslides or mud flows are not likely due to the
distance to the nearest steep slopes and existing flood control channel.
Cracking of most buildings and parking lots in Desert Hot Springs may
be evidence of subsidence of the area due to ground water withdrawal.
No documentation of this phenom.ena exists for this area but is common
i.n other areas where similar conditions exist.
RECOMMENDATIONS
A maximum probable earthquake of Richter magnitude 7.5 is expected
-7-
I I I I I I I I I I I I •• I I I I I I
Robert Oye-Conunercial Building-Desert Hot Springs March 31, 1977
Project No. 1186
along one or more branches of the San Andreas fault zone in this area,
therefore we reconunend that human occupancy structures be designed
accordingly.
Human occupancy structures should not be placed outside of the limits of
the area trenched, unless additional trenching shows those areas to be
free from fault rupture.
Encl; 400-scale map 20-scale map References Trench log
Dist: Robert W. Dye (6)
GSR/mt
Respectfully submitted,
GARY S. RASMUSSEN & ASSOCIATES, INC.
/;~/~ Gary S. Rasmussen Engineering Geologi.st, EG 925
-8-
GARY 8. RASMUSSEN & .A.SSOC!A'I"ES
I I I I I I I I I I I I I I I I I I I
Robert W. Dye Proposed Commercial Building Site
Scale 1",.400' Project No. 1186
" .....
I I I I I I I I I I I I I I I I I I I
Zone covered by trenching, area shown to be free of active faulting
Gary S. Rasmussen & Associa es
Robert W. Dye Desert Hot Springs, California
Project No. 1186
Scale 1""2D'
Proposed Building Location
Property Line
0
"'
"' <::: ·~ _, ~ .. "' <>. 0 .. c..
of<.. I I I I I I I I I I I I I I I I
"' :;; <:::
"' >
"' "' "' ·~ > +.> .. "' "' "' Cl
0 .... -0 ... ....
I I I I I I I I I I I I I I I I I I I
REFERENCES
Allen, C.R., 1957, San Andreas fault zone in San Gorgonio Pass, southern California: Geol. Soc. America Bull., v68, no. 3, p. 315-350.
Bennet, J.H., & Rodgers, D.A., 1975, Crustal movement investigations along the San Andreas fault in southern California, in Crowell, J.C., ed., 1975, San Andreas fault in southern California,""i" guide to San Andreas fault from Mexico to Carrizo Plain: Calif. Div. Mines & Geol. Special Report 118, p. 53-60.
California Department of Water Resources, 1964, Crustal strain and fault movement investigation, Bulletin 116-2.
Desert Hot Springs County Water District, 1976, Miscellaneous files.
Fairchild Carner~ September 29, 1939, Stereoscopic aerial photos, flight no. C-6060, photos 244, 246-251, 1"=1500'.
Hileman, J.A., Allen, C.R., and Nordquist, J.M., 1973, Seismicity of the southern California region, l Jan. 1932 to 31 Pee. 1972: Seismal. Lab. California Institute of Technology, Pasadena, California.
Jennings. C.W., 1975, Fault Map of California, California Division of Mines and Geology, 1:750,000.
Lamar, D.L., Merifield, P.M. and Proctor, R.J., 1973, Earthquake recurrence intervals on major faults in southern California, in Moran, D.E. and others, eds., 1973, Geology, seismicity and environmental impact: Assoc. Engineering Geologists, Spec. Pub., p. 265-276.
Proctor, R.J., 1968, Geology of the Desert Hot Springs-Upper Coachella Valley area, California: Calif. Div. Mines & Geol. Spec. Rpt. 94.
Richter, C.F., Allen, C.R., and Nordquist, J.M., 1958, The Desert Hot Springs earthquakes and their tectonic environment: Seismal. Soc. America Bulletin, p. 315-337.
Rogers, T.H., 1966, Geologic map of California, Olaf P. Jenkins edition, Santa Ana Sheet: California Division of Mines and Geology.
Schnabel, P.B., and Seed, H.B., 1973, Accelerations in rock for earthquakes in the western United States: Seismal. Soc. Amer. Bull., v63, no. 2, p. 501-516.
Tyley, S. J., 1974, Analog model study of the ground water basin of the Upper Coachella Valley, California: U.S.G.S. Water-supply Paper.;2027.
0.A.RY $. Fl.ASMU$Sl:!::N & ASSOCIA'rES
0 0 0 ..
/i9 hf },,.._ ;ri/f-:;_ -·- ·-· - ~-·-· ·-·
5
l ~ ·• N52E
Horizontal Scale 1"=10' Vertical Scale
Gary S. Rasmussen & Associates
- - - - - - - - - - - - - - - - - - -