ML20150E792
| ML20150E792 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 10/07/1966 |
| From: | Case E US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Lemmon D INTERIOR, DEPT. OF, GEOLOGICAL SURVEY |
| Shared Package | |
| ML20150E784 | List:
|
| References | |
| FOIA-88-187 NUDOCS 8807150299 | |
| Download: ML20150E792 (26) | |
Text
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_ Distribution Suppl. '(Proj. No. 419)
DRL Reading R&PRSB Reading bec: E. G. Case P. Norian OCT 7 E J. Newell R. 8. Boyd g
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Assistant Chief Geologist U. S. Geological Survey y Room 4214, 08A Building !
Washington, D. C.
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Dear Mr. Immace:
i In accordance with the sneentantings which were reflected in See,w'wi Olall's letter of March 20, 1964, I su forwarding herewith a regnest '
for a preli=inan site review submitted by the Pacific Gas and Electric i g
Ccapany. This review involves the siting of the Company's proposed nuclear power plant at its site near Diablo Canyon, California. As you will note, this site is quite near the Cayucos Site previously .l reviewed by the Geological Su...i.
d' We would appreciate receiving, by early Movember 1966, a draft rW !
of tha results of a pre 19=4n=7 review by the Geolcgical Su .ey of i those geological and hydrological features of the propoced reegtor Q
.d.a.,.,.%..~s.use:,locaticutehichay.> bate b al gar #3ruipca?. cur salaatiinW4Mesilie6dItN AND' s g- g gIsitIe 7 Please note that the information contained in j the enclosure should not be released or discussed publicly at this time. '
Sincerely yours, Original signed by j,
E. G. Case
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Edson G. Case, Assistant Director !
, Division of Beactor Licensing ;
Enclosure:
1 Prelf=in= 7 Site Bpt. !
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e f / g Att' ached are draf t reports f rom the Geological Survey
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p and Coast & Geodetic Survey concerning four sites 4 / /
/ / / proposed by the California Department of Water to ,cs... .Voa,i> gnits nuians Resources. Copies of these drafts have been pre-Dr. Hann un viously transmitted to the ACRS and should be made final for review of the Committee at its July meeting.
to (s.m. .e. vaita anus um uns Subject to any connents you may have, I plan to Dr. Doan un request the Surveys to officially transmit these reports in their present form Tuesday, July 5. $
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( UNITED STATES DEPARDENT OF THE INTERIOR DRAFT Geol.ogical Survey Miy 26, 1966 Coulter San Luis Obispo County, California f
Cayucos Site e f$
General The Cayucos site is undcriain by rocks of the Franciscan formation which contains many intrusive serpentine bodica. The difference in physical properties between the Franciscan rocks and the serpenti:.cs and within the serpentine bodies themselves between massive serpentine and altered and sheared serpentine is great. This dissimilarity in physical properties, primarily shearing strength, exercises a strong geologic control on slope stability and foundation conditions in terrain undcriain by Franciscan rocks. There are no topographic indications of major landslide probicas within the site area.
Minor slope stability probelms related to cut-slope development during construction can be anticipated.
Faults Detailed mapping which would give diagnostic evidence concerning the )
presence or absence of large faults at or near the site is not availaua and their existence there certainly cannot be precluded. High-angle shcar zones with souge development up to several feet in width are common. Such shear zones are characteristic in Franciscan rocks and are generally considered to relate to a geologically remote, not recent, period of tectonism. The scismically active Nacimiento fault is located approximately 10 miles north-cast of the site. The nearest point to the site on the San Andreas fault in approximately 40 miles, and the Santa Ynez and Big Pine faults pass within 90 miles of the site. An undetermined number of of fchore faults whose exact pocitions and trends are unknown have been postulated in the area approxi-mately 75 miles southwest of the site.
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Soismicity The Cayueos site is located within a zone of active ocismicity. In the period 1934 to 1962, 14 earthquakes with epicentral locations within 20 miles of the site have been recorded. Of those 14 carthquakes, seven had a Richter magnitude between 4.0 and 4.3 and the remainder were less than 4.0. Within the zone betwoon 30 end 40 miles from the site threc epicentral locations with Richter magnitudes of 6.0 and 6.5 have been recorded. The highest intensity assigned to the Cayucos area was VII M.M. associated with the earthquake of November 1927 with a Richter magnitude of 7.3 and an epicentral location 55 miles west of Point Arguello.
Problems because of the complex stratigraphy, the general lack of continuous pappable lithologic units, and the intricacios of localized shearing and attendant structures, the recognition of major throughgoing structural features in Franciscan terrain is difficult. Detailed regional mapping and structural analysis will be required to provide diagnostic evidence that may prove or disprove the existence of major faults south-west of the Nacimiento fault in the vicinity of the Cayucos site.
Massivo serpentine is relatively stable in steep or vertical cuts whereas i
- I cut slopes in sheared serpentine are potentially unstabic on slopes greater l than 1:1. Insofar as bearing capacity under foundations is concerned, the shearing strength of massive serpentine is relatively high but decreases with increasing proportions of shearing and alteration. Voins of soft altered material in hard serpentine may present special problems. llence, for adequate 2
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l geologic cvaluation of the Cayucos sito accurate delinestion of the distri-bution of- serpentino bodies and of the degree of shearing and alteration within the bodies is required. Such delineation can best be provided by detailed geologic mapping combincJ with an adequate sampling and testing program designed to provide sufficient information on the physical properties of the various lithologic units underlying the site to formulate adequate slope and foundation design criteria.
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' UNITED STATES .- t i-
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Coulter
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The Sycamore Canyon site lies adjacent to the beach on the. south flank -)
of the. Santa Monica Mountains. The site is undcriain by a complexly folded, _
faulted and sheared sequence of Miocene sudimentary and _ intrusive igneous rocks. ThereistopographicevidenceinSycar$oreCanyon,beyondthelimits 1
of the site, of landslides in geologic environments similar .to those existing within the site.
Faults Three faults with_large-scale stratigraphic displacement, th) Sycamore Canyon fault, the Baudette fault and the Serrano fault, and several subsi-diary faults of Icsser displacement have been recognized within the site area. Diagnostic evidence as to whether or not any of these faults displace Pleistocene and/or Recent deposits is not availabic. The active San Gabriel fault lies 26 miles northeast of the site. The nearest point to the site on the Santa Ynez fault is 32 miles north; the Newport-Inglewood fault 36 miles cast; the San Andreas fault 46 miles northeast; the Big Pine fault 45 miles north; the Garlock fault 52 miles north; and the White Wolf fault i
56 miles north. An undetermined number of of fshore faults whose exact positions and trends are unknown have been postulated in the Santa Barbara channel south of the site.
Seismicity The Sycamore Canyon site is located within a zone of active scismicity.
In the period 1934 to 1962, 39 carthquakes with magnitudes of 3.0 to 3.9
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Problems The following geologic problems are involved in the consideration of the Sycamore Canyan site.
- 1. The site is within the zone of intersection of several faults, the date of the latest movement or uhich has not been, and perhaps here for dearth of diagnostic stratigraphic criteria cannot be, established.
- 2. There is evidence of serious slope stability problems in the Syca'23re Canyon area which may be found to affect either the site itself or the natural drainage system through the site.
- 3. The sito is located in a zone of active seismicity the relation-ship of which to the f aults through the site has not been established.
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DEPARutEllT OF Tile I!1TEll10it DRAFI: tby 1966 Geologf. cal Survey coulter Ventura County, California Oxnard Site General The Oxnard site is underlain by at least 1,800 feet of unconsolidated, saturated, predominantly fine-grained alluviua. The maximum elevation within the site is 10 feet above sea level'and the relief is low. The general seaward slope of fshore from the site is gentic, approximately 40 feet per mile; however, 1 mile west of the site this gentic slope is dissected by the steep declivity at the held of the Hueneme submarine canyon. Insofar as slope stability is concerned, this relationship imposes steep gradient rather than gentle gradient controls on the submarine topography.
Faults Recognition of faults in an actively ag:;rading alluvial sequence of this type is virtually impossible without extremely detailed subsurface exploration.
The nearest. recognized seismically active faults, the Santa Ynce and Big Pine, are located approximately 30 miles north of the site. The nearest point to the site on the San Andreas fault is approximately 50 miles northeast. An undetermined number of of fshore faults whose exact positions and trends are unknown have been postulated in the Santa Darbara channel south of the site.
Seismicity The Oxnard site is located within a zone of actrie seismicity. In the period 1934 to 1962, 54 earthquakes with epicentral locations within a 20-mile radius of the site have been recorded. Of these 54 carthquakes, four had a Richter magnitude of 4.0 to 4.7 and the remainder were less than i
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(39 4 .-0 . Since 1769, six large earthquakes with entimated or recorded iangal-i tudes of 6.0 or greater have occurred within a 60-mile radius of the uite.
The highest intens'lty assigned to the Oxnard are.i was VII !!.!!. nscociated with Kern County carthquake of 1952 with a Richter magnitude of 7.7 and an epicentral location along the White Wolf fault approximately 75 milea north of the site.
Problems
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Ouring the Alaskan earthquake of 1964, extensive surface rupture, massive liquefaction flow slides on relatively gentle slopes and dif ferentitil compac-tion were observed to have taken place in thick saturated alluvial sections similar to that underlying the Oxnard site. These effects were observed at
, epicentral distances ranging from 30 to more than 100 miles, i
- The potentially unfavorable dynamic response characteristic of the-alluvium at the Oxnard site combined with the steep gradient controls resulting from the location immediately of fshore of the llueneme submarine canyon suggests the Aikelihood that comparable effects resulting from a major.carthquake centered on any one of the active faults located within 100 miles of the Oxnard site may be anticipated.
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. del'AliTitF.NT OF Tild 111T RIOR j DRAFT: llay 1966 Ge 1 gical Sutvey Coulter Tchachapi Site General The proposed plant site is located ou the routocast cdge of the San Joaquin Valley approximately 17 milco south of Arvin and 11 milca north of Gorman.
The site is underlain b/ silty sandstodes of the Tejon formation of Eocene age which dip northwesterly a*. modcrate to steep angles. The rocks of the Tejon formation are der.cribed as being weak when wet and slightly stronger when dry. Boring data indicato artesian groundwater conditions in the vicinity of the site and "suBgest that serious hydrostatic uplift pressures may be encountered at foundation grade."
Faults Five major seismically active faults shouing evidence of recent primary surface rupture occur within a 20 mile radius of the site, llany additional faults with less prominent surface expression but with possibly equal or even greater potential ef fect on the site lic within this area. Evidence cf a flowing spring and juxtaposed divergent bcoding attitudca along the gully entering the plant site at the southeast corner suggest the presence of a fault traversing the site from southeast to northwest.
Water supply for the plant is to be taken from the aqueduct. To the extent that a continuous supply of water represento an operating requirement for the plant, consideration must be given to possible disruption of flow through the aqueduct in those many localitics where the line crosses major fault zonco between the Tchachapi Site and tha ultimat,c source of water to the caot.
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Problems In addition to the high regional seicraicity of the aret. the following prob 1 cms at the Tehachapi: Site must be considered:
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- 1. Poor foundation conditions on weak, saturated,' silty sandstonu with potential hydrostatic uplift pressures at foundacion grade.
- 2. Compicx1y-faulted bedrock adjacent to and perhaps beneath the site.
- 3. Possible interruption of plant water supply by disruption of the aqueduct throughout a broad zone of scismically active terrain east of the site.
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, e DRAFI RF. PORT ON THE SF1SMICITY OF Tild CAYUCOS, l OXNARD. SYCAMO.".C #4NYON. AND TEllACllAPI CALIFORNIA AREA l In response to the request of the Division of Reactor Licensing of the i
Atomic Energy Commission, the Seismology Division of the Coast and Geodetic ,
Survey has prepared this report on the seismicity of Cayucos, Oxnard, Sycamore Canyon, and_Tehachapi, California, and their environs.
The f ault nearest Cayucos is the Nacimiento fault which is inland and trends northwest-southeast parallel to the coast at a distance of about 8 miles from the site. The San Andreas has roughly the same orientation and is approximately 42 ,
miles from the site at its nearest point. Historically, Cayucos has experienced macroseismic dis turbance from at least sixteen carthquakes registering intensities above Modified Mercalli III. The s trongest recorded intensity was MM VII caused ,
by the earthquake of November 4,1927, which occurred of f Point Arguello about 75 miles f rom the site and had a magnitude of 7.5. This produced a maximum acceleration vf 0.13g. On February 23, 1931, a small earthquake occurred in the l immediate vicinity of Cayucos, a result of which a maximum intensity of V was l
produced.
l l 0xnard is in an area that is underlain by deep alluvial deposits and evidence ,
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( of surface faulting is 'not readily detectabic. Ilowever, to the north and east are a number of poorly defined faults of the transcurrent system prevalent in I l this region. The site is approximately 25 miles from the Santa Ynez fault and ,
50 miles from San Andrecs fault. 'It has been subjected to scismic disturbances of HH intensity III at least 35 times during historic timep.
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Q Intensity VII is the highest experienced and occurred un three occasions.
. The firs t on January 9,1857, as the result of an earthquako near Fort Tejon, distance, 50 miles; the second caused by a small nearby earthquake on December 14,
( 1912; and the third on July 21, 1952, as a result of the Kern County carthquake which was 55 miles dis tant and had a mat,nitude of 7.7.
The Sycamore Canyon site is located at a distance of about 26 miles from the l
e San Gabriel fault, 32 miles from the Santa Yne: fault and 36 miles vest of the Newport-Inglewood fault. The nearest point on the San Andreas fault is 46 miles to the northeast. It has been subjected to scismic disturbances of intensity III or more at least 42 times since 1769. A maximum intensity of VI was recorded as a result of 13 earthquakes ranging in distance f rom 10 to 210 miles.
The Tehachapi site is very near the juncture of the San Andreas fault and the f aults of the transcurrent system of southern California. It lies between two seismically active faults, the White Wolf,11 miles to the northeast and the Carlock, 5 miles to the southeast and at a distance of 9 miles from San Andreas which lies to the southwest.
It is an ares of very high seismic activit.y. The most notabic carthquake to occur here was the Kern County carthquake of July 21, 1952. It had a Richter magnitude of 7.7 and a maximum intensity of XI at a point near Bealville, 26 miles f rom the site which would have subjected the latter to an intensity of VIII and an acceleration of .27g.
Using the criterion of the ef fect of a magnitude 8.0 carthquake on the nearest point of the San Andreas f ault to each site the following effcets are postulated:
Cayucos, intensity VIII, acceleration 0.27g; Oxnard, intensity VII, acceleration 0.13g; Sycamore Canyon, intensity VII+, acceleration 0.23g. The intensity given l
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L Y 3 above for Oxnard refers to bedrock; howuver, the site is situated on 1000 f t of alluvial material so that the acceleration could be as much as 3.5 titaca higher.
, To evaluate further this estimated acceleration at Oxnard, a seismic measurement of the ground amplification factor is recommended.
With regard to Tehachapi a_cagnitude 8 shock occurring at the nearcot point on the San Andreas fault would cause an intensity at the site of X+ and a maximum acceleration of .70s. If 'the complex nature of the f ault structure near a the
.iotersection of the Garlock and the San Andreas faults is taken into consideration, there is' a high degree of probability that a shock of magnitude 8 could occur within 5 miles of the site in which case it vould be subjected to intensity XI and a maximum acceleration of .98 An excellent example of the earthquake forces encountered in this region is given in descriptions of the Kern County earthquake damage near Bealville in U. S. Earthquakes,1952, page 17 and the publication. "Earthquakes in Kern County, California during 1952," (see reference) .
Another factor for consideration in evaluating the coastal areas as a reactor site is the possibility of tsunami damage. For the most part, a tsunami is generated by a submarine earthquake or an earthquake located close to coastal areas although only a small percentage of earthquakes of this type have been known to generate measurable water waves. The vertical displacement of submarine blocks of the earth's crust is the most commonly accepted explanation of the cause of these waves. Since it has been observed on land that great earthquakes have caused uplif ts of 30-50 feet and af fected crustal blocks hundreds of miles long and up to a hundred miles wide, it is easy to conceive of auch a crustal movement
- under the ocean generating huge water waves. Slides along the coasts are also I
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thought to be possible sources of tsunamis and great earthquakes originating on *
. the sides of deep oceanic troughs may cause huge masses oi unconsolidated taaterial to slide into the depths, displacing a great amount of water. It has been sug-gested 'also that there is a possible coupling mechanism between tsunamis and large surface waves with perieds over a minute. llistorically, those waves have had amplitudes considerably less than those transmitted directly frw the sources. '
s Along the coast of California there is no well established source areas for the generation of tsunamis. On December 21, 1812, there was a strong submarine earthquake (possibly 7 1/4-7 1/2 magnitude) off the southern California coast which reportedly generated a tsunami that reached land elevations of 50 feet at Gaviota, 30-35 feet at Santa Barbara, etc. However, it has not been possible to definitely substantiate these heights. So employing the results of Iida's work for estimating tsunami wave heights along the Japanese coast and realizing the fauit movements along the California coasts are mos tly strike-slip, it is estimated that tsunami run up (flooding) caused by locally generated tsunamis would not be more than approximately 30 feet. For tsunamis generated by distent sources such as Japan, Aleutians and the extension of the San Andreas fault of f the west coast the tsunami run up at these sites would be approximately 30 feet above mean lower low water.
In suurnary, the Survey believes that within the lifetime of facilitica located l at the above sites and on rock, accelerations in the period range of 0.3 to 0.6 seconds should be taken into account in the designs as follows: Cayucos, 0.27g; Oxnard, 0.13g and as much as 3.5 times greater if on approximately 1800' of alluvium; Sycamore Canyon, 0.23g and Tehachapi 0.9g. For tsunami run up from j i
distant severe marine earthquakes, the coastal sites should be protected to a 1
vertical height of 30 feet above mean lower low water. This 30 feet level is
c c alco adequate protection for any tsunami generated by local carthquakes along the
.cean of southern California.
U. S. Coast and Geodetic Survey Washington, D. C.
May 24, 1966
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EF.:Eth:'N "United States Ear thquakes ,1952," Leonard it. Murphy and William K. Clou<', U. S.
Department of Coanerce, Coas t and Geodetic Survey, Serial tio. 173, 1954 "Earthquakes in Kern County, California durine,1952," California Department of tiatural Resources, Divis ion of Mines Bulletin 171, 1955.
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Di n ta nce--In t : n::it c Date Epicent:s] Area Intensity (Miles) (."~)
Cavucos Oxn'.rd Svear. ore 'n : . .ri VIII-IX 165 45 V 40 V 1769 July 28 Los Angeles region Off Coact of So. Calir X 110 IV 45 VF 75 VI 1812 D2e 21 x 135 III*
1852 oct 26 San Simeon l Ventu a County VIII 120 30 V 35 V 18521:ov 27-30 Los Ange3cc County VIII 365 50 V 15 VI 1855 July 10 Fort Tejon X-XI 115 V 50 VII 70 VI 6 (X) 1857 Jan 9 3 ? III+>
Bakercrleld V .
1870 Jan 3 Ot: ens Valley X -XI 175 IV 170 IV 170 IV 115.I'J" 1872 ?:ar 26 V-VI 120 30 V 35 III 1833 Sept 5 Ventura IV 3G 11I 1835 Apr 7 Bakersfield V-VI 3C (I'J 1890 July 24 Ba}:crofield IX -X 250 III 21 0 V '.7 1892 Fcb 23 B?.ja Cr ' ~ f orn' r-VII-IX U.S.
VIII-IX 169 III 35 VI 35 VI 1893 I.pr 4 Los Angeles recion VI 135 (IV) 1896 Arc 17 Hanford San Ear: ' dino Cot".ty VIII 100 III 80 VI 1899 July 22 San Jacinto IX 130 V 1899 Dec 25 ,
Ma x10.u:.1 Distance--Intenrity .
Date Epicentral Area Intensity (Miles) (X.I) ,' -
Cayvcos Oxnned S ter.or - Tc : - -h 1902 July El Santa E2rbarn County VIII 60 IV l
(2 sini]ne af tershoc': , Jul;. 31) 1902 Dec 12 Los Alamos VII 60 III 1993 Jan 7 Bakersfield V-VI 30I'J-O 1905 Mar 18 Bakersfield VI .
30 IV 1905 Dec 23 Eakersfield VII 30 IV+
1906 Apr 18 San Francisco XI 223 (V) 1908 Sep 4 Bakersfield (2 choc': -) VI 3C l'.
1910 May 6 Ucar Pichop VI ]C'; (III) 1912 Dec 14 oxnard VI-VII M' :: . 25 V Ei 1915 Jan 11 Los Ala.ox VIII 60 IV .
1915 M,:. 23 Southern sierra nev .t V+ 8-3 (I~.G 1916 Oct 2'2 Tejon r: m VII 5 (VII) 1918 Mar 6 Santa Monica (V-VI) 15 V 1918 I.pr 21 Riversice County, M9g 6.8 IX 125 I.V 100 V-VI 1918 Eo'z 19 Santa Meaf.ca Bay VI 15 V
.1919 Jan 25 Tejon rasa V :, (v) 1919 Feb 16 South of Maricopa VII 30 1.
l Ma >:Ir .ua Di s t a nc e --In'n' ~ * ' --
Date Epicentral Area Intensity (Miles) (: _-1)
Cayucon 0::nn ed P're c,:' - Tc.-^:-r *. ~
9 1902 Ju]; 27 Santa Ihrbarn Count VIII 60 IV (2 sitat]ar .'f tershock:. July 31) 1902 Dec 12 1,os Alaraos VII 60 III 1903 Jan 7 Bakersfield V-VI 30 IiG 1905 Mar 18 Bakersfield VI -
30 I'l 1905 Dec 23 Ba'bersfield VII 30 IV+
1906 Apr 18 San Francisco XI 23 ^) (V) 1908 Sep 4 Bakersfield (2 shocks) VI 30 l'.
1910 May 6 Near Bishop VI 180 (III) 1912 Dec 14 oxnard VI-VII m :.:. 25 V-w 1915 Jan 11 Los Alamo: VIII 60 IV .
1915 M,:. 28 Southern S:erra ::ec':t V+ 85 (1~.9 1916 Oct 2'2 Tejon I': no VII 5 (VII) 1918 M,r 6 Santa Me::ica (V-VI) 15 V 1918 Apr 21 Riverside County, :7'c 6.8 IX 125 I.V 100 V-VI 1918 ::o 19 Santa Men. ca n.y VI ,
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'1919 Jan 25 TcJon Pasa V 5 (V) 1919 Feb 16 South of M7r:copa VII 30 lil-t
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Date Eolcen'. el A: ; - In;en: gt (I-:1200) '.
Cav m _ucon 0::n:. I'J _S.veanore Tc: :: .M 1920 June 21 Ingleucod VIII 19.22 Mar lo Cholame Vt_11ey, Mag 6l. IX 45 VI J25 III 103 IV*
1925 June 29 santa inrbara, Mag 6.3 VIII-IX .
1926 Jun 30 Kern River Canyon VI 33+(i 1927 Jul 8 lbkersfield IV 39 III*
1927 ::ov 4 off Pt. Arguello, Mag 7.5 IX-X 75 VII 135 V-VI 155 III 1930 Jon 15 34. 2:'. , 116.9u, Mac. 5.2 VII(2) 100 V -
1930 Aug 30 33. 9n. , 118. 6'.:, 5.2 VII 40 III lo VII 1931 Feb 23 Templeton, Parkrield, V Max.
Cayucoc 1933 Mar lo 33. 6:!. , 138.o'.., Eng 6.3 IX So VI 50 VI 1: (IV) 1933 oct 2 33,8N., 318.1W, "
5.4 VI 40 (V) q 1934 June -7 35. 9:!. , 120.5E, 6.0 VIII(2) 40 V 335 (IV) 1 , (III) 1935 Jnn 23 35. 5:!. , 119.2w, "
4 V ;0 (i11) 1940 oct 10 33. Sn. , 118.1n:, 5 VI 15 V 19:n June 30 34. ' ::. , 2 ' 9. 6.:, "
5.9 VIII loo V 30 VI SS "
1941 rep 14 37. 6:!. , 2 2 8. 7'.:, "
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i~n i:nna Dis tr u ce --In' en r i ty -
Date Epice:J.rr.1 i."en In t' enc i t:r (I:lles) (I;) - .
Ca':vcos Oxm ed S :c s r :- Tc:: -:: n1 194-1 Sep 21 34. 9::. , 318. 9. , Ic - 5 VI i cI 1941 0et 21 33. 8: . , 118. 2u, "
5 VII 55 IV 40 V i
1941 nov 14 33.8n., 118.2u, 55 VII-VIII 55 IV 40 V Q
, 1942 Oct 21 3 3 . 011. , 116.0w, 6.5 VII 190 IV 1 4.5 1944 June 18 3 3 . 911. , 118.2w, 4.4 VI(2) 50 III
" ys v 1946 I: tr 15 35.7n. , 118.11:, 6.3 VIII 129 V 120 V 1947 Apr 10 35.On., 116.Gw, "
6.4 VII 165 V 160 V 1943 Feb 10 36..tn., 118.Rw, "
4.6 v1 Er(III) 1948 Apr 16 3h On., 119.0~?,
- 4.7 VI 35 VI 30 VI 1948 D2e 4 33. 9n. , 116. 4 '.:, "
6.5 VII 155 VI 140 VI
" ' O 19'19 Aug 27 34.5n., 120.5M, 4.9 VI 70 1-III 75 90 1950 Feb'25 34.6n., 119.1w, "
4.7 VI 40 VI 50 V 1951 rae 25 32.8n., 118.4r, 5.9 VI 100 V 85 V .
l52 July 21 35.On., 119.0%,
7.7 XI 110 VI 55 VII 65 u :c .u (180 r. ' .crshoci:c, n=c. h10 and o cer, recorded at Fa< na fre- July 21 tr.
Septe::.~cer 26; 6 af terchcS:s of 5.0 and over on the: 21st).
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1952 July 25 East of Caliente (2 VII 3 0 2 ~.* '
nhocks)
I!ca:' E: :e i.:ou nt s ' n 2 .~ . ' .
1952 Jul 28 VII 1952 Jul 31 North of Caliente VI 23 1I15 1952 tiuc 22 35. 3II. , 113. 9'.:, IMc 5. 8 VIII 70 IV 80 IV 15 V q 1952 Isuc 23 3 4 . 511. , 118.21:,
5.0 v1 60 VI 60 V 1952 ::ov 21 35.8N., 121. 2'.-:, "
- 6. 0 VII 35 VI 11:0 IV 1954 Jan 12 35.o:1. , 119.0',
59 V2I-VIII 55 y 65 V 11 VI
" 23 V 1954 Jan 27 3 5. 111. , I l D . C.; , VI 1954 I~'r 19 33 3n., 316.2.,
- 6. 2 u 180 IV 170 IV .
1954 !a:c 23 35.ca., 129.O'., .
5.1 I'z 10 Iv 195h n,c 16 3 9. 3U. , 12 8. 2..,
7.0 7. 235(IV) 350(IV) 350(IV) 31u(III) 1955 Iiuc 7 35,4 N. , 318. 6'.. ,
4.7 V 30 (II 1955 I:o 21 35.4:!., 118.71, 4.3 V 25 (I'J) 1956 Feb 9 31.8:!., 115. 9ht, "
6.8 VIII-IX 245 IV 260 IV (VI-U.s.)
1957 Jan 29 35.9:1. , 122.11:, 4.9 V 75 IV
" 20 v 1957 :Mr 18 34.11!. . 13 9. 2e:,
5 VI lo VI
5
- (. - .
+'
- I:2xir;.t: . Dic t a:.c e --Ir.n ... ' ;;7 .
D2ie E l icc: ' T.3 r
.,c r I:, ,er,u i: 7 (;.;; 1 e u) _
(: ;) . ., 9 1
Ca :ttc os 0:-:nn: : Svcana: :-
- 1958 Jt:1y 13 3 4. 413. , 119. L'<., :: c. 4.7 VI 25 V 40 IV 1959 Sept 30 3 4 . 41' , 120. 6'<:, 4.5 VI 1961 Jcn 28 3 5. 811. , 118.o'.:, "
53 VI 73 (IV) 1961 ::o. 14 34.9:I. , 119. 0'<!, "
5.0 VI 20 ('O c,
" V 1963 Feb 28 34.9:I. , 1 1 9 0 1-: , 5.0 VI 7 Intencity at Site:
- Entiaated using Gttten1' erg-Richtc: Int. ec Dlstance .
( ) Estimated from nearly rei o:'tn ,
'S y
..~