ML20236L787

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Reply to P Crane 700904 Supplemental Proposed Findings of Fact & Conclusions of Law by R Vrana Re Epicenters
ML20236L787
Person / Time
Site: Diablo Canyon Pacific Gas & Electric icon.png
Issue date: 09/16/1970
From: Vrana R
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FOIA-87-214 NUDOCS 8708100359
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Reply to the September 4,1970 statement of Mr. Rilip Crane, of PG and S.

by Ralph Vrena -

l Bis statement is in reply to the SUPPLtJENTAL rEOH)dED FINDINGS OF

FACT AND CONCLUSIONS OF LA'J SL'DMITTED Bf Ft.CIFIC GL AND El2CTRIC COMk ANY
1. Mr. Crane states on p. 4 of his statement, "Ihe apparer.t northeast-l southwest ali5ncent.cf theca epicenters ic fortuitous and there ic no l

geologic evidccca to suppcrt the thesis that the epicentero defino a northeastward citructural trarf in the area offshore from the Diablo

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,on cite".

1 I' have submitted the report by Lars$nger, j Itr reply at this tim;:

De'.lald, and peter 1969 (ESCA Atlantic Oceanographic :.aboratorier). In it is a deceription and map cf fritltin6 further out en the Murray Sh.cturc Zone the.n the epicenters, but in the same direction as these ar2 plotted (norther.st-southwest). to Vcc Huene 1969 report was alco citad. In it Von Huone supports the idca that ocean ficor feature.s which are quite cloco l

, to tha cpicentera " formed c.leng one or more ncrtheast-trending cpnjuSEt* l l

i fiseures of tho Murray".

2. Noto 1, page 4 of Mr.~ Crane's statement ref arc to some "qpsrent offchore epicentaro " in the rlsht hand corner of my map A. For clarity I add here thct these are pn-shore epicenters which wsre pictted for the large acp, not the enall one suprinposed on the big one f:: ind:x purposes. Tt.o of the epicentora in this upper right hand corner are both in linc. with the offehore epicentera and occurred during the time of the recent a.ctivity along thoce epicenters. Rey wcre not counted as part of the off-chore epicenters because of their distence frca that line, and their proxinity to the San Andreas fault. It is poscible that they are related both to the Su Andreas fault and the off-shore epicenters. Further study is neede 8708100359 870729 PDR FOIA CONNORB7-214 PDR

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3. Mr. Cran) cugg:cta. .,n p. 4 that "th3 earthquakes ca. , probably g':n:rnted I along the dominant northwest trending structures". I have not yet received the map Mr. Devine sentioned at the hearing of Aug. 7 from which he derives northwest trend to the epicenters. Mr. Crane and myself both asked his to .

forward it to me. I agree that euch, but not all, of the structural trends in 1

the off-shore regico are northwest trendingo 2he exceptions are notable and i

have been cited. 2 hey in:lude these epicenters, whose northeast trend is f I

apparent, and the Murray Fracture Zone itself.

4. On page 5, nunber lo, Mr. crane suggests that there are two clusters (of epicenters)which "probably represent two distinct zones of activity. There are i

reasons for thinking otherwise. l

a. A time sequence of four, and possibly five earthquakes on Oct. 23, 1969 chew movement to the southwest in a near straight line 33 niles long. '[his sequence is shown on map A as occurring at 020547 2, 034314 9, 051400.0, 06412.05, f 1

071902 94 Greenwich Mean lico. These quakes are in both of Mr. Crane'a clusters.

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i b. There is insufficient evidence of a clustering of quakes accordin6 to time of occurence, which miSht separate the areas.

c. It is st3?1 not possible to make out even a minor trend in a northwest-southeast line for the more southaetterly " cluster" of epicettera. A northeast-southwast trend in this cluster is apparent.

The evidence points to a serious persibility of a northeast trending active fault ge ne in the re6 1on of the epicenters. I have pasced on a note to one of the geologic journals concerning this poceibility. Perhapa others

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will offer suggestions for evaluating these eAcenters, when thic note is published.

5 On page 5 Mr. Crane speaks about tne "cochanics by which such a feature no the Murray Fault Zone is generated preclude an offshoot at such (45*) an an6 1 e". I reiterate that this does happen to fracture zones ao shom in Menard's " Marine Geology of the pacific" and that the explanation for such an occurence (p. 136, 137) suits the conditions off the California coast near

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the Murray fracture. J i

6. On page 3, number 12, Mr. Crane mentions the extensive geologic inver.tigntion of the cite including a 10 square mile cap which was not k

includ. A k the l'SAR (I do not believe it is satisfact.ory to mention

t. hic rap without produc:.ng it). I tace th;t the cc-sica exceratione hcro been thcro26h A good geologic map of the curr72nding area is cleo neccscary as a m'.n N u requirc:ent according tc : . Jahns own pbliehed etatezente (see p.120 of Aug. 7 testimony), Dr. Jc.hns also acid that a geologic up of 10 aquero milco curvcunding a2 atccic powe +

picut .an nat estisfacter7 He indicated that u ch n;re was done at hblo Canyes, tut it in not in tvidence. In view of t!2e importacco of this r cponol installation I fcol th.st c Seclogic nep of an area within n r_addus cf ten miles frou. the plant is of fundsr.cnta.1 importanca in anseseig geolo3ic hs.na dr. Clarenca Hall of UCM has done some of this vozi but na.:h of the c.na cloce in to the plant has not bcsen doneo 7 h. Craas c2 psge 7,. r.t=ber 15 ccys ths. PG rad I does not ccncede tiud the 'o? 05:,c fcu'.t cxicts. I u.ind n ccn conecr::cd tsar I acesd

% , hhm so c.:e 111th ce tc vicic 2.3 fault c a:Ia :. s did not hc;;; tir.a i

the day of tht hearing en Augur,t 7 470. 7a a p ar:.can telo;. hone cc.1 milica uith m rhich Pa. J:!I? Pof r 4 :c l' t c han d ge, he cy<.ed tri!b wa that faulting in tb vicinit/ of an st;nc porer plant 4 l

l ccat be vi6creusly cou!f.t. I have cought eat faultig in the area of Sa o luto Chiarc se part of a recentch project. khen I turn up something I believe should be considered by PG and E and the Board, I report it. I would feel remise if I did not do co, and I am indebted to the Scenic Shoreline Preservation Conference for encouraging se to testify. Since I live in the area near the plant I owe it to my neighbors (if nothing i

l mcra) te examine what has been dono in evalrating gedo;ric har.erds.

r, My work continuos. If we had a good geologic emp of the Port San Luia quadrangle and aream cloca by, much of our discussion at the hearings concerning on-chore faulting would have been unnecessary. I understand Mr. Crane's position and I welecee criticism of my findings. But it is

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not in the apirit of scientific inquiry to deny the existence of acmething l

because one does not choore to look at it.

Hy reasona for considering that a D. ult exista are theses 1

l 1. A 200 f t. hi5h straight scarp of 25 miles length rising out of l l

the alluvium of the valley floor above Warden Pondo

2. A long etraiEht etream at the foot of this scarp.

3 The cap rock of this scarp in an indurated silt with clay veins which dips into a hill of u:ach older rock. ,

4. Clay veins are atriated en though they have been injected.

5 A san 11 acarp of blue schist bordering the creek bed lines up with the big scarp.

' 6. An extensivo Scucs zone with blocks of serpentine, blua echist, chert, greyrache, quartzite, calcito, and basalt along the Los Ocos Cresh as it enters Morro Bay.

7 ibe c.3.stence of a natural channel in Morro Bay extending into the ocean just north of Morro Rock lining up with fault scarp. l

'6. %e scarp-like appenrance of the face of Morro Rock which is just i

above this channel.

~9 Slivers of Miocene or oligocene (vaquero formation) lying below l eorpentine rock of the valley wallo.

10. Several hundred feet through sand and clay to bedrock on downthrown aide of fault (water well records from Baywood Park).
11. Damned up flood plain of Ios Osos Creek.

1L Change in exit of Chorro Creek from Pacific Ocean to Morro Bay.

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8. In note 3, page 8 of Mr. Crane's statement he said: "In addition, the delineation of the " loc OeosFamit" by Mr. Vrana on map C is not concistent with the argument that the los Oeos Valley is a down-dropped i

block, or graben, beca tso he shows the fault as rening through the valley". At the enda of a graben there is usually a splaying out of I faults. Such eeems to be the came with the Los Oeos fanit. B are is l l nothing inconsistent with the geologic eetting of this fault, and in l

fact its presence explains the existence of Horro Bay which is part of the down-faulted side of this fault.

9 Do page 4 Kr. Crane estimates the length of the combined West Huasna.

Edna and los Or>cs faults to be 40 miles. Clarence Hall, whose work has l been cited frequently, acks:  ;

"Is it possible to trace the complex Huasna-Suey fault zone to the northwest i

l cnd what data can be obtained that will provido evidence as to the amounts 1

end kinds of movement that have taken place along the fault zone, a fault zone that is now known to be approximately 50 miles in extent". (Field Trip Guidebook Har. 23,1968, " Geology of the San Luis Obispo Area" ESA, Junior College j Geology Workshop by C. A. Hall UCLA, and John Bowen, Cuesta College, San Inis Obispo).

The Huaann-Suey fault zone is 50 niles long befcro the Edna or other j I

faulto are added so the length of the combined faults should be anendod l

j upward.

It is natural for geologiste to search out faulta and to speculato as j to their extensions into other areas. his is the case with the W6st Huasna fault. An arm of it may enter the los Osos Valley. Geologic mapping in sufficient detail would clarify this picture. Apropo of this, !!all writen l

(in answer to the question he posed above): " Rose and othar problems can l

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, i 3-probably be answered in part by further detailed geolegic n.appig and a6s determinations of both the sedimentary and volcanic rocks". (ocynanic mine)

10. In hd.s conclusion, p.9, b Crane states., "nothing was retsaled at the t

l heatics i. caused the Staff cr PG cd I; c:nzaltans to chan3e tho l

conlusions stated in their n.rioua reports", by own conce'rn about the offchore epicenters hse increesed since the statemente I made at the a hearing of Austwt 7,1970. Thin con:ern it a result cf a study 'of recearch

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" done mainly by the United States Coolegical Survey (aoland Von Eusne, USGS, ,_

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'Ib ln o Pcrh, California) and the Environmental Sciones Service Ad ministration (ESSA) which includes the United Shates Coarb cLd Geodetic Surrey (report

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by E G. ikraincer, O. E. DeWald, and G. Pet:r of f.tlutic Oceano6 aphic laboratories). 'itese have been qucted in ny first stahment. I triah it noted that the organir.ations which these annore work for (USGS and USC & GS) cra thcae which the Air censulte. Please note also that H. W. Monard's book "fbrine GeoloEy of the Padific" was tr.entioned at the hearing of August 7, 1970 j (p. 57, 58, 59) and therefore pertinent for study in any review of the testimony b:r the participants. I find a clear conflict between the geology of off-shore features described in this te::t and statements made by Dr. Jahns and Dr. Smith at the hearing (p. 91, 97, 98, 104) and described in'ay I

previous statement. It is to the interest of all concerned that this conflict be resolved.  ;

Respectfully, l c , [ 24f94v aam S. v -a g /( Rv

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