ML17276B428
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| Issue date: | 02/28/1982 |
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Text
4 REVIEW OF THE MAGNITUDE'"'F THE JULY 16, 1936 WALLA WALLA AREA EARTHQUAK:.
Report prepared'c Washington Public Power Supply Syste::
Richland, Washington February 1982 Woodward-Clyde Consultants 3 Embarcadero
- Center, Suite 700 San Francisco, CA 94111 C
820510027i 820426 PDR ADOCK 050003'P7 A
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Woodyard.Clyde Consultants TABLE OF CONTENTS
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LIST OF TABLES LIST OF FIGURES ill Summary of Conclusions Surface-Wave Magnitude Magnitude Determined from Wood-Anderson Records Differences Between July ~16, 1936'Calculated
,'Magnitude, M and ML Results of Investigation References R-1 Appendix A Copy of Gutenberg's Worksheet for the July 16, 1936 Earthquake
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Woodyard.Ciyde Consultants LIST OF TABLES Title
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Original Magnitude Computation by Gutenberg for the July 16, 1936 Earthquake Recomputed Magnitude for the July 16P 1936 Earthquake Magnitude Determinations for California Earthquakes Using Newport'Wood-Anderson Seismograms 6
13
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Vjoodward.Clyde Consultants LIST OF FIGURES Title paca e Earthquakes used in the Magnitude Investigation and Califo'rnia Stations Used to Calculate the l936 Earthquake Magnitude Frequency
Response
of the
~ Newport Modified Wood-Anderson Seismograph; GEOTECH Model l7398 15
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Woodyard Chjde Consuttar~ts REVIEW OF THE MAGNITUDE'F THE JULY 16 g 1936 WALLA WALLA AREA EARTHQUAKE
- The purpose of this report is to review the methods that have been used to assess magnitude's for the July 16, 1936, Walla Walla area. earthquake.
The nature jof each of the alternative magnitudes that have been assigned to this event is clarified, and the utility of these types of magnitudes as bases for engineering analyses of earthquake ground motions is evaluated.
Summar of Conclusions
- O
- The results of this review indicate that the 5-3/4 magnitude published by Gutenberg and Richter (1954) for the July 16, 1936 earthquake is a surface-wave magnitude, MS.
Using Gutenberg 's l
original amplitude data and station correcti'ons that were subse-quently established, the magnitude of this event has been recom--
puted as MS 5;7
+ 0,3, which. is very close to the MS of 5.8 originally computed by Gutenberg.
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The magnitude value of 6.1 reported by Woodward-Clyde Consultants (1980) was determined primarily from Calfornia Wood-Anderson seismograph trace amplitudes,'sing the relationships developed by Gutenberg and Richter (1936), in the form of the nomogram presented by Gutenberg and Richter (1942).
The Wood-Anderson data were'ecorded at epicentral distances between 9 degrees and 13.5 degrees, and the periods corresponding to the maximum trace amplitudes are in the range of 2 to 10 seconds.
The magnitude l
thus computed is denoted "M", conforming with the original nota-tion of Richter (1935) and Gutenberg and Richter (1936).
Current usage of the term "local magnitude, ML" is reserved for magnitudes determined from Wood-'Anderson data recorded at dis-
~tances normally restricted to less than 5 degrees, (Richter, 1958).
Originally, however, the formulation for calculating
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Woodward C/yde Consultants magnitudes from Wood-Anderson trace amplitudes was extended out to distances as great as 15 degrees (Gutenberg and Richter, 1936).
At that time, all magnitudes (including those calculated from surface-wave data recorded at teleseismic distances) were denoted simply as "M", since the scale was originally intended to yield compatible magnitude values at all distances.
It has been
- found, however, that magnitudes calculated within different dis-tance ranges are not, in fact, entirely compatible.
Specifi-
- cally, a magnitude, M, calculated from Wood-Anderson trace data recorded at distances in the. range 5 degrees to 15 degrees is not necessarily equivalent to an M<, for two main reasons:
1)
Maximum trace amplitudes recorded on Wood-Anderson instru-ments at distances less than 5 degrees correspond to waves having periods of approximately one second or less, for which the response of the Wood-Anderson is flat.
Periods associ-ated with maximum trace amplitudes recorded at distances-between 5 degrees and 15 degrees,
- however, are generally in the range of 1 to 12 seconds, for which the instrument response becomes progressively less.
2)
The crustal attenuation characteristics along the particular travel paths between the earthquake focus and stations in the distance range of 5 degrees to 15 degrees may not be ade-quately represented by the average attenuation model that is incorporated into the formulation of the original magnitude scale (Richter, 1958).
Comparison of locally computed M> values for recent California earthquakes with M values calculated from 6-to 12-second period maximum amplitude waves recorded at Newport, eastern Washington suggests that the M values thus determined are consistently t
higher than M<.
The average difference for the 10 earthquakes studied is about one-half magnitude unit.
'Because the propaga-tion paths from these Californian earthquakes to Newport are nearly reciprocal to the paths'rom the,1936 epicenter to the I
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Woodyard Clyde ConsUItants California stations that were used to determine its magnitude, this difference between M and ML may also apply to the 1936 earthquake magnitude.
However, the results. of the present study are not sufficient to permit estimation of a rigorous numerical correction to convert M to M> for this earthquake.
Existing empirical relationships used for evaluation of earth-quake ground motions are base'd on the MI, MS, and other magnitude scales.
To our knowledge, no empirical relationships have been developed based on magnitudes determined from Wood-Anderson data in the period range of 2 to 12 seconds.
Therefore, because well-4 calibrated, local data are insufficient to.directly calculate a
reliable local magnitude (M<) for the 1936 earthquake, earthquake t
ground motion evaluations forI this event should be based on the MS value, which has been calculated directly.
Surface-Wave Ma nitude The 5-3/4 magnitud'e for the 1'936 earthquake was first published in the standard reference, "Seismicity of the Earth" (Gutenberg and Richter, 1949; 2nd Edition, 1954).
Geller and Kanamori (1977) have shown that'he ma'gnitudes of most shallow, "class a"
(magnitude greater than, or e'qual to, 7-3/4) earthquakes listed in "Seismicity of the Earth",'are essentially equivalent to 20-il second surface-wave magnitudes, MS, even though MS was not formally defined until 1945 (Gutenberg, 1945),
and the final version of the scale was not presented until 1956 (Gutenberg and
- Richter, 1956a).
This equivalence to MS of magnitudes computed for large, pre-1945 earthquakes from teleseismic observations is to be expected:
the work done by Gutenberg and Richter (1936) to extend Richter's (1935) magnitude scale, M, to distances beyond 15 degrees utilized ground displacement amplitudes of surface waves and essentially established the basis for the MS scale.
I In view of this equivalence, the magnitude 5-3/4 listed in "Seis-micity of the Earth" for the, July 16, 1936 earthquake was assumed
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'Woodyard Clyde Consultants to be a surface-wave magnitude.
To review and verify this magni-tude calculation, Gutenberg's original worksheets were retrieved from the California Institute of Technology.
A copy of the work-sheet for the 1936 earthquake is shown'n Appendix A to this report.
This worksheet confirms that",the original magnitude was calcu-lated using ground displacement amplitudes recorded at distant stations.
These data are reproduced in Table l.
The average of Gutenberg's" magnitude calculatio'ns for 6 stations is 5.8, which was published in 'fractional form as 5-3/4 in "Seismicity of the Earth".
The stations usedg'Pulkovo, Baku, Tashkent,
- Hamburg, De Bilt and Paris are distributed over an azimuthal range of approx-imately 45 degrees (see Table 2)-,
. which is a somewhat limited sample of the radiation pattern from the earthquake.
The magnitudes were recomputed using Gutenberg's original data and relationships for MS presented by.Gutenberg (1945):
MS
= log A log, B +
C +
D where:
A is the zero-,to-peak amplitude of the horizontal compo-nent of maximum ground displacement in microns, I
B is 'the same quantity for the "zero magnitude" or "standard" shock (Richter, 1958) and is given by the following empirically derived relationship (Gutenberg, 1945):
,log B = 1.818
+ 1.656 logb (15' 6
< 130')
(2)
C is the individual" stat'ion correction as given in Gutenberg (1945),
and D is a correction that accounts.for the focal depth and radiation pattern of'he earthquake and for absorption along the path.
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'TABLE.1 ORIGINAL MAGNITUDE COMPUTATION BY 'GUTENBERG FOR THE JULY-tl6 g 1936 EARTHQUAKE*
Station Pulkovo Baku Tashkent Hamburg De Bilt Paris Horizontal Ground Amplitude (microns) 1-1/2 7
'7 6
5.0
- 5. 2 5.2 5.0 5.0 5.0 0.2 0.8
'0. 8 0
~ 7
- 0. 8' 0.8 Magnitude 5.2 6.0 6.0 5.7 5.8 5.8 Average magnitude 5.8
(+ 0.3)
- See Appendix A
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Woodyard Clyde Co@su/lasts TABLE 2 RECOMPUTED MAGNITUDE FOR THE JULY 16, 1936 EARTHQUAKE Station (de
)
AZ Horizonta3.
-log B
log A Ground Amplitude (de
)
(microns)
D MS 016 009 354 030 033 Paris
- 71. 9 037 Pulkovo
- 70. 9 Baku
- 92. 8 Tashkent 92.2 Hamburg
- 71. 0 De Bilt
- 70. 4 1.5 7.0 7.0 5.0 6.0 6.0 4 ~ 88
- 5. 08
- 5. 07
- 4. 88 F 88
- 4. 89
- 0. 18
+0. 04
+0, 1
- 0. 85
-0. 2'0. 1
- 0. 85
+0. 14
+0. 1 0 ~ 70
-0. 23
+P. 1
- 0. 78
-0. 17
+0. 1
- 0. 78
+0. 1
- 5. 20
- 5. 82
- 6. 16
- 5. 45
- 5. 59
- 5. 77 Average MS
=
5.7 t ".3 MS
= log A log B +
C +
D
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This value is very close to the original published value.
For the 1936 earthquake, it appears that Gutenberg effectively estimated D = 0. 1 and set C
=
0 (the station corrections had probably not yet been estimated at the time that this magnitude was originally computed);
if so, the two columns following the amplitude in Table 1 correspond to log B + D" and "log A", respectively in Equation 1.
When the station corrections are not included, over-estimation of the magnitude is by only 2 percent.
)
Ma nitude Determined from Wood-Anderson Records The 1936 earthquake occurred ~at the time when the definition of the magnitude scale was undergoing its initial development.
Richter (1935) defined the magnitude, M, of an earthquake in terms of the trace amplitudep A, recorded on a standard Wood-Anderson seismograph (free-period
=
0.8 second, magnification
=
- 2800, damping ='.8) by the relationship:
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M = log A log Ao (3)
The empirical part of the development of this scale consisted of determining log Ao as a function of distance (log Ao is a normal-N izing factor that accounts for the attenuation of seismic energy with distance).
Richter (1935) accomplished this using Wood-Anderson data recorded at the Pasadena
- stations, and produced a
table of log Ao versus distance, 6, up to 600 km (5.5 degrees).
The table was limited to this distance range at that time only because insufficient data were available for larger distances.
Richter (1935) observed that the data for distances less than 600 km fit the relationship:
log A = 3.37 3 logh (4)
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Vfoodmard-Clyde Consultants Data subsequently collected for the distance range 200 to 1500 km (13.5 degrees) were found to be fairly well represented by this relationship.
Therefore, Gutenberg and Richter (1936) used Equa-tion (4) to extend the magnitude scale to 15 degrees.
ln that
- paper, values of log Ao derived from Equation 4 were plotted as a
l function of distance in the range 5 degrees to 15 degrees (Gutenberg and Richter,
- 1936, Figure 6).
The scale was also extended beyond 15 degrees using the amplitudes of ground dis-placement of surface waves at teleseismic distances, thus pro-viding the basis for the Ms scale.
A nomogram for computing magnitudes from Wood-Anderson trace amplitudes up to distances of 100 degrees was presented by Gutenberg and Richter (1942),
based on Figure 6 of Gutenberg and Richter (1936).
Gutenberg and Richter (1956a) gave a table of log Ao versus distance up to a distance of 1000 km (9 degrees).
The distinction between local magnitudes and surface-wave magni-tudes was first effectively made by Gutenberg (1945),
and the terms M~ and MS were introduced by Gutenberg and Richter in 1956 (Gutenberg and Richter, 1956a,b).
The nomogram presented by Gutenberg and Richter (1942) was used by Woodward-Clyde Consultants (1980) to calculate the magnitude of the 1936 earthquake from the seismograms that had been col-lected to investigate the epicentral location and focal mechanism of this event.
These data include 12 Wood-Anderson seismograms, 11 of which were recorded at stations of the Pasadena and Berkeley networks.
The Wood-Anderson stations used for the mag-nitude calcul'ation were loca/ed at epicentral distances in the range 9 degrees to 15 degre'es.
Records from other types of seis-mographs located within the distance ranges of 5 degrees to 7
degrees and 15 degrees to 24 degrees were also used in the calcu-lation, although the calibrations of these instruments are less certain then those of the Californian Wood-Anderson instruments.
The result of this calculation is a magnitude, M, of 6. 1, as reported by Woodward-Clyde Consultants (1980).
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%oodward.Ciyde Consultants Current usage of the term "lo'cal magnitude",
M>, is restricted to magnitudes determined from Wood-Anderson trace amplitudes using Equation (3) 'for distances normally less t.han 5 degrees (Richter, 1958).
Despite the fact that the scale was originally extended beyond this range, Wood-Anderson magnitudes (M) calcu-lated from data recorded at greater distances cannot be assume'd, in general, to be equivalent to locally calculated M> magnitudes, for two reasons:
1)
At distances up to 5 degrees; maximum trace amplitudes cor-respond to S or surface waves that have periods of about 1
second or less, which are within the flat part of the Wood-Anderson frequency'esponse.
As distance increases beyond 5
- degrees, maximum amplitudes correspond to surface waves that have progressively longer periods for which the maghification of the Wood-Anderson becomes progressively smaller.
- However, magnitudes cal'culated according to the original formulation (Gutenberg and Richter, 1936) for distances less than 15 degrees use the maximum trace amplitude irrespective of the seismograph phase or period.
Gutenberg.and Richter (1936) observed that the variation in the period of the maximum amplitude wave and in the magnification of the Wood-Anderson seismograph is the cause of the divergence of the assumed relationship. expressed by Equation 4,from the observed data in the distance range 6 degrees to 25 degrees (Gutenberg and
- Richter, 1936, Figure 6).
Gutenberg and Richter's (1936) original data indicate systematic deviations in magnitudes C
determined from their adopted log Ao curve; these deviations are high by 0.07 magnitude units at 8 degrees, increasing to 0.24 units at 15 degrees.
2)
As stated by Richter (1958), calculation of magnitudes using II the log Ao versus distance relationship extended to distances beyond 5 degrees is subject to uncertainties arising from lack of adequate data needed to rigorously verify the rela-tionship in this distance'range, differences in seismic wave
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Differences Between Jul 16, 1936 Calculated Ma nitude, M,
~and M
It is clear, therefore, that the magnitude 6.1 calculated for the July 16, 1936 earthquake from Wood-Anderson seismograms should not be assumed to be equivalent to an ML magnitude.
Although there is no simple way to convert this magnitude (or the M>
va'lue) to an equivalent M<, the possible difference between this magnitude and M> was investigated.
The magnitude calculated for the 1936 earthquake might differ from a locally calculated M>
because of a combination of the two factors discussed above:
1)
The magnitude was calculated using the maximum amplitudes o
a waves that have periods (2 seconds to 10 seconds) greater than 1 second.,
2)
The propagation paths from the hypocenter to the stations used include paths, or portions of paths, outside of California and may not be adequately represented by Richter's (1936) plot of log A
versus distance.
As discussed
- above, the observed data in the 10- to 15-degree distance range suggests that Factor 1 (above) may result in mag-nitudes that are too high by 0.07 to 0.24 units.
The magnitude calculated by Woodward-Clyde Consultants (1980) relies primarily on data from ll northern and southern California Wood-Anderson
- stations, which have azimuths in the range 176 degrees to 201 degrees from the epicenter (Woodward-Clyde Consultants,
- 1980, II Tables 6 and 8).
Therefore, the particular characteristics of seismic attenuation along paths within this limited range of azimuths may significantly 'influence the magnitude calculation.
(It should be noted, however., that the magnitudes calculated
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using data from stations outside this range, such as Ferndale
[azimuth 220 degrees],
Tucson
[azimuth 155 degrees],
and College
[azimuth 330 degrees),
are in good agreement with those calcu-lated from the California data)
~
By reciprocity, this path effect should be the same for waves propagating in either direc-tion along the same path (except for the effects of local crustal, structure at the receiver end of each path).
This factor is investigated using data from California earthquakes recorded in eastern Washington.
Each of the earthquakes selected for this investigation occurred close to one of the groups of stations that had been used to calculate the magnitude of the 1936 earthquake.
Station and earthquake locations are shown in Figure 1.
The earthquakes have well-constrained Pasadena or Berkeley local magnitudes, in the range of M> 5.0 to 7.0.
The reported M< selected for each earth-quake (Table 3) is the value calculated from the network (Berkeley or Pasadena) having stations closest to the epicenter; alternative values are shown in parentheses.
All of the earth-quakes produced clear Wood-Anderson seismograms at the station at Newport (NEW), Washington, which is located approximately 2
degrees north of the instrumental epicenter of the 1936 earth-quake.
The shape of the frequency response of the NEW Wood-Anderson seismographs shown in Figure 2 is identical to the stan-dard Wood-Anderson response, trout the NEW instruments are run at a
magnification of 1400,
- 5600, 14,000, or 140,000.
The azimuths from NEW to the selected test earthquakes, from NEW to the California Wood-Anderson stations, and from the epicenter of the 1936 earthquake to the California stations are all within 10
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degrees of each other.
After normalizing the maximum trace amplitudes to a gain of 2800, a magnitude, M, for each of the test events was computed from the NEW Wood-Anderson seismograms, in exactly the same manner as used for the 1936 magnitude calculation.
The periods of the maximum
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Earthquakes recorded at Newport, WA 400
+ FER 38o 1-24-80 0
SFB BR K
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5-27-80 TIN
~FRE Nevada 36o California SBC 1978 1971 O O MWC 1973 p
~ RVR PAS O 2-25-80 0
80 160 Kilometers
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~t 320 Project No.
14940 E Hanford FSAR EARTHQUAKES USED IN THE MAGNITUDE INVESTIGATIONAND CALIFORNIA STATIONS USED TO CALCULATE THE 1936 EARTHQUAKE MAGNITUDE Figure 1
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TABLE 3 HAGNITUDE DETERMINATIONS FOR CALIFORNIAN EARTHQUAKES USING NEWPORT WOOD-ANDERSON SEISHOGRAHS Earthquake AREA A
Epicenter h
Az Corrected LAT LON Hax. Amp(l)
N E
~(De N)
~(ee W)
~(ee
)
~(ee
)
(mm)
(mm)
Average Calculated Reported Hax.
Amp. Hagnitude, HL(2)
H (mm)
M-ML Pe riod (sec)
San Fernando
- 34. 4 118. 4 13.9 004
- 17. 2
- 9. 5
- 13. 4 Feb.
9, 1971s 1400 7.3 6.4P
+0.9
( 6. 7B)
Los Angeles Feb.
21, 1973:
1446'4.1 119.0 14.2 005 1.0 1.0
\\
1.0 6.2 5.9P (5. 6B)
+0. 3 Santa Barbara 34.4 119.7 14.0 007 1.5 1.9 1.7 6.4
- 5. 1P
+l. 3 (5.7B) 10 AREA B
Bishop Sep.
4, 1978:
1643 37.53 118.63 10.8 005 1.1 1.5 1.3 6.0 5.8PNB
+0.2 Hammoth Lakes
- 37. 60 118. 84 10.7 006
- 7. 8
- 16. 5
- 12. 2 Hay 25, 1980'634 6.9
- 6. SP
+0. 4 (6.1B)
Hammoth Lakes
- 37. 57 118. 82
- 10. 7 006 3.9
- 8. 2
- 6. 1 Hay 25D 1980:
1945 6.6 6 ~ 7P (6. 1B)
-0. 1 12
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Earthquake Epicenter h
Az Correct~)
LAT LOH May.
Amp E
~[me te)
~(ce W)
~(ce
)
~(me l
(ltlm)
(mm}
Average Calculated Max.
Amp,. Magnitude, (mm)
Report ~d ML M-M>
Period
<eec>
Mammoth Lakes
- 37. 48 118. 81
- 10. 8 006
- 4. 3
- 7. 6 May 27, 1980!
1451 6.0 6.7
- 6. 3P
+0. 4 (6, 2B)
Mammoth Lakes 37.56 118.89 10.8 006 0.4 0.7 Aug't 1980:
1639 0.6 5.7
- 5. 3P (5 4B)
+0. 4 AREA C
Coyote Lake Aug. 6t 1979:
1705
- 37. 1 121. 5 ll.6 015
- 1. 6
- l. 9 1.8 6.2 5-9B
+0. 3 Livermore Jan 24, 1980'900
- 37. 9 121mB 10.9 017 1.6 5.0 3.3 6.4 5 ~ 5B
+0 9
Notes:
(1) Trace amplitudes normalized to magnification of 2800 (2) Reported MLe P
= Pasadena, B
Berkeley
- Average, Groups A, B and C
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00 Q
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Static magnification = 2800 at 0.25 sec.
1,000 0
(DO C
CJl lO 100 10 0.1 1.0 10.0 100.0 Period, sec.
Project No.
14940 E Hanford FSAR Woodward Clyde Consultants FREQUENCY RESPONSE OF THE NEWPORT MODIFIED WOOD-ANDERSON SEISMOGRAPH:
GEOTECH MODEL 17398 Figure 2
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Woodyard.C/yde Consuttants amplitude waves at NEW for the te'st events are in the range of 6 to 12 seconds.
These M magnitudes were, therefore, calculated using Wood-Anderson data recorded within the same range of azi-muths and with roughly similar periods as the Wood-Anderson data used for the 1936 earthquake magnitude (M) calculation.
The range of epicentral distances from NEW to the test events (10.8 to 14.2
'degrees, Table
- 3) encompasses the distances from the 1936 epi-7 center to the California stations (9 to 13.4 degrees),
although the distances from NEW to specific station/source localities are about 2 degrees greater than the distances from the 1936 epi-center to the same localities.
Results of Investigations The results of this investigation.are shown in Table 3.
Magni-tudes (M) determined from the NEW seismograms are compared with the reported ML values by subtracting the two values, as shown in Column ll of the table.
It'can be seen that, with the exception of one earthquake, the M values are consistently higher than the reported ML values. 'ombining areas A, B, and C, the average difference (M ML) is
+ 0. 50
+ 0. 41.
The results presented in Ta le 3 are not sufficiently definitive to permit estimation of a rigorous numerical correction to con-e vert M values calculated usi'ng seimsic waves that have propagated along the path between California and eastern Washington (and vice versa-) to 'ML.
Specific limitations and uncertainties in the present results are as follows:
1)
There are insufficien't data to assess the difference between M and ML for each of the individual station/source localities; Area B (TIN/Mammoth Lakes) has'he largest data t
- set, and also (when the apparently anomalous result for the May 25, 1945 earthquake is neglected) gives the most consistent result (average
[M ML] = 0.35
+ 0.10)
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Factors that probably contribute to the scatter in the results are the effects of differing source radiation pat-
- terns, focal depths and local crustal structures.,
3)
A station correction for NEW Wood-Anderson magnitudes has never been computed (L. Keriy, Newport, Observatory;
.W. Person, National Earthquake Information Service, personal commmunications, February 1982).
Therefore, the effect on the results of the local crustal structure at NEW has not been removed.
The potential effects of Factors 2 and 3 on the results cannot, at present, be sepa'rated from the effect of attenuation along the path between eastern Washington. and, the station/source locali-ties.
In applying these results to assess the relationship between M> and the M 6.1 calculated for the 1936 earthquake, the following uncertainties also apply:
1),
The, effects of local crustal structure in the epicentral area of the 1936 earthquake and of the foca'1 depth and source radiation pattern of the event have not been assessed.
2.
NEW is 2 degrees farther north than the 1936 epicenter.
This distance is between 15 and 20 percent of the total path distance from.the California stations to the epicenter.
In summary, this study has shown that M magnitudes calculated using data from waves that have propagated along the path between
- California and eastern Washington appear to be consistently higher than M> values calculated from local networks.
These differences probably arise;" in part, from a combination of two k
factors.
The first factor is the systematic divergence of obser-ved amplitudes from the log A
curve that is used to define Richter magnitudes in the distance range of 5 to 15 degrees.
The ET
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Assuming path reciprocity, these results suggest that the M 6,1 calculated for the 1936 earthquake is probably higher than the M> value that would be calculated from local data, if such data were avail-able.
The results of the present study are not sufficient to estimate a rigorous numerical correction for converting M to M>
either for the California eastern Washington path in general, or for the 1936 earthquake in particular.
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Woodyard.Clyde ConsuItants REFERENCES Geller, R.J.
and Kanamori,,H.,
- 1977, Magnitudes of great shallow earthquakes from 1904 to 1952:
Seismological Society of America Bulletin, v. 67' 587 598.
II Gutenberg, B., 1945, Amplitudes of surface waves and magnitudes of shallow earthquakes:
Seismological Society of America Bulletin, v.
35,
- p. 3-12.
Gutenberg, B. and Richter, C. F.,
- 1936, On seismic waves
( third paper):
Gerlands Beitrage Zur Geophys'ik,
- v. 47, p.73-131.
Gutenberg, B.
and -Richter, C. F.,
- 1942, Earthquake magnitude, intensity,
- energy, and acceleration:
Seismological Society of America Bulletin, v. 32, p. 163-191.
I Gutenberg, B.
and Richter, C.F.,
1949, Seismicity of the Earth:
Princeton University Press.
Gutenberg, B. and Richter, C. F., 1954, Seismicity of the Earth (2nd Edition):
Princeton University Press.
Gutenberg, B.
and Richter, C. F.,
- 1956a, Earthquake magnitude, intensity, energy, and,acceleration (second paper):
Seis-mological Society of America Bulletin, v. 46,
- p. 105-145.
Gutenberg, B.
and Richter, C.F.,
- 1956b, Magnitude and energy of earthquakes:
Annali d i Geof isica, v. 9, p. 1-14.
- Richter, C. F.,
- 1935, An instrumental earthquake magnitude scale:
Seismological Society of America Bulletin, v. 25, p.1-32.
Richter, C.F.,
- 1958, Elementary Seismology:
Co.,
San Francisco.
W. H. Freeman and
~ ~
Woodyard Clyde Consultants Woodward-Clyde Consultants, 1980, Seismological review of the July 16, 1936 Milton-Freewater earthquake source region:
Report prepared for the Washington Public Power Supply
- System, Richland, WA.
4
~ 4 2
p i
1 E
L
Woodyard. Clyde ConsultarCs APPENDIX A COPY OF B.
GUTENBERG'S WORKSHEET FOR THE JULY 16'936 EARTHQUAKE
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t Aeromegoetic profile Ground gravity traverse NOTE:
Profiles 320-1280 from Item (1) Table.
Profiles G-C and GO2 from Item (11) Table.
WASHINGTON PUBLIC POWER SUPPLY SYSTEM Nuclear Project No. 2 e
GEOPHYSICAL.COVERAGE OF THE COLD CREEK LINEAMENT Figure 10
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Data sources indexed to Table 2.
Numbers in parentheses correspond to item numbers in the table.
WASHINGTON PUBLIC POWER SUPPLY SYSTEM Nuclear Project No. 2 0
,'EOPHYSICAL COVERAGE OF I THE COLD CREEK LINEAMENT lokm Figure 11
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alluvial fan deposits Unit 3 Pleistocene Touchet siackwater sediments Unit 4 Late Pleistocene'-Holocene loess and alluvium 2
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~ ~ 'l, I I 50 60 40 Distance in teet EXPLANATION Unit 1 Pleistocene(?) alluvial fan deposits Unit 2 Pleistocene(P) alluvial gravel Unit 3 Pleistocene Touchet slacksvater sediments Unit 4 Late Pleistocene-Holocene loess and alluvium . WASHINGTON PUBLIC POWER SUPPLY SYSTEM Nuclear Project No. 2 r 1 LOG OF TRENCH RMT-4 I I Figure 7B 0 Original ground surface Stripped level Idunng excavation) ~M gp 'p Whitish silt l '~"AlS 4aA+s&4~ 4i4 '4'E gled ~Q "h.j~g4vul4iv i(. ~ W 4'0rf>"evan <<~i~7wiqrciije~>',v.' 0 v i I V rr '0 "~ '.:+2~'o~x~s ~ ~,, 0 .Am4~ Whitish silt ~r Cl ClC V +++++++++++++++++++ 'lgi"P 'l4IAt + y+++ ++++++++++ nv Pwca nba I e~g>.>v c ac~, .+;~+>~e~ ~ g~vLR~v ur % OO0 4 ~oD .s CN ~ Lavender~lored fine sand Clastic dike la!most parallel to trench) ~Trench floor 0 1 ~.o 70 80 90 Distance in feet. 110 120 130 140 Ground surface~ 0 EXPLANATION Unit I Pleistocene(?) alluvial fan deposits ...:.':.;.;~i e~'" ..ivi.. '.ri.d 'hfa4 ~Trench floor Unit 2 Pleistocene(?) alluvial gravel Unit 3 Pleistocene Touchet slackwater sediments Unit 4 Late Pleistocene-Holocene loess and alluvium 0 ro "o0 ~fP .<o" 150 Distance in feet 170 WASHINGTON PUBLIC POWER SUPPLY SYSTEM Nuclear Project No. 2 LOG OF TRENCH RMT-4 (continued) Figure 7b 4 o-S~'g I' I voJC P I Carbonaceous horizon Original ground surface Alluvial charcoal fill Excavation debris Carbonaceous horizon <<XI&V ~J::I ~ Top of excavation i E debris Original ground ~=~ ~ q~~~~~ surface 0 'J ~sy OV-EXPLANATION ( ) 0
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Position of maximum depth of Lineament No. 3 t
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United States Geological Survey sJ.r Project No.
'l4940 Hanford fSAR GEOPHYSICAL TRAVERSE AND ANO-MALYLOCATIONS IN THE VICINITY OF THE BUTTE AND GAME FARM HIL Figure 1
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