GEOLOGICAL SURVEY CIRCULAR 672 

Ground Motion Values 

for Use in the Seismic Design of the 

Trans-Alaska Pipeline System 

Ground Motion Values 

for Use in the Seismic Design of the 

Trans-Alaska Pipeline System 

By Robert A. Page, David M. Boore, 

William B. Joyner, and Henry W. Coulter 

G E 0 L 0 G I C A L S U R V E Y C I R C U L A R 672 

Washington J 972 
United States Department of the Interior 

THOMAS S. KLEPPE, Secretary 

Geological Survey 

V. E. McKelvey, Director 

First printing 1972 

Second printing 1976 

Free on application to the U.S. Geological Survey, Notional Center, Reston, Va. 22092 
Figure I. 

2. 

3-b 

3. 

4. 

5. 

b. 

7. 

8 • II 

8. 

9. 

Table 

10. 

II. 

I. 

2. 

3. 

4. 

5. 

CONTENTS 

Page 

Abstract ······---------------------------------··------···---·-··-------··-·----········----·--·-·--- I 

Introduction ·-------·---·-····--··--·---------------------------------------·---------------------- I 

Seismic potential -----------------------------------------------------------------------------· 2 

Design approach ------------------------------------------------------·--·---------------------· 2 

Ground motion values ---------------------------------------------------------------------· 3 

Acceleration ----------------------------·------------·----------------------------------- 4 

Velocity ------------------------------------------------------------------------------------· 9 

Displacement ----------------------------------------·------------------------------------1 0 

Duration -------------------------------------------------------------------------------------- II 

References ----------------------------------------·---------------------·-·------------------------13 

Appendix A, Recurrence intervals -------------------------------------------------14 

Appendix B, Procedure of Newmark and Hall for determination 

of response spectra -------------------------------·----------·-------·---·-------------- 15 

Appendix C, Ground motion data ________________________ ·--------------------------·15 

ILLUSTRATIONS 

Page 

Map of proposed route of trans-Alaska oil pipeline showing seismic zonation and magnitudes of design eartl.~uakes ........ 2 

Accelerogram from 1966 Parkfield earthquake illustrating definition of ground motion parameters .... ---·----------·---------------·--- 4 

Graphs showing: 

Peak horizontal acceleration versus distance to slipped fault as a function of magnitude·---·-------------------------------·---·-----------·--- 5 

Peak horizontal acceleration versus distance to slipped fault (or epicentral distance)_ f~r_ magnitude 5 earth~uakes .......... 6 

Peak horizontal accelerations and 0.05g horizontal durations versus distance to slipped fault for 1966 Parkfiel~ earthquake 7 

Peak horizontal acceleration versus distance to slipped fault (or- epicentral distance) for magnitude 6 earth~uakes .......... 8 

Unfiltered and filtered accelerograms of the 1971 San Fernando earthquake --------------------------------------·------·---·--------·--------------- 9 

Graphs showing: - -- ---

Peak horizontal velocity versus distance to slipped fault (or epicentral distance) for magnitudes 5, 6, and 7 .................... 10 

Peak horizontal dynamic displacement versus distance to slipped fault (or epicentral distance) for mag11itudes 5, 6, 

and 7 ·----------------------------------------------------------------------------- ------------·--------------------------------·------------·----------------------·---·-------·---------·--------- 12 

Duration of shaking versus distance to slipped fault (or epicentral distance) for magnitudes 5, 6, and 7 ........ --------·--··--·-· 13 

Examples of tripartite logarithmic ground and respome spectra ···-------------·-------·-------------------·---·-------·-·-------·--····-·-------·--········· J5 

TABLES 

Page 

Design earthquakes along the pipeline route .... -------------····---·--------··-----------------------------·-------··---------·········---···--·---·---·-······--····-···--···· 2 

Near-fault horizontal ground motion .... ---···------·-------····----·-----··------··---------------------------------------·--·-···---·---····-----------·---···-··············--····· 3 

Peak horizontal ground accelerations from filtered and unfiltered accelerograms at Pacoima dam ........................................ 8 

Peak ground acceleration data for which distances to the causative fault are most accurately known .................................... l b 

Strong motion data plotted on graphs showing peak horizontal acceleration, velocity, and dynamic displaceMent and duratioa of shaking as a function of distance to slipped fau It (or epicentral distance)-··--·---······---·-····--·--··-----·-·····--·---·····-····-- 19 

Ill 

Ground Motion Values for Use in the Seismic Design 

of the T rans-Aiaska Pipeline System 

By Robert A. Page, David M. Boore, William B. Joyner, and Henry W. CoultP.r 

ABSTRACT 

The proposed trans-Alaska oil pipeline, which would 

traverse the state north to south from Prudhoe Bay on 

the Arctic coast to Valdez on Prince William Sound, will 

be subject to serious earthquake hazards over much of 

its length. To be acceptable from an environmental 

standpoint, the pipeline system is to be designed to minimize the potential of oil leakage resulting from seismic 

shaking, faulting, and seismically induced ground deformation. 

The design of the pipeline system must accommodate 

the effects of earthquakes with magnitudes ranging 

from 5.5 to 8.5 as specified in the "Stipulations for Proposed Trans-Alaskan Pipeline System." This report 

characterizes ground motions for the specified earthquakes in terms of peak levels of ground acceleration, 

velocity, and displacement and of duration of shaking. 

Published strong motion data from the Western 

United States are critically reviewed to determine the 

intensity and duration of shaking within several kilometers of the slipped fault. For magnitudes 5 and 6, for 

which sufficient near-fault records are available, the 

adopted ground motion values are based on data. For 

larger earthquakes the values are based on extrapolations from the data for smaller shocks, guided by simplified theoretical models of the faulting process. 

INTRODUCTION 

The route of the proposed trans-Alaska oil 

pipeline from Prudhoe Bay on the Arctic Ocean 

to Valdez on Prince William Sound intersects 

several seismically active zones. Sections of the 

proposed pipeline will be subject to serious 

earthquake hazards, including seismic shaking, 

faulting, and seismically induced ground deformation such as slope failure, differential compaction, and liquefaction. This rep1rt is concerned only with seismic shaking that, if not 

accommodated in the design, could c~use deformation leading to failure in the pipeline, storage 

tanks, and appurtenant structures and equiPment and ultimately to the leakage of oil. It 

might also induce effects such as seiching of 

liquids in storage tanks and liquefaction, land-

. sliding, and differential compaction in foundation materials, all of which could result in deformation and potential failure. 

To protect the environment, the p~oeline system is to be designed so as to minirrize the potential of oil leakage resulting fron1 effects of 

earthquakes. The magnitudes of the earthquakes which the design must accommodate are 

given in "Stipulations for Proposed ':':'rans-Alaskan Pipeline System" ([U.S.] Feieral Task 

Force on Alaskan Oil Development, 1972, Ap-. 

pendix, Sec. 3.4.1, p. 55), hereinafter referred 

to as "Stipulations." This report ct·.~racterizes 

ground motions for the specified de<"1ign earthquakes. 

The seismic design of the propoe-P.d pipeline 

involves a combination of problems not usually 

encountered. In the design of important structures, detailed geologic and soil inY~stigations 

of the site generally provide the background 

data. Such detailed site investigations are not 

economically feasible for a linear structure 

nearly 800 miles long. In addition, a structure 

more limited in extent can be located on competent foundation materials and away from known 
faults, whereas a pipeline traversing Alaska 

from north to south unavoidably crosses active 

faults and encounters a full range of foundation 

conditions from bedrock to water-saturated 

silty sands with a high potential for liquefaction 

(U.S. Geol. Survey, 1971). 

SEISMIC POTENTIAL 

The "Stipulations" specify the earthquake 

potential along the proposed pipeline route in 

terms of design earthquakes in five broad seismic zones as given in table 1 and shown in figure 

1. The zonation is based on the limited existing 

ALASKA 

\ 

' 

\ \ 

\ 

0 100 200 :500 400 500 KM 

Figure I.-Map of proposed route of trans-Alaska oil pipeline 

showing seismic zonation and magnitudes of design earthquakes. 

seismic and geologic data and a rudimentary 

understanding of tectonic processes acting along 

the proposed rqute. If geologic and geophysical 

information along the route were sufficiently detait'ed, the zonation might be more refined and 

possibly less conservative. 

Table I.-Design earthqu.tkes alon;~ the pipeline route 

Seismic zone Magnitude 

Valdez to Willow Lake____ -------------8.5 

Willow Lake to Paxson_________ 7.0 

Paxson to Donnelly Dom•-------------------8.0 

Donnelly Dome to 67°N .7.5 

67°N to Prudhoe Bay 5.5 

The design earthquakes are maximum credible events in the sense that they are the largest 

shocks that are reasonably likely to occur over 

an interval of a few hundred years. Only for the 

magnitude 8.5 and 7.5 zones are there instru2 

mental records of shocks equal to the design 

earthquakes; elsewhere the design er.rthquakes 

exceed the largest recorded shocks. Pecurrence 

intervals for the design earthquakes in the five 

zones from Valdez to Prudhoe Bay are estimated 

to be 200, 200, 200, 50 and 50 years (Appendix 

A). 

Potential for surface or near-surface faulting 

must be assumed for the design earthquakes. 

Surface rupturing was associated with the great 

1899 and 1964 shocks in the southr-rn coastal 

seismic belt. Moreover, the available seismic 

data indicate that earthquakes alon~: the pipeline route are shallow. The most reliable information is from detailed seismic studies near 

Fairbanks (Gedney and Berg, 1969) and at the 

Denali fault crossing (Page, 1971). Focal depths 

in these areas are less than 21 and 13 km (kilometers), respectively. There is no reliable evidence that earthquakes are substantially deeper 

elsewhere beneath the pipeline route" 

In the absence of detailed· geologic information to delineate active faults and to assess the 

seismic risk associated with each fault, the design of the pipeline must allow for the occurrence of the design earthquake anywllere within 

the seismic zone. In particular, the design must 

consider potential ground motion and deformation associated with earthquakes oc~urring at 

shallow depth in the immediate vicirity of the 

pipeline. 

DESIGN APPROACH 

There are two common approaches to seismic 

design of a structure: One utilizes a complete 

time history of ground motion to evaluate dynamic behavior. The other, adopted for the design of the pipeline system (Alyeska Pipeline 

Service Co., 1971), is a quasi-static method in 

which seismically induced stresses are determined from structural response spectra for 

specified levels of ground motion. 

Structural response spectra for tl'~ pipeline 

system are calculated in a three-step process. 

First, ground-motion values appropriate to the 

design earthquakes are specified. Th~n, design 

values of motion are derived by modifying the 

ground-motion values to implicitly allow for 

nonlinear, energy-absorbing mechanisms in the 

vibratory response of the structure, a step re-

_quired by the assumption of purely elastic response, although the actual response is usually 
inelastic and nonlinear for large ground motions. Finally, smoothed tripartite logarithmic 

response spectra are constructed from the design seismic motions by the general procedure 

of Newmark and Hall (1969), outlined in Appendix B. 

The initial step in the design process discussed 

herein characterizes ground motion appropriate 

to the design earthquakes. This step is based 

solely on seismological data and principles and 

does not incorporate factors dependent on soilstructure interactions, deformational processes 

within structures, or the importance of the 

structures to be designed. It involves scientific 

data and interpretation, whereas the subsequent 

steps involve engineering, economic, and social 

judgments relating to the nature and value of 

the structures. 

The choice of parameters with which to specify ground motion was guided by the design approach adopted for the pipeline project. A useful set for the derivation of tripartite structural 

response spectra includes acceleration, velocity, 

displacement, and duration of shaking. 

GROUND MOTION VALUES 

Table 2 characterizes near-fault horizontal 

ground motion for the design earthquakes. The 

intensity of shaking is described by maximum 

values of ground acceleration, velocity, and displacement. In addition to the maximum acceleration, levels of absolute acceleration exceeded 

or attained two, five, and ten times are specified, 

because a single peak of intense motion may 

contribute less to the cumulative damage potential than several cycles of less intense shaking. Levels of absolute velocity 41exceeded or 

attained two and three times are also given. 

There is substantial evidence that the duration of shaking strongly affects tha. extent of 

damage caused by an earthquake; yet the problem of how duration is related to magnitude has 

received little attention in the literature. In this 

study, the measure of duration used corresponds 

to the time interval between the first and last 

peaks of absolute acceleration equal to or larger 

than 0.05 g. Operational definitionr of the acceleration and duration parameters are illustrated on an accelerogram in figure 2. 

The values in table 2 are based on instrumental data insofar as possible. Strong-motion data 

have been obtained within 10 km of the causative fault for shocks as large as rr.~gnitude 6, 

but no accelerograms are available from within 

40 km of the fault for a magnitude 7 shock and 

from within more than 100 km for r. magnitude 

8 shock. Estimates of intensity of near-fault 

ground motion for shocks larger than magnitude 6 are extrapolated from data obtained at 

larger distances or from near-fault data from 

smaller shocks. 

The ground motion values in table 2 are 

subject to several conditions as fC'llows. They 

are for a single horizontal componert of motion. 

The intensity of shaking in the vr-rtical direction is typically less than two-thirds that in a 

horizontal direction. They correspor1 to normal 

or average geologic site conditions and are not 

intended to apply where grounc motion is 

strongly influenced by extreme contrasts in the 

elastic properties within the local geologic section. They characterize free-field ground motion, 

that is, ground motion not affected by the presence of structures. They contain no factor relating to the nature or importance of the structure 

Table 2.-Near-fault horizontal ground motion 

Acceleration (g) Velocity (em/sec) Displacement Magnitude Peak absolute values Peak absolute values (em) Durationl 

(sec I 

1st 2d 5th lOth 1st 2d 3d 

8.5 1.25 1.15 1.00 0.75 150 130 110 100 90 

8.0 1.20 1.10 0.95 0.70 145 125 105 85 60 

7.5 1.15 1.00 0.85 0.65 135 115 100 70 40 

7.0 1.05 0.90 0.75 0.55 120 100 85 55 25 

6.5 0.90 0.75 0.60 0.45 100 80 70 40 17 

5.5 0.45 0.30' 0.20 0.15 50 40 30 15 10 

1Time interval between first and last peaks of absolute acceleration equal to or greater than 0.05 g. 

Notes-1. Italic values are based on instrumental data. 

2. The values in this table are for a single horizontal component of motion at a distance of a few 13-51 km of the causative fault; are for sites at which ground motion is not strongly altered by extreme contrasts in the elastic properties within the local geologic 

section or by the presence of structures; and contain no factor relating to the nature or importance of the structur" being designed. 3. The values of acceleration may be exceeded if there is appreciable high-frequency (higher than 8 Hz) energy. 

4. The values of displacement are for dynamic ground displace"'ents from which spectral components with periods gpeater than 10 to 15 seconds are removed. 

3 
5 

-4 

ltlo 

(j) TIME ( SECONDS) 

3 4 

® To.oeg 

Figure 2.-Accelerogram from 1966 Parkfield earthquake illustrating definition of parameters referred to in table 2. Peaks O"" accelerogram are numbered consecutively I through 10 in order of decreasing amplitude. First, second, fifth, and tenth highest peaks are 

listed in table 2. Duration, To.osg• is the time interval between the first and last peaks of acceleration equal to or greater than 

0.05 gin absolute value. 

being designed. They are not the maximum possible. As mentioned in the following section, 

very little reliable data have been obtained within 10 km of the causative fault. How often these 

values are likely to be exceeded cannot be reliably estimated from the currently existing 

data. The acceleration values may be exceeded 

if there is appreciable energy in frequencies 

higher than 8 Hz (cycles per second) . The displacement values correspond to dynamic ground 

displacements, as would be recorded on a strongmotion instrument having a frequency response 

flat to ground displacement for periods less than 

10 to 15 seconds. 

ACCELERATION 

A plot of peak acceleration against shortest 

distance to the causative fault, including only 

those data for which source distances are most 

accurately known, reveals that peak acceleration 

increases with magnitude at all distances for 

which data exist and attenuates with distance 

r at a rate in the range r-1 •

5 to r-2 ·

0 at distances 

beyond 1tbout 10 km for magnitude 5, about 20 

· km for magnitude 6, and less than 40 km for 

magnitude 7 (fig. 3). 

For distances less than 10 km, there are no 

strong motion data for shocks larger than magnitude 6 and few reliable data for shocks of 

magnitude 5 and 6. The annual issues of "Bnited 

States Earthquakes," published by the U.S. 

Coast and Geodetic Survey, list at least twelve 

magnitude 5 shocks and three magnitude 6 

shocks in which strong motion records were 

obtained at epicentral distances of 16 km or less. 

For nearly all these events, the epicentral dis4 

tance is uncertain by at least 5 to 10 km and for 

some possibly by as much as 25 km, and the 

actual slip surface is not known. Because of the 

rapid rate of attenuation, distance to t:r~ causative fault must be known to 1 or 2 km if the 

data are to be used to establish accelerations 

within a few kilometers of the fault. 

Acceleration-distance data for magnitude 5 

earthquakes recorded on one or more accelerographs within 32 km of the fault are p1otted in 

figure 4. The most reliable and extensi .. Te nearfault data are from the 1966 Parkfield earthquake (m = 5.5). Distances to the fault are unusually well determined for this event, the uncertainty being less than 0.5 km. The F~--.rkfield 

data indicate a zone of little attenuation within 

about 10 km of the fault. In comparison with the 

other data for magnitude 5 shocks, the Parkfield data do not suggest anomalously intense 

shaking for that particular earthquake. In fact, 

the Parkfield data systematically lie beneath the 

points from the 1970 Lytle Creek ear.hquake 

(m = 5.4) ; the discrepancy in accelerat~~ns for 

these two events probably reflects di:ffer~~nces in 

seismic source parameters such as fault length 

and effective stress. The near-fault acce ~ration 

values in Table 2 for magnitude 5.5 are l: f.l.sed on 

the Parkfield data, in particular, on the data 

recorded at a distance of 5 km. The regu]".r variation of acceleration and duration with clistance 

(fig. 5) suggests that the Parkfield data are 

free from anomalous local amplification of 

ground motion. 

No near-fault accelerograms for an earthquake larger than about magnitude 6.6 are 
0 

1.0 

0.52g 

0.08 km 

- 0.1 

t:), 

-

z 

0 

.... 

<( 

0:: 

w 

....J 

w 

u 

u 

<( 

0.01 EARTHQUAKE 

MAGNITUDE 

• 5.0-5.9 

0 6.0-6.9 

• 7.0-7.9 

10 

0 0 

2 

DISTANCE (KM) 

0 

o• 

CJ)i 0 

mo• 

• o•~ 0 o. 0 

~ 

i 

• 

0 

• 

•• 

Figure 3.-Peak horizontal acceleration versus distance to slipped fault as a function of magnitude. Except for 1949 Puge' Sound shock 

(open squares), data shown are those for which distances to fault are most accurately known (tabulated in Appendix C). Straight-line 

segments connect observations at different stations for an individual earthquake, for three magnitude 5 shocks and one magnitude 7 

shock. From top to bottom, suites of magnitude 5 data are from 1970 Lytle Creek (m = 5.4), Parkfield (m = 5.5), and 1957 Daly City 

(m = 5.3) shocks. Closest Parkfield data point lies off plot to left at 0.08 km. For magnitude 6, most data within 100 km are from 

1971 San Fernando earthquake (m = 6.6), and most data beyond 100 km are from 1968 Borrego Mountain earthquake (m = 6.5). Most 

magnitude 7 data are from 1952 Kern County shock (m = 7.7). Open squares are values from 1949 Puget Sound event (m = 7.1 ), for 

which distances are determined to hypocenter assuming minimum focal depth of 45 km. Arrows denote minimum values. 

5 
~ 

z 

0 MAGNITUDE 5.0-5.9 0 

.... 

<t 

0:: EXPLANATION 0 

UJ • ...J 

UJ o• u Distance to fault known 0 u within 2 km 0 <t ., 

0 0 

Distance to fault known 0 J! 

2 2o 0 

within 5 km ...... 

0 0 

t 

Distance to fault known 0 

within 25 km 

0.1 1.0 10 100 

DISTANCE (KM) 

Figure 4.-Peak horizontal acceleration versus distance to slipped fault, if known, or epicentral distance for magnitude 5 earthquakes 

(Appendix C). Included are data from shocks in which at least one accelerogram was obtained within 32 km (dashed vertical 

line) of the fault or epicenter. No data beyond 100 km are plotted. Different symbols denote accuracy to which dist11nce is known. 

Solid circles are 1966 Parkfield data for which distances to slipped fault are known to within 0.5 km. Large open circles are 1957 

Daly City, 1967 Fairbanks, and 1970 Lytle Creek data for which distances to slipped surface are known to within 2-5 km. Small circles correspond to greater uncertainties in distance to source, possibly as large as I 0-25 km. Line segments connect all data for 

individual events with better determined distances. Arrows denote minimum values. 

known to the authors. An accelerogram was obtained at a distance· of about 10 km from the 

surface fault break in the 1940 Imperial Valley 

earthquake, which was given a surface-wave 

magnitude of 7.1 (Richter, 1958, p. 489) ; however, the character of the record indicates that 

this earthquake was a multiple event composed 

of a series of smaller shocks, the largest of 

which had a local Richter magnitude of about 

6.4 (Trifunac and Brune, 1970). Accordingly, 

t be recorded accelerations are more representative of a magnitude 6.5 shock, whereas the dura6 

tions are more characteristic of a 7.0 event. 

Acceleration-distance data for mr.gnitude 6 

earthquakes are plotted in figure 6. The only 

data for which the distance to the fault is known 

to an accuracy of 1 to 2 km are fron the 1971 

Figure 5.-Peak horizontal accelerations and O.OSg horizontal durations versus distance from slipped fault for 1966 

Parkfield earthquake. Values of the first, second, fifth, 

and tenth highest absolute peaks of ac-:-eleration are 

shown. Where two horizontal components are available, 

both values are indicated by top and botbm of vertical 

bars. Only those data from within 15 k111 of the fault 

are shown. 
San Fernando earthquake (m = 6.6). This shock 

produced one accelerogram at a distance of 

about 3 km from the inferred slip surface and 

~ 

z 

2 

1-

<( 

a: 

1.&.1 

_. 

1.&.1 

0 

0 

<( 

0 

1.&.1 

(/) 

z 

0 6 

fi 

a: 

::) 

0 

4 

2 

o~------~------L-------~---

0 5 ~ 15 

DISTANCE FROM FAULT ( KM) 

0.5 

0.4 

0.3 

0.2 

0.1 

5 ~ ~ 

DISTANCE FROM FAULT (KM) 

7 

more than 100 accelerograms at dirtances beyond 15 km. The peak acceleration from Pacoima at 3 km lies beneath a straight-Pne extrapolation of the trend of the data bey<'"ld 10 km; 

this behavior is consistent with a zone of little 

attenuation near the fault as obserYed for the 

Parkfield data in figure 4. 

The maximum acceleration from t]'~ San Fernando earthquake was 1.25 g, nearly double the 

maximum acceleration recorded during any 

earthquake prior to 1971. The accel~ration was 

recorded at a bedrock site adjac~nt to the 

Pacoima dam. Because the Pacoim~ accelerations are so much higher than those recorded 

in previous earthquakes, the questior has arisen 

whether or not the record might be anomalous 

in the sense that the motion may have been 

significantly amplified by various rite factors 

such as the rugged topographic relief, the presence of the dam, and the cracking and minor 

landsliding near the station. The autl''lrs are not 

aware of any investigations of possible site effects that conclusively demonstrate an anomalous amplification (greater than 25-50 percent) 

of recorded motion in the frequency range 1-10 

Hz. The Pacoima ground motion in the period 

range 1 to 2 seconds is not inconsistent with 

that predicated from a simple theor~tical fault 

model for the earthquake (Trifunac, 1972). 

The near-fault acceleration values for magnitude 6.5, table 2, were derived frmn the Pacoima accelerograms of the San Fern.~ndo earthquake. In the Newmark and Hall method for 

estimating velocity response spect:-:-a (Appendix B), the spectral amplitude in the approxi-

:mate frequency range 2-8Hz is dire~tly proportional to the peak ground acceleration. If the 

peak acceleration is dominated by higher frequency energy, the Newmark and Pall method 

overestimates the spectrum in this range. Frequencies higher than 8 Hz contributed significantly to the peak accelerations recorded at 

Pacoima (fig. 7) ; accordingly, tl'~ accelerograms were filtered to remove frequ~ncies higher than about 9Hz. Filtering reducf'q the accelerations by about 25 percent, as se£n in table 3 

and fig. 7. The near-fault acceleration values of 

table 2 for magnitude 6.5 were adopt~d from the 

filtered values. 

Near-fault accelerations for magr.itudes larger than 6.5 were extrapolated from strong mo-
z 

0 

~ a:: 

L&J 0.1 

..J 

L&J 

0 

0 

<( 

• 0 

0 

0 

MAGNITUDE 6.0-6.9 

EXPLANATION 

Distance to • fault known 

within 2 km 

0 

Distance to fault known 

within 5 km 

0 

Distance to fault known 

I 

., 

~ •• 

•• I • 

• 

-

• ••• 2 • 

• 

0 01 within 25 km . ~----------~--~----~----~-----L~~ 1.0 10 

DISTANCE (KM) 

Figure 6.-Peak horizontal acceleration versus distance to slipped fault, if known, or epicentral 

distance for magnitude 6 earthquakes (Appendix C). Included are data from shocks in 

which at least one accelerogram was obtained within 32 km (dashed vertical line) of the 

fault or epicenter. Different symbols denote accuracy to which distance is known. Line segments connect data for individual shocks except for San Fernando data. Arrows denote minimum values. 

tion observations at distances greater than 40 

km and from the near-fault data from smaller 

shocks. The extrapolation was guided by two 

considerations. First, the existing strong motion 

data indicate that peak acceleration increases 

with magnitude at all distances for which data 

exists (fig. 3). Second, theoretical arguments 

(Brune,1970) suggest that near-fault peak acceleration is proportional to the effective stress 

available to cause slippage and to the high-frequency cutoff in the recorded signal. Allowing 

for an increase of effective stress with magniTABLE 3.-Peak horizontal ground accelerations from filtered 

Component 

s 74° w. 

and unfiltered accelerograms at Pacoima dam 

1st 2nd 5th 

unfiltered 1.25 CJ 1.15 CJ 0.69 g filtered .82 . 77 .59 

unfiltered 1.22 1.0 I . 79 

filtered .93 .77 .60 

lOth 

0.57 g 

.44 

.52 

.45 

8 

tude, a value of 1.25 g was adopted for magnitude 8.5, and the values for intermediate magnitudes were interpolated between 1.25 g and 

the value of 0.9 g for magnitude 6.5. The numerous reports of shattered ground anc, of rocks 

and objects apparently thrown into the air in 

the epicentral region of large earthquq.kes (for 

example, Richter, 1958, p. 25-26, 50-51 ; Morrill, 

1971; Barrows and others, 1971) are c0nsistent 

with accelerations of 1 g and greater, although 

various alternative mechanisms that rright produce such effects from less intense shaking have 

been offered in many instances (Richter, 1958, 

p. 25-26) . The acceleration values adopted in 

Table 2 increase markedly between n'agnitude 

5.5 and 6.5 and then less rapidly with magnitude 

above 6.5. 
-

-

z 

0 

0 

~ -1 

ffi I 

..J 

LLI 

(.) 

(.) 

<( 

0 

-I 

0 

UNFILTERED 

FILTERED ( fc = 8.5 Hz ) 

4 8 12 16 20 

Figure 7.-Unfiltered and filtered accelerograms of the 1971 San Fe~nando earthquake from the S. 74° W. accelrrograph component at Pacoima dam. Response of filter is 1.0 at frequencies less than 8 Hz and 0.0 at frequencies greater t'-lan 9 Hz with 

a half-wave cosine taper from 8 to 9 Hz. 

VELOCITY 

The response curve of the standard strong 

motion seismograph operates in the United 

States is flat to acceleration over the frequency 

range of the predominant ground motion. Accordingly, accelerations are measured directly 

from the strong motion recordings, whereas 

velocities are obtained by integration of the 

record. For this reason, there are few velocity 

data in the literature relative to acceleration 

data. 

Peak velocity data in the magnitude range 

5-7 plotted as a function of distance from the 

source (fig. 8) indicate that peak velocity increases with magnitude at all distance for which 

data exist. Those data points for which distance 

9 

to the fault is accurately known (large symbols) 

tend to separate according to magnitude; the 

remaining data confirm this tendency, although 

their behavior is somewhat obscurei by scatter 

arising at least partially from er:-·ors in distances. The plot reveals that beyo~d about 10 

km, peak velocity attenuates less rapidly with 

distance than peak acceleration. 

The near-fault velocity values fo:':" magnitude 

5.5 (table 2) are averages of t1''1 Parkfield 

values recorded at 0.08 and 5.5 kn from the 

fault. The values for magnitude 6.5 are based 

on the San Fernando observations at the Pacoima site about 3 km from the fault surface. For 

the larger magnitudes, the values y•ere extrapolated from those for 5.5 and 6.5 on the as-
-

0 

w 

en 

' :E 

0 

-

0 

0 

..J 

w 

> 

0 

72~/SEC 0 

~ 0 

EARTHQUAKE 

MAGNITUDE 

A 5.0-5.9 

0 6.0-6.9 

• 7.0-7.9 

0 

0 0 

0 

0 

DISTANCE (KM) 

Figure 8.-Peak horizontal velocity versus distance to slipped fault, if known, or epicentral distance for magnitudes 5, 6, 

and 7 {tabulated in Appendix C). Uncertainties in distances are less than 5 km for larger symbols and more than 

5 and possibly as large as 25 km for smaller symbols. Line segments connect data for individual shocks. The c 1,sest 

point to the fault for the Parkfield shock lies off the plot at 0.08 km. Arrows denote minimum values. 

sumption that near-fault velocities increase 

with magnitude, corresponding to an increase 

in effective stress with magnitude. A peak value 

of 150 em/sec (centimeters per second) was 

assumed for magnitude 8.5, and the intervening 

values were interpolated. Prior to the San Fernando earthquake, theoretical estimates of an 

upper limit for near-fault peak velocity were in 

the range 100-150 em/sec (Ambraseys, 1969; 

10 

Brune, 1970). A velocity of 115 cm/sE'~ was recorded at the Pacoima site during the San Fernando earthquake (m = 6.6); hence the assumed value of 150 em/sec for magnitude 8.5 is 

considered reasonable. 

DISPLACEMENT 

Instrumental data on peak dynamic: displacements are less reliable than the data for either 

peak accelerations or velocities. Data on dy-
namic displacements excluding spectral components with periods greater than about 10-15 

seconds are available from double integration of 

accelerograms or directly fr-om displacement 

meters. Both types of data are subject to uncertainties. In the double integration of digitized 

accelerograms, errors may arise from low-frequency noise in the digitization of the original 

accelerogram and from lack of knowledge of the 

true baseline of the accelerogram. On the other 

hand, there are instrumental difficulties associated with displacement meters operating with a 

free period of 10 seconds. The rel~tive accuracy 

of the two types of data is not adequately understood (Hudson, 1970). 

Peak displacement data obtained from double 

integration of accelerograms and from 10-second displacement meters when plotted against 

distance (fig. 9) show no apparent systematic 

difference between the two types of data within 

the scatter of the points. Peak displacement at 

a given distance from the fault, like peak acceleration and velocity, increases with magnitude. 

The near-fault value of peak displacement for 

magnitude 5.5 (table 2) is the mean of the Parkfield values obtained at 0.08 and 5.5 km from 

the fault. For magnitude 6.5 the value is based 

on the Pacoima record for the San Fernando 

earthquake. How peak dynamic displacement 

(for periods less than 10-15 seconds) scales with 

magnitude for larger shocks is uncertain. An 

upper limit to the increase of near-fault dynamic displacement with magnitude is the rate at 

which fault dislocation increases with magnitude. The total fault slip in the 1964 Alaska 

shock (m=8.5) is estimated to have been about 

five times that in the 1971 San Fernando earthquake (m=6.5). Hence, an upper bound" on the 

peak dynamic displacement for magnitude 8.5, 

after removal of low frequency energy, is about 

2m. In this study, a value of 1m is assumed for 

magnitude 8.5, and the values between magnitude 6.5 and 8.5 are smoothly interpolated. 

DURATION 

The measure of duration used in this study 

is the time interval between the first and last 

acceleration peaks equal to or greater than 0.05 

g. Although crude, this measure is readily applied to the existing accelerograms and approximates the cumulative time over which the 

ground accelerations exceed a given level. Comparison of felt reports for earthquakes of mag11 

nitude 5 and 6 with near-fault accele:-:-ograms 

from shocks of similar magnitude suggest that 

the "intense" or "strong" phase of shaking mentioned in felt reports corresponds to accelerations of about 0.05 g and greater. In comoarison, 

the minimum perceptible level of accele:-:-ation is 

0.001 g (Richter, 1958, p. 26). 

Durations obtained for several earthquakes 

in the magnitude range 5-7 indicate tll at for a 

given magnitude, duration decreases with increasing distance from the source, and that at 

a given distance from the source, duration increases for larger magnitudes (fig. 10). The 0.05 

g duration for magnitude 5.5 (table ~:) is the 

mean of the maximum durations for the 1966 

Parkfield shock (m = 5.5) recorded at distances 

of 0.08 and 5.5 km from the fault surface (fig. 

5). The durations for magnitude 6.5 and 7.0 are 

based respectively on the measured O.Of g durations of 13 seconds at Pacoima dam in the 1971 

San Fernando earthquake (m = 6.6) and of 30 

seconds at El Centro in the 1940 Imperial Valley 

earthquake, which was a multiple event characterized by a surface-wave magnitude of 7.1. 

These data were smoothed slightly to obtain a 

regular increase of duration with magnitude in 

table 2. The adopted near-fault durations of 17 

and 25 seconds for magnitudes 6.5 and 7.0 are 

consistent with the duration data in figure 10 

within the scatter of the points. 

In the absence of near-fault data for larger 

magnitudes, durations can be estimated from 

theoretical calculations in corroboration with 

feit observations. Assume that a magnitude 8.5 

earthquake is a multiple event comr~ised of 

several shocks as large as magnitude 7.5 distributed along a fault 500-1,000 km in len~~th. Peak 

accelerations of 0.05 g or greater are expected 

for a magnitude 7.5 earthquake at distances up 

to 100 km (fig. 3). For a rupture propagation 

velocity of 2 to 3.5 km/sec, the 0.05 g duration 

at a near-fault station near the center of the 

fault would be 100 to 57 seconds, respectively. 

In comparison, felt reports of the duration of 

intense· shaking in the aftershock zor~ of the 

1964 Alaska earthquake (m = 8.5) ranged from 

60-90 seconds at Whittier (Kachadoorir.n, 1966) 

to 150 seconds at Kodiak (Kachadoo~ian and 

Plafker, 1967). The tabulated duration of 90 

seconds for magnitude 8.5 (table 2) is c~1nsistent 

with the calculated range of values and with 

felt data from the 1964 shock. 
0 

-::E 

u 

- p ~ I " 

z .o I 

w I ~ I 

:E I I 

w \ I 

\ \ u \ 

\~ :51.0 ' ~ 0 A 0 ~ 

en 

0 EARTHQUAKE 

MAGNITUDE 

A 5.0-5.9 

A 

0 6.0-6.9 • 0 

• 7.0-7.9 \ ci 

0.1 • 2 

• 

DISTANCE (KM) 

Figure 9.-Peak horizontal dynamic displacement for spectral components with periods less than I 0-15 seconds v,,rsus distance to 

slipped fault, if known, or epicentral distance for magnitudes 5, b, and 7 (tabulated in Appendix C). Small symbols are data 

from 10-second displacement meters. Larger symbols are data from double integration of accelerograms, with largest symbols for 

distances uncertain by less than 5 km and the intermediate symbols for uncertainties of 5 to possibly 25 km. line segments join 

data from individual shocks. Dashed curves connect and dashed circles enclose values for same site and corr"onent obtained 

from the two different sources. Arrows denote minimum values. 

12 
30 

-

0 

UJ 20 (/) 

-

z 

0 

..... 

<( 

0:: 

:::) 

0 

• 

0 

EARTHQUAKE 

MAGNITUDE 

• 5.0-5.9 

0 6.0-6.9 

• 7.0-7.9 

40 60 80 

DISTANCE (KM) 

Figure 10.-Duration of shaking versus distance to slipped fault, if known, or epicentral distance for magnitudes 5, 6, and 7. Shown 

is O.OSg duration (see fig. 2 for definition; plotted data are tabulated in Appendix C). Distances represented by larger symbols 

are uncertain by less than 5 km; those indicated by smaller symbols by 5 to possibly 25 km. Arrows denote minimun values. 

The durations for magnitude 7.5 and 8.0 were 

interpolated between the values for magnitudes 

7.0 and 8.5 to obtain a smooth increase in duration with magnitude. 

REFERENCES 

Alyeska Pipeline Service Company, 1971, AI ignment sheet 65 

design, Appendix A-3.1023 of Proiect description of the 

trans-Alaska pipeline system: Houston, Texas, Alyeska Pipeline Service Co., 92 p. 

Ambraseys, N. N., 1969, Maximum intensity of ground movements 

caused by faulting: Fourth World Conference on Earthquake 

Engineering, Santiago, Chile, 1967, Proc., v. I, p. 154-171. 

Barrows, A. G., Kahle, J. E., Weber, F. H., and Saul, R. B., 1971, 

Map of surface breaks resulting from the San Fernando, California, earthquake of February 9, 1971: California Div. Mines 

and Geology Prelim. Rept. No. II, plate I. 

Brune, J. N., 1970, Tectonic stress and the spectra of seismic 

shear waves from earthquakes: Jour. Geophys. Research, v. 

13 

75, p. 4997-5009. 

Gedney, L., and Berg, E., 1969, The Fairbanks e .. rthquakes of 

June 21, 1967: Aftershock distribution, focal mE'chanisms, and 

crustal parameters: Seismol. Soc. America Bull., v. 59, p. 

73-100. 

Hastie, L. M., and Savage, J. C., 1970, A dislocat~on model for 

the 1964 Alaska earthquake: Seismol. Soc. Aonerican Bull., 

v. 60, p. 1389-1392. 

Hudson, D. E., 1970, Ground motion measurement~ in Wiegel, 

R. L., (ed.) Earthquake Engineering: Englewood Cliffs, N.J., 

Prentice-Hall, p. I 07-125. 

Hudson, D. E., Brady, A. G., Trifunac, M. G., and VP<tyaraghavan, 

A., 1971, Strong-motion earthquake accelerogr<"'rtS, digitized 

and plotted data, Volume 2, A: California lnst. Technology, 

Earthquake Eng. Research Lab. Rept. 71-50, p. 321. 

Kachadoorian, R., 1966, Effects of the earthquake of March 27, 

1964 at Whittier, Alaska: U.S. Geol. Survey Prof. Paper 

542-B, 21 p. 
Kachadoorian, R., and Plafker, G., 1967, Effects of the earthquake of March 27, 1964 on the communities of Kodiak and 

nearby islands: U.S. Geol. Survey Prof. Paper 542-F, 41 p. 

Morrill, B. J., 1971, Evidence of record vertical accelerations at 

Kagel Canyon during the earthquake, in The San Fernando, 

California, earthquake of February 9, 1971: U.S. Geol. 

Survey Prof. Paper 733, p. 177-181. 

Newmark, N. M., and Hall, W. J., 1969, Seismic design criteria 

for nuclear reactor facilities: Fifth World Conference on 

Earthquake Engineering, Santiago, Chile, 1967, Proc., v. 

2, p. 37-50. 

Page, R. A., 1971, Microearthquakes on the Denali fault near 

the Richardson Highway, Alaska [abs.]: Am. Geophys. Union 

Trans., v. 52, p. 278. 

-- 1972, Crustal deformation on the Denali fault, Alaska, 

1942-1970: Jour. Geophys. Research, v. 77, p. 1528-1533. 

Plafker, G., 1969, Tectonics of the March 27, 1964 Alaska earthquake: U.S. Geol. Survey Prof. Paper 543-1, p. 174. 

Richter, C. F., 1958, Elementary Seismology; San Francisco, W. 

H. Freeman and Co., 768 p. 

Richter, D. H. and Matson, N. A., 1971, Quaternary faulting in 

the eastern Alaska Range: Geol. Soc. America Bull., v. 82, 

p. 1529-1539. 

Stout, J. H., Brady, J. B., Weber, F., and Page, R. A., 1972, Evidence for Quaternary movement on the McKinley strand of 

the Denali fault in the Delta River area, Alaska: Geol. Soc. 

America Bull. (in press). 

Sykes, L. R., 1972, Aftershock zones of great earthquakes, seismicity gaps, and earthquake prediction for Alaska and the 

Aleutians: Jour. Geophys. Research, v. 76, p. 8021-8041. 

Trifunac, M. D., 1972, Stress estimates for the San Fernando, 

California, earthquake of February 9, 1971: Main event and 

thirteen aftershocks: Seismol. Soc. America Bull., v. 62, p. 

721-750. 

Trifunac, M. D., and Brune, J. N., 1970, Complexity of energy 

release during the Imperial Valley, California earthquake of 

1940: Seismol. Soc. America Bull., v. 60, p. 137-160. 

[U.S.] Federal Task Force on Alaskan Oil Development, 1972, 

Introduction and summary, v. I ol Final environmental impact 

statement, proposed trans-Alaska pipeline: U.S. Dept. Interior 

interagency rept., 386 p.; available only from the Natl. Tech. 

lnf. Service, U.S. Dept. Commerce, Springfield, Va., NTIS 

PB-206921-1. 

U.S. Geological Survey, 1971, Preliminary engineering geologic 

maps of the proposed trans-Alaska pipeline route [compiled 

by 0. J. Ferrians, R. Kachadoorian, and F. R. Weber]: U.S. 

Geol. Survey open-file report. 

Wiggins, J. H., 1964, Effect of site conditions on earthquake 

intensity: American Soc. Civ. Eng., Structural Div., v. 90, 

p. 279-313. 

APPENDIX A-RECURRENCE INTERVALS 

Estimates of recurrence intervals for the design earthquakes are based on the historic seismic record and tectonic arguments. In the interpretation of the seismic history, the width of 

each seismic zone transverse to the pipeline 

route is assumed to be equal to the characteristic length of faulting for the specified magni14 

tude. 

In the southern coastal zone, earthquakes as 

large as the design earthquakes occurred in 

1899 near Yakutat Bay and in 1964 in Prince 

William Sound. This pattern is consistent with 

a recurrence interval of less than 100 years; 

however, tectonic considerations irrlicate that 

the average long-term interval beh<~Teen design 

earthquakes is longer. In the framework of global tectonics, the 12 m of thrusting involved in 

the 1964 earthquake (Hastie and Savage, 1970) 

would require 200 years of stPain accumulation 

at the local convergence rate of 6 cn/yr (centimeters per year) for the Pacific and North 

American plates. Geologic evidence. of vertical 

movements in Prince William Sound (Plafker, 

1969) indicates episodes of tectonic deformation between quiescent periods of t.he order of 

800 years. On Middleton Island the total uplift 

in each deformational episode is 2.5-3 times that 

for the 1964 earthquake. The geolo~ic evidence 

suggests a long-term average recmTence interval of about 300 years for an event comparable 

to the 1964 earthquake. An interval of 200 years 

is adopted for the magnitude 8.5 zone. The lack 

of seismic activity in the area between Yakutat 

Bay and the 1964 aftershock zone. during the 

past 50 years has led Sykes (1972) to identify 

this part of the Aleutian-Alaskan seismic belt 

as a likely site of a future earthquake larger 

than magnitude 7. 

The magnitude 8.0 zone includes the Denali 

fault system, an active strike-slip system that 

displays geologic evidence for an average Holocene slip rate of at least 3 cm/yr (Richter and 

Matson, 1971). Assumption of a 6~m offset for 

a magnitude 8.0 event and a 3 cm/yr slip rate 

gives a recurrence interval of 200 years. The 

lack of observable fault-slip and teleseismically 

recorded earthquakes on the fault system in the 

vicinity of the pipeline route and to the east 

indicates that the fault system ]'as been effectively locked for at least 30 ~rears (Page, 

1972). An undeformed neoglacial n1oraine lying 

athwart the recently active fault trace is evidence that no major episode of faulting has 

occurred within the past 170 year~ (Stout and 

others, 1972). 

Understanding of the tectonic f':'amework of 

the magnitude 7.5 zone is not adequate for estimating recurrence intervals. Ona. shock ap-
proaching the design magnitude has occurred 

on the pipeline route in this century, a magnitude 7.3 shock in 1937. A recurrence interval of 

50 years is assumed. 

In the magnitude 7.0 and 5.5 zones, there is 

no historic record of shocks as large as the design earthquakes. For the Willow Lake to Paxson zone, the record of earthquakes equal to or 

larger than magnitude 7.0 is probably complete 

for at least 50 years. From 67° N to Prudhoe 

Bay, the record for events as small as magnitude 5.5 is possibly complete since 1935, when 

a seismic station was established at College. 

Recurrence intervals of 200 and 50 years are 

assumed for the two zones. 

APPENDIX B-PROCEDURE OF NEWMARK 

AND HALL FOR DETERMINATION OF 

RESPONSE SPECTRA 

A response spectrum for a given level of 

damping is defined by the maximum responses 

(usually expressed in terms of displacement, 

velocity, or acceleration) of linear, single-degree-of-freedom oscillators (with different free 

periods but identical values of damping) when 

subjected to a specified time history of ground 

motion. A single spectrum is a plot of the maximum responses as a function of oscillator period 

or frequency; there is a different response spectrum for each level of damping. The_ usefulness 

of the response spectrum comes from the ability 

to model engineering structures by equivalent 

simple damped oscillators and to estimate 

stresses induced by the particular ground motion from knowledge of the equivalent period 

and damping of the structure and of the appropriate response spectrum. 

The values of parameters describing the actual ground motion may be modified for nonlinear energy-absorbing mechanisms before being used in the construction of a response spectrum. In the following example of the Newmark 

and Hall method for constructing response spectra, the ground motion values are not modified. 

The example is illustrative only of the general 

method and not of an application to a specific 

problem. 

Response spectra calculated from accelerograms often contain many peaks and troughs, 

hence prudent design requires the use of an 

15 

envelope of the actual response spectrum. Newmark and Hall (1969) describe a graphical 

method for determining envelope response 

spectra. First a tripartite logarithmic "ground 

motion spectrum" is constructed with three 

lines representing ground displacement, velocity, and acceleration. These lines are then 

shifted upward on tripartite log paper, by 

amounts depending on damping, to reflect the 

dynamic amplification of the ground motion in 

the structure. The amounts by which the lines 

are shifted are derived empirically from recorded accelerograms and are subject to revision 

as new data become available. This procedure, 

using the amplification factors give!l by Newmark and Hall (1969), is illustrated in figure 11, 

where the velocity response spectrum for 2 per-

<:) 

LaJ 

(/) 

-(/) 

LaJ 

5•ot-~:...--

~ 

>-

.,_ 

(3 

0 

-J 

LaJ 

> 

0.1 I 

FREQUENCY (CPS) 

Figure I I.-Example of tripartite logarithmic grC'und (dashed) 

and response (solid) spectra (after Newmark and Hall, 1969). 

Accelerations and displacements may be read fr,,m the plot in 

addition to velocities. Response spectrum is for damping value 

of 2 percent of critical. 

cent damping is estimated for a ground motion 

characterized by ground displacement of 12 

inches, velocity of 16 inches per Sf'~ond, and 

acceleration of 0.33 g. At high and low frequencies, the response spectrum must theoretically 

equal the ground acceleration and dis"llacement, 

respectively ; this accounts for the slope that 

connects the 1.4 g and 0.33 g lines. The corresponding line at the low frequency side is off the 

graph to the left. 
APPENDIX C-GROUND MOTION DATA 

In studying the dependence of peak ground 

acceleration upon magnitude and distance to 

the causative fault, the strong-motion literature was critically reviewed in an effort to compile data for which distances to the fault are 

most reliable, that is, most accurately determined. By restricting the determination to use 

of only the most reliable data and further to 

data from a single event, a r-1 •

5 to r-2 •

0 dependence of acceleration upon distance is clearly observed for distances as small as 10 km for magnitude 5, 20 km for magnitude 6, and less than 

40 km for magnitude 7 (fig. 3). The importance 

of restricting the data set in determining the 

near-fault dependence of acceleration upon distance is graphically demonstrated in figure 4, 

where the scatter in the entire data set is about 

an order of magnitude greater than the scatter 

for a single earthquake in figure 3. Because of 

the r-1 ·

5 to r-2 ·

0 attenuation of acceleration, the 

location of the inferred fault is particularly critical at small distances where the data are few. 

The data plotted in figure 3 are summarized 

in table 4. The tabulated accelerat~''>n value is 

the larger of the peak values obtain~d from the 

two horizontal accelerograms. Distance is measured to the closest point on the slipped surface 

of the fault. Except for the Imperial Valley, 

Hebgen Lake, and Puget Sound earthquakes, 

the slipped surface is inferred from the spatial 

distribution of aftershocks located with data 

from seismographs operated in most cases in 

the immediate vicinity of the after~hock area. 

The distance for the Imperial Vall?.y ·shock is 

the closest distance to the surface breakage 

along the Imperial fault. For the Hebgen Lake 

and Puget Sound shocks, distances t<' the slipped 

surface are equated respectively to epicentral 

distance of the main shock and to hypocentral 

distance (assuming a minimal focal depth of 45 

km). The uncertainties in the distances are 

given in the last column of table 4. 

Table 4.-Peak ground acceleration data for which distances to the causative fault are most accurately known. 

DATE EARTHQUAKE MAG STATION ACC OIST UNCER 

yR MO OA G KM KM 

MAGNITUDE 5.0-5.9 

57 03 22 DALY CITY,CALIFORNIA 5.3 S-f.,GOLOEN GATE PARK .13 a. 2-5 

Se~.,STATE BLDG. • 11 12 • 

S.F.,ALEXANDER BLDG. • 056 14 • 

S.F.,SO. PACIFIC BLDG. • 049 14 • 

OAKLAND • 048 24 • 

SAN JOSE • 001 58 • 

66 06 28 PARKFIELO,CALIFORNIA 5.5 CHOLAME-SHANOON 2 .52 o.oa 0.5 

CHOLAME-SHANOON 5 .48 5.5 

CHOLAME-SHANOON 8 .28 9.6 

TEMBLOR .42 10·6 

CHOLAME-SHANOON 12 .074 14.9 

SAN LUIS OBISPO .019 59. 

TAFT •009 101• 

BUENA VISTA •001 107. 

CACHUMA DAM • 003 132 • 

HOLLISTER .003 137. 

SANTA BARBARA • 005 154 • 

CASTAIC • 005 199 • 

UCLA • 001 254 • 

PASADENA • 001 265 • 

67 06 21 FAIRBANKS, ALASKA 5.4 COllEGE • 06 15 • 2-5 

16 
Table 4.-Peak ground acceleration data for which distances to the causative fault are most accurately known-Contin•1ed 

OATF. EARTHQUAKE MAG STATION ACC DIST' UNCER 

YR MO DA G KM KM 

70 09 12 LYTLE CK.,CALIFORNIA 5.4 WRIGHTWOOD .195 15. 2-5 

CEDAR SPRINGStRANCH .087 18. 

CEDAR SPRINGS,DAM .072 18· 

DEVILS CANYON .193 19. 

SAN BERNARDINO .125 28. 

COLTON .049 29. 

PUDDINGSTONE DAM • 022 32 • 

LOMA LINDA • 068 34 • 

SANTA ANITA DAM .057 46. 

MAGNITUDE 6.0-6.9 

40 05 19 IMPERIAL VALLEY,CALIF. 6.4 EL CENTRO .36 10. 2-5 

68 04 09 BORREGO MTN.,CALIF. 6.5 EL CENTRO .12 45. 2 

SAN DIEGO • 030 105 • 

PERRIS RESERVOIR .018 105. 

SAN ONOFRE .041 122. 

COLTON • 023 130 • 

SAN BERNARDINO .018 132. 

DEVILS CANYON .011 141. 

CEDAR SPRINGS • 006 147 • 

SANTA ANA .014 157· 

SAN DIMAS ·017 168. 

LONG BEACH,UTIL.BLOG. .005 187. 

LONG BEACH,S.CAL.ED. .oo8 187. 

SANTA ANITA RES. • 004 190 • 

VERNON • 011 196 • 

PASAOENAtFAC.CLUB • 009 197 • 

PASAOENA,SEISMO.LAB. .oo1 200· 

L.A.,suBWAY TERM• • oo8 203 • 

l•A.,EDISON • 010 203 • 

PEARBLOSSOM • 006 203 • 

WESTWOOD • 006 208 • 

GLENDALE • 024 208 • 

HOLLYWOOD STOR.PE LOT • 007 211 • 

PACOIMA DAM • 009 229 • 

FAIRMONT RESERVOIR • 003 249 • 

LAKE HUGHESt1 • 009 253 • 

DAVIS DAM ·003 259. 

CASTAIC .008 262. 

GORMAN .013 281. 

PORT HUENEME .003 288. 

SANTA BARBARA • 002 341 • 

BAKERSFIELD • 003 342 • 

TAFT • 002 359 • 

71 02 09 SAN FERNANDO, CALIF. 6.6 PACOIMA DAM 1.24 3. 2 

L.A., GRIFFITH PARK • 18 16 • 

PASADENA, SEISMO. LAB. • 19 17 • 

SANTA ANITA DAM • 24 25 • 

LAKE HUGHES 112 .37 26. 

LAKE HUGHES 19 • 16 29 • 

TEJON • 03 70 • 

17 
Table 4.-Peak ground acceleration data for which distances to the causative fault are most accurately known-Continued 

DATE: 

YR MO DA 

11 02 oq 

EARTHQUAKE MAG STATION 

SAN FERNANDO (CONTINUED) SANTA FELICIA DAM 

LAKE HUGHES 14 

CASTAIC 

LAKE HUGHES t1 

PALMDALE 

FAIRMONT RESERVOIR 

PEARBLOSSOM 

PUDDINGSTONE DAM 

PALOS VERDES ESTATES 

OSO PUMP PLANT 

tONG BEACH TERM· 

WRIGHTWOOD 

PORT HUENEME 

GRAPEVINE 

hHEELER RIDGE 

CEDAR SPRINGS RANCH 

CEDAR SPRINGS DAM 

COLTON 

SAN JUAN CAPISTRANO 

MARICOPA ARRAY 

BUENA VISTA 

SAN ONOFRE 

TAFT 

HEMET 

ANZA 

SHANDON ARRAY 

MAG~ITUOE 7.0-7.9 

49 04 13 PUGET SOUND, WASH• 

52 07 21 KERN COUNTY, CALIF. 

~9 08 18 HEBGEN LAKE, MONT. 

1.1 OLYMPIA 

SEATTLE 

7.7 TAFT 

SANTA BARBARA 

HOLLYWOOD STORAGE,BSMT 

HOLLYWOOD STORAGE, LOT 

PASADENA 

WESTWOOD 

L.A. SUBWAY TERM. 

L.A. OCCIDENTAL LIFE 

VERNON 

LONG BEACH 

SAN LUIS OBISPO 

COLTON 

BISHOP 

SAN DIEGO 

HOLLISTER 

HAWTHORNE 

EL CENTRO 

OAKLAND 

S.F. SO. PACIFIC BLDG. 

7.1 BOZEMAN 

BUTTE 

HELENA 

HUNGRY HORSE DAM 

18 

ACC 

G 

• 24+ 

• 19 

• 39 

• 17 

• 13 

• 10 

• 15 

• 09 

• 04 

.05 

·03 

• 05 

• 03 

• 01 

• 03 

.02 

.03 

• 04 

• 04 

• 01 

• 01 

·02 

.02 

• 05 

.04 

• 01 

.31 

.074 

.20 

.14 

.059 

.064 

• 055 

.022 

.032 

• 026 

.037 

• 016 

.014 

.014 

·018 

.005 

.010 

• 004 

.004 

• 001 

• 004 

.068 

• 050 

• 022 

• 002 

DIST UNCER 

lUI KM 

29 • 

30 • 

30 • 

32 • 35 • 

35 • 43 • 48 • 

52 • 

51t· 

58. 

61 • 

71 • 

73 • 88 • 

94. 

94. 

97 • 

102 • 

120 • 

122 • 

128. 

130. 

142 • 176. 

228 • 

48.+10-25 

69.+ 

42. 

85. 

107. 

107 • 

109. 

110. 

115. 

117 • 

122 • 

145. 

148. 

156· 

224. 

282. 

293 • 359. 

370 • 

407. 

425 • 

2-5 

95. 5-15 

175 • 

217 • 454 • 
Figures 4 and 6 provide comparison of the 

better acceleration data for magnitudes 5 and 

6, respectively, with acceleration data for which 

distances to the fault are less well known. The 

figures include accelerations recorded within 100 

km of the fault or epicenter for shocks that provided one or more accelerograms within 32 km. 

Table 5 summarizes the data, which were obtained from several sources, including the annual issues of "United States Earthquakes." 

The tabulated acceleration is the larger of the 

two peak horizontal values. The tabulated distance is the closest distance to the slipped fault, 

if determinable, or epicentral distance. The uncertainty in distance is indicated by the letter 

A, B or C, representing estimated uncertainties of less than 2 km, 2-5 km, and 5-25 km, respectively. 

Table 5 also summarizes the velocity, displacement and duration data pJotted in figures 

8, 9 and 10, respectively. Figure 8 illustrates the 

dependence of peak horizontal ground velocity 

upon magnitude and distance. The velocity data, 

derived by integration of ac~elerograns, were 

obtained primarily from three sources (Hudson 

and others 1971; Wiggins, 1964; and Ambraseys, 1969). The tabulated velocity is tl'o. larger 

of the two peak horizontal values. 

The displacement data in figure 9 ar~ derived 

from displacement records obtained e;ther directly from 1 0-second displacement meters or 

analytically by double integration of accelerograms. Data from the 10-second displacement 

meters are taken from the annual issues of 

"United States Earthquakes." Displr,~ements 

obtained from twice-integrated accelerograms 

are primarily from Hudson, Brady, T'rifunac, 

and Vijayaraghavan (1971) and corre~pond to 

ground motion from which spectral cornponents 

with periods longer than about 15 H7. are removed. The tabulated displacement is tl'e larger 

of the two peak horizontal values. 

The 0.05 g durations plotted in figure 10 were 

measured from published accelerograms. The 

larger of the two horizontal durations is tabulated. 

Table 5.-Strong motion data plotted on graphs showing peak horizontal acceleration, velocity, and dynamic displacement ard duration 

of shak_ing as a function of distance to slipped fault (or epicentral distance) 

OlTE EARTHQUAKE MAG STATION DISTANCE ACC VEL OISP OUR 

YR MO DA KM • G CM/SEC CM •• SEC 

MAGI~ITUOE 5·0-5.9 

33 10 02 LONG BEACH 5.4 VERNON lit c .115 2·0 

LONG BEACH 15 .011 1.0 

L A SUB TERM 19 ·082+ .8 0 o.o+ 

wEsTwooo 24 .009+ 

HOLLYWOOD STOR 27 .033+ 

PASADENA 30 .005+ .2 0 

34 07 06 N CALIF COAST 5.7 EUREKA 149 t .9 D 

35 01 02 c MENDOCINO 5.8 EUREKA 117 c .1+0 

35 11 28 HELENA, MONT 5.2 HELENA 8 c .082 3.9 

37 02 07 C MENDOCINO 5.8 FERNDALE 84 c 3.8 .6+0 

38 5 31 SANTA ANA MT 5.5 COLTON 47 c .2+0 

L A SUB TERM 78 .1-0 

38 09 12 C MENDOCINO 5.5 FERNDALE 51 c &.1 

ItO 05 19 IMPERIAL VAL 5.2 EL CENTRO 16 c .077 0·5 

ItO 12 20 C MENDOCINO 5.5 FERNDALE 91 c 4.4 

EUREKA 103 .5 0 

41 07 Ol SANTA BARBARA 5.9 SANTA BARBARA 14 c .175+ 20.3 

L A SUB TERM 127 .2 D 

19 
Table 5.-Strong motion data plotted on graphs showing peak horizontal acceleration, velocity, and dynamic displace"'''ent and duration 

of shaking as a function of distance fo slipped fault (or epicentral distance)-Continuec' 

DATE EARTHQUAKE MAG STATION DISTANCE ACC VEL DISP OUR 

YR MO DA K·M • G CM/SEC CM ** SEC 

4-1 10 21 GARDENA 5. VERNOM 13 c .017 

l A CHAMB COM lit .018 

L A SUB TERM 16 .009 .3 0 

L A EDISON 16 .009 

LONG BEACH 17 .013 

WESTWOOD 20 .005 

HOLLYWOOD STOR 21 .006 

41 11 lit TORRANCE 5.5 lONG BEACH 15 t .050 

VERNON 19 .019 

L A CHAMB COMM 20 ·014 

L A SUB TERM 22 .009 .It 0 

l A EDISON 22 .009 

WESTWOOD 25 .009 

HOLLYWOOD STOR 25 .008 

43 08 29 BIG BEAR lAKE 5.5 COLTON 39 c .3 0 

45 os 15 BORREGO VAL 5.7 EL CENTRO 68 c 1.0 

47 05 27 c MENDOCINO 5.2 FERNDALE 30 c .5+D 

47 09 23 c MENDOCINO 5.3 FERNDALE 77 c .1 0 

48 08 18 c MENDOCINO 5.0 FERNDALE 26 c .1-0 

49 03 09 HOLLISTER 5.2 HOLLISTER 21 c ·20 7.6 6.5 

SAN JOSE 48 .oo4 

S F SO PACIFIC 119 .1-D 

50 07 29 CALIPATRIA 5.5 EL CENTRO 35 c 1.0 

51 01 24 CALIPATRIA 5.6 EL CENTRO 30 c .033 4.3 

51 07 29 MULBERRY 5.0 HOLLISTER 34 c 1.1 

51 12 25 SAN CLEMENTE I 5.9 L A SUB TERM 137 c .3 D 

52 09 22 PETROLIA 5.2 FERNDALE 38 c 6.4 1.9 0 

53 06 14 IMPERIAl 5.5 EL CENTRO 12 c .045 6.9 

54 01 27 TEHACHAPI 5.0 ARVIN 19 c .045 

54 02 01 BAJA CALIF 5.6 El CENTRO 60 c 1.1 

54 04 25 WATSONVILLE 5.3 HOlliSTER 20 c .059 3.9 0.5 

55 08 08 s w NEVADA 5.2 HAWTHORNE 24 c .010 

55 09 04 SAN JOSE 5.5 SAN JOSE 10 t .13 10.8 2.8 A 1.5 

OAKLAND 64 .007 

HOLLISTER 67 • 048 4.5 

S F ALEXANDER 71 .008 

S F SO PACIFIC 73 .011 

55 10 23 WALNUT CREEK 5.4 SUISUN BAY BRG 8 c .12 

BERKELEY 21 .020 

OAKLAND 29 .023 

S F SO PACIFIC 36 .022 

S F STATE 42 .023 

20 
Table 5.-Strong motion data plotted on graphs showing peak horizontal acceleration, velocity, and dynamic displacement anc4 duration 

of shaking as a function of distance to slipped fault (or epicentral distance)-Continued 

DATE EARTHQUAKE MAG STATION DISTANCE ACC veL DISP OUR 

YR MO DA KM • G CM/SEC CM •• sec 

55 12 17 BltAWLEY 5.4 El CENTRO 22 c .083+ 5.1 1.0+ 

57 03 22 DALY CITY 5.3 S F GDLDN GATE 8 B ·129 4.9 2.3 A 1.5 

S F STATE 12 .105 5.1 1.1 A 1.0 

S F STATE 12 1.1 D 

S F ALEXANDER lit .056 2.9 1.3 A o.o+ 

S F So PACIFIC lit .Oit9 5.0 1.it A o.o 

OAKLAND 2it .Oit8 2.0 1.5 A o.o 

SAN JOSE 58 .007 

57 04 25 CALIPATRIA 5.2 El CENTRO 51 c .6 D 

57 04 25 CALIPATRIA 5.1 EL CENTRO 51 c .4 D 

60 01 19 HOLLISTER 5.0 HOLLISTER 8 c .064 3.0 

61 04 09 HOLLISTER 5.6 HOLLISTER 20 c .193 17.1 3.8 A 5.5 

62 08 30 LOGAN, UTAH 5.7 LOGAN 7 c .12 2.5 

63 02 28 FORT TE-JON 5.0 WHEELER RIDGE 8 c .058 

66 06 28 PARKFIELD 5.5 CHOLAME-SHAN 2 O.lA .52 72.2 22.3 A 12.0 

CHOLAME-SHAN 5 5.5 .48 27.3 8.4 A 8·5 

CHOLAME-SHAN 8 9.6 .21 12.6 6·7 A 9·0 

TEMBLOR 10.6 .42 21·0 1.1 A 5.5 

CHOLAME-SHAN12 14•9 .074 6.5 7.1 A 5.0 

SAN lUIS DBISP 59 .019 

67 06 21 FAIRBANKS,AK 5.4 COLLEGE 15 8 .06 

67 12 10 N CALIF COAST 5.8 FERNDALE 32 c .10 1.0 

70 09 12 LYTLE CREEK 5·4 WRIGHTWOOD 15 8 .195 2.5 

CEDAR SPR RCH 18 .087 

CEDAR SPR DAM 18 .072 

DEVILS CANYON 19 .193 4.5 

SAN BERNARDINO 28 .125 1.0 

COLTON 29 .049 

PUDDINGSTONE D 32 .022 

LOMA LINDA 34 .068 

SANTA ANITA D 46 .057 

MAGNITUDE 6.0-6.9 

33 03 11 LONG BEACH 6.3 LONG BEACH 5 c .23+ 7.0+ 

VERNON 20 .17 20.0 7.5 

L A SUB TERM 25 .06 5·0 

33 06 25 W NEVADA 6.1 S F SO PACIFIC 302 c .2+0 

34 06 07 PARKFIELD 6. PASADENA 298 ·2 0 

34 12 30 MEXICAllt MEX 6.5 EL CENTRO 64 c. 15.5 

L A SUB TERM 328 .3 D 

35 10 31 HELENA 6.0 HELENA 7.5C ·16 16•8 1.5 

37 03 25 COAHUILA VAl 6. COLTON 94 c ·2 D 

PASADENA 160 .1 D 

L A SUB TERM 167 .3 D 

21 
Table 5.-Strong motion data plotted on graphs showing peak horizontal acceleration, velocity, and dynamic displacement and duration 

of shaking as a function of distance to slipped fault (or epicentral distance )-Continued 

DATE EARTHQUAKE MAG STATION DISTANCE Ate VEL DJSP DUR 

YR MO DA KM • G CM/SEC C:M •• SEC 

ItO 05 19 IMPERIAL VAL 6.1t EL cENTRO 10 B .36 36.9 19.B A 

l A SUB TERM 300 .9 D 

ltl 02 09 c MENDOCINO 6·0 FERNDALE 89 c 3.5 

EUREKA 107 .a D 

41 C5 13 c MENDOCINO 6. FERNDALE 211 c 0.9 

41 10 0"3 c MENDOCINO 6.4 FERNDALE 67 c 5.6 

EUREKA a2 ... 9 D 

42 10 21 BORREGO VAL 6.5 El CENTRO 4a t 6.0 

COLTON 172 .It D 

L A SUB TERM 241 ... a D 

46 03 15 WALKER PASS 6.3 PASADENA 177 c .-.5+D 

l A SUB TERM 18a .-It 0 

47 04 10 MANIX 6.2 COLTON 123 c ... It D 

48 12 04 DESERT HOT SPG 6.5 COLTON 93 c .-3 D 

PASADENA 167 .,4 D 

L A SUB TERM 178 .. a D 

51 10 08 C MENDOCI,..O 6.0 FERNDALE 41 c 7.4 2.-7 A 

FERNDALE 41 1.-0 0 

54 03 19 SANTA ROSA MTS 6.2 EL CENTRO 80 c 2.5 

54 11 12 BAJA CALIF 6.3 EL CENTRO 150 c 3.8 

54 12 21 HUMBOLDT CO 6.5 EUREKA 20 c .29 31.6 14.1 A a.o 

FERNDALE 40 .21 35.6 14.2 A 11.0 

FERNDALE 40 6.4+D 

56 02 09 BAJA CALIF 6.8 EL CENTRO 122 c 7.0 4.1 A 

EL CENTRO 122 4.2 D 

56 J2 09 BAJA CALIF 6.1 EL CENTRO 122 c 2.7 2.3 A 

EL CENTRO 122 1 .. 0+D 

56 10 11 C MENDOCINO 6·0 FERNDALE 121 c 1.3 

65 04 29 SEATTLE, WASH 6·5 SEATTLE 63 c 17.0 

OLYMPIA 84 16.0 

67 12 11 KOYN4t INDIA 6.3 KOYNA 5 c .62 25.3 

68 04 09 BORREGO MTN 6.5 El CENTRO 45 8 25.a 12.-2 A 3.0 

SAN DIEGO 105 6.1 4.-4 A 

22 
Table 5.-Strong motion data plotted on graphs showing peale horizontal acceleration, velocity, and dynamic displacement ar<'f duration 

of shaking as a function of distance to slipped fault (or epicentral distance)-Continued 

O~TE 

yl( MO OA 

71 02 09 

EARTHQUAKE MAG STATION DISTANCE ACC VEl DISP OUR 

SAN FERNA'iDO 6.6 PACOIMA DAM 

L A GRIFFITH 

PASADENA,SEIS 

SANTA ANITA 0 

LAKE HUGHES 12 

LAKE HUGHES 9 

SANTA FELICIA 

LAKE HUGHES 4 

CASTAIC 

KM * G CM/SEC CM •~ SEC 

3 8 1.24 115. 43. A 13.0 

16 .18 10.0 

17 .19 7.0 

25 ·24 11.5 

26 • 37 14.0+ 

29 .16 4.5+ 

29 .24 6.5+ 

30 .19 4.0 

30 • 39 ta.o+ 

LAKE HUGHES 1 32 .17 9·0 

PALMDALE 

FAIRMONT RES 

PEARBLOSSOM 

PUDDINGSTONE 

PALOS VERDES 

OSO PUMP PLANT 

LUNG BEACH TRM 

WRIGHTWOOD 

TEJON 

35 ·13 

35 .10 

43 .15 

0 48 .09 

MAGNITUDE 7•0-7.9 

PORT HUENEME 

GRAPEVINE 

WHEELER RIDGE 

CEDAR SPR RCH 

CEDAR SPR DAM 

COLTON 

40 05 19 IMPfRIAl VAl 7.1 El CENTRO 

49 04 l3 PUGET SND,WASH 7.1 OLYMPIA 

SEATTLE 

52 07 21 KERN COUNTY 7.7 TAFT 

SANTA BARBARA 

HOllYWOOD BSMT 

HOLLYWOOD LOT 

PASADENA 

PASADENA 

L A SUB TERM 

COLTON 

54 12 16 FALLON, NEV 1.0 S F SO PACIFIC 

L A SUB TERM 

NOTES: 

* UNCERTAINTY IN DISTANCE: A•LESS THAN 2 KM 

8•2 TO 5 KM 

52 .04 

54 .05 

58 .03 

61 .05 

10 .03 

71 .03 

73 .07 

88 .03 

94 • 02 

94 .03 

97 .04 

10.8 

48+ c 

69+ 

42 8 

85 

107 

107 

109 

109 

115 

156 

404 

584 

C•5 TO POSSIBLY 25 KM 

21.0 

17·7 

19.3 

9.4 

8.9 

9.1 

** SOURCE OF DISPLACEMENT DATA: A=DOUBLE INTEGRATION OF ACCELEROGRAM 

0=10-SEC DISPLACEMENT METER 

23 

29·5 

23·0 

15.0 

9·2 A 19.5 

5.8 A 10.5 

5.9 A 

6.4 A 

2.9 A 

4.5 D 

5.7 D 

2.6 D 

1.4 0 

3.6 D 

'tiGP 0 6 9 1• 3 54 -1 9 7 6