Structure and Velocities of the Northeastern

Santa Cruz Mountains and the Western Santa

Clara Valley, California, from the SCSI-LR

Seismic Survey

By R.D. Catchings, M.R. Goldman, and G. Gandhok1

Open-File Report 2006-1014

U.S. Department of the Interior

U.S. Geological Survey

1

U.S. Geological Survey, 345 Middlefield Rd, MS 977, Menlo Park, CA 94025
2

U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia 2006

Revised and reprinted: 2006

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3

Introduction

The Santa Clara Valley is located in the southern San Francisco Bay area of

California and generally includes the area south of the San Francisco Bay between the

Santa Cruz Mountains on the southwest and the Diablo Ranges on the northeast (Fig. 1a).

The area has a population of approximately 1.7 million including the city of San Jose,

numerous smaller cities, and much of the high-technology manufacturing and research 

area commonly referred to as the Silicon Valley (2000 U. S. Census;

http://quickfacts.census.gov/qfd/states/06/06085.html). Major active strands of the

San Andreas Fault system bound the Santa Clara Valley, including the San Andreas fault

to the southwest and the Hayward and Calaveras faults to the northeast; related faults

likely underlie the alluvium of the valley (CWDR, 1967). This report focuses on 

subsurface structures of the western Santa Clara Valley and the northeastern Santa Cruz

Mountains and their potential effects on earthquake hazards and ground-water resource

management in the area. Earthquake hazards and ground-water resources in the Santa

Clara Valley are important considerations to California and the Nation because of the

valley’s preeminence as a major technical and industrial center, proximity to major

earthquakes faults, and large population.

To better assess the earthquake hazards of the Santa Clara Valley, the U. S.

Geological Survey (USGS) has undertaken a program to evaluate potential earthquake

sources and potential effects of strong ground shaking within the valley. As part of that

program, and to better assess water resources of the valley, the USGS and the Santa Clara

Valley Water District (SCVWD) began conducting collaborative studies to characterize

the faults, stratigraphy, and structures beneath the alluvial cover of the Santa Clara Valley 

in the year 2000. Such geologic features are important to both agencies because they 

directly influence the availability and management of groundwater resources in the

valley, and they affect the severity and distribution of strong shaking from local or

regional earthquakes sources. As one component of these joint studies, the U. S.

Geological Survey acquired more than 28 km of combined seismic reflection/refraction 

data from the Santa Cruz Mountains to the central Santa Clara Valley in December 2000 

(Fig. 1a). The seismic investigation included both high-resolution (~5-m shot and sensor

spacing) and relatively lower-resolution (~50-m sensor) seismic surveys from the central

Santa Cruz Mountains to the central part of the valley (Fig. 1a-c). Collectively, we refer
4

to these seismic investigations as the 2000 western Santa Clara Seismic Investigations

(SCSI). Results of the lower-resolution study, referred to as SCSI-LR, are presented in 

this report, and results of the high-resolution seismic study (SCSI-HR) are presented in a

separate report by Catchings et al. (2005).

Local Geology, Tectonics, and Hydrogeology

The Santa Clara Valley is part of the topographic depression that forms the San 

Francisco Bay between the Santa Cruz Mountains and the Diablo Range (Fig. 1a).

Surficial and near-surface sediments within the Santa Clara Valley largely consist of PlioPleistocene to Holocene clastic deposits (clay, silt, sand, and gravel) from the adjacent

mountain ranges and marine sediments (CDWR, 1967; Wagner, 1990; Wentworth et

al., 1998; McLaughlin et al., 2001). The composition of basement rocks beneath the

valley is not known but is assumed to be the same as those in the adjacent mountain 

ranges (Fig. 1d). These rocks include the Jurassic to Cretaceous Franciscan Complex 

(marine sediments, largely mélanges, including serpentine, volcanic, and metamorphic

rocks), the Coast Ranges Ophiolite (ultramafic to intermediate igneous rocks), and the

Great Valley Sequence (McLaughlin et al., 2001). The Jurassic-Cretaceous rocks are, in 

places, overlain by Eocene to Pliocene marine sediments and intercalated volcanic rocks.

At least one recently drilled borehole near the center of the valley encountered

serpentinite at about 225 m depth (Orze et al., 2003), which is likely part of the Coast

Ranges Ophiolite.

Within the adjacent mountain ranges, rocks are highly faulted and folded (Fig. 1d)

due to tectonism, much of which is associated with the San Andreas fault system

(CDWR, 1967; McLaughlin et al., 2001). Similarly faulted and folded rocks underlie

the Santa Clara Valley beneath the near-surface Quaternary alluvium, as evidenced by 

strike-slip and reverse faults and folded strata that have been mapped on uplifted ridges

(for example, Santa Teresa Hills and the Sierra Azul) within the valley (McLaughlin et

al., 2001). Some of the buried faults are active, as shown by seismic events recorded 

beneath the valley (Zoback et al., 1995; ANSS Catalog, 2003-

anss@quake.geo.berkeley.edu). Differential movement on these faults may have

produced a series of basement highs and lows, several-kilometer-deep basins near the

margins (i.e., Cupertino and Evergreen basins), and a relative basement high near the

center of the valley (CWDR, 1967; Stanley et al., 2002).
5

Near-surface consolidated and low-permeability Franciscan Complex rocks are

regarded as non-water bearing and not a significant contributor to the hydrogeology of

the valley. Fresh-water-bearing deposits that form the ground-water reservoir within the

Santa Clara Valley are chiefly of Quaternary age, and they include the semi-consolidated,

Plio-Pleistocene non-marine Santa Clara Formation (SCFm), associated marine deposits

of Pliocene and Pleistocene age, and the overlying Pleistocene-to-Holocene

unconsolidated alluvial and bay deposits (CWDR, 1967). Lateral variations in the

thickness of the SCFm are poorly known, but the SCFm has been encountered in 

boreholes at depths ranging from about 30 m to several hundred meters within the valley.

Where exposed in the adjacent Santa Cruz Mountains, the SCFm is locally tightly to

mildly folded and faulted and consists of poorly sorted conglomerate, sandstone,

siltstone, and clay that is as much as 600 m thick in outcrop (Dibblee, 1966;

McLaughlin et al., 2001). Where it crops out on the southwest flanks of the valley, the

SCFm dips 10 to 30 degrees to the east (CDWR, 1967), but locally, the SCFm dips at 60 

degrees to vertical or is overturned where associated with faulting along the southwest

Santa Clara Valley margin. The SCFm is assumed to similarly dip beneath the alluvial

cover. The unconsolidated alluvial and bay deposits (clay, silt, sand, and gravel) that

overlie the SCFm contain the most productive aquifers of the ground-water reservoir

(Poland, 1971). Minimum depths to the water table are highly variable within the valley,

but generally range from about 10 to 40 m below ground surface (CWDR, 1967).

SCSI Data Acquisition

The SCSI survey consisted of two seismic surveys along nearly the same transect,

an ~18-km-long, lower-resolution (50-m sensor; 1-km shot spacing) survey from the San 

Andreas fault to downtown San Jose (Fig. 1a), and an ~10-km-long, high-resolution (5-m

shot and sensor spacing) survey between shot points 1 and 10 of the lower-resolution 

survey (Fig. 1b,c). Each survey was acquired in a manner that yields both seismic

refraction and seismic reflection images of the subsurface. This report describes data

acquisition, processing, and analysis for the lower-resolution (SCSI-LR) survey.

We used 11 buried explosions (shot points 1-11) ranging in size from about 12 to

23 kg to generate seismic sources approximately every kilometer along the central part of

the N-60o-E-trending profile (Fig. 1). To record the blasts, we placed 416 “Texan”

seismographs, with single-element, Mark Products 1-10BTM, vertical-component, 4.5-
6

and 40-Hz geophones, every 50 m along the profile. The 4.5-Hz and 40-Hz geophones

alternated in sequence along the profile, such that there was 100 m spacing between 

geophones of the same frequency. The Texan seismographs were programmed to record 

the 11 blasts during specific time windows between the hours of 12:00 am and 5:00 am,

when cultural noises were relatively low. Sixty seconds of data were recorded for each 

shot at a sampling rate of 1 ms. Seismographs were then retrieved the following day, and 

the data were downloaded to a computer. The internal timing of the seismographs was

checked using Global Positioning System (GPS) clocks before and after deployment, and 

a linear drift was assumed. Acquisition parameters for the SCSI-LR survey are given in

Table 1.

To account for variations in the SCSI profile geometry, each shot point and 

geophone location was surveyed using an electronic distance meter (EDM) or Global

Positioning System (GPS) with theoretical accuracies of a few centimeters (see

Appendices 1-3). Seismograph elevations varied by about 250 m along the profile (Fig.

2a). Lateral variations in the seismograph array (with respect to a line connecting the

first and last shot points) were less than about 500 m within the shot array (Fig. 2b).

However, northeast and southwest of the shot array, the seismograph array varied from

this line by about 2.5 km. Relative to the seismograph array length (17.7 km), individual

seismographs varied by about 2.8% and 14% within and outside of the shot array,

respectively. Because the major deviation from an ideally linear profile was not within 

the shot array (Fig. 2c), the non-linearity of seismographs outside of the shot-point array 

has a minimal effect on the modeled structure of the Santa Clara Valley. The shot array 

was about 12.4 km long (Fig 2c), and shot point elevations varied by about 150 m (Fig.

2d). Relative to a line connecting the end points of the shot array, individual shots varied 

laterally from an ideal profile by about 200 m or 1.6% of the shot line length. Most of

the non-linearity of the seismic profile was required because of the high degree of

urbanization in the study area.

For velocity modeling and reflection stacking, we redefined arrays to remove

redundant stations as shown in Appendix 2.
7

Table 1. Acquisition parameters for the SCSI low-resolution seismic profile. Distance is

relative to the first seismograph.

Parameter Length Number Type Spacing

Profile 17.7 km 1 2-D

Geophone 17.7 km 416 4.5 & 40 Hz, Vertical 50 m

Shot Points 12.4 km 11 Explosion 1 km

Seismograph 17.7 km 416 Reftek RT125 (Texan) 50 m

Record 60 s 4576 SEGY

Sample Rate 1 ms

Data Processing

We minimally processed the shot gathers presented in this report (Fig. 3). After

individual shot gathers were assembled, we used trace editing to remove noisy or dead 

traces, and we bandpass-filtered the data to accommodate the varying frequency ranges

of the geophones.

Seismic Data

Unreduced SCSI-LR shot gathers are shown in figure 3a-k, with low bandpass

filtering (2-4-10-20 Hz) applied. A total of 60 s of data were acquired, but we present

only the first 6 s in figure 3. Although the urban environment was noisy, useful seismic

energy from the shots propagated across the seismic profile for most shots. Surface-wave,

air-wave, and some shear-wave arrivals are also present on most shot gathers. Nearvertical and wide-angle reflections are also observed on all shot gathers, which allow

low-fold reflection images to be developed. The complex topography on the preCenozoic basement structure beneath the Santa Clara Valley is inferred from the nonlinear moveout of refracted arrivals (Fig. 3).

Seismic Velocity Modeling

To develop P-wave tomographic seismic velocity models of the subsurface along

the SCSI seismic profile, we inverted first-arrival refractions from usable seismograms

using a modified version of an algorithm by Hole (1992). The velocity inversion method 

uses 2- or 3-D raytracing (Fig. 4a) to match observed and calculated travel times until a

suitable fit is obtained for all arrivals from all shots. A total of about 4500 first-arrival
8

picks were available from the data. We used reciprocal shot and receiver travel times to 

improve accuracy of the first-arrival picks. A maximum error of 10 ms was allowed 

between reciprocal P-wave travel time picks. In parameterizing the P-wave model, we

used 50-m by 50-m horizontal and vertical grid spacings and a 2-D starting model

derived from composite 1-D velocity models, calculated from shot gathers. We used 

multiple 2-D starting velocity models, but regardless of the starting model used,

successive velocity inversions yielded similar final 2-D velocity models, suggesting that

velocity structure is fairly well resolved. In general, the model is best resolved where we

have the highest density of ray coverage (Fig. 4a). We applied a smoothing routine to the

inversion that yielded an approximately 100- to 300-m vertically and horizontally 

smoothed final model (Fig. 4b). The ray density diagram is colored white (masking)

where we have less than 2 ray paths within a given 50m2grid. The corresponding 50m

2

areas of the velocity model have similarly limited ray coverage, but to better visualize the

velocity model, we present the model without masking.

The minimum depth of velocity imaging is related to the shot (1 km) and 

geophone (50 m) spacing, the model grid spacing (50 m), and the amount of smoothing

used in modeling. Therefore, velocities in the upper 100 m are a smoothed average of the

velocities within those depth ranges. The maximum depth of velocity imaging was

limited by the maximum distance that clear first arrivals could be measured on the shot

gathers (Fig. 3). Because of the noisy urban environment, clear first arrivals were

measurable to varying distances for each shot, but first arrivals were measurable to 

minimal distances greater than 10 km from the source for most shots.

Although we used vertical-component geophones and explosive-source shots,

shear-wave energy was generated and recorded for some of the shots, particularly those

shots within or near bedrock (Fig. 3). We used the same picking parameters and 

tomographic modeling code to develop an S-wave velocity model of the subsurface along 

the SCSI seismic profile (Fig. 5b). The secondary shear-wave arrivals were not as

clearly measurable to distances as great as those of the first-arrival P-wave, resulting in 

shallower depths for the S-wave model. The secondary S-wave arrivals were also less

reliably picked, and as a result, we have less confidence in the S-wave model than the Pwave model, particularly at depths below 1.5 km. For both the P-wave and S-wave

arrivals, we used reciprocity between shot and receiver pairs to increase accuracy.
9

Seismic Velocity and Related Images

P-Wave Velocity Model

First-arrival refractions were measurable to sufficient distances to develop a Pwave velocity model to maximum depths of about 3 km (Fig. 4b). Observed velocities

are highly variable across the model but are generally highest (~ 5- to 6.5 km/s) at depth

below the Santa Cruz Mountains and also near the base (~3 km) of the velocity model

below the Santa Clara Valley. Velocities are lowest (< 1600 m/s) at the surface within

the Santa Clara Valley, where Quaternary sediments are exposed at the surface.

Relatively low velocities (< 3 km/s) persist to the greatest depths (~1.5 km) near the

central part of the seismic profile (Cupertino Basin), but there are appreciable lateral and 

vertical variations in velocity. For example, one prominent feature of the model is the

velocity anomaly near Los Gatos, where relatively high-velocity (~4.5 km/s) rocks

overlie lower-velocity (~4.0 km/s) rocks. Such reversals in velocity indicate complex 

structures because on crustal scales, lower-velocity rocks usually overlie higher-velocity

rocks. The general upper-crustal (3 km) pattern along the profile consists of relatively 

high velocities within the Santa Cruz Mountains and the central Santa Clara Valley (San 

Jose area) and low velocities beneath the Cupertino Basin.

S-Wave Velocity Model

S-wave arrivals are observed best near the southwestern part of the seismic

profile within harder rocks. Within the alluvium of the Santa Clara Valley, limited 

generation and/or propagation of S-wave arrivals resulted in poor resolution of the deeper

structure on the northeast end of the seismic profile. The S-wave model is most reliably 

developed for the upper 1.5 km of the profile, but a poorly resolved model, resulting from

uncertainties in picking secondary arrivals, was determined for the upper 3 km near the

center of the seismic profile. Velocities range from 0.5 km/s near the surface to about 3.5

km/s within the base of the model. Low- and high-velocity features within the S-wave

velocity model are similar to those of the P-wave model, including relatively higher nearsurface velocities in the Santa Cruz Mountains and thicker, low-velocity deposits in the

Cupertino Basin. The S-wave velocity model also shows a velocity inversion similar to

that observed for the P-wave velocity model beneath the Los Gatos area. The lowest Swave velocities (0.5 km/s) correspond to near-surface sediments, which appear to be
10

thickest within the Cupertino basin. The highest S-wave velocities (~3.5 km/s) are

observed in the Santa Cruz Mountains and at the base of the model.

Models of Vp/Vs and Poisson's Ratios

Variations in Poisson's and Vp/Vs ratios can yield information about crustal

composition and physical conditions of the crust, such as water saturation and crack 

density (faulting). We developed a Vp/Vs ratio model from the P- and S-wave velocity

models (Fig. 6a). The Vp/Vs ratio model was calculated to the maximum depths of the

S-wave velocity model (~3 km), but the Vp/Vs ratios are probably most reliably 

determined at depths less than 1.5 km. Vp/Vs ratios vary from about 1.5 to about 3.6,

with the highest ratios occurring near the surface, particularly in the vicinity of water

reservoirs in the Los Gatos area, and near the northeastern part of the seismic profile.

The lowest ratios (~1.5) are calculated for depths between 0.5 and 1 km below Lexington

Reservoir and at depths in excess of 1.5 km near the northeastern part of the seismic

profile. Although such low Vp/Vs ratios could be related to faulting (Catchings, 1999),

Vp/Vs ratios below 1.5 km on the northeastern part of the profile are not well constrained 

due to the poor constraints on S-wave velocities in that part of the profile.

A model of Poisson's ratio was developed along the SCSI profile using the P- and 

S-wave velocities (Fig. 6b). Due to properties of P- and S-wave propagation, Poisson’s

ratio (v) can be determined using the following relations (Thomsen, 1990; Schon, 1996):

v = (E/2u) –1 = (3K-2u)/(6K+2u) = [(Vp/Vs)

2

] –2/[2(Vp/Vs)

2

] -2

Where u = shear modulus, E= Young’s modulus, K = Bulk modulus, Vp = compressional

or P-wave velocity, and Vs = shear or S-wave velocity.

The modeled Poisson’s ratios (PR) show considerable lateral variation along the

SCSI-LR profile, with the highest values (~0.46) near the surface and lowest values of

about 0.05. Due to the poor S-wave measurements on the northeastern end of the model

below about 1.5 km depth, very low PR values (~0.05) in that area of the model are

probably not reliable. Some other areas of the PR model, however, show relatively low

PR values (~0.26), which are consistent with average values (~0.24-0.29) for common 

plutonic rocks (Christensen, 1996).
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Seismic Reflection Processing

In acquiring the seismic data, we used a shoot-through geometry, whereby shots

were systematically fired through a stationary recording array. The combination of

multiple sources and multiple receivers, which were spread over long distances,

permitted both reflection and refraction data to be simultaneously acquired.

In seismic-reflection data processing, we followed procedures similar to those

outlined by Brouwer and Helbig (1998). Processing steps included geometry 

installation, independent trace editing, timing corrections, elevation static corrections,

automatic gain control (AGC), bandpass filtering, F-K filtering (or surgical muting),

velocity analysis (from refractions, semblence, and borehole-velocity measurements),

normal-move-out (NMO) correction, stretch muting, common-depth-point (CDP)

stacking, post-stack AGC, post-stack bandpass filtering, and post-stack deconvolution.

For depth-migrated sections, we used Kirchoff pre-stack depth migration after velocity 

analysis. Principal parameters used in processing are shown in Table 2.

In trace editing, noisy traces (due to cultural noises) or redundant traces (due to

geometry) were removed from the shot gathers before stacking or migrating, leaving 

approximately 366 channels per shot gather. We surgically muted first-arrival

refractions, and we applied bottom muting by surgically removing all arrivals between 

the surface waves. Elevation statics, migration, and velocity analysis were accomplished 

using the tomographic velocity model from both the lower- and higher-resolution SCSI

profiles. For velocities at depths in excess of those determined by the tomography 

velocity model, we used parabolic methods, and we inferred velocities based on 

laboratory-determined velocity-depth (pressure) relations (Carmichael, 1989).

Table 2. Reflection Processing Parameters for the SCSI Profile

Maximum Fold 11

CDP Spacing 25 m

AGC

Prestack

Poststack

2000 ms

300 ms

Bandpass Filter

Prestack

Poststack Low

5-10-80-160 Hz

5-10-50-100 Hz

Deconvolution (filter length,

prediction dist., application gate)

700 ms, 65m, 0-5000 m

Migration (frequency, aperture,

angle)

200, 8000, 30
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Seismic Reflection Images

A migrated seismic reflection image along the SCSI profile was developed from

about meter 2300 to about meter 17000 of the SCSI-LR profile (Fig. 7). The length of

the reflection image was largely determined by the position of the shot point array, and to 

a lesser extent, by the curvature of the recording array on the southwestern part of the

seismic profile. In general, the seismic reflection image shows that the Santa Clara Valley

is more reflective to greater depths than the Santa Cruz Mountains, but appreciable lateral

variations in reflectivity are observed both within the valley and the mountains. The

seismic image also shows that the upper few kilometers of the crust is complex, with 

folded and faulted strata. Because of the complexity of the structure, interpretation of the

seismic reflection image is difficult. However, in the discussion section below, we

combined the available data (velocities, velocity ratios, reflection, and geologic) to

develop an interpretative model.

Combined Velocity and Seismic Reflection Images

We superimposed the velocity models onto the seismic reflection image so that

direct comparisons between P- and S-wave velocities, their ratios, and the reflection 

image could be made (Figs. 8a-d). The combined P-wave velocity and reflection image

shows appreciable variation in the velocities of the layered rocks (Fig. 8a). Near the

southwestern end of the profile (meters 2300 to 5000), near-surface, layered rocks have

velocities ranging from about 3000 to 5000 m/s in the upper 500 m depth. However,

layered rocks beneath the Cupertino Basin (~meter 9000) have velocities less than 3000 

m/s in the upper 1.5 km depth. Higher velocities (>3500 m/s) at relatively shallow (<

1000 m) depths are also observed near meter 11000. Deeper, less reflective rocks

generally have velocities in excess of 3500 m/s, and a prominent northeast-dipping

reflector generally marks the boundary between the higher-velocity rocks and the lowvelocity rocks. As discussed below, the higher-velocity and less-reflective rocks

probably correlate with basement rocks.

Similar variations in the S-wave velocity structure are observed (Fig. 8b). Most of

the highly reflective rocks have S-wave velocities less than 2000 m/s in the upper 1.5 km

beneath the Santa Clara Valley. The high reflectivity and low S-wave velocities are

consistent with the presence of sedimentary rocks in that depth range. The rocks
13

underlying these probable sediments at depth (> 3 km) beneath the Cupertino Basin are

not as reflective and have lower S-wave velocities (<3000 m/s) than rocks at similar

depths in the adjacent Santa Cruz Mountains and central Santa Clara Valley. Because

these rocks are poorly reflective, they are probably not horizontally layered sedimentary

rocks (i.e., probably mélange or related Franciscan rocks or massive Coast Ranges

Ophiolitic rocks), and as discussed below, the low S-wave velocities are probably related 

to fractured and faulted rocks beneath the Cupertino Basin. There are similar variations in

Vp/Vs and Poisson's ratios, whereby high Vp/Vs (> 2.8) and Poisson's (0.38) ratios are

largely confined to the highly reflective near-surface (probably water saturated) deposits

in the Santa Clara Valley (Figs. 8c and 8d, respectively). Low Vp/Vs (< 2.0) and 

Poisson's (0.25) ratios are largely limited to poorly reflective deeper rocks. These Vp/Vs

and Poisson’s ratios are more consistent with common igneous rocks than sedimentary 

rocks (Christensen, 1982; 1996).

Geologic Maps and Cross Sections

The near-surface geology along the SCSI profile includes deposits and rocks

ranging in age from Holocene to Jurassic (McLaughlin et al., 2001). As many as seven 

recognizable fault zones, each with multiple fault strands, are mapped at the surface

within the Santa Cruz Mountains between the San Andreas fault and the center of the

SCSI profile (Fig. 1d). Each of the fault zones may be several tens of meters wide and 

includes folded and faulted rocks of varying geologic ages. Published cross sections

(McLaughlin et al., 2001) for the Santa Cruz Mountains show a series of near-vertical

strike-slip and lower-angle reverse faults (with associated antithetic faults). Many of

these faults dip to the southwest at the surface where exposed and are inferred to dip

southwestward toward (and presumably join with) the San Andreas fault at depth

(McLaughlin et al., 2001). Along the Santa Clara Valley segment of the SCSI profile,

rocks are covered by Holocene-to-Pleistocene alluvial deposits (Helley et al., 1994), and 

the lithology of the subsurface rocks and associated structures are poorly known below

the surface. However, the shallow-depth subsurface lithology and structures can be

inferred from geophysical data and lithologic logs from a number of nearby boreholes

(Stanley et al., 2002). The lithology and structure beneath part of the Santa Clara

Valley can also be inferred from rock exposures within the Santa Teresa Hills,

approximately 5 km east-southeast of the SCSI profile. Rocks within the Santa Teresa
14

Hills range in age from Quaternary to Jurassic and include geologic materials ranging

from sediments to ophiolitic rocks. Similar rocks conceivably underlie the Santa Clara

Valley along the SCSI profile. Structures observed in the Santa Teresa Hills may also 

provide clues to the subsurface structure beneath part of the SCSI profile, including the

dips of some faults and stratigraphic units. McLaughlin et al. (2001) interpret a

predominant northeasterly dip for most faults and stratigraphic units in the Santa Teresa

Hills. Thus, similar structures may underlie the Santa Clara Valley segment of the SCSI

profile.

Comparison with Available Well Data

Data from two recently drilled wells (McGlincey and Willow wells - see Fig.

1a,c) along and adjacent to the SCSI profile can be compared with the SCSI seismic data.

The 240-m-deep McGlincey well was located near meter 12500 (shot point 9) of SCSI

profile, and the 254-m-deep Willow well was located at the northeast end of the SCSI

profile (Orze et al., 2003). Borehole data from the McGlincey well included P- and Swave velocity measurements and lithologic well logs, which can be compared with SCSI

velocity data (Fig. 9). In general, there is close agreement between the borehole sonic

velocities and the SCSI refraction velocities. Seismic P-wave velocities in the

McGlincey well range from about 1500 m/s at 5 m depth to about 2500 m/s at 100 to 200

m depth (Hansen et al., 2004), with an average P-wave velocity ~2200 m/s in the 20 m

to 240 m depth range. Where the McGlincey well projects to the SCSI profile, SCSI Pwave velocities range from about 2050 m/s within 50 m of the surface to about 2200 m/s

at 250 m depth, with an average velocity of about 2100 m/s. SCSI S-wave velocities in

the vicinity of the McGlincey well range from about 500 m/s at the surface to about 850

m/s at 240 m depth, with an average S-wave velocity of about 700 m/s. S-wave

velocities measured in the McGlincey well vary from about 500 to 1000 m/s, with an 

average S-wave velocity of about 750 m/s in the upper 250 m. Thus, both P-wave and Swave velocities from the SCSI profile and those from the McGlincey well are

comparable, given the relatively low resolution of the SCSI data. Velocity data are not

available for the Willow well, but comparisons can be made based on lithologic logs

from both wells.

We also used the lithologic information from oil wells (Stanley et al., 2002) and 

the McGlincey and Willow wells (Newhouse et al., 2004; Fig. 1c) to constrain probable
15

rock types at shallow depths along the SCSI profile. Near the central part of the SCSI

profile, Stanley et al. (2002) used lithologic logs from oil wells that were drilled during

the late 19thand early 20thcenturies to interpret the lithology in the upper 800 m. They

interpret Quaternary sediments to overlie Miocene sediments in the upper few hundred

meters along the central part of the SCSI profile, with Miocene rocks extending to more

than 800 m below the surface in the deepest oil well. We plotted the interpreted well logs

in their approximate locations on the SCSI-LR reflection image (Fig. 7). The well logs

indicate that the Quaternary-Miocene boundary correlates with a prominent reflector that

extends across most of the western Santa Clara Valley. Because of the relatively low

resolution of the SCSI-LR reflection images, reflective layers are averaged over about

depth ranges of about 100 m. Thus, SCSI-LR reflection image would generate

reflections that are approximately centered on the Quaternary-Miocene boundary where

the Quaternary sediments are less than about 100 m thick.

In all but one of the well logs analyzed, Stanley et al. (2002) interpreted Miocene

sediments at the bottom of the wells. In the one excepted well, they interpret Franciscan 

or Coast Ranges Ophiolitic rocks at about 100 m depth in the vicinity of Vasona

Reservoir. However, we interpret the seismic data as being more consistent with the

presence of Miocene sediments at 100 m depth in the vicinity of Vasona Reservior

because apparent Miocene layers appear laterally continuous in that area (Fig. 7).

A hard, relatively low-velocity (~2200 m/s) rock, which correlates with the base

of the ground-water aquifer (Newhouse et al., 2004), was encountered in the McGlincey 

well at about 240 m depth, and this rock correlates with a reflector at the same depth in

the SCSI reflection image (Fig. 7). Paleontological data from the McGlincey well

indicate that Miocene rocks underlie SCFm rocks (C. Wentworth, Pers. Comm., 1994)

at about the depth (240 m) of our SCSI reflector. The reflector is largely continuous

across the Santa Clara Valley northeast of SP 5 (~meter 8000) along the SCSI profile.

The correlation between the ground-water aquifer (as revealed in the various wells) and 

the SCSI reflector suggests that the base of the ground-water aquifer may be traced 

laterally across most of the western Santa Clara Valley on the SCSI reflection image

(Fig. 7, 8b). This reflector and others above and below it appear to be vertically offset by 

at least tens of meters in several places along the profile, suggesting that the groundwater aquifer system is faulted in places along the profile.
16

Only sedimentary rock was observed at the base of the McGlincey well at ~240

m, but serpentinite was found at the base of the Willow well at about 245 m depth. The

two wells are separated laterally by about 5 km, and the difference in lithology at the base

of the two wells suggests that there is a major lithologic change in shallow subsurface

rocks over the 5-km distance. The change in shallow-depth (~upper 250 m) lithology 

between the McGlincey well and the Willow well (which is located about 0.7 km ENE of

the northeast end of the SCSI profile; Fig. 1c) is indicated by an abrupt change in the

reflectivity pattern near meter 15000 of the SCSI profile (Fig. 7).

Interpretation and Discussions

The complex tectonic setting and history of the eastern Santa Cruz Mountains and 

the western Santa Clara Valley makes interpretation of seismic velocity and reflection

images difficult. Multiple fault zones with northeast- and southwest dips and both strikeslip and reverse motions are superimposed upon rocks ranging in composition from

sedimentary to ultramafic (Dietz and Ellsworth, 1997; Simpson, 2004; McLaughlin et

al., 2001). Because similar tectonism and structural complexity are likely beneath the

alluvium of the western Santa Clara Valley, seismic reflection images are difficult to

interpret, especially for the deeper (older) structures. By combining the reflection and

refraction images with other data, such as seismicity data, geologic mapping, and 

borehole data, we present non-unique interpretations of the upper 3 km of the crust that

may be important in evaluating water resources and earthquake hazards.

Structure of the Groundwater Aquifer System

The maximum depth of the ground-water aquifer in the Santa Clara Valley is

poorly determined, but it is generally assumed to correlate with the maximum depth of

the Pliocene to Holocene semi-consolidated and unconsolidated sediments (CDWR,

1967). Although older consolidated rocks, such as Franciscan rocks, may contain water,

they are unlikely to be a major part of the ground-water aquifer system because of their

low permeabilities. Therefore, the seismic P-wave velocities, which increase with 

ground-water saturation or consolidation, can be used to help constrain lateral variations

in the ground-water aquifer system across the Santa Clara Valley. Vp/Vs and Poisson’s

ratios are also sensitive to the presence of water in unconsolidated sediments, and 

therefore, these measures should also be indicative of lateral variations in the ground-
17

water aquifer system. Due to the relatively low resolution of the SCSI-LR profile,

however, the velocities and their ratios may be indicative of structures over vertical and

lateral ranges of 50 to 300 m.

Because compressional-wave velocities (Vp) greatly increase in unconsolidated 

sediments which are more than 90% water saturated (Nur, 1982), saturated 

unconsolidated sediments generally have minimum P-wave velocities of about 1500 m/s

(Schon, 1996; Catchings et al., 1999a;b; Gandhok et al., 1999). The shallowest Pwave velocities imaged along the SCSI profile range from about 1500 m/s to about 2000 

m/s in the upper 100 m (Fig. 4b, 8a). These velocities, which are averaged over at least

50-m intervals, are consistent with velocities expected of the shallow ground-water

aquifer along SCSI profile, as the minimum depths to the ground-water aquifer along the

SCSI profile is known to range from about 10 to 50 m (Table 3). Because of the wide

(50 m) spacing of seismographs (low resolution), the velocity images do not provide

information about the upper ~25 m, and therefore, the minimum depth of the groundwater aquifer cannot be inferred from the SCSI-LR P-wave velocity data alone.

However, minimum depths are inferred from the SCSI-HR velocity data to be about 5 to

40 m along the SCSI profile (Catchings et al., 2005). The maximum depth of the

ground-water aquifer along the SCSI profile, however, can be inferred on the basis of

higher-velocity rocks (~2200 to 2300 m/s), which are typically too consolidated 

(impermeable) to act as efficient ground-water aquifers. Within the McGlincey well,

consolidated sedimentary rocks (~2200 m/s) form the base of the ground-water aquifer at

about 240 m depth (Hansen et al., 2004). If similar rocks extend across the western Santa

Clara Valley at the base of the ground-water aquifer, lateral variations in the depth to 

ground water may be inferred on the basis of the rocks (faulted or fractured), degree of

saturation, and compositional variations. In particular, for similar sequences of rocks,

those rocks that have experienced significant faulting would have lower P-wave

velocities than rocks that have not been faulted. Another problem with using the P-wave

velocities to infer lateral variation in the ground-water aquifer system is the probable

lateral variation in ground-water saturation. Because the SCSI-LR profile was situated 

along and between recharge ponds, reservoirs, and the Los Gatos Creek, some of the

velocity measures are likely averages of velocities within a few hundred meters of major

sources of ground-water recharge. For example, within the Santa Clara Valley, areas

along the SCSI-LR profile near major recharge ponds, reservoirs, or Los Gatos Creek 
18

appear to have relatively high velocities at relatively shallow depths, suggesting relatively 

saturated sediments at relatively shallow depths (Fig. 4b). Conversely, those areas that

are more distant from recharge ponds, reservoirs, or Los Gatos Creek have relatively low

velocities at shallow depths. In places, both the ground-water aquifer system and the

underlying Miocene sediments are probably variable in saturation and the degree of

faulting, resulting in laterally variable velocities.

Shear-wave velocities (Vs) are much less sensitive to water saturation. Thus,

unconsolidated saturated sediments tend to have higher Vp/Vs ratios than consolidated 

saturated sediments, and both have higher Vp/Vs ratios than unsaturated sediments. For

example, Gibbs et al. (2000) show Vp/Vs ratios that range from about 3 to about 5 for

most unconsolidated and saturated sediment sites surveyed in southern California, but

they show most consolidated sediments to have Vp/Vs ratios of about 2.5 or less.

Consolidated and saturated sediments would have significantly lower Vp/Vs ratios, such 

as those (~2.2) for 100% saturated Massilon sandstone (Nur, 1982), than unconsolidated 

and saturated sediments.

Because both Vp and Vs data are available from the SCSI profile, Vp/Vs ratios

can be used to infer lateral variation and depth of water-saturated sediments, which may 

be indicative of the degree of water recharge into the subsurface along the SCSI profile

(Fig. 6a, 8a). However, high Vp/Vs ratios can also be caused by features other than fluid 

saturation, such as the presence of highly faulted strata or serpentinite, both of which 

have been found within the Santa Clara Valley and the eastern Santa Cruz Mountains. At

the McGlincey well (shot point 9), a Vp/Vs ratio of 2.7 correlates with the base of the

ground-water aquifer (Fig. 6a, 8a). If one assumes that the sedimentary rocks underlying

the shallow subsurface are not highly faulted, then the 2.7 Vp/Vs contour may infer

lateral variations in the ground-water aquifer. The thickest deposits with Vp/Vs ratios of

2.7 or higher occur between shot point 1 and 3, near shot point 5, and northeast of shot

point 10. Between shot points 5 and 10, it is unlikely that there are significant deposits of

serpentinite at shallow depths; thus, the 2.7 Vp/Vs ratio contour is probably indicative of

lateral variations in the base of the ground-water aquifer in that area. However, because

of the possible presence of serpentinite in various other areas along the profile, the 2.7

Vp/Vs ratio contour may not correlate with the base of the ground-water aquifers in those

areas along the SCSI profile.
19

Poisson’s ratio is also sensitive to high levels of groundwater saturation. For

crustal materials, Poisson’s ratio typically varies between about 0.15 and 0.5 (Schon,

1996), where a Poisson’s ratio of 0.5 is indicative of fluids. In the shallow crust, high 

values (> ~0.43) of Poisson's ratio probably correlate with saturated sediments or unusual

rock types. In the vicinity of the McGlincey well, the base of the ground-water aquifer

(~240 m) correlates with a Poisson’s ratio of about 0.43, but faulting and the presence of

serpentinite may also affect the Poisson’s ratios. As with the Vp/Vs ratios, however, the

lateral variations in Poisson’s ratio (0.43, as measured at the base of the McGlincey well)

likely outline the ground-water aquifer between shot points 5 and 10, where near surface

deposits are probably sedimentary.

On the basis of the Vp, Vp/Vs, and Poisson’s ratios found at the base of

unconsolidated deposits in the McGlincey well and lateral variations in these values

along the SCSI profile, we suggest that the thickest (up to 300 m) ground-water aquifer is

located between shot points 9 and 10. If, however, there are not significant serpentinite

deposits or faulting near shot point 3, the velocity data are also consistent with the

presence of a thick aquifer in that area.

Near-Surface (< 250 m) Structure

Near-surface strata along the SCSI profile are dominated by a series of faults and 

folds in the Santa Cruz Mountains (Fig. 1d) (McLaughlin et al., 2001). The SCSI

seismic reflection images show folds that persist into the subsurface to several hundred 

meters depth or more. Between meters 3000 and 7000 of the SCSI profile, the shallow

(~50 to 250 m) strata appear folded, with dips as high as 45 degrees, and associated faults

may dip both northeastward and southwestward as much as 80 degrees (Fig. 7).

Within the Santa Clara Valley, the folds are largely covered at the surface by 

unfolded or mildly folded alluvium, but the deeper (older) strata below about 200 m

depth appear similarly faulted and folded as those in the Santa Cruz Mountains. The

SCSI reflection image suggests that some subsurface strata in the Santa Clara Valley 

have dips greater than 30 degrees. The similarity in faulting and folding between the

deeper valley structure and the near-surface mountain strata suggests that both areas have

experienced similar tectonism. However, either the tectonism may have slowed in the

valley, or deposition of near-surface Pliocene to Holocene sediments in the valley is

sufficiently high that ongoing tectonism remains covered.
20

Strata above about 200 m depth in the Santa Clara Valley are gently folded (Fig.

7), with wavelengths of about 2 km or more and both southwest and northeast dips (3 to 

10 degrees). From about meter 7000 to about meter 9000, the shallow-depth strata

largely dip (3 to 6 degrees) northeastward, but from about meter 9000 to meter 10000, the

shallow-depth strata dip (~6 degrees) southwestward along the limb of an apparent fold 

that apexes at about meter 10200. From meter 10200 to about meter 11500, the shallowdepth strata also dip (~6 degrees) northeastward. Between meters 11500 and 13000, the

shallow-depth strata are largely horizontal to about meter 13000, where they dip (~3-7

degrees) southwestward to the end of the SCSI profile. Some of the near-surface strata

beneath the alluvium appear to be faulted, but because the SCSI reflection image does not

image the near surface (upper few tens of meters) strata, it is not possible to determine

the minimum depth of faulting from these data. However, the seismic image shows

evidence of faulting near the base of the ground-water aquifer. Such faults may affect

ground-water recharge and flow across the valley.

Basin Depth and Structures

Basement rocks beneath the Santa Clara Valley are presumed to be the same as

those in the eastern Santa Cruz Mountains, the Santa Teresa Hills, and the New Almaden

areas, which consist of Franciscan Complex rocks and parts of the Coast Ranges

Ophiolitic sequence, strata of the Great Valley sequence, and early Tertiary (Eocene) to

mid-Tertiary (Miocene) rocks (McLaughlin et al., 2001). The Franciscan Complex is

composed of a variety of penetratively sheared rocks including Cretaceous and Jurassic

basaltic volcanic rocks, cherts, and sandstone, Cretaceous melange (blueshist,

amphibolite, chert, basaltic volcanics, conglomerate and metadiorite), limestone,

volcanics, and tuff. Within the Santa Clara Valley, the basement rocks are overlain by

Miocene to Holocene sediments (Stanley et al., 2002). Basement rocks and the overlying

sediments are likely to have significantly different velocities, which can be used to infer

basement depth along the SCSI profile.

Shot point 1 was located within basement rocks consisting of Franciscan melange

rocks (McLaughlin et al., 2001). At the surface, these rocks have a P-wave velocity of

about 3000 m/s (Fig. 4b), but at depths of 2 km or less, these rocks would experience

lithostatic pressures of about 50 KPa, resulting in P-wave velocity increases due to 

compaction (Carmichael, 1989). Laboratory measurements on pressurized Franciscan 
21

rocks show that compressional velocities (~4.35 to about 6.0 km/s) vary widely in the

upper few kilometers (Stewart and Peselnick, 1977). When pressurized to about 0.5 

kbar, the Franciscan rocks used in Stewart and Peselnick’s (1977) investigation 

increased in velocity an average of about 0.4 km/s. Assuming similar Franciscan 

basement rocks beneath the valley as at the surface at shot point 1, and assuming an 

increase in velocity of about 0.4 to 0.5 km/s due to lithostatic pressure, such Franciscan 

mélange rocks beneath the Cupertino Basin would have velocities of about 3400 to 3500

m/s. The 3500 m/s velocity contour is located at about 1600 m depth in our velocity 

image, suggesting basement is about 1600 to 1800 m deep along the SCSI profile

between shot points 5 and 6 and between shot points 9 and 10 (Fig. 4b), if basement

beneath the Cupertino Basin is composed of such Franciscan rocks.

A similar analysis of the velocities of the Miocene sediments within the Santa

Clara Valley can be made. On the basis of numerous P-wave measurements in deep 

boreholes, Press (1966) showed the range of velocities typical of sandstones and shales

of various ages and varying depths of burial (Fig. 10). Miocene sandstones and shales

typically have P-wave velocities that range from about 2200 m/s at about 300 m depth to 

about 2900 m/s at 2 km depth (Press, 1966). In contrast, the SCSI P-wave velocity 

image shows that velocities beneath the central Cupertino Basin are approximately 4500 

m/s at 2 km depth. Comparison of the borehole sonic velocities and the SCSI refraction 

velocities suggest that sandstone and shale sediments of any age between Miocene and 

Jurassic are probably no deeper than about 1600 to 1800 m in the Cupertino Basin (Figs.

10a). Brocher et al. (1997) made a similar analysis of sonic velocities as a function of

depth from boreholes in the San Francisco Bay area. They show that the average velocity 

for sedimentary rocks at about 1800 m depth is less than 3500 m/s, but at depths in excess

of 1800 m, the SCSI refraction data show that velocities are more than 4500 m/s (Fig.

10b). Both comparisons of the SCSI refraction velocities with sonic velocities suggest

that the deepest sediments along the SCSI profile are probably not more than about 1800 

m.

We also interpret a maximum depth to basement of 1600 to 1800 m along the

SCSI profile from the SCSI reflection image (Fig. 7). The reflectivity pattern, which is

indicative of layered sedimentary rocks, abruptly changes to a pattern of en echelon

northeast-dipping reflectors at depths of approximately 1600 to 1800 m depth near the

central Cupertino Basin (meter 9000). These en echelon reflectors are part of a high-
22

amplitude series of reflectors that extend to the near surface southwest of Lexington 

Dam, where geologic mapping shows a northeast-dipping thrust fault separates

Franciscan rocks from Coast Ranges Ophiolitic rocks (McLaughlin et al., 2001).

Because of its upward projection toward the thrust fault and because of the high basement

velocities (up to 6.5 km/s at 3.5 km depth) in the northeastern Santa Cruz Mountains, we

interpret the high-amplitude, northeast-dipping reflector as a contact between the Coast

Ranges Ophiolite and Franciscan Complex rocks. As the Franciscan and Coast Ranges

Ophiolite are considered basement rocks, the en echelon reflectors at about 1800 m depth

beneath the Cupertino Basin, which may have resulted from tectonic wedging of Coast

Ranges Ophiolitic rocks into Franciscan Complex rocks (R. McLaughlin, Pers. Comm.,

2004), are also likely to be basement rocks.

Our velocity- and reflectivity-based estimates to the top of basement (or

maximum depth of Miocene sediments) are consistent with at least one other estimate of

the minimum thickness of Miocene sediments beneath the western Santa Clara Valley.

Based on chemical analysis of oil from a well along the seismic profile, Stanley et al.

(2002) suggest that the oil producing rocks (top of the oil-generative window) could be

buried as shallowly as 1600 to 1800 m below the surface, although their preferred depth 

range is between 2100 and 2500 m (p. 36). Thus, the chemical analyses do not require

present-day sediments below 1600 to 1800 m depth in the western Santa Clara Valley.

On the basis of gravity modeling, the depth to basement beneath the Cupertino

Basin in the vicinity of the SCSI-LR profile has been estimated at about 3.5 to 4 km

depth (R. Jachens, Pers. Comm., 2001; Stanley et al., 2002). However, the velocity 

and reflectivity data from out study suggest that sediments of the Cupertino Basin are less

than about 1800 m thick in the vicinity of the SCSI-LR profile.

Faulting Relationships:

Numerous faults are mapped at the surface in the eastern Santa Cruz Mountains

(McLaughlin et al., 2001), and beneath the alluvium cover of the western Santa Clara

Valley, faults are also inferred from previous geophysical and borehole investigations

(CDWR, 1967). Most of the prominent reverse faults in the eastern Santa Cruz

Mountains are interpreted to dip southwestward toward the San Andreas fault, with some

antithetic, northeast-dipping normal faults that merge with the southwest-dipping faults at

depth (McLaughlin et al., 2001). In contrast, many of the mapped faults and
23

stratigraphic units near the edge of the Santa Clara Valley and within the Santa Teresa

Hills (~ 5 km south of the seismic profile) dip steeply to the northeast (McLaughlin et

al., 2001).

Because of the relatively low resolution of the SCSI-LR profile and the

complexity of the subsurface structure, fault structures to depths of several hundred 

meters along the SCSI-LR profile are best determined from the SCSI-HR profile images

(Catchings et al., 2005) and from known surface faults (Fig. 7). Although the SCSI-LR

and SCSI-HR profiles are not everywhere coincident, when SCSI-HR interpreted faults

are superimposed on the SCSI-LR reflection image, apparent stratigraphic offsets on the

SCSI-LR reflection image coincide with most of the interpreted faults to depths of about

600 m (Fig. 7). Below about 600 m, the fault structures are not well resolved on the

SCSI-LR reflection image, but there appear to be near-vertical offsets of stratigraphic

layers that extend to several kilometers depth (Fig. 11). On the basis of offset layers and 

the dips of faults at shallow depths, we suggest that many of the near-surface faults merge

at depths of one to three kilometers into several discrete, largely southwest-dipping fault

zones.

Surface and near-surface (trenching) geologic mapping (McLaughlin et al.,

2001) shows that most of the faults along the SCSI profile dip at high angles (~75 to 80 

degrees), and our seismic images also indicate that the high-angle (75 to 80 degrees)

faults extend to at least 600 m depth (Fig. 7). Focal mechanisms for the best-recorded 

earthquakes within a few kilometers of the SCSI-LR profile also show that most of the

faults between about 1 to 20 km depth are relatively high-angle, reverse faults (Figs. 7 

and 11). Thus, it is likely that many of the fault zones within the western Santa Clara

Valley merge with the San Andreas fault zone at depths of 3 to 15 km. However, seismic

events centered northeast of the Cupertino Basin indicate that there may also be one or

more fault zones that either merge with the San Andreas fault at depths of 15 to 30 km, or

they are separate fault zones that do not merge with the San Andreas at all (Fig. 12).

Summary

The seismic images from this study show the larger-scale features of the upper few

kilometers of the crust. The seismic images provide structural constraints, including (1)

the thickness of the sedimentary rocks within the Santa Clara Valley, (2) depth to and
24

lateral variations in basement rocks, (3) distribution and structure of subsurface faults,

and (4) probable lateral variations in the ground-water aquifer system.

We suggest that Miocene sandstone and shales are thickest (1600 to 1800 m) beneath 

the central Cupertino Basin, but thin rapidly toward the center of the basin and near its

southwestern edge. In places in the northeastern Santa Cruz Mountains surface mapping 

shows that the Miocene rocks are underlain by Franciscan Complex rocks (McLaughlin

et al, 2001), and the same structural relationship may exist beneath the Santa Clara

Valley. However, serpentinite observed at relatively shallow depths (~245 m) in the

Willow well (Orze et al., 2003), near the northeast end of the SCSI-LR profile, suggests

that at least parts of the Santa Clara Valley are underlain by rocks of the Coast Ranges

Ophiolite. This observation is somewhat consistent with our seismic reflection image,

whereby a high-amplitude northeast-dipping reflector extends from surface exposures of

the Coast Ranges Ophiolite in the Santa Cruz Mountains to the base of the Cupertino

Basin, and back toward the shallow subsurface in the vicinity of the Willow well (Fig.

11). On the basis of the reflection image, we suggest that Miocene sediments of the

western Santa Clara Valley may be underlain by a wedge of Coast Ranges Ophiolitic

rocks that has been thrust beneath the valley. These rocks have relatively high velocities

(~6.5 km/s) within the Santa Cruz Mountains. Similar high-velocity (~6.4 to 6.5 km/s)

rocks have been observed to the north of the SCSI-LR profile, beneath the San Francisco 

Bay, (Catchings et al, 2004) and below the eastern side of the Santa Clara Valley

(Catchings et al., unpublished data). Such high-velocity rocks are consistent with 

ultramafic rocks that compose parts of the Coast Ranges Ophiolite (Carmichael, 1989),

but such high velocities are not consistent with most Franciscan rocks at that depth

(Stewart and Peselnick, 1977).

Offset reflectors and folded Pre-Pliocene strata suggest multiple faults beneath the

alluvium of the Santa Clara Valley. Offset strata imaged on the SCSI-LR reflection

image show that some of the faults offset the base of the ground-water aquifer system.

Such shallow-depth faulting implies at least post-Pliocene movement on faults beneath 

the Santa Clara Valley, and SCSI-HR images show that many of these fault extend to the

near surface or to within about 10 m of the surface (Catchings et al., 2005).

Furthermore, earthquakes recorded over the past 30 years show that similar faults are

presently active at depths of 1 to 30 km. These stratigraphic relationships and 

earthquakes recorded beneath the valley clearly indicate the presence of potentially
25

hazardous earthquake faults beneath the Santa Clara Valley. These faults represent a

potential hazard both from the standpoint of local sources beneath a large population base

and increased ground amplification due to regional sources, such as the San Andreas

fault. The maximum magnitudes of earthquakes that can be generated from the imaged 

faults are unknown but are related to the lengths of the faults. The seismicity pattern and 

mapped faults near the base of the mountains suggest that the valley faults may extend 70

km or more. Where they extend to the shallow depths, these faults probably cause lateral

variations in the ground-water aquifer by acting as barriers to lateral flow across the

valley.

Lateral variations in P-wave velocities, Vp/Vs and Poisson’s ratios, and reflection 

images, correlated with borehole data, indicate that the maximum depth of the groundwater aquifer is variable across the Santa Clara Valley, varying from less than 50 m to

about 300 m. Quaternary deposits that form the ground-water aquifer system appears to 

thicken eastward of Vasona Dam, with the thickest deposits in the area northeast of the

city of Campbell (shot point 11). The thinnest Quaternary deposits are located 

southwestward of Vasona Reservoir, with the possible exception of isolated basins, such 

as that beneath the city of Los Gatos. Most lateral variations in the depth of the groundwater aquifer system correlate with apparent fault offsets in subsurface reflectors,

suggesting that the ground-water aquifer is faulted in multiple locations across the

western part of the valley. The SCSI reflection images suggest that the Quaternary rocks

are faulted at various locations along the length of the SCSI-LR profile, including the

central part of the valley between Campbell and San Jose. A short seismic profile

acquired farther to the northeast of the end of the SCSI-LR profile suggests similar

faulting extends beneath the eastern downtown area of San Jose (Catchings et al., 2000),

but our 2000 SCSI-LR seismic profile did not extend far enough to the northeast to

address that area.

The dimensions and velocities of the low-velocity Cupertino Basin are important

parameters needed to understand potential ground shaking resulting from movement on

regional and/or local faults. The velocity and reflection images suggest that the Cupertino 

Basin is about 1600 to 1800 m deep, which is about one-half the depth previously 

suggested from potential fields studies (R. Jachens, Pers. Comm., 2001; Stanley et al.,

2002). Although other factors, such as basin shape, velocities, location of the sources,

type of fault, etc., are important contributors, the shallower depth of the Cupertino Basin 
26

may also indicate less hazard from amplification of seismic waves in the valley than

previously believed. However, the seismic images also suggest multiple faults beneath 

the valley, some of which are active, as indicated by earthquakes recorded over the past

few decades (Fig. 12) and by near-surface traces of the faults imaged on the seismic

reflection images (Fig. 11). Slip on any one of the major faults may trap fault-zone

guided waves into the general fault system, and produce amplified seismic waves within 

the each of the fault zones. However, the principal hazard for the Santa Clara Valley may

be the high-amplitude seismic energy generated by the reverse faults that underlie the

valley.
27

Acknowledgements:

This work was jointly funded by the U.S. Geological Survey’s (USGS)

Earthquake Hazards Program and the Santa Clara Valley Water District (SCVWD). We

than IRIS-PASSCAL for providing the Texan seismographs, and we especially thank 

Bob Greschke and Pete Ulbricht, who provided technical support during the seismic

investgation. We thank numerous individuals and organizations, including the SCVWD,

the City of Los Gatos, City of Campbell, Open Space District, Los Gatos High School,

Del Mar High School, and the San Jose Water Company, who provided permits and 

access to their properties. We thank Alonzo Aballo, Joe Catchings, Coye Criley, Coyn 

Criley, Courtney Criley, Ed Criley, Samuel V. Gudino, Samuel R. Gudino, Silvia

Gudino, Ron Kaderabek, Grey Jensen, Shawn Hanson, Lora Kiger, David Reneau, Jose

Rodriguez, Paul Singh, Jeffrey Thacker, and John VanSchaack, who assisted in data

acquisition. We thank Lora Kiger for helping with many of the logistical challenges of

this investigation, and we also thank Lora Kiger and John Hamilton for providing

precision survey data. We thank Carl Wentworth, David Schwartz, and Jack Boatwright,

who provided administrative assistance. We thank Bob Mclaughlin for scouting and 

recommending the Santa Cruz Mountains segment of the SCSI profile northeast of

Lexington Reservoir. Thanks to Tom Brocher, Bob McLaughlin, and Peter Martin, who

provided reviews of this manuscript.

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models, first-arrival travel times, and geometries of the 1991 and 1993 USGS landbased controlled-source seismic investigations in the San Francisco Bay area,

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pp.

Catchings, R. D., G. Gandhok, M. R. Goldman, C. E. Steedman, and R. Hanson (2005).

Near-surface structure and velocities of the northeastern Santa Cruz Mountains and 

the western Santa Clara Valley, California from seismic imaging, U.S. Geological

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Christiansen, N.I. (1982). Seismic Velocities in R.S. Carmichael ed., Handbook of

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Christiansen, N. I. (1996). Poisson’s ratio and crustal seismology, J. Geophys. Res., 101,

p. 3139-3156

Dibblee, T.R., Jr. (1966). Geology of the Palo Alto quadrangle, Santa Clara and San Mateo 

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Dietz, Lynn D., and William L. Ellsworth (1997). Aftershocks of the Loma Prieta Earthquake and 

their tectonic implications, in The Loma Prieta, California Earthquake of October 17, 1989:

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Gandhok, G., R. D. Catchings, M. R. Goldman, E. Horta, M. J. Rymer, P. Martin, and 

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measurements and geological conditions at thirteen sites in the Los Angeles, California

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Helley, E.J., R.W. Graymer, G.A. Phelps, P.K.Showalter, and C.M. Wentworth (1994).

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30

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31

Figures

Fig. 1 (a) Location map of the southern San Francisco Bay area and the Santa Clara

Seismic Imaging (SCSI) profile. Shot points and seismograph locations for the SCSI

profile are shown in the inset. Major faults (from Bortugno et al., 1991), roadways, and

selected cities are also shown. Inferred faults that cross the SCSI profile in the Santa

Clara Valley are shown only at their inferred crossing. The Cupertino (CB) and 

Evergreen (EB) Basins (from Stanley et al., 2002) are outlined as dashed lines. (b) Shot

points (Shot point #) of the southwestern half of the SCSI low-resolution (SCSI-LR)

seismic profile. The brown asterisks show the locations of individual seismographs of

the southwestern part of the SCSI-LR profile. The green asterisks show the locations of

shot points along the southwestern part of the SCSI high-resolution (SCSI-HR) seismic

profile. Where the profile overlap, the SCSI-HR (green) shot points are shown on top.

The base map is from the USGS 7.5 minute Los Gatos quadrangle. (c) The locations of

the northeastern parts of the SCSI-LR and SCSI-HR seismic profiles, plotted as in figure

1b. The base map is from the USGS 7.5 minute Los Gatos quadrangle. Recently drilled 

USGS/SCVWD water wells (McGlincey, Willow, and STPK) are shown by the red dots,

with distances to the wells shown. (d) Geologic map (from McLaughlin et al., 2001) of

the northeastern Santa Cruz Mountains with the southwestern part of the SCSI profiles

plotted as in figure 1b. Note the numerous faults mapped along the seismic profile. See

McLaughlin et al. (2001) for map legend.

Fig. 2. Geometry of the SCSI-LR profile. Variation in seismograph array (a) elevation 

and (b) linearity. Variation in shot-point array (c) elevation and (d) linearity. Note that

most of the non-linearity occurs outside of the shot-point array. (e) Fold as a function of

common depth point (CDP) along the SCSI profile.

Fig. 3. (a-k) Shotgathers for SCSI-LR shot points 1-11, respectively. Several prominent

reflectors are highlighted on the southwestern end of the seismic profile. Some of these

reflectors project to the surface at a fault contact between rocks of the Coast Ranges

Ophiolite and Franciscan rocks.

Fig. 4. (a) Ray density diagram showing raypaths for P-waves and redundancy for shot

and receiver pairs along the SCSI profile. (b) P-wave velocity model for the upper 3 km

along the SCSI profile. Distance is relative to the southwestern most geophone, located 

near the San Andreas fault. Depth is relative to the lowest elevation along the SCSI

profile. The shallow depth white contour denotes the 2200 m/s velocity contour, which 

correlates with the base of the ground-water aquifer system in the McGlincey water well,

located approximately at meter 12500 of the velocity model. The other white velocity

contour denotes the 3000 m/s velocity contour, which correlates with Franciscan 

basement rocks at the surface at shot point 1 (meter 3500). The red contour denotes the

3500 m/s contour, which is the probably the maximum velocity for similar basement

rocks at 2 km depth.

Fig. 5. (a) Ray density model showing raypaths for S-waves and redundancy for shot and 

receiver pairs along the SCSI profile. (b) S-wave velocity model for the upper 5 km

along the SCSI profile. Depth and distance are the same as those in figure 4b. Velocities

below about 1500 m depth are poorly constrained due to uncertain picks on the shot

gathers.
32

Fig. 6 Vp/Vs ratio model along the SCSI profile. Depth and distance are the same as

those in figure 4b. The 2.7 Vp/Vs ratio contour, which correlates with the base of the

ground-water aquifer in the McGlincey well (~meter 12500) is shown in white. Due to 

the presence of serpentinite and faults along the profile, high values of Vp/Vs ratios in

various places are not necessarily related to the ground-water aquifer along all of the

SCSI profile. (b) Poisson’s ratio model along the SCSI profile. Depth and distance are

the same as those in figure 4b. The 0.43 Poisson’s ratio contour, which correlates with 

the base of the ground-water aquifer in the McGlincey well (~meter 12500) is shown in 

white. Low values of Poisson’s ratio below 1.5 km depth are not well constrained.

Fig 7. (a) Migrated seismic reflection image of the upper 1000 m along the SCSI profile.

Red vertical arrows above the reflection image denote the locations of mapped faults

(McLaughlin et al., 2001) along the SCSI-LR profile. Blue arrows indicate interpreted

faults. (b) Migrated reflection image from figure 7a, with the locations of faults as

interpreted on the SCSI-HR reflection images (Catchings et al., 2005). Focal

mechanisms for earthquakes within about 3 km of the SCSI profile are shown below the

reflection image. Most focal mechanisms indicate northeast striking, high-angle (~75 to

90 degrees) faults. (c) Migrated reflection image from figure 7a, with interpretative

strata, derived from surface mapping and wells along the profile. Yellow indicates

Quaternary sediments, blue indicates Miocene strata, and green indicates Franciscan 

rocks.

Fig. 8. (a) Seismic reflection image from figure 7 with the unmasked P-wave velocity

model from figure 4b superimposed. (b) Seismic reflection image from figure 7 with the

unmasked S-wave velocity model from figure 5b superimposed. (c) Seismic reflection 

image from figure 7 with the Vp/Vs model from figure 6a superimposed. (d) Seismic

reflection image from figure 7 with the Poisson’s ratio model from figure 6b 

superimposed. Wells located along or near the seismic profile are shown in yellow. See

Stanley et al. (2002) for well descriptions.

Fig. 9. Comparison of P- and S-wave sonic velocities from the McGlincey well (see fig.

1) with SCSI refraction velocities. The SCSI velocities, which are averaged over 50-100 

m intervals are comparable to the sonic logs over similar depth ranges.

Fig. 10. (a) Average P-wave velocities of sandstone and shale as a function of age (from

Press, 1966) and comparison with velocities determined along the SCSI-LR profile

beneath the Cupertino Basin (meter 9000). Tertiary sandstone and shale are known to 

underlie the near-surface Quaternary deposits in the western Santa Clara Valley (Stanley 

et al, 2002). This comparison suggests that sandstones and shales are probably confined 

to the upper 1600 m beneath the Santa Clara Valley. (b) Comparison of velocity-depth 

relationships from sonic velocities obtained from boreholes in the San Francisco Bay area

(from Brocher et al., 1998) and SCSI refraction velocities. Sonic velocities are derived

from boreholes drilled in various sedimentary basins in the San Francisco Bay area, and 

refraction velocities are from a vertical profile at meter 9000 of the SCSI velocity model

(fig. 4b). The SCSI and average sonic velocities differ significantly at about 1600 to

1800 m depth, suggesting that sediments of the Cupertino Basin are probably not deeper

than 1600 to 1800 m.
33

Fig. 11 Seismic reflection image from figure 7, with probable rock types and 

interpretative faults outlined at shallow depths. Interpretative rock types are based on 

known stratigraphy at the surface, borehole data, and continuity of reflectors.

Interpretative faults are based on fault mapped at the surface, SCSI-HR reflection images

(Catchings et al., 2005), and offset reflectors on the SCSI-LR image. Focal mechanism

for well-recorded earthquakes within 3 km of and along the seismic profile are shown 

below the SCSI-LR reflection image.

Fig 12 Interpreted seismic image figure 11 with earthquakes that have been recorded

over the past 3 decades within 3 km of the SCSI profile. Although locations are not

precise, there are at least two separate zones of seismicity along the SCSI profile.

Seismicity below each of these zones extend to depths greater than 25 km, but only 

earthquakes in the upper 14 km are shown here.
Los Gatos

Seismic Profile

San Andreas

Hayward

San Francisco 

Bay

Daly City

San Jose

Union City

Hayward

Fremont

San Mateo

Livermore

Menlo

Park

Lexington Dam Santa Cruz Mountains

Diablo Ranges

Santa Clara Valley

Fig. 1a

McGlincey

Well

Willow

Well STPK

Well

Legend

Water Wells

Shot Points

Historical Faults

Holocene Faults

Quaternary Faults

CALIFORINIA

Area of 

Figure

San

Francisco

Pacific

Ocean

San Andreas fault

Los

Angeles

Pacific Ocean

Seismographs

(Low Resolution)

High-Res. Array

Approximate

Boundary of 

Basins

CB = Cupertino Basin

EB = Evergreen Basin

CB

EB
SCSI-LR Shot Point

SCSI-LR Seismograph

SCSI-HR Profile

From USGS 

San Jose West Quadrangle

Shot point 5

Shot point 4 

Shot point 3

Shot point 2

Shot point 1

0 1

Fig. 1b
SCSI-LR Shot Point

SCSI-LR Seismograph

Wells

SCSI-HR Profile Willow Well I-280
1 .5 0 1 KILOMETER

CALIF.

MAP LOCATION

SCSI-HR and/or LR Profiles

SCSI-Seismographs

SCSI-LR Shot Points Fig. 1d
-1000

0

1000

2000

3000

REC Y

0 5000 10000 15000

REC X

Geophone

0

50

100

150

200

250

300

REC Z

0 5000 10000 15000 20000

0 5000 10000 15000 20000

Geophone

0

2.5

5

7.5

10

12.5

Fold

0 200 400 600 800

CDP

Fold

0

50

100

150

0 10000 15000 20000

Shotpoint

-400

-300

-200

-100

0

100

200

300

400

0

5000

5000 10000 15000 20000

Shotpoint

Elevation (m)

Distance from first shotpoint (m)

Distance from first geophone (m)

Distance from first geophone (m)

Lateral variation (m)

Distance from first shotpoint (m)

SW NE

Fig. 2

A

B

C

D

E
Fig 3a
Fig. 3b
Fig. 3c

Shot Point 3
Fig. 3d
Fig. 3e
Fig. 3f
Fig. 3g
Fig. 3h
Fig. 3i
Fig. 3j
Fig. 3k
Pwave

0.2 0.2

0.4 0.4

0.6 0.6

0.8 0.8

1 1

1.2 1.2

1.4 1.4

1.4

1.4

1.6 1.6

1.6

1.8 1.8

1.8

1.8

2 2

2

2

2

2

2

2.2

2.2

2.2

2.2

2.2

2.2

2.2

2.4

2.4

2.4

2.4

2.4

2.6

2.6

2.6

2.6

2.6

2.8

2.8

2.8

2.8

2.8

3

3 3.2

3.2 3.2

3.4

3.4

3.4

3.6

0 5000 10000 15000

Vp/Vs Ratio

1.52.02.53.03.5

1000

2000

3000

Depth (m)

0

Distance (m)

SW NE Lexington Dam SP 1 SP 2 SP 3 SP 4 SP 5 SP 6 SP 7 SP 8 SP 9 SP 10 SP 11Blossom Hill Rd Vasona Dam Highway 85Highway I-280

San AndreasFault

Los Gatos Campbell

Cupertino Basin

San Jose

0.02 0.02

0.02

0.02

0.04 0.04

0.04

0.04

0.06 0.06

0.06

0.06

0.06

0.08 0.08

0.08

0.08

0.1 0.1

0.1

0.1

0.12 0.12

0.12

0.12

0.14 0.14

0.14

0.16 0.16

0.16

0.18 0.18

0.18

0.2 0.2

0.2

0.22 0.22

0.22

0.24 0.24

0.24

0.24

0.26 0.26

0.26

0.26

0.28 0.28

0.28

0.28

0.3 0.3

0.3

0.3

0.3

0.3

0.32

0.32

0.32

0.32

0.32

0.32

0.34

0.34

0.34

0.34

0.34

0.34

0.36

0.36

0.36

0.36

0.36

0.36

0.38

0.38

0.38

0.38

0.38

0.38

0.4

0.4

0.4

0.4

0.4

0.42

0.42

0.42

0.42

0.44

0.44

0 5000 10000 15000

Poisson's Ratio

0.050.150.250.350.45

1000

2000

3000

Depth (m)

0 Distance (m)

SW NE Lexington Dam SP 1 SP 2 SP 3 SP 4 SP 5 SP 6 SP 7 SP 8 SP 9 SP 10 SP 11 Blossom Hill Rd Vasona Dam Highway 85Highway I-280

San AndreasFault

Los Gatos Campbell

Cupertino Basin

San Jose

Fig. 6

A

B
0

100

200

300

400

500

0

100

200

300

400

500

0

100

200

0

50

100

150

200

SAFAldercroft Fault ZoneSoda Sprngs t Fault ZoneLime Kiln t Fault ZoneBerrocal Fault Zone

Depth (m)

ShannonFault Zone

Mapped Faults Probable Buried Faults SCSI_HR Imaged Faults Wells

McGlincey WellWillow Well

A

B

19981107 05:32 49.18 16.52 121 57.57 DEPTH = 7.42 KM

MAG = 2.24 D

P

T

110,20,80

301,70,94

19900210 06:15 9.62 17.09 121 57.65 DEPTH = 3.72 KM

MAG = 2.05 D

P

T

345,5,–40

115,87,–94

19900210 06:15 9.62 17.09 121 57.65 DEPTH = 3.72 KM

MAG = 2.05 D

P

T

345,5,–40

115,87,–94

19890601 09:17 14.43 15.16 121 57.74 DEPTH = 7.62 KM

MAG = 1.57 D

P

T

90,20,50

312,75,103

19891222 06:17 34.08 14.37 121 57.58 DEPTH = 2.10 KM

MAG = 1.57 D

P

T

30,5,170

130,89,85

12.36 121 57.69 DEPTH = 2.50 KM MAG = 1.38 D

P

T

280,90,90

P 145,0,135

T

310,90,–90

85,0,–135

1000

0

C

Fig. 7
1000

1500

2500

4500

5000

5000

5500

Lglow.a2 inversion 25

1000

2000

3000

Depth (m)

0

Velocity (m/s)

20003000400050006000

0

1000

2000

3000

4000

3000 6000 9000 12000 15000

line 1rr k1 ax6 p3.1 v3: bottom mute, agc=100, bp=5-10-20-40 mig=200,8000,80 poststack: bp=6-10-20-40, agc=200; decon150

0

20Fold

0

250Elev(m)

DISTANCE (m)

SW NE Lexington Dam SP 1 SP 2 SP 3 SP 4 SP 5 SP 6 SP 7 SP 8 SP 9 SP 10 SP 11 Blossom Hill Rd Vasona Dam Highway 85Highway I-280

San AndreasFault

Los Gatos Campbell

Cupertino Basin

San Jose

Depth (m)

500 500

2000

2500

3500

1000

2000

3000

Depth (m)

0 0

1000

2000

3000

4000

3000 6000 9000 12000 15000

line 1rr k1 ax6 p3.1 v3: bottom mute, agc=100, bp=5-10-20-40 mig=200,8000,80 poststack: bp=6-10-20-40, agc=200; decon150

DISTANCE (m)

Depth (m)

Fig. 8

A

B

S-Wave Velocity (m/s) 1000 1500 2000 2500 3000

McGlincey Well

Willow Well Willow Well

McGlincey Well
0.68421 1

1.42

1.4

1.682

2

2

2.2

2.2

2.2

2.4

2.6

2.6

3.2

3.4

Vp/Vs Ratio

1.52.02.53.03.5

Depth (m)

0

1000

2000

3000

4000

0

1000

2000

3000

3000 6000 9000 12000 15000

line 1rr k1 ax6 p3.1 v3: bottom mute, agc=100, bp=5-10-20-40 mig=200,8000,80 poststack: bp=6-10-20-40, agc=200; decon150

0

20

Fold

0

250Elev(m)

DISTANCE (m)

SW NE Lexington Dam SP 1 SP 2 SP 3 SP 4 SP 5 SP 6 SP 7 SP 8 SP 9 SP 10 SP 11 Blossom Hill Rd Vasona Dam Highway 85Highway I-280

San AndreasFault

Los Gatos Campbell

Cupertino Basin

San Jose

Depth (m)

0.02

0.02

0.02

0.04

0.04

0.04

0.06 0.06

0.06

0.06

0.08 0.08

0.08

0.1 0.1

0.1

0.12

0.12

0.12

0.14 0.14

0.16 0.160.18 0.18

0.2 0.2

0.22 0.220.2468 0.3

0.34

0.36

0.38

0.38

0.4

0.4

Poisson's Ratio

0.050.150.250.350.45

Depth (m)

0

1000

2000

3000

0

1000

2000

3000

4000

3000 6000 9000 12000 15000

line 1rr k1 ax6 p3.1 v3: bottom mute, agc=100, bp=5-10-20-40 mig=200,8000,80 poststack: bp=6-10-20-40, agc=200; decon150

DISTANCE (m)

Depth (m)

Fig. 8

C

D

McGlincey Well

Willow Well

McGlincey Well

Willow Well
0

50

100

150

200

250

300

Depth (m)

0

500

100015002000250030003500

Velocity (m/s)

Velocity Comparisons - McGlincey Well/Refraction

Vs (Refraction)

Vp (Refraction)

Vs (Borehole)

Vp (Borehole)

Fig. 9
0

500

1000

1500

2000

2500

3000

3500

4000

Depth (m)

150020002500300035004000450050005500

P-Wave Velocity (m/s)

Sandstone and Shale Velocities and

Santa Clara Refraction Velocities

Jurassic

Cretaceous

Eocene

SCSI

Refraction

Tertiary

(Post Eocene)

Fig. 13a

A

Comparison of Bay Area Sonic Velocity Regression

and Refraction Velocities From the Cupertino Basin

Refraction 

Velocities

Sonic 

Velocities

B

Fig. 10

Adapted From Press (1966)

Adapted From Brocher et al. (1997)
Franciscan

Miocene

Quaternary

Coast Ranges Ophiolite

0

1000

2000

3000

4000

3000 6000 9000 12000 15000

line 1rr k1 ax6 p3.1 v3: bottom mute, agc=100, bp=5-10-20-40 mig=200,8000,80 poststack: bp=6-10-20-40, agc=200; decon150

0

20

Fold

0

250

Elev(m)

DISTANCE (m)

SW NE Lexington Dam SP 1 SP 2 SP 3 SP 4 SP 5 SP 6 SP 7 SP 8 SP 9 SP 10 SP 11 Blossom Hill Rd Vasona Dam Highway 85Highway I-280

San AndreasFault

Los Gatos Campbell

Cupertino Basin

San Jose

Depth (m)

Fig. 11

McGlincey WellWillow Well

12.36 121 57.69 DEPTH = 2.50 KM

MAG = 1.38 D

310,90,–90

0

100

200

300

400

500

0

100

200

0

50

100

150

200

Wells

Faults

19981107 05:32 49.18 

16.52 121 57.57

DEPTH = 7.42 KM

MAG = 2.24 D

P

T

110,20,80

301,70,94

19900210 06:15 9.62 

17.09 121 57.65

DEPTH = 3.72 KM

MAG = 2.05 D

P

T

345,5,–40

115,87,–94

19900210 06:15 9.62 

17.09 121 57.65

DEPTH = 3.72 KM

MAG = 2.05 D

P

T

345,5,–40

115,87,–94

19890601 09:17 14.43 

15.16 121 57.74

DEPTH = 7.62 KM

MAG = 1.57 D

P

T

90,20,50

312,75,103

19891222 06:17 34.08 

14.37 121 57.58

DEPTH = 2.10 KM

MAG = 1.57 D

P

T

30,5,170

130,89,85

12.36 121 57.69 DEPTH = 2.50 KM MAG = 1.38 D

P

T

280,90,90

P 145,0,135

T

310,90,–90

85,0,–135
Franciscan

Miocene

Quaternary

Coast Ranges Ophiolite

0

1000

2000

3000

4000

3000 6000 9000 12000 15000

line 1rr k1 ax6 p3.1 v3: bottom mute, agc=100, bp=5-10-20-40 mig=200,8000,80 poststack: bp=6-10-20-40, agc=200; decon150

0

20

Fold

0

250

Elev(m)

DISTANCE (m)

SW NE Lexington Dam SP 1 SP 2 SP 3 SP 4 SP 5 SP 6 SP 7 SP 8 SP 9 SP 10 SP 11 Blossom Hill Rd Vasona Dam Highway 85Highway I-280

San AndreasFault

Los Gatos Campbell

Cupertino Basin

San Jose

Depth (m)

McGlincey WellWillow Well

12.36 121 57.69 DEPTH = 2.50 KM

MAG = 1.38 D

310,90,–90

0

100

200

300

400

500

0

100

200

0

50

100

150

200

Wells

Faults

0

2

4

6

8

10

12

14

Depth (km)

Fig. 12
60

Appendix 1 Shot Point Locations

Shot 

Point 

Number

Nearest 

Station

Dist(m)

Along

Profile

Lateral Dist 

(m) From

Profile

Elevation

(m)

UTM

Northing

UTM

Easting

1001 99 3440.79 0 140.22 4118014.9 589542.1

1002 127 4552.43 -103.18 116 4119058 589940

1003 158 5828.47 -53.07 74 4120181 590548

1004 182 7152.01 184.29 76 4121264 591345

1005 205 8288.63 -3.83 70.94 4122367 591677.7

1006 233 9561.46 -175.57 51.87 4123585 592085.2

1007 257 10533.85 127.25 0.43 4124324 592786

1008 279 11616.69 -51.03 39.73 4125374.4 593103.8

1009 302 12667.49 135.68 24 4126235 593735

1010 342 14196.01 82.82 15 4127630 594362

1011 379 15925.97 0 14 4129219 595051
61

Appendix 2 Seismograph Locations Along Profile

Station # Dist (m) Along

Profile

Lateral Dist (m)

From Profile

Elevation (m)

1 0 2597.63 251

2 24.47 2549.94 259

3 44.44 2506.7 243

4 80.04 2465.79 247

5 106.63 2436 238

6 146.2 2403.17 226

7 166.02 2382.29 228

8 186.29 2360.06 230

9 192.39 2318.06 231

10 162.75 2269.12 224

11 225.21 2223.92 231

12 258.55 2187.47 228

13 283.45 2142.91 222

14 282 2092.36 222

15 285.88 2045.88 219

16 316.13 2003.15 206

17 296.7 1965.9 193

18 319 1909.25 203

19 365.5 1910.9 199

20 408.56 1891.96 203

21 444.1 1860 201

22 489.79 1848.67 192

23 539 1846.77 191

24 559 1799.05 184

25 583.42 1758.06 171

26 602.96 1711.68 171

27 650.12 1680.69 172

28 684.29 1654.98 167

29 727.39 1629.33 178

30 761.65 1587.97 173

31 781.62 1544.72 172

32 808.25 1508.22 175

33 839.85 1463.71 172

34 882.09 1434.03 178

35 926.02 1419.12 181

36 977.52 1408.28 181

37 1024.98 1400.55 180

38 1070.29 1379.38 179

39 1112.95 1352.84 186

40 1153.84 1324.93 191

41 1175.13 1284.38 189

42 1213.36 1251.09 186

43 1244.48 1212.39 173

44 1283.54 1189.84 157

45 1321.27 1164.6 169

46 1358.99 1141.6 181

47 1406.2 1103.9 190
62

48 1430.6 1067.39 186

49 1459.96 1022.86 177

50 1491.07 986.4 179

51 1531.95 958.5 179

52 1582.57 945.87 172

53 1632.23 942.62 179

54 1680.27 915.66 175

55 1727.31 902.56 176

56 1770.84 880.04 180

57 1810.42 847.21 182

58 1836.25 795.5 172

59 1868.25 758.6 170

60 1898.5 715.86 176

61 1930.47 683.43 175

62 1961.18 639.36 167

63 2002.52 610.12 164

64 2044.71 587.15 166

65 2082.98 549.39 171

66 2106.22 483.35 171

67 2132.15 418.23 166

68 2164.24 367.91 170

69 2219.89 338.32 168

70 2278.21 311.87 170

71 2336.42 301.08 175

72 2385.81 272.34 173

73 2440.85 266.45 168

74 2494.18 250.26 167

75 2549.75 234.08 168

76 2608.46 215.24 162

77 2665.82 198.18161

78 2738.37 182.56 166

79 2859.87 271.03 164

80 2913.63 257.97 164

81 2950.48 230.94 170

82 2974.46 189.06 175

83 2993.19 129.7 171

84 3046.87 127.83 175

85 3087.3 101.26 173

86 3137.45 92.21 171

87 3184.91 84.47 165

88 3233.76 68.25 157

893274.17 43.92 154

90 3319.12 10.68 145

91 3371.06 0.74 141

92 3398.74-18.89 138.44

93 3409.76-21.18 138.12

94 3417.07-23.55 138.05

95 3420.43-24.87 138.19

96 3431.72-28.19 138.27

97 3443.42-32.94 137.86

98 3455.57-36.57 137.47

99 3443.66-0.96 140.26
63

100 3465.58-42.05 137.02

101 3479.12-47.37 135.9

102 3488-51.52 135.33

103 3496.89-55.66 135

104 3479.4-35.92 136.48

105 3523.75-59.96 133.48

106 3580.65-56.18 131.82

107 3636.01-7.51 130.45

108 3710.88 11.95 116.04

109 3763.66-16.45 111

110 3822.76-33.36 110

111 3877.37-46.73 109.78

112 3925.8-65.86 108.96

113 3961.13-99.84 107.86

114 3998.17-134.43 106.86

115 4040.94-170.28 105.91

116 4086.23-194.66 105.47

117 4133.59-208.03 104.55

118 4188.66-204.58 103.28

119 4236.84-180.02 101.43

120 4278.69-152.01 100.56

121 4329.12-148.72 99.56

122 4397.93-145.89 100.1

123 4445.95-163.82 99.95

124 4495.41-171.31 96.96

125 4544.55-195.81 93.98

126 4526.01-97.99 119

127 4552-106.31 114

128 4599.09-126.12 114

129 4651.05-138.3 120

130 4697.18-148.73 111

131 4582.15-228.11 92.37

132 4620.1-259.03 92.01

133 4656.03-295.42 91.65

134 4691.64-330.42 91.51

135 4730.04-361.12 91.32

136 4774.96-383.54 91.26

137 4822.71-394.98 90.41

138 4873.37-393.48 90.12

139 4969.34-373.25 89.55

140 5018.49-359.86 89.41

141 5065.36-339.33 88.5

142 5106.31-310.66 87.65

143 5149.54-287.79 87.4

144 5201.87-267.94 86.67

145 5245.76-244.39 87.05

146 5290.57-210.37 85.36

147 5335.78-190.26 84.59

148 5380.57-167.15 83.73

149 5428.33-153.19 83.63

150 5474.99-134.9 83.32

151 5525.35-114.31 81.7
64

152 5577.28-95.71 81.18

153 5627.61-78.79 80.06

154 5675.07-59.11 79.69

155 5717.56-33.42 78.93

156 5761.09-8.35 77.88

157 5804.66 16.8 76.83

158 5828.47-53.07 75

159 5848.27 41.83 75.78

160 5889.16-66.76 77.89

161 5902.52 61.73 75.67

162 5936.62-67.91 76.96

163 5957.03 76.5 75.18

164 5986.57-67.63 77.13

165 6010.86 99.17 74.33

166 6041.6-64.04 76.36

167 6091.68-63.03 74.83

168 6141.32-62.25 75.16

169 6191.84-60.13 75.2

170 6240.69-55.06 75.16

171 6298.79-49.08 74.2

172 6334.66-2.65 72.1

173 6370.84 43.75 70

174 6411.03 73.58 70.15

175 6453.47 100.07 72.12

176 6498.7 118.17 72.17

177 6547.71 118.36 70.92

178 6606.62 111.02 70.23

179 6665.52 103.67 69.54

180 6724.57 107.74 69.86

181 7104.38 150.88 85

182 7152.04 179.82 76

183 7178.2 146.9 86

184 7242.31 55.2 62

185 7291.11 47.92 64

186 7335.87 41.51 75

187 7390.92 35.62 67

188 7438.41 23.41 67

189 7483.2 12.53 67

190 7540.18-14.37 62

191 7585.7 1.14 68

192 7635.28 9.07 62

193 7685.33 15.67 49

194 7734.52 16 55

195 7784.19 12.75 57

196 7833.85 9.5 58

197 7883.89 16.1 53

198 7938.98 17.54 62.06

199 7993.89 19.52 62.2

200 8043.38 0.97 64.83

201 8100.31-12.2 69.85

202 8147.19-6.16 69.8

203 8205-3.49 69.99
65

204 8257.87-5.2 70.3

205 8284.14-1.62 70.94

206 8316.65-0.56 72.01

207 8356.5-8.12 66.32

208 8396.71 17.91 64.68

209 8436.97 44.03 63.04

210 8486.97 83.18 62.48

211 8528.66 115.62 62.28

212 8576.47 142.59 62.66

213 8632.2 128.34 61.57

214 8668.88 87.12 61.6

215 8706.64-23.04 57.92

216 8757.77-98.33 55.4

217 8801.23-123.26 55.19

218 8845.99-155.74 55.02

219 8892.6-184.68 54.57

220 8937.75-215.24 54.44

221 8982-244.24 53.23

222 9031.46-263.76 53.52

223 9080.24-276.05 53.54

224 9125.47-291.04 53.58

225 9188.47-296.39 49.68

226 9230.33-282.87 50.55

227 9272.06-269.4 51.43

228 9317.94-254.96 52.54

229 9365.69-240.11 52.02

230 9413.71-224.72 51.89

231 9461.42-210.63 51.67

232 9509.31-195.28 51.83

233 9562.78-173.54 51.49

234 9603.85-202.21 47.74

235 9632.09-258.55 50.54

236 9683.11-276.95 50.49

237 9734.12-295.34 50.43

238 9781.12-314.22 50.23

239 9827.13-333.5 50.16

240 9875.64-344.31 47.4

241 9923.61-355.75 47.34

242 9967.88-361.36 49.21

243 10017.05-357.45 52.32

244 10065.97-349.52 49.2

245 10113.16-337.18 49.13

246 10154.88-309.66 48.59

247 10195.96-280.5 48.49

248 10232.19-247.39 47.92

249 10270.12-214.89 47.85

250 10311.81-188.81 47.54

251 10359.52-175.38 47.14

252 10403.42-152.06 47.19

253 10445.21-133.94 47.4

254 10402.85 53.48 46

255 10466.55 92.37 44
66

256 10496.82 113.14 42

257 10533.86 125.02 40

258 10586.84 94.51 31

259 10649.11 78.38 39

26010747.89 52.65 43.27

261 10787.57 85.3 43.03

262 10827.94 114.59 42.74

263 10870.24 141.71 42.49

264 10920.18 156.71 42.38

265 10973.96 160.47 42.46

266 11019.1 157.77 42.33

267 11067.33 154.78 42.18

268 11117.22 151.54 41.9

269 11166.8 147.89 41.91

270 11217.86 142.06 42.16

271 11265.58 135.76 41.94

272 11314.2 115.2 41.97

273 11360.11 97.3 41.67

274 11405.77 77.97 41.82

275 11452.31 60.22 41.59

276 11499.27 39.47 41.7

277 11545.71 24.21 40.23

278 11589.91 0.58 39.78

279 11620.31-50.2439.75

280 11674.46-28.73 39.47

281 11721.32-47.42 39.26

282 11768.33-62.4 39.12

283 11821.63-68.22 38.92

284 11870.58-64.32 38.45

285 11942.36-78.33 35.55

286 11998.54-73.08 30.96

287 12045.47-81.22 30.17

288 12093.89-93.33 30.05

289 12142.22-104.95 29.97

290 12189.7-122.16 30.25

291 12236.74-134.59 30.05

292 12287.8-145.88 30

293 12336.27-157.9 30

294 12384.74-169.92 30

295 12433.21-181.94 29.99

296 12478.36-192.1 29.84

297 12529.78-204.68 29.99

298 12578.26-211.47 29.73

299 12630.04-216.31 29.32

300 12645.62-4 34

301 12600.73 88.27 33

302 12670.17 136.59 24

303 12729.11 84.21 31

304 12788.03 34.07 31

305 12852.65-65.68 28

306 12679.3-219.7 29.82

307 12729.43-219.27 29.37
67

308 12781.11-216.83 29.3

309 12829.74-211.76 29.44

310 12877.65-193.86 20

311 12925.9-186.39 22

312 12975.89-170.85 24

313 13023.19-156.22 23

314 13069.61-141.15 24

315 13115.09-121.17 24

316 13160.13-102.09 24

317 13206.98-86.12 23

318 13252.94-69.72 22

319 13294.92-61.39 23

320 13343.95-36.46 16

321 13390.82-22.73 21

322 13437.68-9 21

323 13476.46 10.93 25

324 13523.33 24.66 25

325 13577.42 28.16 18

326 13637.95 71.94 18

327 13650.92 71.13 23

328 13690.36 58.43 22

329 13726.17 54.19 30

330 13817.48 42.73 24

331 13855.49 42.98 28

332 13900.67 41.94 20

333 13949.86 42.27 27

334 13992.36 40.32 30

335 14039.84 28.11 23

336 14077.59 0.64 38

337 14110.62 11.14 28

338 14138.63 36.37 26

339 14170.38 103.22 23

340 14178.83 110.21 23.5

341 14187.28 117.2 24

342 14223.5 118.33 15

343 14266.38 126.22 11

344 14307.86 142.6 14

345 14340.99 137.45 22

346 14379.46 136.37 28

347 14432.67 138.07 33

348 14463.53 137.38 15

349 14495.28 138.48 30

350 14541.73 146.84 13

351 14581.54 146.22 14.5

352 14616.05 134.82 16

353 14647.05 114.01 15

354 14679.89 85.6 15

355 14712.27 58.54 16

356 14738.39 30.09 12

357 14764.02 9.69 15

358 14807.07-7.02 13

359 14844.7-16.61 10
68

360 14883.59-14.56 11

361 14919.29-3.148

362 15014.11-2.95 13

363 15124.96 4.949

364 15156.18 18.57 10

365 15203.94 31.85 12

366 15252.18 41.57 14

367 15308.02 50.899

368 15353.49 73.17

369 15411.14 79.34

370 15462.45 97.532

371 15513.83 104.587

372 15559.82 116.52 10

373 15615.7 119.138

374 15668.83 132 10

375 15714.33 149.75 10

376 15763.44 163.49 10

377 15812.54 177.24 10

378 15898.01 101.78 14

379 15912.58 63.42 10

380 15919.72-1.38 19

381 15861.19 192.32 10

382 15910.3 203.83 11

383 15962.1 216.258

384 16012.55 228.227

385 16063.91 239.747

386 16113.01 253.487

387 16163.45 267.688

388 16213.92 277.415

389 16264.37 291.616

390 16312.6 301.336

391 16347.85 314.089

392 16396.51 326.938

393 16446.96 338.89 11

394 16493.39 351.73 18

395 16544.29 364.59 18

396 16593.38 380.578

397 16647.85 393.95

398 16699.64 406.326

399 16751 417.859

400 16796.98 429.780

401 16844.73 445.310

402 16876.02 447.75 12

403 16930.48 463.327

404 16983.17 475.33

405 17032.27 489.041

406 17081.37 502.792

407 17133.6 518.345

408 17188.02 538.383

409 17234.07 541.372

410 17324.67 569.268

411 17373.34 579.875
69

412 17423.83 587.36 3

413 17561.34 622.27 4

414 17606.89 633.31 6

415 17648.37 649.68 5

416 17700.16 662.1 6
70

Appendix 3 Seismograph UTM Locations

PASSCAL

Seismograph

Number

Station # UTM Northing UTM Easting Elevation (m) Geo. Freq.

553 2 4113781 590355 281 4.5

557 3 4113824 590323 289 40

554 4 4113861 590293 273 4.5

551 5 4113911 590272 277 40

559 6 4113948 590257 268 4.5

442 7 4113998 590245 256 40

560 8 4114025 590235 258 4.5

561 9 4114053 590224 260 40

562 10 4114077 590189 261 4.5

696 11 4114072 590132 254 40

558 12 4114148 590119 261 4.5

555 13 4114194 590101 258 40

552 14 4114236 590072 252 4.5

556 15 4114257 590026 252 40

563 16 4114281 589986 249 4.5

102 17 4114327 589961 236 40

100 18 4114326 589919 223 4.5

101 19 4114371 589878 233 40

110 20 4114412 589900 229 4.5

106 21 4114459 589902 233 40

109 22 4114505 589889 231 4.5

105 23 4114551 589899 222 40

103 24 4114596 589919 221 4.5

108 25 4114635 589885 214 40

107 26 4114675 589859 201 4.5

104 27 4114713 589826 201 40

111 28 4114769 589819 202 4.5

574 29 4114811 589811 197 40

455 30 4114861 589807 208 4.5

133 31 4114910 589785 203 40

41 32 4114947 589755 202 4.5

456 33 4114987 589734 205 40

52 34 4115035 589708 202 4.5

134 35 4115086 589700 208 40

207 36 4115132 589706 211 4.5

70 37 4115183 589719 211 40

201 38 4115229 589733 210 4.5

180 39 4115279 589734 209 40

66 40 4115329 589729 216 4.5

175 41 4115378 589722 221 40

580 42 4115415 589695 219 4.5

573 43 4115464 589682 216 40

517 44.2 4115509 589661 203 4.5

578 44 4115554 589658 187 40

209 45 4115599 589652 199 4.5

567 46 4115643 589648 211 40

47 47 4115702 589635 220 4.5
71

485 48 4115740 589613 216 40

507 49 4115786 589586 207 4.5

460 50 4115830 589567 209 40

132 51 4115879 589560 209 4.5

587 52 4115930 589571 202 40

433 53 4115976 589590 209 4.5

149 54 4116031 589587 205 40

524 55 4116079 589596 206 4.5

511 56 4116128 589595 210 40

501 57 4116178 589583 212 4.5

566 58 4116224 589548 202 40

50 59 4116269 589529 200 4.5

59 60 4116315 589504 206 40

576 61 4116358 589489 205 4.5

38 62 4116405 589463 197 40

436 63 4116455 589455 194 4.5

401 64 4116503 589453 196 40

483 65 4116554 589436 201 4.5

404 66 4116604 589387 201 40

458 67 4116656 589340 196 4.5

412 68 4116707 589309 200 40

139 69 4116770 589307 198 4.5

183 70 4116834 589309 200 40

607 71 4116891 589325 205 4.5

406 72 4116948 589321 203 40

596 73 4117000 589340 198 4.5

403 74 4117055 589349 197 40

579 75 4117112 589359 198 4.5

582 76 4117173 589368 192 40

593 77 4117232 589378 191 4.5

409 78 4117304 589396 196 40

604 79 4117374 589529 194 4.5

408 80 4117428 589541 194 40

605 81 4117473 589533 200 4.5

407 82 4117513 589506 205 40

428 83 4117556 589461 201 4.5

610 84 4117605 589483 205 40

402 85 4117653 589477 203 4.5

522 86 4117702 589491 201 40

492 87 4117748 589505 195 4.5

411 88 4117799 589512 187 40

177 89 4117846 589508 184 4.5

609 90 4117901 589498 175 40

497 91 4117952 589512 171 4.5

450 92 4118004 589510.5 168.05 40

74 10001 4117985.5 589506.6 168.44 99

431 10002 4117996.4 589509.4 168.12 99

743 10003 4118007.6 589510.8 168.19 99

116 10004 4118019.2 589512.8 168.27 99

681 10005 4118031.8 589513.7 167.86 99

130 10006 4118044.3 589515.8 167.47 99

121 10007 4118055.7 589515.3 167.02 99
72

529 10008 4118070.2 589516.5 165.9 99

664 10009 4118080 589516.7 165.33 99

750 10010 4118089.8 589516.9 165 99

445 93 4118017.9 589542.5 170.26 40

879 94 4118065.4 589526.9 166.48 4.5

413 94.5 4118115.8 589524.9 163.48 40

447 95 4118165.2 589553.4 161.82 4.5

405 96 4118193.4 589621.5 160.45 40

482 97 4118252 589672 146.04 4.5

597 98 4118311.9 589669.8 141 40

80 99 4118372.4 589680.7 140 4.5

57 100 4118427.3 589692.8 139.78 40

451 101 4118479.2 589697 138.96 4.5

594 102 4118525.9 589682.1 137.86 40

830 103 4118574.4 589667.4 136.86 4.5

165 20001 4119032 589933 149 99

464 20002 4119059 589937 144 99

178 20003 4119110 589940 144 99

486 20004 4119162 589952 150 99

73 20005 4119208 589963 141 99

844 104 4118628.6 589654.1 135.91 99

136 105 4118680 589652.2 135.47 4.5

417 106 4118728.4 589661.1 134.55 40

81 107 4118776.3 589688.5 133.28 4.5

46 108 4118808.7 589731.8 131.43 40

86 109 4118833.9 589775.4 130.56 4.5

508 110 4118877.7 589800.6 129.56 40

79 111 4118938.2 589833.5 130.1 4.5

55 112 4118989.2 589838.6 129.95 40

85 113 4119036.9 589853.7 126.96 4.5

512 114 4119091.8 589853.4 123.98 40

82 115 4119139.8 589841 122.37 4.5

506 116 4119187.5 589830 122.01 4.5

78 117 4119235.8 589813.2 121.65 4.5

49 118 4119283.2 589797.5 121.51 40

75 119 4119331.2 589786.9 121.32 4.5

441 120 4119381.4 589786.6 121.26 40

84 121 4119429.3 589797.4 120.41 4.5

425 122 4119474.1 589821.1 120.12 40

514 124 4119551.3 589881.6 119.55 40

45 125 4119589.5 589915.3 119.41 4.5

840 126 4119622.5 589954.4 118.5 40

40 127 4119646.6 589998.2 117.65 4.5

503 128 4119675.3 590037.8 117.4 40

523 129 4119713.5 590078.7 116.67 4.5

414 130 4119742.5 590119.2 117.05 40

148 131 4119767.7 590169.5 115.36 4.5

418 132 4119799.4 590207.5 114.59 40

513 133 4119829.4 590248 113.73 4.5

500 134 4119866.1 590281.6 113.63 40

77 135 4119899.9 590318.6 113.32 4.5

518 136 4119936 590359.3 111.7 40
73

25 137 4119974.4 590398.9 111.18 4.5

419 138 4120012.1 590436.3 110.06 40

30 139 4120046 590474.9 109.69 4.5

581 140 4120072.8 590516.7 108.93 40

83 141 4120100.8 590558.4 107.88 4.5

420 142 4120128.8 590600.2 106.83 40

843 143 4120156.9 590641.9 105.78 4.5

424 144 4120196.8 590683.7 105.67 40

841 145 4120239.2 590721 105.18 4.5

422 146 4120277.5 590765.1 104.33 40

505 147 4120181 590548 115 4.5

504 148 4120241.5 590562.5 107.89 40

89 149 4120284.6 590582.4 106.96 4.5

87 150 4120329.3 590604.7 107.13 40

93 151 4120377.1 590632.2 106.36 4.5

416 152 4120421.6 590655.2 104.83 40

143 153 4120465.8 590677.8 105.16 4.5

421 154 4120510.2 590702 105.2 40

544 155 4120551.8 590728.1 105.16 4.5

415 156 4120601.3 590759.1 104.2 40

141 157 4120613 590816.6 102.1 4.5

172 158 4120625 590874.2 100 40

546 159 4120647.9 590918.7 100.15 4.5

577 160 4120674.3 590961.2 102.12 40

488 161 4120706.9 590997.4 102.17 4.5

34 162 4120750.8 591019.2 100.92 40

27 163 4120806.9 591038.6 100.23 4.5

590 164 4120863 591058 99.54 40

547 165 4120914.2 591087.7 99.86 4.5

832 40001 4121236 591294 115 99

612 40002 4121266 591341 106 99

757 40003 4121304 591323 116 99

90 401 4121402 591269 92 4.5

474 402 4121449 591284 94 40

88 403 4121492 591298 105 4.5

469 404 4121544 591317 97 40

154 405 4121592 591327 97 4.5

95 406 4121637 591337 97 40

542 407 4121700 591338 92 4.5

33 408 4121734 591372 98 40

203 409 4121775 591401 92 4.5

569 410 4121817 591429 79 40

435 411 4121861 591451 85 4.5

570 412 4121907 591470 87 40

540 413 4121953 591489 88 4.5

568 414 4121995 591517 83 40

69 415 4122043.8 591542.6 92.06 4.5

36 416 4122092.2 591568.6 92.2 40

541 417 4122144.8 591573.8 94.83 4.5

571 418 4122201.7 591587.1 99.85 40

545 419 4122241.1 591613.2 99.8 4.5

589 420 4122291.8 591641.1 99.99 40
74

29 421 4122340 591662.9 100.3 4.5

31 422 4122362 591677.7 100.94 40

510 423 4122390.7 591693 102.01 4.5

881 424 4122429.8 591703.8 96.32 40

548 425 4122454.4 591744.9 94.68 4.5

525 426 4122479 591786.1 93.04 40

868 427 4122506.6 591843.3 92.48 4.5

480 428 4122529.7 591890.8 92.28 40

127 429 4122560.7 591936.1 92.66 4.5

871 430 4122617 591947.9 91.57 40

400 431 4122668.1 591927.1 91.6 4.5

391 432 4122750.6 591844.9 87.92 40

54 433 4122829.7 591799.9 85.4 4.5

394 434 4122879.7 591796.7 85.19 40

867 435 4122934.2 591787.3 85.02 4.5

393 436 4122988.8 591781.9 84.57 40

125 437 4123042.8 591774.4 84.44 4.5

392 438 4123095.3 591767.9 83.23 40

481 439 4123148.3 591772.2 83.52 4.5

60 440 4123197.5 591782.7 83.54 40

861 441 4123244.7 591789.2 83.58 4.5

874 442 4123303.6 591812.2 79.68 40

863 443 4123335.2 591842.8 80.55 4.5

839 444 4123366.7 591873.3 81.43 40

876 445 4123401.5 591906.5 82.54 4.5

140 446 4123437.8 591940.9 82.02 40

72 447 4123474.1 591975.9 81.89 4.5

397 448 4123510.7 592009.6 81.67 40

146 449 4123546.9 592044.5 81.83 4.5

198 601 4123585.3 592087.6 81.49 40

550 602 4123634.8 592080 77.74 4.5

509 604 4123685 592041.9 80.54 4.5

176 605 4123738.9 592047.9 80.49 40

443 606 4123792.8 592053.9 80.43 4.5

444 607 4123843.3 592057.7 80.23 40

187 608 4123893.1 592060.7 80.16 4.5

196 609 4123941.4 592072.4 77.4 40

195 610 4123989.5 592083.3 77.34 4.5

193 611 4124031.7 592097.8 79.21 40

189 612 4124074.1 592123 82.32 4.5

197 613 4124114.5 592151.7 79.2 40

199 614 4124151.4 592183.6 79.13 4.5

191 615 4124176.7 592226.7 78.59 40

188 616 4124200.7 592271 78.49 4.5

99 617 4124218.6 592316.7 77.92 40

96 618 4124238.3 592362.6 77.85 4.5

465 619 4124264.2 592404.4 77.54 40

475 620 4124301.1 592437.5 77.14 4.5

466 621 4124330.2 592477.8 77.19 40

92 622 4124359.7 592512.5 77.4 4.5

94 623 4124239 592662 76 40

498 625 4124279 592725 74 40
75

97 626 4124297 592757 72 4.5

399 701 4124325 592784 70 40

208 702 4124386 592780 61 4.5

206 703 4124449 592793 69 40

76 704 4124549 592813.5 73.27 4.5

179 705 4124570.2 592860.3 73.03 40

26 706 4124593.5 592904.4 72.74 4.5

734 707 4124619.5 592947.4 72.49 40

543 708 4124657.7 592982.9 72.38 4.5

423 709 4124704.3 593010 72.46 40

128 710 4124746 593027.5 72.33 4.5

585 711 4124790.6 593046.1 72.18 40

539 712 4124836.8 593065.2 71.9 4.5

866 713 4124882.9 593083.8 71.91 40

865 714 4124931.3 593101.1 72.16 4.5

438 715 4124976.9 593116.5 71.94 40

549 716 4125029.6 593119.5 71.97 4.5

205 717 4125078.7 593123.7 71.67 40

389 718 4125128.2 593126.5 71.82 4.5

395 719 4125177.8 593131.1 71.59 40

862 720 4125229.1 593133.2 71.7 4.5

71 721 4125277.5 593140 70.23 40

864 722 4125327.6 593138.3 69.78 4.5

463 801 4125377.3 593106.1 69.75 40

35 802 4125416.4 593149.3 69.47 4.5

32 803 4125466.7 593153.2 69.26 40

390 804 4125515.5 593160.5 69.12 4.5

755 805 4125565.9 593178.8 68.92 40

598 806 4125608.1 593203.9 68.45 40

833 807 4125678.7 593223 65.55 4.5

741 808 4125726.8 593252.5 60.96 40

502 809 4125772.5 593265.9 60.17 40

221 810 4125821.3 593276.4 60.05 4.5

212 811 4125869.8 593287.3 59.97 40

487 812 4125920 593292.8 60.25 40

124 813 4125967.7 593302.4 60.05 4.5

211 814 4126018.5 593314.8 60 40

532 815 4126067.3 593325.4 60 40

224 816 4126116.1 593336 60 4.5

530 817 4126164.9 593346.6 59.99 40

168 818 4126209.9 593357.4 59.84 40

113 819 4126261.6 593368.8 59.99 4.5

526 820 4126308.1 593384.1 59.73 40

223 821 4126356.7 593402.6 59.32 40

214 822 4126402.4 593421.3 59.82 4.5

158 823 4126447.2 593443.8 59.37 40

760 824 4126492.5 593468.8 59.3 40

837 825 4126533.9 593494.8 59.44 4.5

150 826 4126569 593532 50 40

534 827 4126609 593560 52 40

490 90001 4126277 593600 64 99

753 90002 4126196 593663 63 99
76

135 90003 4126237 593737 54 99

754 90004 4126313 593716 61 99

43 90005 4126388 593697 61 99

166 90006 4126490 593636 58 99

120 828 4126647 593596 54 4.5

521 829 4126683 593630 53 40

672 830 4126718 593664 54 40

117 831 4126750 593702 54 4.5

592 832 4126782 593739 54 40

623 833 4126817 593774 53 40

126 834 4126851 593809 52 4.5

742 835 4126885 593835 53 40

531 836 4126918 593879 46 40

123 837 4126954 593912 51 4.5

457 838 4126990 593945 51 40

586 839 4127016 593980 55 40

216 840 4127052 594013 55 4.5

156 841 4127099 594040 48 40

479 842 4127134 594106 48 40

440 843 4127146 594111 53 4.5

144 844 4127187 594117 52 40

614 845 4127221 594129 60 40

119 846 4127308 594159 54 4.5

519 847 4127342 594176 58 40

44 848 4127383 594195 50 40

477 849 4127427 594217 57 4.5

468 850 4127466 594234 60 40

528 851 4127514 594244 53 40

679 852 4127560 594236 68 40

219 853 4127585 594260 58 4.5

112 854 4127599 594295 56 40

747 10101 4127598 594369 53 99

744 10102 4127602.5 594379 53.5 99

138 10103 4127607 594389 54 99

740 2074 4127639 594406 45 40

159 2073 4127674 594432 41 40

155 2072 4127704 594465 44 4.5

432 2071 4127736 594475 52 40

439 2070 4127771 594491 58 40

875 2069 4127818 594516 63 4.5

153 2068 4127846 594529 45 40

583 2067 4127874 594544 60 40

202 2066 4127912 594572 43 4.5

495 2065 4127948 594589 4.5 40

186 2064 4127984 594594 46 40

68 2063 4128021 594589 45 4.5

484 2062 4128063 594578 45 40

62 2061 4128104 594568 46 40

204 2060 4128140 594554 42 4.5

494 2059 4128172 594547 45 40

473 2058 4128218 594551 43 40

538 2057 4128256 594559 40 4.5
77

137 2056 4128290594578 41 40

732 2055 4128317 594604 38 40

67 2054 4128402 594646 43 4.5

662 2053 4128498 594702 39 40

665 2052 4128520 594728 40 40

145 2051 4128557 594761 42 4.5

619 2050 4128596 594791 44 40

210 2049 4128642 594824 39 40

878 2048 4128673 59486437 4.5

611 2047 4128722 594895 34 40

736 2046 4128760 594934 32 40

448 2045 4128803 594963 37 4.5

410 2044 4128839 594994 40 40

157 2043 4128888 595021 38 40

185 2042 4128930 595056 40 4.5

427 2041 4128963 595092 40 40

745 2040 4129001 595126 40 40

618 2039 4129039 595160 40 40

761 2038 4129076 595195 40 4.5

751 2037 4129115 595227 41 40

462 2036 4129156 595261 38 4.5

620 11001 4129149 595130 44 99

452 11002 4129179 595102 40 99

173 11003 4129214 595047 49 99

151 2035 4129196 595294 37 4.5 515 2034 4129237 595327 37 40

613 2033 4129275 595361 37 40

835 2032 4129314 595396 38 4.5

472 2031 4129355 595427 35 40

446 2030 4129394 595462 36 40

615 2029 4129433 595492 36 40

192 2028 4129459 595519 39 4.5

668 2027 4129497 595552 38 40

42 2026 4129537 595585 41 40

453 2025 4129573 595617 48 40

220 2024 4129613 595651 48 4.5

164 2023 4129650 595687 38 40

735 2022 4129693 595723 35 40

181 2021 4129734 595757 36 40

430 2020 4129775 595790 39 4.5

667 2019 4129811 595821 30 40

115 2018 4129847 595856 30 40

114 2017 4129874 595872 42 40

520 2016 4129916 595910 37 4.5

48 2015 4129958 595944 33 40

56 2014 4129996 595978 31 40

142 2013 4130034 596012 32 40

595 2012 4130074 596049 35 4.5

622 2011 4130114 596091 33 40

152 2010 4130154 596114 32 40

122 2009 4130223 596179 38 40

91 2008 4130262 596210 35 4.5
78

459 2007 4130304 596239 33 4.5

222 2004 4130412 596331 34 4.5

215 2003 4130448 596361 36 4.5

535 2002 4130478 596394 35 4.5

845 2001 4130519 596428 36 4.5