Where's the Hayward Fault? 

A Green Guide to the Fault 

By Philip W. Stoffer 

This report describes self-guided field trips to one of North America's most dangerous 

earthquake faults—the Hayward Fault. Locations were chosen because of their easy access using 

mass transit and/or their significance relating to the natural and cultural history of the East Bay 

landscape. 

Open-File Report 2008-1135 

U.S. Department of the Interior 

U.S. Geological Survey 
ii

U.S. Department of the Interior 

DIRK KEMPTHORNE, Secretary 

U.S. Geological Survey 

Mark D. Myers, Director 

U.S. Geological Survey, Reston, Virginia 2008 

For product and ordering information: 

World Wide Web: http://www.usgs.gov/pubprod/

Telephone: 1-888-ASK-USGS 

For more information on the USGS—the Federal source for science about the Earth, 

its natural and living resources, natural hazards, and the environment: 

World Wide Web: http://www.usgs.gov

Telephone: 1-888-ASK-USGS 

Suggested citation: 

Stoffer, Philip W., 2008, Where’s the Hayward Fault? A green guide to the fault: U.S. 

Geological Survey Open-File Report 2008-1135, 88 p.

[http://pubs.usgs.gov/of/2008/1135/]. 

Any use of trade, product, or firm names is for descriptive purposes only and does not 

imply endorsement by the U.S. Government. 

Although this report is in the public domain, permission must be secured from the 

individual copyright owners to reproduce any copyrighted material contained within 

 this report. 
iii

Table of Contents

Introduction to This Guide .............................................................................................................1

Transportation Alternatives ........................................................................................................1

Take A Virtual Tour of the Hayward Fault ..................................................................................3

Which trip would be best to go on? ............................................................................................3

Chapter 2—Introduction to the Hayward Fault ..............................................................................5

Observing the Hayward Fault...................................................................................................11

Chapter 3 - Point Pinole Regional Shoreline...............................................................................13

Chapter 4 - Contra Costa College ...............................................................................................16

Chapter 5 -Treasure Island and Yerba Buena Island ..................................................................20

Chapter 6 - U.C. Berkeley and Berkeley Hills..............................................................................23

Chapter 7 – Monclair Village .......................................................................................................36

Chapter 8 – Oakland Hills ...........................................................................................................39

Chapter 9 – Oakland Zoo-San Leandro-Fairmont Hospital .........................................................43

Chapter 10 – Downtown Hayward...............................................................................................49

Chapter 11 – Downtown Fremont ...............................................................................................57

Chapter 12 – Mission San Jose-South Fremont..........................................................................62

Chapter 13 – Now and Then: Comparison of Selected Historic USGS Topo Maps with 

Modern Satellite Views Along the Hayward Fault........................................................................68

Glossary......................................................................................................................................77

Selected References...................................................................................................................87
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List of figures 

Figure 1. Locations of selected field trip destinations to observe features associated with the Hayward 

Fault. 

Figure 2. Location of the Hayward Fault. 

Figure 3. Earthquake map of the Hayward Fault and surrounding region. 

Figure 4. 1868 Hayward Earthquake Shaking Intensity Map with the BART System. 

Figure 5. Geologic block diagram [with the Hayward Fault]. 

Figure 6. Cross sections along the Hayward Fault [with legened]. 

Figure 7. Trace of the Hayward Fault at Point Pinole Regional Shoreline, Bay Area, California. Figure 8. 

Commuter train in the vicinity of the Hayward Fault in Point Pinole Regional Shoreline. 

Figure 9. View south from the Pinole Point Trail toward the hillslope escarpment (left) of the Hayward 

Fault. 

Figure 10. View looking north along the shoreline near where the Hayward Fault trace vanishes beneath 

the waters of San Pablo Bay. 

Figure 11. Trace of the Hayward Fault in the Contra Costa College area in Richmond, California. 

Figure 12. Offset curb along the Campus Circle parking area on the north side of the campus of Contra 

Costa College. 

Figure 13. Rows of bricks offset by fault creep on a patio area next to the Campus Circle on the north side 

of the campus of Contra Costa College. 

Figure 14. Strain and shear from creep on the Hayward Fault result in fractures in the asphalt of Parking 

Lot 10 on the campus of Contra Costa College. 

Figure 15. Strain and shear from creep on the Hayward Fault result in fractures in the asphalt of Parking 

Lot 10 on the campus of Contra Costa College. 

Figure 16. Free parking is available on the Contra Costa College campus in the vicinity of the Hayward 

Fault. 

Figure 17. Creep along the Hayward Fault has caused structural damage to the now-abandoned El Portal 

School. 

Figure 18. Creep along the Hayward Fault has caused structural damage to the now-abandoned El Portal 

School. 

Figure 19. Creep along the Hayward Fault has offset sidewalks near the entrance to the now-abandoned 

El Portal School. 

Figure 20. Map of the Yerba Buena and Treasure Island area mid span on the Bay Bridge between San 

Francisco and Oakland, California. 

Figure 21. View east toward the eastern section of the Bay Bridge from Treasure Island. 

Figure 22. View east toward the eastern section of the Bay Bridge from Treasure Island. 

Figure 23. View looking west toward San Francisco at the suspension section of the Bay Bridge west of 

Treasure Island. 

Figure 24. Location of the Hayward Fault in the Berkeley area, California. 

Figure 25. A Google satellite image showing the location of the Hayward Fault relative to Bowles Hall, 

California Memorial Stadium, a deflected stream (Hamilton Creek) and offset curbs on Dwight Avenue. 

Figure 26.The Hayward Fault crosses the University of California, Berkeley campus [near or beneath the 

southwest wing (left) of the Bowles Residence Hall on the southeast side of campus. 

Figure 27. View looking south past the goal post near the north end of California Memorial Stadium [in the 

vicinity of the Hayward Fault]. 

Figure 28. California Memorial Stadium straddles the Hayward Fault and its walls display visible structural 

damage as a result of slow creep along the fault trace. 

Figure 29. Offset of the rim wall of California Memorial Stadium produced by creep along the Hayward 

Fault. 

Figure 30. View looking north from the offset seating in section KK where damage to the stadium by the 

creeping Hayward Fault is most obvious. 

Figure 31. View looking west along a broken-up sidewalk on Dwight Way near Hillside Avenue in 

Berkeley. 

Figure 32. One of the offset curbs where Dwight Way in Berkeley crosses the Hayward Fault. 

Figure 33. View looking east up Tanglewood Path just downhill of the intersection of Stonewall Road 

(near the Claremont Hotel in Berkeley). 

Figure 34. Trailhead to Claremont Canyon Regional Preserve near the intersection of Tanglewood Path 
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and Stonewall Road (near the Claremont Hotel in Berkeley). 

Figure 35. The Claremont Hotel. The Hayward Fault passes near the southeast corner of the building. 

Figure 36. The Hayward Fault runs through the parking lot and beneath the corner of the building near the 

south entrance to the Claremont Hotel. 

Figure 37. Fractures in the asphalt of the Claremont Hotel parking lot are probable evidence of surface 

movement associated with the Hayward fault. 

Figure 38. A Google Earth image map showing the location of the Hayward Fault and associated features 

in the Lake Temescal area. 

Figure 39. View of Lake Temescal from the north. The active trace of Hayward Fault runs along the 

eastern shore of the lake. 

Figure 40. Cracks in the pavement reveal the trace of the creeping Hayward Fault at Lake Temescal 

Regional Recreation Area. 

Figure 41. En echelon fractures from creep along the Hayward Fault in the pavement in front of the Park 

Office in Lake Temescal Regional Recreation Area. 

Figure 42. View looking north at the entrance to an old railroad bridge tunnel in Temescal Regional 

Recreation Area. 

Figure 43. View of an offset curb and crack in the side of the old railroad bridge tunnel near the south end 

of Lake Temescal Regional Recreation Area. 

Figure 44. View southwest from an overlook on Tunnel Road near Highway 24 near where it crosses the 

Hayward Fault. 

Figure 45. View southwest across Highway 24 toward the PG&E Claremont Substation near Lake 

Temescal. 

Figure 46. View of the western portal of the Caldecott Tunnel on Highway 24. 

Figure 47. View looking down (southwest) into Claremont Canyon [from near the intersection of Grizzley 

Peak Boulevard and Marlborough Terrace]. 

Figure 48. Folded sedimentary rocks (ribbon chert of Franciscan Formation of Jurassic age) located (near 

the intersection of Grizzley Peak Boulevard and Marlborough Terrace). 

Figure 49. View looking southwest from an overlook area on Grizzley Peak in the Berkeley Hills in 

Charles Lee Tilden Regional Park. 

Figure 50. View looking west toward the Golden Gate from an overlook on Grizzley Peak in the Charles 

Lee Tilden Regional Preserve. 

Figure 51. View looking east from Skyline Boulevard in the East Bay Hills (east of Berkeley) toward 

Round Top Hill in Sibley Volcanic Regional Preserve. 

Figure 52. This display of labeled rocks is in front of the kiosk and restrooms at Sibley Volcanic Regional 

Preserve. 

Figure 53. Location of the Hayward Fault in the Monclair Village area. 

Figure 54. This view looks north along Moraga Avenue at the intersection with Mountain Boulevard in 

Monclair Village, where the Hayward Fault crosses the intersection. 

Figure 55. This view looks north along the trace of the Hayward Fault where it crosses through Monclair 

Recreation Center, a small park just north of Monclair Village. 

Figure 56. This broken stonewall is along the trace of the Hayward Fault in Monclair Recreation Center. 

Figure 57. View along an old damaged and repaired wall in the Hayward Fault zone in Monclair 

Recreation Center (park), along the sag pond formed by the fault. 

Figure 58. Location of the Hayward Fault in the Oakland (East Bay) Hills area. 

Figure 59. The Chabot Space & Science Center is located along the crest of the East Bay Hills on Skyline 

Boulevard, east of Oakland. 

Figure 60. South-facing view from an overlook along Skyline Boulevard located about 1 mile south of the 

Chabot Space & Science Center in Joaquin Miller Park. 

Figure 61. The Oakland Mormon Temple (Church of Jesus Christ of Later-day Saints) is located near the 

intersection of Lincoln Avenue and Highway 13. 

Figure 62. Fault creep along the Hayward Fault may be responsible for this offset stairway and wall on 

the northeast corner of the Interstakes Building on the [Mormon] temple grounds. 

Figure 63. View looking west from the Oakland Mormon Temple toward downtown Oakland with the Bay 

Bridge and San Francisco in the distance. 

Figure 64. View is looking south from the grounds of the Oakland Mormon Temple. 

Figure 65. Map of the Hayward Fault in the San Leandro-Oakland Zoo-Fairmont Hospital area. 

Figure 66. Offset curb in the lower parking lot access road near the Oakland Zoo Education Center 
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entrance close to the park entrance station. 

Figure 67. Display about the Hayward Fault in the Children's Playground in the Oakland Zoo. 

Figure 68. Garden of plants that had living relatives during the Cretaceous Period on display at the 

Oakland Zoo near the trace of the Hayward Fault. 

Figure 69. Historic photograph of the damage to the Estudillo House in San Leandro. 

Figure 70. Historic photograph by Carleton Watkins showing the condition of the Alameda County 

Courthouse after the 1868 Hayward earthquake. 

Figure 71. View looking south at the intersection of Davis and Clarke Streets at the location where the 

Alameda County Courthouse used to stand before being destroyed by the 1868 Hayward earthquake. 

Figure 72. The Hayward Fault crosses a low divide where stream erosion has produced a linear stream 

valley. 

Figure 73. Google Earth view of the San Leandro Hospital grounds showing locations of features 

associated with the Hayward Fault. 

Figure 74. Fairmont Hospital is an Alameda County facility in San Leandro. 

Figure 75. View of the Fairmont Hospital campus drive on the south side of the main building. 

Figure 76. Fractured and broken wall revealing the location of the creeping Hayward Fault in the rear 

(east side) of Fairmont Hospital. 

Figure 77. Map showing the Hayward Fault in the downtown Hayward area. 

Figure 78. View of an offset curb at the southwest corner of Prospect Street and Rose Street north of 

downtown Hayward. 

Figure 89. The roots of this old tree have split the curb and sidewalk on Prospect Street just north of the 

intersection with Rose Street. 

Figure 80. View west along Simon Street from the intersection of Prospect Street in Hayward (Mission 

Boulevard is in the distance). The slope in the foreground is a scarp of the Hayward Fault 

Figure 81.This view is a close up of the displacement of the curb shown in fig. 82. The view looks west 

along Simon Street from the intersection of Prospect Street in Hayward 

Figure 82. Offset curbs and fractures in the pavement are visible along the creeping trace of the Hayward 

Fault in the municipal parking area between Avenue A and Hotel Avenue on the east side of Mission 

Boulevard. 

Figure 83. This view looks east along an alley between Avenues B and C in downtown Hayward where 

the creeping Hayward Fault has offset sidewalks, buildings, and just about everything along its trace. 

Figure 84. Hayward's old City Hall was built in 1930 directly on the Hayward Fault. 

Figure 85. This sidewalk displays right-lateral offset that is typical for the older structures built across the 

creeping Hayward Fault. This sidewalk is on the north side of old City Hall in downtown Hayward. 

Figure 86. View from the side of a small hill east of the intersection of Jackson Street and Mission 

Boulevard. 

Figure 87. A twisted (displaced) cement wall of an old sandbox play area in Memorial Park near 

downtown Hayward. 

Figure 88. This old, low stonewall in Memorial Park near downtown Hayward has been displaced by 

creep along the Hayward Fault. 

Figure 89. View north past a low stonewall that has been offset by creep along the Hayward Fault. 

Figure 90. The Pierce’s house in Hayward—knocked off its foundation by the 1868 earthquake. 

Figure 91. Edminton Grain Warehouse and flour mill—collapsed during the 1868 earthquake. 

Figure 92. Edminton Grain Warehouse—collapsed during the 1868 earthquake 

Figure 93. Location of the Hayward Fault in the Fremont Central Park area. 

Figure 94. The Fremont BART station is the current terminus of the rail line. The track ends a very short 

distance from the Hayward Fault. 

Figure 95. Tule Pond is a sag pond that fills a natural depression formed by two strands of the Hayward 

Fault. 

Figure 96. The Hayward Fault crosses through Fremont's Central Park. This view shows two USGS 

interns photographing offset curbs and fractures where the fault crosses Sailway Drive on the west shore 

of Lake Elisabeth. 

Figure 97. Close-up view of an offset curb on Sailway Drive in Fremont Central Park. 

Figure 98. View looking southwest across Paseo Padre Parkway toward a low hill on Baylis Street. The 

hill is an escarpment along the Hayward Fault. 

Figure 99. View north across Paseo Padre Parkway toward Lake Elisabeth from the corner of Baylis 

Street. Fractures in the pavement are from creep along the Hayward Fault. 
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Figure 100. View of an offset curb on the north side of Rockett Drive near the intersection of Paseo Padre 

Parkway near Fremont Central Park. 

Figure 101. View of an offset curb and an attempt to repair fractures in the pavement on the south side of 

Rockett Drive near the intersection of Paseo Padre Parkway near Fremont Central Park. 

Figure 102. This view shows water mains of the Hetch Hetchy water system (water mains #1 and #2) 

exposed in the vicinity where they cross the Hayward Fault along Grimmer Boulevard. 

Figure 103. Location of the Hayward Fault in the Mission San Jose area in southern Fremont, California. 

Figure 104. Mission San Jose was founded in 1797. The original church building was constructed of 

adobe and completed in 1809. The church was nearly completely destroyed by the 1868 earthquake. 

Figure 105. A new church constructed of wood was built on the rock foundation of the old church. 

However, the wooden building was moved and the San Jose Mission church was rebuilt (restored) to look 

like the original; construction was completed in 1985. 

Figure 106. This small memorial park on Washington Boulevard is an Ohlone Indian burial ground where, 

according to a local marker on the site, as many as 4,000 Ohlone people were buried 

Figure 107. View looking east along Washington Boulevard shows an offset curb and sidewalk near the 

entrance to the Ohlone Village Shopping Center in Fremont. The sidewalk was probably buckled by 

growth of the tree. 

Figure 108.This view is looking east at the property owned by BART near Osgood and Washington in 

Fremont. The photo shows the ruins of the Gallegos (Palmdale) Winery, which was built into a hillside that 

is a fault scarp of the Hayward Fault. 

Figure 109. The Mission Peak landslide occurred on March 22, 1998 and was a partial reactivation of a 

large bedrock landslide complex that has developed over many thousands of years on the western face 

of Mission Ridge 

Figure 110. Detail of the headwall escarpment area of the Mission Peak landslide. 

Figure 111. View looking east toward Mission Peak from near the trailhead for Mission Peak Regional 

Park on Stanford Avenue in Fremont 

Figure 112. Arroyo Agua Caliente Park is located in southern Fremont at the intersection of Paseo Padre 

Parkway and Parkmeadow Drive. 

Figure 113. En echelon fractures in the pavement near the intersection of Gardenia Way and Ivy Way on 

the southwest side of Arroyo Agua Caliente Park in Fremont. 

Figure 114. Point Pinole from portions of two maps: 1916 Mare Island 15’ quadrangle (north half) and 

1895 San Francisco 15’ quadrangle (south half 

Figure 115. Point Pinole as captured from current Google Earth satellite imagery. The red line indicates 

known locations of the Hayward Fault 

Figure 116. San Pablo (Richmond) area from the 1895 San Francisco 15’ quadrangle. 

Figure 117. The satellite image of the Richmond area from February 2008 shows nearly complete urban 

development across the alluvial plain and upland hills east of the Hayward Fault. Contra Costa College 

(CCC) straddles the fault along the break in slope just to the northeast of the symbol location for San 

Pablo. 

Figure 118. Berkeley from the 1895 San Francisco 15’ quadrangle. 

Figure 119. This satellite view shows that the California Memorial Stadium next to the University of 

California, Berkeley, bisected by the Hayward Fault in the northeast corner of the image. 

Figure 120. The Lake Temescal and Berkeley Hills area from the 1897 Concord 15’ quadrangle map. 

Figure 121. The modern satellite image shows the route of Highway 24 through the Caldecott Tunnel. 

Figure 122. The Oakland Hills area from the 1897 Concord 15’ quadrangle. 

Figure 123. The modern satellite image shows that urban development has expanded nearly to the 

ridgeline of the Oakland Hills. 

Figure 124. The San Leandro area from the 1899 Hayward 15’ quadrangle map. 

Figure 125. Modern satellite view shows that the San Leandro area is now densely urbanized, as is most 

of the alluvial plain of the East Bay region. 

Figure 126. 1899 Hayward 15’ quadrangle map showing that the Hayward area remained relatively 

undeveloped until the beginning of the 20th Century. 

Figure 127. Modern satellite image showing that both the alluvial plain west of the Hayward Fault and the 

hill country east of the fault are now intensely urbanized. 

Figure 128. The villages of Irvington and Mission San Jose are the only significant settlements visible on 

this portion of the 1906 Livermore 15’ quadrangle. 

Figure 129. The City of Fremont now encompasses the alluvial plain west of the Diablo Range. 
viii

Figure 130. Agua Caliente area from the 1899 San Jose 15’ quadrangle shows that the natural South Bay 

wetlands had not yet been disturbed. 

Figure 131. Modern satellite image showing the southern end of the creeping section of the Hayward 

Fault. 
1

Where's the Hayward Fault? A Green Guide to 

the Fault 

By Philip W. Stoffer 

Introduction to this guide 

This field-trip guidebook was compiled to help commemorate the 140th anniversary of an 

estimated M 7.0 earthquake that occurred on the Hayward Fault at approximately 7:50a.m., 

October 21st, 1868. Although many reports and on-line resources have been compiled about the 

science and engineering associated with earthquakes on the Hayward Fault, this report has been 

prepared to serve as an outdoor guide to the fault for the interested public and for educators. The 

first chapter is a general overview of the geologic setting of the fault. This is followed by ten 

chapters of field trips to selected areas along the fault, or in the vicinity, where landscape, 

geologic, and man-made features that have relevance to understanding the nature of the fault and 

its earthquake history can be found. See figure 1 for a location map of field trip destinations. A 

glossary is provided to define and illustrate scientific term used throughout this guide. 

Why a “Green Guide” to the Hayward Fault? A “green” theme helps conserve resources 

and promotes use of public transportation, where possible. Although access to all locations 

described in this guide is possible by car, alternative suggestions are provided. To help conserve 

paper, this guidebook is only available on-line only; however, select pages or chapters (field 

trips) within this guide can be printed separately to take along on an excursion. 

Transportation alternatives 

The discussions below highlight transportation alternatives to visit selected field trip locations. In 

some cases, combinations, such as a ride on BART and a bus, can be used instead of automobile 

transportation.. For other locales, bicycles can be an alternative means of transportation. 

Transportation descriptions on selected pages are intended to help guide fieldtrip planners or 

participants choose trip destinations based on transportation options, interests, or special needs 

(see below). 

San Francisco Bay Area Rapid Transit District 

BART provides rail access to San Francisco and throughout the East Bay region, with links to 

other metropolitan air, rail, and bus services. Most field trip locations described in this guide are 

easily accessible by BART, or a combination of BART and an AC Transit metro bus. Figure 4 

shows the proximity of the Hayward Fault to the Bart rail system to field trip sites. Visit 

www.bart.gov for more information about BART stations, schedules, and fares. With station 

stops fairly evenly distributed throughout the East Bay's piedmont urban corridor, BART 
2

provides close access to many locations along the Hayward Fault. Each field trip destination map 

describes where the most convenient BART service is provided. BART Transit Connection Maps

are available both online and as brochures in most stations. The field trips closest to BART 

stations are in downtown Hayward and downtown Fremont. 

Alameda-Contra Costa Transit District 

AC Transit provides bus service throughout the Alameda and Contra Costa Counties 

metropolitan region with links to other regional transportation hubs (air, rail, and bus). Visit 

www.actransit.org for information about routes, connections, schedules, and fares. AC Transit 

provides convenient connection to BART stations. Bus service is described with each destination 

map where convenient service is located; walking distances greater than about a mile to the 

closest BART station are noted. 

Bicycle Access 

Bicycle access to locations along the Hayward Fault can be an alternative to driving. San 

Francisco Bay Area bicycle routes and information can be found online at http://511.org. Bikes 

are allowed on most BART trains (see the BART website for exceptions and rules). All AC 

Transit buses have bike racks that can accommodate two bicycles. Some of the locations 

described in the field trip destination map pages are either not easily accessible by BART or AC 

Transit buses alone, but access is possible by bicycle (or car). Note also that some locations 

described herein may be strenuous and require long uphill and downhill rides (such as along the 

Skyline Drive in the East Bay Hills—a very popular biking destination). Safety is always a 

concern when riding bicycles in unfamiliar places. Bike route information is provided if 

locations along the fault are on or near established bike routes. 

Hiking Access 

Some walking is required to all destinations along the Hayward Fault, but some destinations 

require more significant distances to walk to see all the sites recommended. The Hayward Fault 

passes through a variety of landscape terrains (hilly, forested areas to flat urban landscapes). A 

hiking symbol is included if recommended field trip destinations require more than a mile walk, 

or if trailheads to parkland are accessible along the route. 

Wheelchair Access 

Wheelchair access to locations along the Hayward Fault is possible in some locations near 

BART and AC Transit stops. Wheelchair access to the fault may be best at Contra Costa College 

campus, Monclair Village, downtown Hayward, some locations in downtown Fremont, and 

Mission San Jose. 

Automobile Access 

All field trip locations along the Hayward Fault are accessible by automobile. Some locations 

described in this report are not accessible with public transportation and bicycle access may be 

too strenuous or time consuming. However, these sites are included because they may be of 

interest when planning a field trip or they are important to help understand the significance of the 

Hayward Fault. To go green, take someone with you, and plan your route in advance. Field 

trip planners for school or special interest groups may save time and resources by contracting a 

charter van or bus service. For instance, AC Transit will provide access to groups of 20 or more 
3

to Chabot Space & Science Center with advanced reservations. The Oakland Zoo also has 

discount rates for large groups.

Take a virtual tour of the Hayward Fault 

All the photographs in this guidebook can be viewed online on a companion website at 

http://3dparks.wr.usgs.gov/haywardfault. The website contains larger format versions of the images 

with interpretive information presented in this guide, the same images without interpretive 

information, and 3D photographs—images that require red-and-cyan 3D viewing glasses to get 

the stereographic effect. All images on the website are ideal for online viewing, printing, or 

projecting, such as in a classroom Powerpoint presentation. A WWW search on “3D glasses” 

will yield many distributors of red-and-cyan viewing glasses, ranging from simple, inexpensive 

paper-frame glasses to high-end frame glasses with glass lenses. 

Which trip would be best to go on? 

The answer varies depending on your interests, time limits, and abilities. Suggestions are as 

follows. 

If you have children: The best place, without a question, would be to go to the Oakland Zoo. 

There is a Hayward Fault exhibit in the Children’s playground area within the zoo. Other good 

options with children would be to visit Monclair Village where there is a children’s playground 

in the recreation center (park) just north of downtown. You could also have lunch downtown. In 

Fremont, next to the BART station is the Tule Pond Preserve that has children-oriented 

programs. A picnic in Memorial Park in Hayward or Central Park in Fremont would also be 

good options for children. 

If you want to see fault-related impacts on infrastructure: The best place to see impacts on 

infrastructure is in downtown Hayward where many features can be observed in a relatively 

small area. It is easy to get to downtown Hayward from BART and a walk along the fault 

between Memorial Park to the corner of Rose Street and Prospect Street, and return, is a little 

more than two miles. On foot, this might take several hours if you include visits to the Hayward 

Historical Society Museum and include a lunch stop at a restaurant along the route. To the north, 

another good choice would be the Contra Costa College trip, but go there only on a weekend or 

when classes are not in session. Both Monclair Village and Fremont Central Park trips offer good 

views of offset curbs and walls. 

The easiest trips using mass transit: The Hayward and Fremont trips are closest to BART 

stations. Most of the others would require taking a bus or riding a bike. The trip to the Oakland 

Hills is really not an option with mass transit. Also, the trip to Buena Vista Island and Treasure 

Island is really only suited for automobile travel with crossing the Bay Bridge as part of a 

scheduled trip. 

If you want to ride a bike: The Berkeley area would be a good choice, especially if you are 

willing to tackle the ride up to the ridgeline of the Berkeley Hills. In the South Bay, a bike tour 

through the neighborhoods between Mission San Jose and Arroyo Caliente Park would be a 

moderately easy and scenic ride. 

If you want a scenic hike: All the trip destinations could be turned into hikes, but most would 

be in urban residential settings. Point Pinole Regional Park has many miles of scenic trails, as do 

Tilden, Claremont Canyon, Sibley Volcanic, and other parks and preserves in the Berkeley Hills. 

An easy, scenic walk would be around Lake Temescal. A very popular, long (strenuous) hike in 

the South Bay is to the top of Mission Peak (near Mission San Jose). 
4

Best places to see “geology”: Rocks and landscape features are best seen at Point Pinole along 

the shoreline and in outcrop locations throughout the Berkeley Hills. 

Figure 1. Locations of selected field trip destinations to observe features associated with the 

Hayward Fault. Locations were chosen based on public access, and some locations discussed highlight 

regional geologic features, historic buildings, or infrastructure. General locations of field trip destinations, 

shown as green boxes, are projected on a satellite image (modified from USGS Quaternary earthquake 

fault data and imagery retrieved from Google Earth). 
5

Chapter 2—Introduction to the Hayward Fault 

Although over time regional inhabitants had known about or experienced many earthquakes, the 

Hayward Fault “introduced itself” to the modern world in the form of the 1868 Hayward 

earthquake. The 1868 earthquake was originally called the Great San Francisco earthquake prior 

to the 1906 earthquake on the San Andreas Fault. The name, Hayward Fault, wasn’t applied until 

A.C. Lawson used the term in his 1908 report to the new California Earthquake Commission 

after the 1906 San Francisco earthquake. 

Figure 2. Location of the Hayward Fault. Fault systems in the San Francisco Bay region are shown on 

a satellite composite image modified from Google Earth. Faults that have had major earthquakes in 

historic times (since 1776) are shown in red. Fault that display movement or earthquake history in roughly 

the last 10,000 years (Holocene Epoch) are shown in orange. Older faults that display evidence of having 

activity in the last 2 million years (Quaternary Period) are shown in yellow. Fault data from Graymer and 

others (2006).

The Hayward Fault is a major earthquake fault that runs for nearly 50 miles (70 km) through the 

East Bay of the San Francisco Bay region (fig. 2). The fault and the associated greater system of 

Bay Area faults, have been known to generate great earthquakes in the past and will continue 

doing so in the future. For its length, the Hayward Fault has probably been studied more than any 

fault in the world. And for good reason—the Hayward Fault is a known killer. The fault runs 

through, or near to, some of the most densely urbanized areas in North America. These areas also 

support a large portion of California's economy—the region encompassing the fault is host to a 

maze of transportation, energy, water, telecommunications, waste disposal, and emergency 

infrastructure that supports millions of people (figs. 3 and 4). 
6

Figure 3. Earthquake map of the Hayward Fault and surrounding region. (Map modified from Sleeter 

and others, 2004). The map shows the epicenter and magnitude for earthquakes between 1970 and 

2003. The epicenter of the estimated magnitude 7.0 earthquake in 1868 was probably in the Hayward or 

Fremont area, but the surface rupture extended from Fremont to Berkeley (see USGS Earthquake 

Hazards Program, 2007). The red star shows an educated guess about the epicenter for the 1868 

earthquake (no reliable record of the earthquake exists from that period). The yellow star shows the 

location of the recent M 5.4 Alum Rock earthquake of October 30, 2007 on the Calaveras Fault (near 

where it merges with the southern end of the Hayward Fault system). 
7

Figure 4. 1868 Hayward Earthquake Shaking Intensity Map with the BART System. The map of the

of the San Francisco Bay Region shows the location of the BART rail system, the location of the Hayward 

Fault, and the earthquake shaking intensity from the USGS 1868 Hayward earthquake shakemap. The 

BART system is a useful indicator of the intensely urbanized corridor of the East Bay region relative to the 

location of the fault. For more information about the 1868 Hayward earthquake and its shakemap, see 

USGS Earthquake Hazards Program, 2007. 
8

The Hayward Fault has a long and complex geologic history, and the character and history of the 

fault is continuously debated. Like almost all major earthquake faults in the San Francisco Bay 

region, the Hayward Fault is a right-lateral strike-slip fault, with the western side of the fault 

moving northward relative to the eastern side. The modern "Hayward Fault" is perhaps tens of 

millions of years old, but also is imprinted on older fault systems that formed millions of years 

earlier. Rocks of many ages and compositions are found along the fault—some of them are "far 

traveled" by the cumulative movements associated with the plate-tectonic evolution of western 

North America. The East Bay fault system (which includes the Hayward Fault) has accumulated 

as much at 107 miles (175 km) of right-lateral offset in the last 12 million years. Of this total, the 

Hayward Fault is responsible for about 60 miles (100 km) of the offset, with 36 miles (60 km) 

having occurred in the past 6 million years (Graymer and others, 2002). 

The southern end of the Hayward Fault is complex. At depth in the region south of Fremont, the 

Hayward Fault merges with the central Calaveras Fault. In this region, the fault plane of the 

Hayward Fault dips gently at the surface but grows increasingly steeper with depth (determined 

on the basis of seismic and other geophysical data—see the geologic block diagram and cross 

section at Mission Peak near Fremont, figs. 5 and 6). Farther north, the plane of the Hayward 

Fault is steeper, approaching nearly vertical in profile (see the cross sections near San Leandro, 

Berkeley, and Richmond, fig. 6). At Point Pinole Regional Shoreline, the Hayward Fault runs 

offshore beneath San Pablo Bay. Beneath San Pablo Bay, the Hayward Fault probably merges 

with other fault systems in the North Bay, possibly the Rodgers Creek Fault. 

A Creepy Fault: In earthquake terminology, creep is the slow, more or less continuous 

movement occurring on faults due to ongoing tectonic deformation that does not happen during 

major earthquakes. The Hayward Fault is actively moving, year-by-year. This is unlike other 

earthquake faults in the region that are locked between major earthquakes (like the San Andreas 

Fault in the Santa Cruz Mountains, San Francisco Peninsula, and north of the Golden Gate), or 

faults that are inactive or typically ancient faults that are no longer active. Detailed U.S. 

Geological Survey (USGS) investigations into movements along the Hayward Fault show the 

fault creep averages about 0.2 in (5 mm) per year. However, this creep occurs at different rates 

and in different locations and can also vary significantly from one year to the next. Just as creep 

is an observable surficial phenomenon, fault motion is also taking place at different levels in the 

earth extending downward to the base of the brittle crust—roughly 8 miles (12 km) in the San 

Francisco Bay region. 

Just as surface creep varies, motion rates at depth vary as well. Some areas-at-depth along the 

fault zone may be temporarily locked whereas other locations are gradually moving. When 

stresses build up in the locked portions the fault will eventually rupture, or break, releasing 

energy in the form of an earthquake. Small, almost imperceptible earthquakes happen daily along 

the Hayward and other Bay Area faults. Larger (and fortunately, less frequent) earthquakes 

typically occur deeper in the crust or when larger locked sections of the fault yield to rupture. For 

more information about earthquakes and current earthquake activity in the region, check out the 

USGS Maps of Recent Earthquake Activity in California-Nevada

(http://quake.usgs.gov/recenteqs/latestfault.htm). 
9

 

Figure 5. Geologic block diagram. This diagram 

shows generalized surficial geology with a cross 

section that shows the geologic interpretation at 

depth perpendicular (northwest to southeast) to 

the Hayward Fault (viewed toward the northwest). 

The cross section cuts through Mission Peak near 

Fremont (on the right) and crosses the south end 

of San Francisco Bay near San Jose and 

Mountain View (on the left). This cross section 

shows that at its south end the Hayward Fault dips 

moderately to the northeast, steepening as it 

merges with the central Calaveras Fault at depth 

(in the foothills of the Diablo Range east of San 

Jose in the vicinity between Alum Rock Park and 

Mount Hamilton). The "creeping" portion of the 

Hayward Fault system is shown in red. Note that 

the vertical scale is exaggerated about 2 times the 

horizontal scale. The cross section on the face of 

the block diagram is about 10 miles wide (15 km). 

The image was generated from a USGS 3D 

geologic map of the Hayward Fault zone.
10

Figure 6. Cross sections along the Hayward Fault (see 

legend information on Fig. 5). These four block diagrams 

show geologic cross sections perpendicular to the Hayward 

Fault with a draped image of the land surface (modified from 

Google Earth). The view for all figures is towards the 

northwest. The character of the fault and subsurface rocks 

are interpreted from USGS geologic and geophysical data. 

The "creeping" portion of the Hayward Fault is shown in red. 

Note that the vertical scale is exaggerated about 2 times the 

horizontal scale. The cross sections on the face of the block 

diagrams are about 10 miles (15 km) across. 

A. Mission Peak area (cross section south of Fremont). 

The cross section cuts through Mission Peak near Fremont 

(on the right) and crosses the south end of San Francisco 

Bay near San Jose and Mountain View (on the left). It 

shows that at the south end of the Hayward Fault, the dip 

angle flattens out near the surface (along the mountain 

front). To the south, the fault becomes a series of 

interconnecting low angle faults that merge eventually with 

the central Calaveras Fault (in the foothills of the Diablo 

Range east of San Jose in the vicinity between Alum Rock 

Park and Mount Hamilton). 

B. San Leandro area (cross section between Hayward 

and Oakland). The cross section cuts through the East Bay 

Hills (on the right) and the East Bay alluvial plain next to 

San Francisco Bay south of Oakland (on the left). By 

comparison to the Mission Peak area, the Hayward Fault in 

the San Leandro area has a nearly vertical profile. East of 

the Hayward Fault, a structural basin preserves a thick 

accumulation of Great Valley Sequence. West of the fault, 

the San Leandro Gabbro (Jgb) is a large intrusive igneous 

body that has unique physical properties compared to the 

Franciscan rocks (mostly volcanic and sedimentary rocks) 

or the Great Valley Sequence (sedimentary rocks). Gabbro 

is physical properties more like granitic rocks—being both 

harder and more brittle than sedimentary rocks. Geologists 

suggest that that where the Hayward Fault is in contact with 

the gabbro, it may be more prone to producing higher 

magnitude earthquakes than in surrounding areas. 

C. Berkeley area cross section. The cross section cuts 

through the Berkeley Hills (on the right) and the East Bay 

alluvial plain in the vicinity of the Bay Bridge (on the left). By 

comparison to the San Leandro area to the south, the body of San Leandro Gabbro pinches out to the 

north, and the Great Valley Sequence (east of the Hayward Fault) comes in contact with Jurassic 

ophiolite (mostly serpentinite) and Franciscan Formation rocks (mostly metabasalt, chert, and sandstone). 

D. Richmond area cross section. The cross section cuts through the north end of Berkeley Hills (on the 

right) and the East Bay alluvial plain just south of Point Pinole (to the left). 
11

Observing the Hayward Fault

The selected field trip destinations described in this report include access to the fault in public 

places in regional parks, college campuses, public institutions, or in urban areas where features 

can be accessed from streets, sidewalks, or parking areas. Some of the selected destinations 

described in this report are not on the Hayward Fault. However, they are included because they 

provide information about the regional geology and geologic history, landscape features, or 

important infrastructure or historical sites that share a heritage with the earthquakes and creep 

history associated with the Hayward Fault. Fault research requires studying landforms from 

predevelopment photographs and research of historical maps and records—which may be 

difficult to acquire even if they exist—and then digging of trenches to verify that faults exist in 

the subsurface (if the ground hasn't already been disturbed by previous excavation). Maps of the 

[known] traces of the Hayward Fault system have been published by the California Geological 

Survey in a map series called the Alquist-Priolo

Fault and landscape features Places where best to see them 

Offset curbs, sidewalks, and walls Contra Costa College, Berkeley Memorial Stadium, 

Monclair Village, downtown Hayward, and Fremont 

Central Park area 

En echelon cracks Contra Costa College, downtown Hayward, Arroyo Agua 

Caliente Park (South Fremont) 

Fault scarps Point Pinole, Hayward 

Sag Ponds Lake Temescal (Berkeley), Tule Lake and Lake Elisabeth 

(Fremont) 

Linear valleys, shutterridges Lake Temescal, Hayward, views from Oakland Hills 

Landslides Point Pinole, Mission San Jose (Mission Peak landslide) 

Cultural or historic features 

Historic buildings from 1868 era Downtown San Leandro, Mission San Jose 

Museums and exhibits Mission San Jose, Tule Pond, Hayward Area Historical 

Society Downtown Museum, Oakland Zoo 

Field trips to examine the Hayward Fault show the relationships of the fault to the landscape that 

it has created. Large geomorphic features associated with fault systems, such as rift valleys and 

linear mountain fronts, may be easy to observe from a distance. However, many of the features 

that can be observed up close along the fault trace are subtle and may not be recognizable 

without guidance. Features such as cracks in pavement or sidewalks occur practically 

everywhere, and most form from ground settling after construction. In some cases, offsets in 

sidewalks and curbs are generated by rapid tree growth or the natural down-slope movement of 

soil and rock rather than by the slow movements associated with creep along a fault. Also, the 

idea that a fault can be drawn as a simple narrow line on a map is often different from what can 

be observed on the ground. Fault traces can be complex—on a map scale they may appear as a 

line, but up close they may appear complex because of the variable physical properties of 

surficial materials (such as asphalt, concrete, buildings, soil, bedrock, etc.). Note that the term 

creep is also used to describe the movement of soil and landslide deposits. Faults and landslides 

produce many similar landscape features and may occur together. However, fault movement is 

caused by stresses from tectonic forces in the crust, whereas landslides are surficial processes 

that move materials down slope under the force of gravity. 
12

A fault trace can change over time—measured in periods of thousands to millions of years. The 

trace of a fault may evolve, split, move to a more "convenient" (easier to rupture) location, or 

even be absent due to local bedrock conditions. Meanwhile, erosion is competing with the 

tectonic forces that are moving one side of the fault versus the other, or uplifting in one area 

while sinking (subsiding) in another. Over long periods of time, the impact of movement along 

the East Bay fault system has also resulted in the uplift of mountains (the Berkeley, Oakland, or 

East Bay Hills). Meanwhile, both surficial erosion and sediment deposition, and sea level 

changes (associated with the formation and melting of continental ice sheets), have impacted the 

surface of the land between what is now the hills (to the east) and the bay (to the west). For most 

of its length the Hayward Fault crosses (and offsets) old alluvial fans descending from the hills 

onto a gentle sloping surface (locally called the Piedmont) before merging with the bays. Yearby-year, and millennium-by-millennium, streams have carved channels down the slope and 

across the trace of the fault. Likewise, the fault has continued to move, either by slow-moving 

surface creep or the sudden jump during a major earthquake every century or two (1-2 meters 

offsets are typical during great earthquakes). These competing forces, tectonics versus erosion, 

have gone on in the past and will continue into the future and have created many of the landscape 

features along the trace of the fault. 

The critical factors are when, where, what, and how a major earthquake on the Hayward Fault 

will impact the San Francisco Bay Area. Worst-case scenarios are dire, and negative impacts will 

affect the entire nation's economy and social fabric as well as those of the Bay Area. The most 

likely scenario is a repeat of an earthquake like the 1868 earthquake that ruptured a significant 

portion of the Hayward Fault (from Fremont to Berkeley). Scientists suggest that the Hayward 

Fault and the Rodgers Creek Fault in Sonoma County (north of San Pablo Bay) are probably 

interrelated, although their trends are offset by several miles in map view. When asked, many 

scientists who have studied the Bay Area fault systems agree that one of the worst-case scenarios 

for an earthquake in the Bay Area would be if the Hayward and Rodgers Creek faults were to 

rupture at the same time. 

The recent Alum Rock earthquake of October 30, 2007 (8:05 p.m.) occurred near the junction of 

the Hayward and Calaveras Faults. The earthquake struck about seven miles east of the city of 

Milpitas. The moderate earthquake had a magnitude of 5.4 and ruptured at a depth of five miles. 

This moderate earthquake resulted in minor damage throughout the San Jose and southern East 

Bay region and briefly received much media attention. However, the Alum Rock earthquake was 

miniscule compared to the potential for a great earthquake on the Hayward Fault or other major 

faults in the San Francisco Bay Area. 

The most recent great earthquake on the Hayward Fault occurred in 1868, and the estimated 

frequency of the past five major earthquakes is, on average, about every 140 years (USGS 

Earthquake Hazard Program, 2007). Simple math illustrates that we are due, almost overdue, for 

another major earthquake on the Hayward Fault. While the date, duration, magnitude, and 

regional impact of such an earthquake are speculative, its occurrence is exceedingly probable 

(USGS Earthquake Hazard Program, 2003). We cannot prevent it from happening so 

earthquake preparedness is essential. See the USGS Earthquake Preparedness website: 

<http://quake.usgs.gov/prepare/prepare.html>.) 
13

Chapter 3 - Point Pinole Regional Shoreline 

Figure 7. Trace of the Hayward Fault at Point Pinole Regional Shoreline, Bay Area, California. 

Cameras designate photograph locations; purple numbers indicate figure references.

What to look for: Point Pinole is an excellent location to observe how global climate change 

and earthquakes have impacted the San Francisco Bay Area landscape. The effect of the 1868 

Hayward Fault earthquake on the Pinole area is unknown because this area was largely unsettled 

in 1868 when the land was still divided into large ranchos (ranches). The Point Pinole area has a 

rich history, best noted for an eighty-year period (1880-1960) when it was home to four 

explosives manufacturing companies (nitroglycerin and dynamite). During this period, the area 

was kept isolated from the public. 

At Point Pinole, USGS investigations suggest that the fault continues northward under the San 

Pablo Bay. The fault runs along the base of a northwest-trending linear slope that at the downhill 

end intersects Parchester Marsh. The fault extends offshore near the northern end of low bluffs 

created by coastal erosion. Although the fault is covered by soil and landslide debris from the hill 

slope (scarp), complex fault-related structures in patches of bedrock can be seen along the 

shoreline during low tide. Within the Pinole Point Regional Shoreline, the Bay View Trail along 
14

the western shore of the park provides the best views of the landscape features associated with 

the Hayward Fault. 

The fault is responsible for uplift of the landscape, while coastal erosion is wearing it away. As 

little as 10-15 thousand years ago the San Pablo and San Francisco Bays did not exist when sea 

level was about 350 feet (100 meters) lower during the peak of the last Ice Age. At that time, 

Point Pinole would have been a forested ridge above a gradual sloping plain that descended to 

the Sacramento River, which flowed in its channel about a mile north of the current shoreline. 

The river flowed through the Golden Gate and perhaps another 30 miles (50 km) to the west 

before it entered the Pacific Ocean. Since that time, close to 100 large earthquakes have occurred 

on the Hayward Fault, and the earth on the west side of the fault has moved northward perhaps 

hundreds of feet relative to the east side of the fault. 

Access Options 

 BART: The closest BART station (about 3 miles) is the Richmond terminal at West 

Barnet Avenue. 

AC Transit: The AC Transit line #71 serves Point Pinole daily and connects with both the 

Richmond and El Cerrito Del Norte BART stations (see www.511.org for details for bus 

schedules). The AC Transit line #71 also serves the Contra Costa College field trip area (Chapter 

3). 

Bike: The Park is about 3 miles from the Richmond BART station. Bicyclists should 

examine possible routes on a street map and should be extra cautious when riding during peak 

traffic hours on busy street routes. 

 Hike: Point Pinole Regional Shoreline has more than 12 miles of hiking trails. Park 

brochures with trail maps (showing the fault trace) and park-access shuttle information are 

available in the parking area. The Bay View Trail along the western shore of the park provides 

the best views of the landscape features associated with the Hayward Fault. The hike to the 

location where the fault runs offshore is a little more than a mile from the trailhead. The trails are 

dirt and gravel and are not accessible to typical wheelchairs. 

Car: From I-80 in Richmond, take the Richmond Parkway exit and go west toward 

San Francisco Bay. Cross San Pablo Avenue and take the Point Pinole/Giant Highway exit. Turn 

right (north) at Giant Highway. Continue north and cross the railroad tracks. The park entrance is 

on the left past the railroad tracks. There is currently a $6 daily state park parking fee. 
15

Figure 8. Commuter train in the vicinity of 

the Hayward Fault in Point Pinole 

Regional Shoreline. This view looks south 

toward Richmond from a park trail 

overpass near the Point Pinole Regional 

Shoreline trailhead parking area (and AC 

Transit metro bus stop for the park). The 

bridge is on a hillslope (fault scarp) of the 

Hayward Fault (trace shown by red line). 

Parchester Marsh adjacent to the Bay is 

on the right (west) side of the rail line. 

Figure 9. View south from the Pinole Point 

Trail toward the hillslope escarpment (left) 

of the Hayward Fault. The fault runs 

across the break in slope where it meets 

Parchester Marsh (on the right). 

Figure 10. View looking north along the 

shoreline near where the Hayward Fault 

trace vanishes beneath the waters of San 

Pablo Bay. Complex small-scale fold- and 

fault-related structures can be observed in 

the bedrock between gravel and sand 

deposits. Wave erosion along the 

shoreline undercuts the hillslope, causing 

landsliding along the scarp of the 

Hayward Fault. 
16

Chapter 4 - Contra Costa College 

Figure 11. Trace of the Hayward Fault in the Contra Costa College area in Richmond, California. 

Cameras designate photograph locations; purple numbers indicate corresponding figures.

What to look for: Contra Costa College campus straddles the Hayward Fault and displays 

abundant evidence of active creep along the fault zone (offset curbs and cracks in pavement). El 

Portal School (now abandoned) is adjacent to the campus and displays creep damage to the 

building and sidewalks. This area was little developed at the time of the 1868 Hayward 

earthquake. 

Access Options 

BART: The Richmond BART Station is the closest to the community college campus, 

about 2 miles away. 

AC Transit: The AC Transit line #71 runs between the Richmond BART Station and the 

community college campus. AC Transit: The AC Transit line #71 also serves Point Pinole and 

connects with El Cerrito Del Norte BART Station farther south (see www.511.org for details of 

bus schedules). 
17

Bike: The City of Richmond is actively developing bike routes throughout the area. Contra 

Costa College is about two miles from the Richmond BART Station. 

Hike and wheelchair access: Once on the community college campus it is a short 

and easy walk to see features associated with the creeping fault. Both the El Portal School and 

the community college provide easy access for wheelchairs. 

Car: Parking can be an issue when the college is in session, but it is relatively easy 

to find parking on the weekends. 

Figure 12. Offset curb along the Campus 

Circle parking area on the north side of 

the campus of Contra Costa College. 

Note that this offset curb shows 

displacement that is left lateral (not right 

lateral—see strike-slip fault defined in the 

Glossary). Displacements that are 

atypical of the fault motion may reflect 

complex ground motion, rotation of 

surface blocks, or may not even be fault 

related (for example, such a displacement 

can be caused by a tree growing nearby). 

Figure 13. Rows of bricks offset by fault 

creep on a patio area next to the Campus 

Circle on the north side of the campus of 

Contra Costa College. 
18

Figure 14. Strain and shear from creep on 

the Hayward Fault result in fractures in 

the asphalt of Parking Lot 10 on the 

campus of Contra Costa College. Car 

keys and a standard four- inch wide 

parking stripe are scale. 

Figure 15. Strain and shear from creep on 

the Hayward Fault result in fractures in 

the asphalt of Parking Lot 10 on the 

campus of Contra Costa College. This 

shows how creep produced a series of 

right-stepping en-echelon fractures. This 

view looks south toward the abandoned 

El Portal School. This parking area is 

usually full when classes are in session. 

Figure 16. Free parking is available on the 

Contra Costa College campus in the 

vicinity where the Hayward Fault offsets a 

curb on Castro Street next to the 

abandoned El Portal School. 
19

Figure 17. Creep along the Hayward Fault 

has caused structural damage to the nowabandoned El Portal School located next 

to the Contra Costa College campus. This 

view looks east along the side of the 

building. 

Figure 18. Creep along the Hayward Fault 

has caused structural damage to the nowabandoned El Portal School located next 

to the Contra Costa College campus. This 

view is perpendicular, facing north, 

compared to the view in Fig. 17. 

Figure 19. Creep along the Hayward Fault 

has offset sidewalks near the entrance to 

the now-abandoned El Portal School 

located next to the Contra Costa College 

Campus. 
20

Chapter 5 -Treasure Island and Yerba Buena Island 

Figure 20. Map of the Yerba Buena and Treasure Island area mid span on the Bay Bridge between 

San Francisco and Oakland, California. Purple numbers designate photograph locations. 

What to look for: Yerba Buena Island consists mostly of natural bedrock, whereas Treasure 

Island was constructed of landfill; the two islands are connected by a causeway. Treasure Island 

was created in 1939 for the Golden Gate International Exposition from fill dredged from the Bay. 

A brief stop on the islands is recommended for field trips starting on the San Francisco 

Peninsula. From the islands it is easy to observe earthquake retrofit and replacement operations 

on the eastern span of the Bay Bridge. Views of the Bay Bridge (east and west spans), San 

Francisco, and the Bay are spectacular from the islands. 

Because Treasure Island is built from fill, it experienced extensive liquefaction during the M 6.9 

Loma Prieta earthquake of 1989—and it is expected to again in an anticipated Hayward Fault 

earthquake. Liquefaction occurs during earthquakes where shaking causes loosely consolidated 

sediments that are saturated with water to loose cohesion and become fluid. Once a zone of 

liquefaction occurs, it can cause the surrounding consolidated materials to shift or rupture. Sand, 

mud, and fluids can erupt on the surface along fissures. Areas of intense liquefaction can result in 

extreme damage to the landscape and any building and infrastructure built on those areas. 
21

Access Options 

Most of Yerba Buena and Treasure Islands belong to the U.S. Coast Guard and are inaccessible 

without permission. However, the exits on Interstate 80, about mid span on the Bay Bridge, are 

accessible to the public. Pull offs on the causeway to Treasure Island provide scenic vistas of the 

San Francisco Bay area (including views of the east and west extensions of the Bay Bridge). At 

the time of this writing, the eastern span of the Bay Bridge is under major earthquake retrofit 

construction. 

BART and Muni Bus: The islands are served by a single Muni bus route—the 108 

Treasure Island. The bus route connects to the Trans Bay Terminal at Mission between 1st Street 

and Fremont in San Francisco (between the Embarcadero and Montgomery Street BART 

Stations). 

 The islands are not accessible directly by bicycle from either San Francisco or 

the East Bay. Because most of the two islands are owned and managed by the U.S. Coast Guard, 

there is very limited access to places to bike, hike, or have wheelchair access. 

Car: There are exits to Treasure Island on both directions on Interstate 80 about mid 

way across the Bay Bridge. Use caution when exiting and entering the highway. 

Figure 21. View east toward the 

eastern section of the Bay Bridge 

from Treasure Island. This photo 

taken in late summer of 2007 shows 

the construction of the more 

earthquake resistant design for the 

new section of the bridge. 
22

Figure 22. View east toward the 

eastern section of the Bay Bridge 

from Treasure Island. This photo 

taken in late summer of 2007 shows 

the construction of the more 

earthquake resistant design for the 

new section of the bridge. The 

Hayward Fault runs along the 

western flank of the Berkeley (East 

Bay) Hills near Berkeley and 

Oakland in the distance. 

Figure 23. View looking west toward 

San Francisco at the suspension 

section of the Bay Bridge west of 

Treasure Island. This photo was 

taken in late summer of 2007. 
23

Chapter 6 - U.C. Berkeley and Berkeley Hills 

Figure 24. Location of the Hayward Fault in the Berkeley area, California. Purple numbers designate 

photograph locations. 

What to look for: The University of California Berkeley is the largest employer in the East Bay, 

with 20,000 employees and 30,000 students. The Hayward Fault runs through part of the 

campus. As a result of the 1868 earthquake, starting in the 1870s new buildings constructed on 

the Berkeley campus were designed to be earthquake resistant. Creep along the Hayward Fault is 

responsible for damage to sidewalks, buildings, and infrastructure throughout the Berkeley area. 

The fault is also responsible for a variety of landscape features including scarps, deflected 

drainages, Lake Temescal is in a linear rift valley through which Highway 13 also runs. A trip 

into the Berkeley Hills provides scenic vistas of the urbanized alluvial plain in the Berkeley area 

bisected by the Hayward Fault, a shutterridge adjacent to Lake Temescal, and features of an 

ancient volcanic complex exposed at Sibley Volcanic Preserve and along roadways on Grizzly 

Peak ridge. 

Access Options 

 BART: The Downtown Berkeley and Rockridge BART Stations provide access to AC 

Transit services in the Berkeley area. 

AC Transit: The AC Transit line #7 provides access to many locations on or near the fault 

including California Memorial Stadium and Claremont Hotel. The bus route connects to both the 

Berkeley and Rockridge BART Stations (see www.511.org for details of bus schedules). AC 
24

Transit line #59 and 59A provide access from the Rockridge BART Station to both Lake 

Temescal Regional Recreation Area and the Monclair Village field trip area (Chapter 6). 

Bike: All locations along the fault between U.C. Berkeley and Lake Temescal are an easy 

bike ride. Destinations in the Berkeley Hills, while popular for bicyclists, would be strenuous to 

the casual rider. 

 Hike: The walk between U.C. Berkeley and the Claremont Hotel is about 1.5 miles (2 km) 

in one direction. Shorter round-trip walks (under 2 miles) include the hikes around Lake 

Temescal Regional Recreation Area or Sibley Volcanic Regional Preserve. Longer, more 

strenuous hikes would include treks in Claremont Canyon Regional Preserve or in Tilden 

Regional Park. 

 Wheelchair access: Wheelchair access is difficult at any of the locations in the Berkeley 

area because of the steep grades of the hillslopes. Once in the parking area at the south end of 

Temescal Park, there is wheelchair access to both the cracks in the pavement from fault creep, 

the offset tunnel, and to the shore of the lake (the lake was modified from a natural sag pond 

along the deflected Temescal Creek. 

Car: It is best to leave your car at home if you go to Berkeley, especially when 

school is in session, a ball game is taking place, during rush hour, or when other activities are 

going on in the area (which is usually all the time). A car is necessary to access the parks in the 

Berkeley Hills (Tilden and Sibley Volcanic Regional Parks). 
25

Figure 25. A Google satellite image showing 

the location of the Hayward Fault relative to 

Bowles Hall, California Memorial Stadium, a 

deflected stream (Hamilton Creek) and offset 

curbs on Dwight Avenue. California Memorial 

Stadium was built over another deflected 

stream (Strawberry Creek draining from 

Strawberry Canyon—to the right [east] of the 

stadium). 

Figure 26.The Hayward Fault crosses 

the University of California, Berkeley 

campus. However, with so much 

construction history there is little visible 

evidence on the campus itself. In this 

view, the Hayward Fault is thought to 

run along the slope just behind Bowles 

Residence Hall on the southeast side 

of campus. It grazes the back corner of 

the building (the library), The California 

Memorial Stadium is out of view just to 

the right (south) of this playing field. 
26

Figure 27. View looking south past the 

goal post near the north end of 

California Memorial Stadium. Beyond 

the stadium, the Hayward Fault 

continues south along the base of a 

slope into residential neighborhoods of 

Berkeley. In the stadium, the fault runs 

through the playing field and through 

the section of seats (section KK) in the 

distance to the right of the goal post. 

Figure 28. California Memorial Stadium 

straddles the Hayward Fault and its 

walls display visible structural damage 

as a result of slow creep along the fault 

trace. This crack in the wall is near the 

north entrance to the stadium, close to 

the photograph of the goal post shown 

in the previous image. Similar cracks in 

walls can be seen in many locations 

within the stadium. 

Figure 29. Offset of the rim wall of 

California Memorial Stadium produced 

by creep along the Hayward Fault. This 

photo is of an offset cement wall in 

section KK, row 64; the offset of about 

7 inches (18 cm) is between seats 22 

and 23. 
27

Figure 30. View of the offset outer wall 

on the south side of Berkeley Memorial 

Stadium in section KK where damage 

to the stadium by the creeping 

Hayward Fault is most obvious. 

Figure 31. View looking west along a 

broken-up sidewalk on Dwight Way 

near Hillside Avenue in Berkeley. The 

surface trace of the Hayward Fault is 

complex at this location. 

Figure 32. One of the offset curbs 

where Dwight Way in Berkeley crosses 

the Hayward Fault. 
28

Figure 33. View looking east up 

Tanglewood Path just downhill of the 

intersection of Stonewall Road (near 

the Claremont Hotel in Berkeley). The 

pathway has been heavily damaged by 

both mass wasting on the hillslope and 

by creep along the Hayward Fault. 

Figure 34. Trailhead to Claremont 

Canyon Regional Preserve near the 

intersection of Tanglewood Path and 

Stonewall Road (near the Claremont 

Hotel in Berkeley). The trace of the 

Hayward Fault is just downslope of the 

trailhead. The steep slope is part of the 

scarp of the Hayward Fault. 

Figure 35. The Claremont Hotel. The 

Hayward Fault passes near the 

southeast corner of the building and 

runs along the base of the slope near 

the tall eucalyptus trees on the far side 

of the building in this view. 
29

Figure 36. The Hayward Fault runs 

through the parking lot and beneath the 

corner of the building (on the right side 

of the photograph) near the south 

entrance to the Claremont Hotel. 

Figure 37. Fractures in the asphalt of 

the Claremont Hotel parking lot are 

probable evidence of surface 

movement associated with the 

Hayward fault. This fracture between 

cars in valet parking displays evidence 

of pull-apart (tension) offset. The 

mapped trace of the fault is in the 

parking lot behind and above these 

cars (also visible to the right in fig. 36). 
30

Figure 38. A Google Earth image map 

showing the location of the Hayward 

Fault and associated features in the 

Lake Temescal area. The Buena Vista 

neighborhood is on the shutterridge on 

the west side of the fault at Lake 

Tamescal. Highway 13 runs south from 

the intersection of Highway 24 down 

the rift valley of the Hayward Fault for 

much of its route. Temescal Lake was 

built during 1866 and1869 by damming 

Temescal Creek, which happens to be 

offset more than 1.5 miles (2 km) rightlaterally by the fault. The ridge to the 

west blocks the outflow of the creek, 

but the blockage is caused by the large 

displacement and the slowing of the 

stream by the reduced gradient along 

the fault, and probably not by 

"sagging". 

Figure 39. View of Lake Temescal from 

the north. The active trace of Hayward 

Fault runs along the eastern shore of 

the lake. The lake is a modified sag 

pond along the straight valley of 

Temescal Creek. 
31

Figure 40. Cracks in the pavement 

reveal the trace of the creeping 

Hayward Fault at Lake Temescal 

Regional Recreation Area. This view 

shows the location of the cracks in the 

pavement on Broadway adjacent to the 

north end of the park. Cracks also can 

be seen in the retaining wall of 

Highway 24 where it crosses the fault. 

Figure 41. En echelon fractures from 

creep along the Hayward Fault in the 

pavement in front of the Park Office in 

Lake Temescal Regional Recreation 

Area. The Park Office is located near 

the south end of the lake. 

Figure 42. View looking north at the 

entrance to an old railroad bridge 

tunnel in Temescal Regional 

Recreation Area. The tunnel displays 

evidence of creep from movement 

along the Hayward Fault. The tunnel is 

at the south entrance to the park on 

Broadway Terrace near the 

intersection with Highway 13. The 

tunnel was probably constructed 

around 1918 for the Sacramento 

Northern Railway, a subsidiary of the 

Western Pacific Railroad, and was an 

electric train system that linked the 

state capitol in Sacramento with 

Oakland until train service ceased in 

1983. 
32

Figure 43. View of an offset curb and 

crack in the side of the old railroad 

bridge tunnel near the south end of 

Lake Temescal Regional Recreation 

Area (the tunnel is also shown in fig 

42). 

Figure 44. View southwest from an 

overlook on Tunnel Road near 

Highway 24 near where it crosses the 

Hayward Fault. Homes occupy the top 

of the forested shutterridge on the west 

side of the Hayward Fault rift valley. 

The Bay Bridge and San Francisco are 

visible in the distance. The overlook 

has exhibits commemorating the 

Oakland Hills Firestorm of 1991. The 

fire killed 25 people and injured 150 

others. The fire consumed or damaged 

2,843 single-family dwellings and 437 

apartment and condominium units and 

burned an estimated 1,520 acres (6.2 

km2). 

Figure 45. View southwest across 

Highway 24 toward the PG&E 

Claremont Substation near Lake 

Temescal. The tree-covered slope 

beyond the electrical power station is 

on the west side of the Hayward Fault 

rift valley incised by Temescal Creek. 

Downtown Oakland is in the distance. 

The tree-covered ridge is a 

shutterridge ("shutting in" and diverting 

Temescal Creek). Lake Temescal is to 

the right of this view taken from Tunnel 

Road, north of Highway 24. The 

neighborhood of Buena Vista is built on 

the shutterridge west of the Hayward 

Fault rift valley. 
33

Figure 46. View of the western portal of 

the Caldecott Tunnel on Highway 24. 

The Caldecott Tunnel cuts through the 

Berkeley Hills. Construction of the 

tunnel began in 1929, and the first two 

tunnel bores were completed in 1937; 

a third bore was completed in 1964. An 

additional bore has been approved for 

construction. The western portal of the 

Caldecott Tunnel is located in 

Claremont Canyon, about one mile 

upstream from Lake Temescal. The 

forested ridge above the tunnel is 

mostly within the Robert Sibley 

Regional Preserve. 

Figure 47. View looking down 

(southwest) into Claremont Canyon 

from near a water storage tank in the 

Berkeley Hills (near the intersection of 

Grizzley Peak Boulevard and 

Marlborough Terrace—the water tank 

is just to the right of this photo).The rift 

valley of the Hayward Fault and the 

shutterridge near Lake Temescal run 

diagonally through the upper part of the 

image. This area was burned during 

the Oakland Hills Firestorm of 1991. 

The western portal of the Caldecott 

Tunnel on Highway 24 is just to the left 

of this view. 

Figure 48. Folded sedimentary rocks 

(ribbon chert of Franciscan Formation 

of Jurassic age) located near the water 

tank and the view in fig. 47. The chert 

is exposed in a cut in the Berkeley Hills 

(near the intersection of Grizzley Peak 

Boulevard and Marlborough Terrace). 

The chert formed from radiolarian ooze 

originally deposited in a deep, marine 

setting far from any source of 

continental sediments. Today these 

rocks help form the ridgeline of 

Grizzley Peak—reflecting the long, 

complex geologic evolution of the San 

Francisco Bay Area landscape. 
34

Figure 49. View looking southwest from 

an overlook area on Grizzley Peak in 

the Berkeley Hills in Charles Lee Tilden 

Regional Park. The view looks down 

the valley of Strawberry Creek 

(Strawberry Canyon). California 

Memorial Stadium is in the lower right. 

The densely urbanized alluvial plain of 

Berkeley and northern Oakland, and 

the Bay Bridge and hills of San 

Francisco are in the distance. The 

Hayward Fault cuts through the 

stadium and runs along the base of the 

forested hillside on the left. Strawberry 

Creek also has a right-lateral offset 

caused by displacement of the stream 

channel along the Hayward Fault. 

Figure 50. View looking west toward 

the Golden Gate from an overlook on 

Grizzley Peak in the Charles Lee 

Tilden Regional Preserve. The City of 

Berkeley is on the alluvial plain at the 

western base of the Berkeley Hills. 

Alcatraz, the Golden Gate Bridge, and 

the highlands of southern Marin County 

are in the distance. The Hayward Fault 

runs along the base of the forested 

slope in the foreground. 
35

Sibley Volcanic Regional Park 

Sibley Volcanic Regional Park preserves the remnant of an old volcano that formed about 10 million 

years ago as the San Andreas Fault System (including the Hayward Fault) formed across the region. The 

fault ruptured through the Earth's crust, allowing magma to migrate to the surface and erupt as volcanoes. 

Volcanic rocks crop out in many places along the Hayward, San Andreas, and other faults in the region. 

Studies of volcanic rocks throughout the region demonstrate that the oldest volcanoes (about 10-18 

million years old) lie to the south of the Bay Area and younger ones exist to the north of San Pablo Bay 

(including the relatively young and active Clear Lake-Sonoma Volcanic Field—less than 5 million years 

old). The study of the volcanic rocks has helped reveal much information about the age of the fault 

system and the rates that the faults have moved through time.

Figure 51. View looking east from Skyline 

Boulevard in the East Bay Hills (east of 

Berkeley) toward Round Top Hill in Sibley 

Volcanic Regional Preserve. The peaks 

on Round Top Hill are the remains of 

ancient volcanic stocks—the underground 

passages or vents that magma flowed 

along to erupt at the surface. Some of the 

magma that cooled to stone in the 

passages (becoming the stocks). These 

rocks are more resistant to erosion than 

the rock formed from ash, cinders, and 

lava flows that accumulated on the flanks 

of the ancient volcanic area. Also note the 

landslide (slump) near the left of center in 

the image.

Figure 52. This display of labeled rocks is 

in front of the kiosk and restrooms at 

Sibley Volcanic Regional Preserve. The 

preserve is host to the remnants of a 

volcano and associated rocks that 

accumulated about 10 million years ago 

and are now exposed by tectonic folding 

and uplift, and erosion. The park features 

about a mile of easy walking trails that 

lead to the stocks of the old volcano. 

Sedimentary rocks (mudstone, sandstone 

and conglomerate) and volcanic rocks 

(basaltic lava and tuff) are exposed along 

the trails. The parking area for the park is 

located a short distance east of the 

intersection of Grizzly Peak Boulevard on 

Skyline Boulevard. The park is not 

accessible via public transportation. 

However, the park is along the Oakland 

#59 bike route that follows Skyline 

Boulevard.
36

Chapter 7 – Monclair Village

Figure 53. Location of the Hayward Fault in the Monclair Village area. Purple numbers designate 

photograph locations. 
37

What to look for: Monclair Village straddles the Hayward Fault along the (appropriately 

numbered) California Highway 13, which runs down the Hayward Fault rift valley north of 

Berkeley. Both the streets and sidewalks display evidence of subtle creep along the fault. The 

Monclair Recreation Center, a small park on the north side of downtown, has offset stonewalls 

next to a modified sag pond formed by the fault. The village has a small-town feel and is a 

pleasant destination for a field trip (you can dine in restaurants right on the fault!). The Monclair 

Village area was unsettled at the time of the 1868 earthquake so damage in the area at that time 

is unknown. 

Access Options 

 BART: Monclair Village is accessible by bus service from the Rockridge BART Station. 

Slightly more distant bus service to Monclair Village is provided from the Oakland City 

Center/12th Street BART Station. 

AC Transit: The AC Transit line #59 and 59A begins at the Rockridge BART station and 

provides service to both Lake Temescal (Berkeley field trip area) and Monclair Village. AC 

Transit line #15 provides service to Monclair Village from the Oakland City Center/12th Street 

BART Station (see www.511.org for details of bus schedules). 

Bike: Monclair Village is about a three-mile bicycle ride (one way) from the Rockridge 

BART Station but the field trip could include a visit to the Lake Temescal area (see Chapter 5). 

 Hike and wheelchair access: From Monclair Village it is a short and easy walk to 

examine evidence of the fault between the intersection of Moraga Avenue and Mountain 

Boulevard and the pond area in Monclair Recreation Center. 

Car: Monclair Village is accessible from Highway 13 at the Moraga Exit about two 

miles south of the interchange with Highway 24. 

Figure 54. This view looks north along 

Moraga Avenue at the intersection with 

Mountain Boulevard in Monclair Village, 

where the Hayward Fault crosses the 

intersection. The fault passes beneath 

the gas station sign and just to the left 

of the gas station building. North of the 

gas station the fault crosses through 

several walls, streets, and buildings in 

the downtown area. 
38

Figure 55. This view looks north along 

the trace of the Hayward Fault where it 

crosses through Monclair Recreation 

Center, a small park just north of 

Monclair Village. The trees are on a low 

shutterridge on the left (west) side of 

the fault (located about where the 

people are standing). 

Figure 56. This broken stonewall is 

along the trace of the Hayward Fault in 

Monclair Recreation Center. The park is 

located just north of downtown Monclair 

Village. 

Figure 57. View along an old damaged 

and repaired wall in the Hayward Fault 

zone in Monclair Recreation Center 

(park). Montclair Park's pond is not a 

sag pond. It was formed artificially 

around 1910 by the construction of a 

railroad fill of the Oakland-Antioch line. 

Passenger service on the rail ended in 

1941, and freight service ceased in 

1957. 
39

Chapter 8 – Oakland Hills

Figure 58. Location of the Hayward Fault in the Oakland (East Bay) Hills area. Purple numbers 

designate photograph locations.

What to look for: This trip highlights landscape features formed by the Hayward Fault in the 

Oakland (East Bay) Hills. The rift valley of the Hayward Fault reflects the long geologic history 

required to uplift the mountains and erode the valleys and canyons draining the upland. 

Imprinted on the landscape is the effect of countless numbers of earthquakes and the steady 

displacement by creep along the Hayward Fault. The rift valley is a result of an increased rate of 

erosion of the fractured bedrock in the fault zone. 

The Oakland Mormon Temple (Church of Jesus Christ of Later-day Saints) is located on Lincoln 

Avenue near the intersection with Highway 13 (Warren Freeway). The temple is perhaps the 

most visible manmade feature along the Hayward Fault. Its location perched on a hilltop 

(shutterridge) along the fault makes it visible from practically anywhere in the San Francisco 

Bay Area on a clear day. Fractures along the fault can be traced on nearby streets and on the 

temple grounds, and the fault crosses through the Interstakes Building next to the main temple. 

This area was unsettled at the time of the 1868 earthquake. 
40

Access Options 

 BART: This trip is not easily accessible from the nearest BART station at Lake Merritt. 

AC Transit: The AC Transit provides limited charter bus service to groups of 20 people 

or more to the Chabot Space & Science Center. Charter bus service can be arranged from starting 

locations, such at the Lake Merritt, McArthur, or Fruitvale BART Stations. (Contact AC Transit, 

or see www.511.org for details about access to the Chabot Space & Science Center). 

Bike: Skyline Boulevard along the Oakland (East Bay) Hills ridgeline is a very popular 

destination for long and strenuous bike rides (not recommended, however, for the casual rider). 

 Hike and wheelchair access: Joaquin Miller Park, Roberts Recreation Area, and 

Redwood Regional Park are all popular hiking destinations in the forested ridgeline near the 

Chabot Space & Science Center. Wheelchair access would be easy to the California Mormon 

Temple from the parking area near the Visitor Center. 

Car: The Oakland Mormon Temple is not accessible from public transportation. The 

temple, parks in the Oakland Hills, and Chabot Space & Science Center are accessible from the 

Lincoln Avenue exit on California Highway 13. 

Figure 59. The Chabot Space & 

Science Center is located along the 

crest of the East Bay Hills on Skyline 

Boulevard, east of Oakland. Skyline 

Boulevard runs along much of the 

ridgeline from the southern Berkeley 

Hills and the East Bay Hills, providing 

exceptional views of redwood and 

mixed evergreen forests and views of 

the San Francisco Bay region.
41

Figure 60. South-facing view from an 

overlook along Skyline Boulevard 

located about 1 mile south of the 

Chabot Space & Science Center in 

Joaquin Miller Park. The view shows 

the rolling upland of the East Bay Hills 

east of Oakland near Merritt College. 

The Hayward Fault crosses the 

western flank of the East Bay Hills in 

the valley beyond the grass-covered 

hill. The highly urbanized alluvial plain 

of the East Bay is in the upper right.

Figure 61. The Oakland Mormon 

Temple (Church of Jesus Christ of 

Later-day Saints) is located near the 

intersection of Lincoln Avenue and 

Highway 13. The pinnacle-like towers 

and massive white granite facade of 

the temple and associated buildings 

are perhaps the most visible landmark 

on the Hayward Fault in the East Bay 

region. The hilltop location of the 

temple provides fantastic views of the 

San Francisco Bay region, as well as 

the rift zone and shutterridges formed 

by the Hayward Fault on which the 

temple buildings and ground were 

constructed.

Figure 62. Fault creep along the 

Hayward Fault may be responsible for 

this offset stairway and wall on the 

northeast corner of the Interstakes 

Building on the temple grounds.
42

Figure 63. View looking west from the 

Oakland Mormon Temple toward 

downtown Oakland with the Bay 

Bridge and San Francisco in the 

distance.

Figure 64. View is looking south from 

the grounds of the Oakland Mormon 

Temple. The Hayward Fault extends 

south across this rolling upland region 

east of downtown Oakland, crossing 

through older established 

neighborhoods before extending 

through the sedimentary cover of the 

alluvial plain west of the East Bay 

Hills in the vicinity of the towns of 

Hayward and Fremont (far in the 

distant right side of this image).
43

Chapter 9 – Oakland Zoo-San Leandro-Fairmont Hospital

Figure 65. Map of the Hayward Fault in the San Leandro-Oakland Zoo-Fairmont Hospital area. 

Purple numbers designate photograph locations.
44

What to look for: San Leandro was one of the most heavily damaged communities in the 1868 

Hayward earthquake. The fault crosses the grounds of the Oakland Zoo and the San Leandro 

Hospital complex. Cracks in the pavement caused by fault creep can be seen in the pavement on 

the road near the entrance to the Oakland Zoo. Recently, part of the San Leandro Hospital 

complex had to be abandoned and dismantled because it was built directly on the Hayward Fault. 

Evidence of the creep can be seen throughout the parking areas on the east and south sides of the 

hospital in the form of offset curbs, fractures in pavement, broken walls, and a scarp. South of 

the hospital, the trace of the fault rises into the western flank of the Oakland Hills east of 

Interstate 580. On Fairmont Drive, the fault offsets a curb and follows a linear valley. The 

historic Alameda County Courthouse and Estudillo House were destroyed and heavily damaged 

(respectively) in the 1868 Hayward earthquake. In the hills, the fault zone has changed the 

course of a stream valley below Lake Chabot Dam. While most of these features can be seen 

without charge, the Oakland Zoo has an entrance fee; the zoo offers group rates and educational 

services. (See figures 67 through 78.) 

Access Options 

 BART: The San Leandro and Coliseum/Oakland Airport BART Station are a bus or bike 

ride away from the Oakland Zoo and Knowland Arboretum Park. The San Leandro and Bay Fair 

BART Stations are roughly the same distance from Fairmont Hospital. 

AC Transit: AC Transit line #98 provides service to the Oakland Zoo and Knowland 

Arboretum Park from the Coliseum/Oakland Airport BART Station. The AC Transit line #82 

and #82 L provide service to Fairmont Hospital from both the San Leandro and Bay Fair BART 

Stations. (See www.511.org for details of bus schedules.) 

Bike: The bicycle ride to the Oakland Zoo and Knowland Arboretum Park from the San 

Leandro Bart station is about 3 miles and could include a visit to the site of the Alameda County 

Courthouse and Estudillo House. The bicycle ride to Fairmont Hospital is about three miles for 

either the San Leandro or Bay Fair BART Stations. The ride up Fairmont Boulevard to the trace 

of the fault would add an additional two miles to the trip. 

 Hike and wheelchair access: All locations at either the Oakland Zoo or the 

Fairmont Hospital are an easy walk and would also be accessible by wheelchair. A hike through 

the Oakland Zoo and Knowland Arboretum Park would be easy and enjoyable. 

Car: Both the Oakland Zoo and Knowland Arboretum Park and Fairmont Hospital 

are close to exits on I-580 and have ample parking. 
45

Figure 66. Offset curb in the lower 

parking lot access road near the 

Oakland Zoo Education Center 

entrance close to the park entrance 

station.

Figure 67. Display about the Hayward 

Fault in the Children's Playground in 

the Oakland Zoo. The fault runs past 

the otter tank and through a bear pen 

(in the distance beyond what is visible 

in this image).

Figure 68. Garden of plants that had 

living relatives during the Cretaceous 

Period (before about 65 million years 

ago during the Age of Dinosaurs) on 

display at the Oakland Zoo near the 

trace of the Hayward Fault. Besides 

having animals, the Oakland Zoo also 

has some fossil exhibits.
46

Figure 69. Historic photograph of the 

damage to the Estudillo House in San 

Leandro. This was the home of the 

family of José Joaquín Estudillo, 

grantee of Rancho San Leandro and 

founder of what became the city of San 

Leandro. The landmark is located at 

550 West Estudillo Avenue (image 

courtesy of the Bancroft Library). 

Figure 70. Historic photograph by 

Carleton Watkins showing the 

condition of the Alameda County 

Courthouse after the 1868 Hayward 

earthquake. One person was killed 

when the courthouse collapsed. Note 

that the building on the far left 

appeared to escape damage and still 

had its chimney. The old courthouse 

was located at the intersection of Davis 

and Clarke Streets. 

Figure 71. View looking south at the 

intersection of Davis and Clarke 

Streets at the location where the 

Alameda County Courthouse used to 

stand before being destroyed by the 

1868 Hayward earthquake. 

Commemorative plaques are on 

display at the corner outside of the 

modern school building that was built 

on the old courthouse grounds. 
47

Figure 72. The Hayward Fault crosses 

a low divide where stream erosion has 

produced a linear stream valley. This 

view is looking north from a bend in the 

road along Fairmont Drive in the 

vicinity of the Alameda County Juvenile 

Hall in the foothills east of San 

Leandro. 

Figure 73. Google Earth view of the 

San Leandro Hospital grounds showing 

locations of features associated with 

the Hayward Fault. The fault crosses 

the hospital grounds at the rear (east 

side) of the buildings. The building with 

the red roof in the lower right was 

modified to remove part of the wing 

built on the fault. 

Figure 74. Fairmont Hospital is an 

Alameda County facility in San 

Leandro. Some of the original hospital 

buildings were constructed on the 

Hayward Fault but were later 

abandoned or modified. Evidence of 

the active creep of the fault can be 

seen on the hospital grounds in the 

form of cracks in the pavement and 

older walls and offset curbs, 

particularly on the east and south sides 

of the main hospital building. 
48

Figure 75. View of the Fairmont 

Hospital campus drive on the south 

side of the main building. Fractures in 

the older pavement and offset curbs 

are visible along the drive and 

surrounding parking areas. This view 

looks north along a steep slope that 

probably represents a modified scarp 

of the Hayward Fault. 

Figure 76. Fractured and broken wall 

revealing the location of the creeping 

Hayward Fault in the rear (east side) of 

Fairmont Hospital. 
49

Chapter 10 – Downtown Hayward

Figure 77. Map showing the Hayward Fault in the downtown Hayward area. Purple numbers 

designate photograph locations.
50

What to look for: Seldom has a city paid so great a price to have an earthquake and fault named 

after it. The 1868 Hayward earthquake damaged nearly every building in the then town of 500 

residents. Downtown Hayward is perhaps the most famous destination of the Hayward Fault. 

The old City Hall (abandoned) is a classic landmark of a building slowly being torn apart by the 

steady creep along the Hayward Fault. The trace of the fault can be followed from block to block 

where the creep offsets building walls, sidewalks, curbs, and other infrastructure. En echelon 

cracks appear in pavement. Many of the buildings downtown have been retrofitted for 

earthquakes (bolts are visible holding old brick buildings together). Sites just outside the 

immediate downtown area display fault scarps, offset walls, and offset street curbs. Gravels 

exposed on the hillside in the fault scarp near Jackson Street indicate the movement of the fault 

has offset old alluvial fan deposits. The Hayward Area Historical Society Museum, with 

interesting 1868 earthquake memorabilia, is located on the corner of Main and C Streets. (See 

figures 80 through 91 for views of damage in Hayward.) 

Access Options 

 BART: The Hayward BART Station is three blocks from old City Hall. All the locations 

are within easy walking distance of the BART station. 

AC Transit: The AC Transit line #82 bus runs south on Mission Boulevard from Avenue 

C to both the Bay Fair and San Leandro BART Stations (including past the Fairmont Hospital 

fault locality in Chapter 8). The # 99 bus runs north Avenue C on Avenue C to both the South 

Hayward and Union City BART stations. (See www.511.org for details of bus schedules). 

Bike: All locations are on city or residential streets. Caution should be used when riding 

bicycles. 

 Hike: All locations on the map can be visited with an easy walk of just over two miles. 

Several restaurants are on or near the walking route along Mission Boulevard. 

 Wheelchair access: Downtown Hayward between the old City Hall and Hotel Avenue is 

easily accessible by wheelchair. Both Memorial Park and the Hayward Area Historical Society 

Museum are also wheelchair accessible. 

Car: All areas are easily accessible by car. 
51

Figure 78. View of an offset curb at 

the southwest corner of Prospect 

Street and Rose Street north of 

downtown Hayward. The 

displacement of the curb is consistent 

with the relative right-lateral 

displacement of the Hayward Fault. A 

right-lateral displacement refers to the 

relative motion of the two sides of a 

strike-slip fault. Offset features along 

the Hayward Fault show that the west 

side is moving northward relative to 

the east side of the fault. 

Figure 79. The roots of this old tree 

have split the curb and sidewalk on 

Prospect Street just north of the 

intersection with Rose Street. The 

tree is growing in the active trace of 

the Hayward Fault, which closely 

follows Prospect Street in this area.

Figure 80. View west along Simon 

Street from the intersection of 

Prospect Street in Hayward (Mission 

Boulevard is in the distance). The 

slope in the foreground is a scarp of 

the Hayward Fault. The active trace of 

the fault crosses the street where the 

street curb (on the left side of the 

street) shows displacement from 

creep.
52

Figure 81.This view is a close up of 

the displacement of the curb shown in 

fig. 81. The view looks west along 

Simon Street from the intersection of 

Prospect Street in Hayward. The view 

highlights the right-lateral 

displacement of the curb caused by 

the creeping Hayward Fault.

Figure 82. Offset curbs and fractures 

in the pavement are visible along the 

creeping trace of the Hayward Fault in 

the municipal parking area between 

Avenue A and Hotel Avenue on the 

east side of Mission Boulevard. Many 

of the buildings in the area show 

various stages of retrofit and 

structural repairs, but the slow fault 

creep never ceases.

Figure 83. This view looks east along 

an alley between Avenues B and C in 

downtown Hayward where the 

creeping Hayward Fault has offset 

sidewalks, buildings, and just about 

everything along its trace.
53

Figure 84. Hayward's old City Hall 

was built in 1930 directly on the 

Hayward Fault. This view is looking 

northeast across Mission Boulevard. 

Over the years, fault creep has 

severely damaged the building. Two 

strands of the fault occur here—one 

passes beneath the front of the 

building (shown here) and the other 

crosses behind the building. Damage 

to the building can be viewed by 

looking through the front side 

windows, and offset and cracks can 

be seen in the sidewalks around the 

building. Downtown residents are 

used to seeing frequent fault tours 

where it is easy to trace the fault 

where it crosses streets and alleys, 

and cuts through buildings, for three 

blocks between old City Hall 

northward to Hotel Avenue. 

Figure 85. This sidewalk displays 

right-lateral offset that is typical for the 

older structures built across the 

creeping Hayward Fault. Car keys are 

shown for scale. This sidewalk is on 

the north side of old City Hall in 

downtown Hayward. While walking 

around downtown Hayward, it is 

interesting to see evidence of past 

and present attempts to fix or prevent 

damage to buildings and 

infrastructure caused by the creeping 

fault. Some buildings that had 

originally been constructed on the 

fault have been torn down and 

replaced with small open space 

parks.
54

Figure 86. View from the side of a 

small hill east of the intersection of 

Jackson Street and Mission 

Boulevard. The view is looking 

northwest along Mission Boulevard 

and the downtown area in the vicinity 

of old City Hall. Ongoing road 

maintenance has mostly masked the 

creeping trace (or traces) of the 

Hayward Fault here, but the hill 

represents an eroded scarp along the 

trace of the Hayward Fault. Gravel in 

the soil on the slope reveals that the 

bedrock in the Hayward area consists 

of relatively poorly consolidated 

alluvial fan (see glossary) and stream 

channel deposits. These kinds of 

deposits underlie the urbanized 

alluvial plain between San Francisco 

Bay and the East Bay Hills. However, 

the sediments closer to the bay 

become mud, and many areas in the 

urbanized region around the bay have 

been filled in over the years.

Figure 87. A twisted (displaced) 

cement wall of an old sandbox play 

area in Memorial Park near downtown 

Hayward. The slow creep of the 

Hayward Fault caused the warping of 

the cement. This cement wall is about 

30 feet south of an old stonewall that 

also shows right-lateral displacement 

along the trace of the Hayward Fault.
55

Figure 88. This old, low stonewall in 

Memorial Park near downtown 

Hayward has been displaced by 

creep along the Hayward Fault. This 

view is looking east. 

Figure 89. View north past a low 

stonewall that has been offset by 

creep along the Hayward Fault 

(shown in fig. 88). The fault trace is in 

the path area between the two 

segments of the wall and continues 

toward the base of the stairs. The 

steep slope in the distance beyond 

the stairway is a fault scarp. 
56

Historic Pictures of the 1868 Hayward Earthquake Damage 

Not many photographs or accounts survive from the 1868 Hayward earthquake, partly because 

the East Bay region was sparsely populated at the time. Below are three famous photographs 

taken after the earthquake that illustrates the kind of damage caused by the earthquake. 

Figure 90. The Pierce’s house in 

Hayward—knocked off its 

foundation by the 1868 earthquake. 

Image courtesy of the Bancroft 

Library, University of California, 

Berkeley. 

Figure 91. Edminton Grain 

Warehouse and flour mill—

collapsed during the 1868 

earthquake. The hills in the distance 

are the fault scarp/shutterridge of 

the Hayward Fault along Prospect 

Street between Hotel Avenue and 

Rose Street on the south side of 

downtown Hayward. Image 

courtesy of the Bancroft Library, 

University of California, Berkeley. 

Figure 92. Edminton Grain 

Warehouse—collapsed during the 

1868 earthquake. This view shows 

the rail lines that are now the 

location of the rails at the modern 

Hayward BART Station (on B 

Street). Image courtesy of the 

Bancroft Library, University of 

California, Berkeley. 
57

Chapter 11 – Downtown Fremont 

Figure 93. Location of the Hayward Fault in the Fremont Central Park area. Purple numbers 

designate photograph locations. 

What to look for: Fremont experienced very strong shaking in the 1868 earthquake. The 

Fremont Central Park area offers a good view of a variety of offset street curbs, fractures in 

pavement, scarps, and sag ponds that have formed along the trace of the Hayward Fault. 
58

Access Options 

 BART: Cracks in the pavement of the parking area at the Fremont BART station are a 

result of creep along the Hayward Fault. All locations along this route are within walking 

distance from the Bart Station. 

AC Transit: The AC Transit line #218 connects to the Fremont BART station and runs 

past Fremont Central Park. (See www.511.org for details of bus schedules). 

Bike: All sites are easily accessible by bicycle. 

 Hike: Total walking distance from the Fremont BART Station to all locations on this field 

trip would be about 2 miles. 

 Wheelchair access: The fault locations in Fremont Central Park on Sailway Drive and at 

the intersections of Rockett Drive and Baylis Street are easily accessible by wheelchair. The 

latter two locations are accessible from a parking area on the opposite side of Paseo Padre 

Parkway. 

Car: All locations are easily accessible by car. 

Figure 94. The Fremont BART station 

is the current terminus of the rail line. 

The track ends a very short distance 

from the Hayward Fault. Cracks in the 

pavement caused by slow creep of the 

fault can be seen in the train parking 

area on the southeast side of the train 

station. This view is looking southeast 

at the BART station with Mission Peak 

in the distance. 
59

Figure 95. Tule Pond is a sag pond 

that fills a natural depression formed by 

two strands of the Hayward Fault (the 

active trace is on the west, or left side 

of this image; another inactive trace is 

on the right side of the pond). The 

pond has been modified at different 

times in the modern history of the 

region, but it still provides an example 

how fault movements modify the 

landscape, in this case as a small pullapart structural basin. The Fremont 

BART station is just to the west (left) of 

this north-facing view of Tule Pond. 

The pond is now a small nature 

preserve in the center of the urban 

landscape. 

Figure 96. The Hayward Fault crosses 

through Fremont's Central Park. This 

view shows two USGS interns 

photographing offset curbs and 

fractures where the fault crosses 

Sailway Drive on the west shore of 

Lake Elisabeth. Look for the offset 

curbs and fractures in the pavement 

about 200 feet east of the intersection 

of Sailway Drive and Paseo Padre 

Parkway. 

Figure 97. Close-up view of an offset 

curb on Sailway Drive in Fremont 

Central Park (in the same location as 

fig. 98). 
60

Figure 98. View looking southwest 

across Paseo Padre Parkway toward a 

low hill on Baylis Street. The hill is an 

escarpment along the Hayward Fault. 

Fractures in the pavement and offset 

curbs near the intersection reveal 

evidence of creep on the fault. 

Figure 99. View north across Paseo 

Padre Parkway toward Lake Elisabeth 

from the corner of Baylis Street. 

Fractures in the pavement are from 

creep along the Hayward Fault. The 

1906 Niles 15 minute quadrangle 

topographic map shows that what is 

now Lake Elisabeth was called The 

Lagoon and was a natural lake (a large 

sag pond) on the relatively 

undeveloped alluvial plain that is now 

Fremont. 
61

Figure 100. View of an offset curb on 

the north side of Rockett Drive near the 

intersection of Paseo Padre Parkway 

near Fremont Central Park. 

Figure 101. View of an offset curb and 

an attempt to repair fractures in the 

pavement on the south side of Rockett 

Drive near the intersection of Paseo 

Padre Parkway near Fremont Central 

Park. This photo is on the opposite 

side of the street from fig. 102. 

Figure 102. This view shows water 

mains of the Hetch Hetchy water 

system (water mains #1 and #2) 

exposed in the vicinity where they 

cross the Hayward Fault along 

Grimmer Boulevard near the 

intersection of Paseo Padre Parkway 

(near Fremont Central Park). The 

water mains have been retrofitted and 

buried in the vicinity of the Hayward 

Fault nearby. Two other more recently 

constructed water mains associated 

with the Hetch Hetchy system cross 

the Hayward Fault in south Fremont. 
62

Chapter 12 – Mission San Jose-South Fremont

Figure 103. Location of the Hayward Fault in the Mission San Jose area in southern Fremont, 

California. Purple numbers designate photograph locations.

 

What to look for: Mission San Jose is both an active Catholic church and a museum with 

collections of archeological and historical artifacts. The original mission was destroyed in the 

1868 Hayward earthquake but was later rebuilt in the fashion of the original building. The 

mission was built near a number of Ohlone villages. 

The southernmost accessible location to easily see the creeping Hayward Fault is in the vicinity 

of Arroyo Agua Caliente Park. The park is host to a sag pond (filled with cattails). Cracks in the 

pavement can be seen at the intersection of Gardenia Way and Ivy Way. The historic Gallegos 

(Palmdale) Winery ruins near the intersection of Osgood Road and Washington Blvd is off limits 

to the public on land owned by BART. 
63

The Mission Peak landslide is visible from throughout the area and provides an ominous 

presence on the mountain front above the Mission San Jose area. The landslide is not accessible 

to the public because of safety concerns. Details of damage and vistas are shown in figures 106 

through 115. 

Access Options 

 BART: The closest BART station is the end of the line in Fremont about 3 miles to the 

north. Plans are underway to extend BART service southward to the Irvington area (west of 

Mission San Jose and adjacent to the Hayward Fault) in the not-to-distant future. 

AC Transit: The AC Transit line #217 and #218 extend to Mission San Jose and Ohlone 

College; #218 continues to Arroyo Aqua Caliente Park. (See www.511.org for details of bus 

schedules.) 

Bike: All locations shown on the map are easily accessible by bicycle. Most area roads are 

wide and some are designated bike routes. Caution should be used in the vicinity of interstate 

interchanges and construction sites. Bicycles are allowed on select trails in the Mission Peak 

Regional Preserve. 

 Hike: Mission Peak Regional Preserve is a popular hiking destination with many miles of 

trails available. A trailhead is located near Ohlone College and another is on Stanford Avenue off 

of Mission Boulevard. Hiking in the preserve ranges from moderate to extremely strenuous and 

is not recommended in hot weather. 

 Wheelchair access: Mission San Jose and Arroyo Agua Caliente Park are accessible to 

wheelchairs; other locations are not recommended. 

Car: Because of the distances involved between stops, driving is a logical option to 

this field trip area. Parking in the Mission San Jose area can be difficult while classes are in 

session at Ohlone College, and the parking areas for the Mission Peak Regional Preserve can fill 

up on weekends.
64

Figure 104. Mission San Jose was 

founded in 1797. The original church 

building was constructed of adobe and 

completed in 1809. The church was 

nearly completely destroyed by the 

1868 earthquake. This historic 

stereograph of Mission San Jose was 

taken before the 1868 Hayward 

earthquake. Photograph by Thomas 

Houseworth. 

Figure 105. A new church constructed 

of wood was built on the rock 

foundation of the old church. However, 

the wooden building was moved and 

the San Jose Mission church was 

rebuilt (restored) to look like the 

original; construction was completed in 

1985. The mission is still used for 

religious services and has a unique 

historical collection of artifacts in a 

museum in one of the remaining 

original adobe buildings next door that 

survived the 1868 earthquake. 
65

Figure 106. This small memorial park 

on Washington Boulevard is an Ohlone 

Indian burial ground where, according 

to a local marker on the site, as many 

as 4,000 Ohlone people were buried. 

The location of Mission San Jose was 

chosen because of its proximity to a 

large native population in the South 

Bay region that subsisted off the 

abundant food supply of the South Bay 

and oak woodlands of the Diablo 

Range nearby. This burial ground is 

about 0.5 mile west of Mission San 

Jose and 0.5 mile from the Hayward 

Fault. 

Figure 107. View looking east along 

Washington Boulevard shows an offset 

curb and sidewalk near the entrance to 

the Ohlone Village Shopping Center in 

Fremont. The sidewalk was probably 

buckled by growth of the tree. No 

known fault creep has been mapped in 

the area (the Hayward Fault is about a 

mile to the west of this location). 

Features like this illustrate how difficult 

and time consuming fault finding can 

be. 

Figure 108.This view is looking east at 

the property owned by BART near 

Osgood and Washington in Fremont. 

The photo shows the ruins of the 

Gallegos (Palmdale) Winery, which 

was built into a hillside that is a fault 

scarp of the Hayward Fault. In the 

brush-covered field is a stone 

perimeter wall built in 1884. By 1985, 

this stone wall had been offset by 2.5 

feet of accumulated right-lateral creep 

on the main trace of the Hayward Fault 

(Lienkaemper, 2006). 
66

Figure 109. The Mission Peak 

landslide occurred on March 22, 1998 

and was a partial reactivation of a large 

bedrock landslide complex that has 

developed over many thousands of 

years on the western face of Mission 

Ridge. Although the landslide 

displaced a great volume of rock and 

debris, fortunately no structures were 

damaged in the neighborhoods at the 

base of the slope. 

Figure 110. Detail of the headwall 

escarpment area of the Mission Peak 

landslide. See landslide features 

described in the Glossary. 

Figure 111. View looking east toward 

Mission Peak from near the trailhead 

for Mission Peak Regional Park on 

Stanford Avenue in Fremont. The 

upland part of the eastern flank of 

Mission Peak is a steep hogback ridge 

of Briones Sandstone, a soft Mioceneage marine sandstone that is partly 

responsible for the formation of 

landslides on the mountainsides above 

Fremont. The Mission Fault, part of the 

regional system of faults that include 

the Hayward and Calaveras Faults, 

crosses through the valley at the base 

of the steep cliff below the peak. 
67

Figure 112. Arroyo Agua Caliente Park 

is located in southern Fremont at the 

intersection of Paseo Padre Parkway 

and Parkmeadow Drive. The "hot water 

stream" no longer flows in the park, but 

it does have a natural sag pond area 

filled with cattails (visible behind the 

trees and to the right). The sag pond 

was formed by the active trace of the 

Hayward Fault. Nearby, the Spanish 

called the warm springs Agua Caliente 

(hot water). Americans developed a 

health spa and resort that utilized the 

hot water until the springs stopped 

flowing after the 1868 earthquake, 

causing the resort and surrounding 

businesses to close down. 

Figure 113. En echelon fractures in the 

pavement near the intersection of 

Gardenia Way and Ivy Way on the 

southwest side of Arroyo Agua 

Caliente Park in Fremont. The creeping 

section of the Hayward Fault continues 

for a couple of miles south of the park 

but is not accessible to the public. 

South of this area, the fault splays into 

strands that cross into the foothills of 

the Diablo Range east of San Jose. It 

is in the southern extension, south of 

Mission Boulevard, where the Hayward 

Fault is now thought to converge with 

the Central Calaveras Fault. 
68

Chapter 13 – Now and Then: Comparison of Selected Historic 

USGS Topo Maps with Modern Satellite Views Along the 

Hayward Fault 

This chapter compares historic U.S. Geological Survey topographic maps (1:62,500 scale; 15 

minute quadrangles) with equivalent satellite images captured from Google Earth in February 

2008. The topo maps were made 30 to 50 years after the 1868 Hayward earthquake but illustrate 

how sparsely the East Bay region was populated at the beginning of the 20th century. The recent 

satellite images help illustrate how many people and how much property and infrastructure will 

be impacted by another major earthquake on the Hayward Fault. 

Figure 114. Point Pinole from 

portions of two maps: 1916 

Mare Island 15’ quadrangle 

(north half) and 1895 San 

Francisco 15’ quadrangle 

(south half). In the late 19th

Century the Point Pinole area 

was a site where explosives 

were manufactured. The 

small black dots show the 

locations of buildings that 

existed when the area was 

mapped—none of which exist 

in the park today. 

Figure 115. Point Pinole as 

captured from current Google 

Earth satellite imagery. The 

red line indicates known 

locations of the Hayward 

Fault. The land north and 

west of the rail lines is 

unoccupied parkland of Point 

Pinole Regional Shoreline. 

The land on the opposite side 

of the tracks that is intensely 

developed was sparsely 

populated ranch land at the 

time of the 1868 Hayward 

earthquake. 
69

Figure 116. San Pablo 

(Richmond) area from the 

1895 San Francisco 15’ 

quadrangle. The only 

significant settlement 

shown on the map was 

along what is now 

McDonald Avenue in 

Richmond and near the 

San Pablo Railroad Station. 

The rail lines are still 

maintained for freight and 

commuter traffic. The 

modern BART station is a 

short distance north of the 

historic station shown on 

the map. 

Figure 117. The satellite 

image of the Richmond 

area from February 2008 

shows nearly complete 

urban development across 

the alluvial plain and upland 

hills east of the Hayward 

Fault. Contra Costa College 

(CCC) straddles the fault 

along the break in slope 

just to the northeast of the 

symbol location for San 

Pablo. The gray in the 

image represents 

pavement, rooftops, or 

other manmade features. 
70

Figure 118. Berkeley from 

the 1895 San Francisco 15’ 

quadrangle. The University 

of California, Berkeley was 

established on March 5, 

1868 from the merger of 

two earlier academic 

institutions: the College of 

California (a private 

institution) and the 

Agricultural, Mining, and 

Mechanical Arts College (a 

land grant institution). The 

board of trustees of the 

College of California 

established the name 

Berkeley in 1866. 

Figure 119. The Berkeley 

area is one of the most 

urbanized landscapes in 

the East Bay. This satellite 

view shows that the 

California Memorial 

Stadium next to the 

University of California, 

Berkeley, bisected by the 

Hayward Fault in the 

northeast corner of the 

image. 
71

Figure 120. The Lake 

Temescal and Berkeley 

Hills area from the 1897 

Concord 15’ quadrangle 

map. The lake was a 

natural sag pond on the 

Hayward Fault. Temescal 

Creek is offset where it 

intersects the active fault 

zone. Very few people 

lived in the area at the 

time of the 1868 Hayward 

earthquake. 

Figure 121. The modern 

satellite image shows the 

route of Highway 24 

through the Caldecott 

Tunnel. Urban 

development has 

expanded across the 

alluvial plain into the 

Berkeley Hills. 
72

Figure 122. The Oakland 

Hills area from the 1897 

Concord 15’ quadrangle. 

This area was sparsely 

populated at the time of 

the 1868 Hayward 

earthquake. By the turn 

of the century, however, 

Oakland was already 

encroaching into the hills 

east of the city. 

Figure 123. The modern 

satellite image shows that 

urban development has 

expanded nearly to the 

ridgeline of the Oakland 

Hills. The yellow dot 

shows the location of the 

Oakland Mormon Temple 

(Church of Jesus Christ 

of Later-day Saints). The 

temple is one of the most 

visible manmade features 

along the Hayward Fault 

and can be seen from 

throughout the Oakland 

area. 
73

Figure 124. The San 

Leandro area from the 

1899 Hayward 15’ 

quadrangle map. San 

Leandro was a small 

village at the time of the 

1868 Hayward 

earthquake and remained 

that way until the turn of 

the 20th Century. The 

Alameda County 

Courthouse there was 

destroyed by the 

earthquake. 

Figure 125. Modern 

satellite view shows that 

the San Leandro area is 

now densely urbanized, 

as is most of the alluvial 

plain of the East Bay 

region. 
74

Figure 126. 1899 

Hayward 15’ 

quadrangle map 

showing that the 

Hayward area 

remained relatively 

undeveloped until the 

beginning of the 20th

Century. The town was 

originally named 

“Haywards.” Much of 

the development of the 

East Bay region 

happened when people 

fled across the Bay to 

settle after the 1906 

San Francisco 

earthquake. 

Figure 127. Modern 

satellite image showing 

that both the alluvial 

plain west of the 

Hayward Fault and the 

hill country east of the 

fault are now intensely 

urbanized. 
75

Figure 128. The 

villages of Irvington and 

Mission San Jose are 

the only significant 

settlements visible on 

this portion of the 1906 

Livermore 15’ 

quadrangle. “The 

Lagoon” and “Tule 

Pond” were natural sag 

ponds and wetlands 

formed by movement 

on the Hayward Fault. 

Figure 129. The City of 

Fremont now 

encompasses the 

alluvial plain west of the 

Diablo Range. “The 

Lagoon” (now Lake 

Elisabeth) is part of 

Fremont Central Park, 

and Tule Pond is 

adjacent to the Fremont 

BART Station. 

Interstate 680 crosses 

the Hayward Fault in 

the old Irvington 

neighborhood. 
76

Figure 130. Agua 

Caliente area from the 

1899 San Jose 15’ 

quadrangle shows that 

the natural South Bay 

wetlands had not yet 

been disturbed. The 

narrow alluvial plain 

between the Bay and 

the western flank of the 

Diablo Range was 

already an important 

transportation corridor. 

Warm Springs was a 

resort and spa until the 

1868 earthquake. 

Figure 131. Modern 

satellite image showing 

the southern end of the 

creeping section of the 

Hayward Fault. The 

development of the 

narrow alluvial plain 

has expanded 

westward into the 

marshlands of the 

South Bay, where salt 

evaporator ponds have 

replaced most of the 

natural wetlands. 
77

Glossary 

 Note that words in italics are defined elsewhere in this glossary. 

Alluvial fan. An outspread, gently sloping mass of sediment deposited by a stream where it 

issues out of the mouth of a narrow canyon draining from and upland area. Viewed from above, 

an alluvial fan typically has the shape of an open fan with the apex being at the mouth of the 

canyon. Alluvial fans are common in arid to semi-arid regions but can be covered with forests in 

the California Coast Ranges. Alluvial fans may merge together to form an apron-like slope along 

the base of a mountain front. 

Alluvium. A general term for unconsolidated sediments deposited by flowing water on stream 

channel beds, flood plains, and alluvial fans. The term applies to stream deposits of recent times 

and it does not include subaqueous deposits, such as in lakes or undersea. 

Anaglyphic image. A type of photographic image or drawing that can create a three-dimensional 

view when viewed through colored filter glasses—red-and-cyan colored lenses are most 

common (standard). Anaglyphic images are created using two standard photographs taken in 

parallel position a short distance apart, then colors are subtracted from the two images (blue and 

green from the left image, and red from the right image) before the two images are merged into a 

reconstructed image (called an anaglyph). The red colored lens filters out green and blue from 

the anaglyphic image whereas the cyan colored lens filters out the red. With red-and-cyan 3D 

viewing glasses on, the brain reconstructs a 3D view from the original stereo pair of images used 

to make the anaglyphic image. Standard anaglyphic 3D glasses are worn with the red lens over 

the left eye. 

Basalt. A dark-colored igneous rock, commonly extrusive (from volcanic eruptions) and 

composed primarily of the minerals of calcic plagioclase and pyroxene, and sometimes olivine. 

Basalt is the fine-grained equivalent of gabbro. 

Beheaded stream. Streams draining across an active strike-slip fault trace may be captured by 

an adjacent stream. With loss of its water supply or a source of sediments, the older channel will 

remain as a beheaded stream channel as fault motion continues. 

Cenozoic. The era of time spanning about 65 million years ago to the present. The term applies 

to rocks that formed or accumulated in that time period. The Cenozoic Era is subdivided into the 

Tertiary and Quaternary periods. 

Chert. A hard, dense sedimentary rock, consisting chiefly of interlocking microscopic crystals of 

quartz and may contain opal. It has a conchoidal fracture and may occur in a variety of colors. 

Coast Range Ophiolite. An assemblage of mafic and ultramafic igneous rocks of Jurassic to 

possibly Cretaceous age and whose origin is associated with the upper mantle and the lower 

oceanic crust of the ancient Farallon Plate. The Farallon Plate predates the development of the 

San Andreas Fault system, and rocks of the Farallon Plate were either subducted or partially 

accreted (merged) into the crust that now makes up the Coast Ranges. The Coast Range 

Ophiolite is associated with serpentinite terranes throughout much of coastal central and 
78

northern California. The modern Juan de Fuca Plate offshore of the Cascades volcanic range in 

Oregon and Washington is a remnant of what was once the greater Farallon Plate. 

Colluvium. A general term applied to loose and incoherent surficial deposits, usually at the base 

of a slope and brought there chiefly by gravity. 

Conglomerate. A coarse-grained sedimentary rock composed of rounded to subangular 

fragments (larger than 2 mm in diameter) set in a fine-grained matrix of sand or silt, and 

commonly cemented by calcium carbonate, iron oxide, silica, or hardened clay; the consolidated 

equivalent to gravel. 

Creep. In earthquake terminology, creep is the slow, continuous movement occurring without 

large earthquakes on faults due to ongoing tectonic deformation. In landslide terminology, creep 

is slow, more or less continuous down slope movement of surface materials (mineral, rock, and 

soil particles) under gravitational stresses. 

Cretaceous. The final period of the Mesozoic Era (after the Jurassic Period and before the 

Tertiary Period of the Cenozoic Era). The Cretaceous Period began about 144 million years ago 

and ended about 65 million years ago. 

Debris flow. A moving mass of rock fragments, soil, and mud in which more than half of the 

particles are larger than sand size (otherwise it would be a mudflow) and with 70 to 90 percent of 

the material consisting of sediment (the rest is water and trapped gases). Slow debris flows may 

only move a few feet per year, whereas rapid ones can reach speeds greater than 100 miles per 

hour. Debris flows can display either turbulent or laminar flow characteristics. 

Debris flood. A typically disastrous flood, intermediate between the turbid flood of a mountain 

stream and a debris flow, ranging in sediment load between 40 to 70 percent (the rest is water 

and trapped gases). 

Deflected drainage. A stream that displays offset by relatively recent movement along a strikeslip fault. Fault motion and characteristics of the bedrock adjacent to and within a fault zone can 

influence erosion patterns and diversion of stream drainages over time. 

Dip. The angle that a rock layer or any planar feature makes with the horizontal, measured 

perpendicular to the strike and in a vertical plane.

Dip-slip faults. Inclined fractures where the blocks have mostly shifted vertically. If the rock 

mass above an inclined fault moves down, the fault is termed normal, whereas if the rock above 

the fault moves up, the fault is termed reverse. A reverse fault in which the fault plane is inclined 

at an angle equal to or less than 45° is called a thrust fault. 

Earthquake. Ground shaking caused by a sudden movement on a fault or by volcanic 

disturbance. 
79

Earthquake fault. An active fault that has a history of producing earthquakes or is considered to 

have a potential of producing damaging earthquakes on the basis of observable evidence. Not all 

faults are active or are considered earthquake faults. 

Epicenter. The point on the Earth’s surface above the point at depth in the Earth’s crust where 

an earthquake begins. 

Escarpment. A long, more or less continuous cliff or relatively steep slope facing in one general 

direction, separating two level or gently sloping surfaces, and produced by earthquake faulting or 

erosion. 

Extrusive rock. Igneous rock that forms from the eruption of molten material at the surface. 

Extrusive rocks include lava flows and pyroclastic material such as volcanic ash or cinders. 

Fault. A fracture or crack along which two blocks of rock slide past one another. This movement 

may occur rapidly, in the form of an earthquake, or slowly, in the form of creep. Types of faults 

include strike-slip fault, normal fault, reverse fault, and thrust fault. 

Fault line (or fault trace). The trace of a fault plane on the ground surface or other surface, such 

as on a sea cliff, road cut, or in a mine shaft or tunnel. A fault line is the same as fault trace. 

Faults lines can often be difficult to resolve from general surface observation due to cover by 

younger sediments, vegetation, and human-induced landscape modifications. 

Fault zone. A fault or set of related faults that is expressed as a zone of numerous small fractures 

or of “breccia” or “fault gouge.” A fault zone may be hundreds of feet wide and may locally 

have a complex structure. 

Fault system. A collection of parallel or interconnected faults that display a related pattern of 

relative offset and activity across an entire region (for example, the San Andreas Fault system). 

Fault scarp. An escarpment or cliff formed by a fault that reaches the Earth’s surface. Most fault 

scarps have been modified by erosion since the faulting occurred. 

Franciscan Formation. An assemblage of rocks exposed throughout the Coast Ranges of 

California that consists of a mix of volcanic rocks, chert, shale, greywacke sandstone, limestone, 

basalt, and other oceanic crustal rocks that have been partially metamorphosed during their 

migration from place of origin in a deep ocean basin to being accreted by plate tectonic forces 
80

onto the west coast of North America. The name Franciscan was first applied to bedrock of 

Jurassic and Cretaceous age in the San Francisco region, but the name is commonly used 

throughout much of coastal central and northern California. 

Gabbro. A group of dark-colored, basic intrusive igneous rocks composed principally of calcicplagioclase minerals (labrodorite or bytonite) and augite, and with or without olivine and 

orthopyroxene. It is the approximate intrusive equivalent of basalt. 

Geologic time scale. Geologists have subdivided periods in Earth's history is measured periods 

spanning millions of years (Ma). Segments of time periods have been named to help define the 

chronology of events (such as mountain range formation), the formation of rock units (such as 

the age of a lava flow), the age of fossils, organizing geologic map units, and other purposes. 

Below is a standard geologic time scale listing names of major time periods with time span 

information. 

Click on image for larger view. 

Geomorphology - the study of the earth's surface including classification, description, nature, 

origin, and development of landforms and their relationships to underlying structures and the 

history of geologic changes as recorded by these surface features. Examples of geomorphic 

features associated with faults are illustrated below. 
81

Graben. An elongate, structurally depressed crustal area or block of crust that is bounded by 

faults on its long sides. A graben may be geomorphically expressed as a rift valley or pull-apart 

basin. 

Great Valley Sequence. A thick sequence of late Mesozoic age sedimentary rocks (150 to 65 

million years old). These rocks consist mostly of shale, sandstone, and conglomerate and are 

exposed throughout parts of California’s Coast Ranges and underlie much of the Great Valley 

west of the Sierra Nevada Range. The Great Valley Sequence represents sedimentary material 

deposited in shallow shelf to deep-sea environments along the western continental margin mostly 

before the development of the modern San Andreas Fault System. 

Holocene. The name applied to the time span that corresponds with the post-glacial warming 

period in which we now live. The Holocene Epoch began about 11,000 years ago (at the end of 

the Pleistocene Epoch of the Quaternary Period), about the time that human population growth 

and distribution expanded worldwide. 

Igneous rock. A rock that solidified from molten or partly molten material (referring to magma 

underground or lava on the surface). The word igneous also applies to the processes related to 

the formation of such rocks. Examples of igneous rocks include granite, gabbro, and basalt. 

Intensity. A measure of ground shaking describing the local severity of an earthquake in terms 

of its effects on the Earth’s surface and on humans and their structures. The Modified Mercalli 

Intensity (MMI) scale, which uses Roman numerals, is one way scientists measure intensity. 
82

Intrusive rocks. Igneous rocks that form from the process of emplacement of magma in preexisting rock. Intrusive igneous rocks typically cool slowly compared to extrusive igneous rocks 

formed on the Earth’s surface and therefore commonly have a coarse crystalline texture (like 

granite or gabbro). The word intrusive applies to both the intrusion process and the rock so 

formed. 

Jurassic. The second period of the Mesozoic Era (after Triassic Period and before Cretaceous 

Period); the Jurassic spans the period of time between about 206 and 144 million years ago. 

Landslide. A general term covering a wide variety of mass-movement landforms and processes 

involving the down slope transport of soil and rock under the influence of gravity. Usually the 

displaced material moves over a relatively confined zone or surface of shear. Landslides have a 

great range of shapes, rates, patterns of movement, and scale. Their occurrence reflects bedrock 

and soil characteristics and material properties affecting resistance to shear. Landslides are 

usually preceded, accompanied, and followed by perceptible creep along the surface of sliding 

and/or within the slide mass. Slumps, debris flows, rockfalls, avalanches, and mudflows are all 

forms of landslides. 

Linear trough. A straight valley that may be bounded by linear fault scarps. A linear trough may 

be a graben or a rift valley and may be modified by erosion. 
83

Linear drainage. A stream drainage that follows the trace of a fault. Stream alignment may be a 

result of strike-slip fault motion or the erosion of sheared and pulverized rock along a fault zone. 

Linear ridge. A long hill or crest of land that stretches in a straight line. It may indicate the 

presence of a fault or a fold (such as an anticline or syncline). If it is found along a strike-slip 

fault it may be a shutterridge or a pressure ridge. 

Linear scarp. A straight escarpment where there is a vertical component of offset along a 

fault (either normal or reverse). Linear scarps may also form when preferential erosion removes 

softer bedrock or soil along one side of a fault. 

Mafic. A mnemonic term combining and “Ma” (for magnesium) and “Fe” (for ferric iron). The 

term is used to describe dark-colored igneous minerals rich in iron and magnesium, as well as the 

rocks that bear those minerals. See also ultramafic. 

Magnitude (M). A numeric measure that represents the size or strength of an earthquake, as 

determined from seismographic observations. 

Mesozoic. The era of geologic time spanning about 248 to 65 million years ago. The Mesozoic 

Era follows the Paleozoic Era and precedes the Cenozoic Era. The Mesozoic Era is subdivided 

into the Triassic, Jurassic, and Cretaceous Periods. The term also applies to rocks that formed 

and accumulated in that time period. 

Metamorphic. Pertaining to the process of metamorphism or to its results. Metamorphism is the 

mineralogical, chemical, and structural adjustment of solid rocks to physical and chemical 

conditions imposed at depth below the surface and below surficial zones where processes of 

sedimentation, compaction, and cementation take place. Examples of metamorphic rocks include 

slate, marble, quartzite, greenstone, gneiss, and schist. 

Miocene. An epoch of the late Tertiary Period, after the Oligocene Epoch and before the 

Pliocene Epoch, representing the time span between about 23.8 and 5.3 million years ago. 

Normal fault. A fault in which the hanging wall appears to have moved downward relative to 

the foot wall. The dip angle of the slip surface is between 45 and 90 degrees. Many normal faults 

in mountainous regions form from gravitational pull along mountainsides and may be associated 

with the headwall escarpment of slumps. 

Oblique-slip faults. Faults that display significant components of both horizontal (strike-slip) 

and vertical (dip-slip) motion. 

Offset drainage. A stream that displays offset by relatively recent movement along a strike-slip 

fault. A better term is deflected drainage.

Ophiolite. An assemblage of mafic and ultramafic igneous rocks ranging from basalt to gabbro 

and peridotite, including rocks derived from them by later metamorphism (such as serpentinite), 
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and whose origin is associated with the upper mantle and the formation of oceanic crust at 

spreading centers in deep ocean basin settings. 

Paleozoic. The era of geologic time spanning about 543 to 248 million years ago. The Paleozoic 

Era follows the Precambrian Era and precedes the Mesozoic Era. The term also applies to rocks 

that formed and accumulated in that time period. 

Plate tectonics. The scientific theory that the Earth’s outer shell is composed of several large, 

thin, relatively strong “plates” that move relative to one another. Movements on the faults that 

define plate boundaries produce most earthquakes. 

Pleistocene. The Quaternary Period is subdivided into the Pleistocene Epoch and the Holocene 

Epoch. The Pleistocene Epoch represents the time span of about 1.8 million to about 11,000 

years ago. Many episodes of continental glaciation and intervening ice-free periods occurred 

within the Pleistocene Epoch. The Holocene Epoch began about 11,000 years ago, about the time 

that human population growth and distribution expanded worldwide. 

Pliocene. An epoch of the late Tertiary Period following the Miocene Epoch and proceeding the 

Quaternary Period (or Pleistocene Epoch) and representing the time span from about 5.3 to 1.8 

million years ago. The cycles of ice-age glaciations and intervening warming periods began in 

Pliocene time. 

Plutonic rock. A rock formed at considerable depth by crystallization of magma and/or by 

chemical alteration. It is usually medium- to coarse-grained with a granitic texture. 

Pressure ridge. A pressure ridge is a topographic ridge produced by compressional forces along 

a strike-slip fault zone. Pressure ridges typically are located where there are bends along a fault 

or where faults intersect or stepover. Pressure ridges can be shutterridges and can occur on one 

or both sides of a fault or within a fault zone. 

Pull-apart basin. A surface depression will form along a fault where down warping of the 

surface occurs, such as from a developing fold or a fault-bounded graben. Closed depressions 

can form where extensional bends or stepovers occur along a strike-slip fault zone. 

Quaternary Period. The period of time spanning about 1.8 million years ago to the present. The 

Quaternary Period is subdivide into two unequal epochs–the Pleistocene Epoch extends from 

about 1.8 million years ago to about 11,000 years ago, and the Holocene Epoch that extends 

from about 11,000 years ago to the present. The Quaternary Period encompassed many cycles of 

ice-age continental glaciations and intervening warming periods. The Holocene Epoch 

corresponds with the last warming period in which we now live. 

Reverse fault. A fault in which the hanging wall has moved up relative to the foot wall. 

Rift valley. A valley that has formed along a tectonic rift. Rift valleys may be grabens or pullapart basins, may be structurally complex, and are typically modified by erosion. 
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Rockfall. The relatively free falling or precipitous movement of a newly detached segment of 

bedrock of any size from a cliff or very steep slope; it is most frequent in mountainous areas 

during spring when there is repeated freezing and thawing of water in cracks in rock. Movement 

may be straight down or in a series of leaps and bounds down the slope; it is not guided by an 

underlying slip surface (like a slump). 

Rupture zone. The area of the Earth through which fault movement occurred during an 

earthquake. For large earthquakes, the section of the fault that ruptured may be several hundred 

miles in length. Ruptures start at several miles depth and may or may not extend up to the ground 

surface. 

Sag pond. If a natural depression associated with a fault or associated with a pull-apart basin 

along a fault system can hold water, even temporarily, it is called a sag pond. 

Scarp. A line of cliffs produced by faulting, slumping, or erosion. Scarp is an abbreviation for 

the word escarpment—the meaning is the same. 

Sedimentary rocks. Materials consisting of sediments or formed by deposition. The word 

sedimentary applies to both the processes and the products of deposition. Examples of 

sedimentary rocks include shale, sandstone, conglomerate, limestone, and chert. 

Seismic hazard. The potential for damaging effects caused by earthquakes. The level of hazard 

depends on the magnitude of likely quakes, the distance from the fault that could cause quakes, 

and the type of ground materials at a site. 

Seismicity. Seismicity means earthquake activity, or the likelihood of an area being subject to 

earthquakes, or the phenomenon of earth movements. 

Serpentinite. An ultramafic rock consisting almost wholly of serpentine-group minerals (such as 

antigorite and chrysotile) derived from the alteration of peridotite. Accessory chlorite, magnetite, 

and talc may be present. 

Shutterridges. A shutterridge is a ridge formed by vertical, lateral, or oblique displacement on a 

fault that crosses an area having ridge and valley topography, with the displaced part of the ridge 

“shutting in” the valley. Shutterridges typically are found in association with offset drainages. 

Sidehill benches. A step-like surface on the side of a hill or mountain. Both recent fault activity 

or erosional differences of bedrock lithology across a fault may produce sidehill benches and 

associated linear scarps. Sidehill benches may also form from slumping that may or may not be 

associated with faulting. 

Slickensides. A polished and striated rock surface produced by friction along a fault. 

Slip. The relative displacement of formerly adjacent points on opposite sides of a fault, measured 

along the fault surface. 
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Slump. A type of landslide where the downward slipping mass of unconsolidated material or 

rock moves as a unit. A slump block usually displays backward rotation and on a more or less 

horizontal axis parallel to the slope or cliff from which it descends. Slumps typically form a 

fault-like escarpment and may occur at the head of a landslide. 

Spreading center. A linear area where new crust forms where two crustal plates are moving 

apart, such as along a mid-oceanic ridge. Spreading centers are typically seismically active 

regions in ocean basins and may be regions of active or frequent volcanism.

Stepover. Closely spaced strike-slip faults within a greater fault zone over which the total 

displacement is distributed. 

Strike. The direction taken by a structural surface, such as a layer of rock or a fault plane, as it 

intersects the horizontal. 

Strike-slip fault. A generally vertical fault along which the two sides move horizontally past 

each other. If the block opposite an observer looking across the fault moves to the right, the slip 

style is termed “right lateral.” If the block moves to the left, the motion is termed “left lateral.” 

California’s San Andreas Fault is the most famous example of a right-lateral strike-slip fault. 

Strike-slip faults produce produce a variety of landforms including shutterridges, pull-apart 

basins, sag ponds, and deflected streams. 

Subduction zone. A boundary along which one plate of the Earth’s outer shell descends (subducts) at an angle beneath another. A subduction zone is usually marked by a deep trench on the 

sea floor. An example is the Cascadia Subduction Zone offshore of Washington, Oregon, and 

northern California. Most tsunamis are generated by subduction-zone-related earthquakes. 

Terrace. A relatively level bench or step-like surface breaking the continuity of a slope. Natural 

bench-like terrace features include elevated-marine terraces (along rising sea coasts), stream 

terraces (along incising streams), or structural terraces (such as along a fault). 

Tertiary. The first period of the Cenozoic Era (after the Cretaceous Period of the Mesozoic Era). 

The Tertiary Period spans the time of about 65 to 1.8 million years ago. The Tertiary Period is 

subdivided into 5 epochs—Paleocene, Eocene, Oligocene, Miocene, and Pliocene). It is followed 

by the Pleistocene Epoch of the Quaternary Period. 

Thrust fault. A fault with a dip angle of 45o or less over its extent on which the hanging wall 

appears to have moved upward relative to the foot wall. Horizontal compression or rotational 

shear is responsible for displacement. (See also reverse fault and oblique-slip fault.) 

Transform fault. A special variety of strike-slip fault along which the displacement suddenly 

stops or changes form. Many transform faults are associated with mid-oceanic ridges and plate 

boundaries that show pure strike-slip displacement, like the San Andreas Fault. 

Ultramafic. A rock composed chiefly of mafic minerals (rich in iron and magnesium, and less 

than about 45 percent silica, such as olivine, augite, or hypersthene. Pyroxene and serpentinite 

are ultramafic rocks.
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Selected References

1868 Hayward Earthquake Alliance, 2007, [organization website], http://1868alliance.org/. 

Bryant, W.A., and Cluett, compilers, 2000, Fault number 55a, Hayward Fault zone, northern 

Hayward section; Fault number 55b, Hayward Fault zone, southern Hayward section; and 

Fault number 55c, Hayward Fault zone, southeast extension section, in Quaternary fault 

and fold database of the United States: U.S. Geological Survey website: 

http://earthquakes.usgs.gov/regional/qfaults. 

California Geological Survey, 2007, Alquist-Priolo earthquake fault zones: State of California, 

Department of Conservation, California Geological Survey website: 

http://www.conservation.ca.gov/CGS/rghm/ap/Pages/Index.aspx. 

Earthquake Engineering Research Institute (EERI), 1996, Scenario for a magnitude 7.0 

earthquake on the Hayward Fault: Earthquake Engineering Research Institute Report HF96, 119 p., http://haywardfault.eeri.org/

Graymer, R.W., Bryant, W., McCabe, C.A., Hecker, S., and Prentice, C.S., 2006, Map of 

Quaternary-active faults in the San Francisco Bay region: U.S. Geological Survey 

Scientific Investigations Map 2919, http://pubs.usgs.gov/sim/2006/2919/. 

Graymer, R.W., Moring, B.C., Saucedo, G.J., Wentworth, C.M. , Brabb, E.E., and Knudsen, 

K.L., 2006, Geologic map of the San Francisco Bay region: Geological Survey Scientific 

Investigations Map 2918, http://pubs.usgs.gov/sim/2006/2918/. 

Graymer, R.W., Sarna-Wojcicki, Walker, J.P., McLaughlin, R.J., and Fleck, R.J., 2002, Controls 

on timing and amount of right-lateral offset on the East Bay fault system, San Francisco 

Bay region, California: Geological Society of America Bulletin, v. 114, no. 12, p. 1471-

1479. 

Hellweg, P., 2003, The Hayward Fault at U.S. Berkeley – A Field Trip: 8 p. 

http://seismo.berkeley.edu/docs/hf_trip.pdf. 

Lienkaemper, James J., 2006, Digital database of recently active traces of the Hayward Fault, 

California: U.S. Geological Survey Digital Data Series 177 

http://pubs.usgs.gov/ds/2006/177/. [This resource is also found on the web at: Active 

traces of the Hayward Fault—Virtual tour using Google Earth: U.S. Geological Survey, 

Earthquake Hazards Team website: 

http://earthquake.usgs.gov/regional/nca/haywardfault/.] 

Rabamad, C., 2006, The San Francisco-Oakland Bay Bridge, in, Prentice, C.S, Scotchmoor, J.G., 

Moores, E.M, and Kiland, J.P., eds., 1906 San Francisco Earthquake Centennial Field 

Guides: Geological Society of America Field Guide 7, p. 107-109. 

Sleeter, B.M., James P. Calzia, J.P., Walter, S.R., Wong, F.L. and Saucedo, G.J., 2004, 

Earthquakes and faults in the San Francisco Bay area (1970-2003): U.S. Geological 

Survey Scientific Investigations Map I-2848, http://pubs.usgs.gov/sim/2004/2848/. 

Sloan, D., and Wells, D., 2006, The Hayward Fault, in Prentice, C.S, Scotchmoor, J.G., Moores, 

E.M, and Kiland, J.P., eds., 1906 San Francisco Earthquake Centennial Field Guides: 

Geological Society of America Field Guide 7, p. 273-331. 

Stoffer, Philip W., 2006, Where's the San Andreas Fault? A Guidebook to tracing the fault on 

public lands in the San Francisco Bay region: U.S. Geological Survey General 

Information Product 16, 123 p. http://pubs.usgs.gov/gip/2006/16/. 

U.S. Geological Survey, Earthquake Hazards Program, 2003, Is a powerful quake likely to strike 

in the next 30 years? U.S. Geological Survey Fact Sheet 039-03, 

http://pubs.usgs.gov/fs/2003/fs039-03/. 
88

U.S. Geological Survey, Earthquake Hazards Program, 2007 [website], Active traces of the 

Hayward Fault: http://earthquake.usgs.gov/regional/nca/haywardfault/. 

U.S. Geological Survey, Earthquake Hazards Program, 2007 [website], October 21, 1868 

Hayward Fault earthquake: http://earthquake.usgs.gov/regional/nca/1868/. 

U.S. Geological Survey, Earthquake Hazards Program, 2007 [website], Historic earthquakes, 

Hayward, California, 1868 October 21 15:53 UTC, Magnitude 6.8: 

http://earthquake.usgs.gov/regional/states/events/1868_10_21.php. 

U.S. Geological Survey, Earthquake Hazards Program, 2007 [website], New shakemaps for the 

1868 Hayward earthquake: http://earthquake.usgs.gov/regional/nca/1868/shakemap/. 

U.S. Geological Survey, Earthquake Hazards Program, 2007, Magnitude 5.4 – San Francisco 

Bay area, California, 2007 October 31 03:04:54 UTC [Alum Rock earthquake]: 

http://earthquake.usgs.gov/eqcenter/eqinthenews/2007/nc40204628/.