On October 17, 1989, at 5:04:15 p.m. (PDT), a magnitude 6.9 earthquake severely shook the San Francisco and Monterey Bay regions. The epicenter was located near Loma Prieta peak in the Santa Cruz Mountains, approximately 14 km (9 mi) northeast of Santa Cruz and 96 km (60 mi) south-southeast of San Francisco.
The 1989 Loma Prieta earthquake ended decades of tranquility in the San Francisco Bay region. It was a wakeup call to prepare for the potentially even more devastating shocks that are inevitable in the future. Since 1989, the work of the U.S. Geological Survey and other organizations has improved understanding of the seismic threat in the Bay region, promoted awareness of earthquake hazards, and contributed to more effective strategies to reduce earthquake losses. These efforts will help reduce the impact of future large quakes in the San Francisco Bay region.
-Robert Page, U.S. Geological Survey
Ground Shaking Animations
To better understand the distribution of shaking from past and anticipated future earthquakes, seismologists have constructed computer models of earthquakes and the resulting ground shaking. This movie shows shaking intensity as the seismic waves travel away from the earthquake epicenter over time.
Eventpage
Tectonic summary, maps and data.
Shakemap
Map showing ground motion and shaking intensity based on instrumental measurements of shaking along with information about local geology and the earthquake’s location and magnitude.
Did You Feel It?
Map of shaking intensity based on 15,000+ reports from citizens who experienced the earthquake.
USGS Professional Papers on Loma Prieta Summaries:
Four Loma Prieta Earthquake Professional Papers, each containing multiple chapters, document the magnitude 6.9 earthquake that shook the San Francisco and Monterey Bay regions.
- Professional Paper 1550: Earthquake Occurrence
- Professional Paper 1551: Strong Ground Motion and Ground Failure
- Professional Paper 1552: Performance of the Built Environment
- Professional Paper 1553: Societal Response
Faultline: Remembering Loma Prieta
A personal account of the events unfolding, by Mary K. Miller of the Exploratorium.
1989 Earthquake Reports and Photographs
From the Virtual Museum of the City of San Francisco.
Below are publications associated with this project.
Reported investments in earthquake mitigation top $73 to $80 billion in the San Francisco Bay Area, California, since the 1989 Loma Prieta earthquake
The October 17, 1989, Loma Prieta, California, earthquake: selected photographs
Progress toward a safer future since the 1989 Loma Prieta earthquake
The Loma Prieta, California, Earthquake of October 17, 1989: Earthquake occurrence
The Loma Prieta, California, Earthquake of October 17, 1989: Strong ground motion and ground failure
The Loma Prieta, California, Earthquake of October 17, 1989: Performance of the built environment
The Loma Prieta, California, Earthquake of October 17, 1989: Societal response
- Overview
On October 17, 1989, at 5:04:15 p.m. (PDT), a magnitude 6.9 earthquake severely shook the San Francisco and Monterey Bay regions. The epicenter was located near Loma Prieta peak in the Santa Cruz Mountains, approximately 14 km (9 mi) northeast of Santa Cruz and 96 km (60 mi) south-southeast of San Francisco.
The 1989 Loma Prieta earthquake ended decades of tranquility in the San Francisco Bay region. It was a wakeup call to prepare for the potentially even more devastating shocks that are inevitable in the future. Since 1989, the work of the U.S. Geological Survey and other organizations has improved understanding of the seismic threat in the Bay region, promoted awareness of earthquake hazards, and contributed to more effective strategies to reduce earthquake losses. These efforts will help reduce the impact of future large quakes in the San Francisco Bay region.
-Robert Page, U.S. Geological Survey
Ground Shaking Animations
To better understand the distribution of shaking from past and anticipated future earthquakes, seismologists have constructed computer models of earthquakes and the resulting ground shaking. This movie shows shaking intensity as the seismic waves travel away from the earthquake epicenter over time.Eventpage
Tectonic summary, maps and data.Shakemap
Map showing ground motion and shaking intensity based on instrumental measurements of shaking along with information about local geology and the earthquake’s location and magnitude.Did You Feel It?
Map of shaking intensity based on 15,000+ reports from citizens who experienced the earthquake.USGS Professional Papers on Loma Prieta Summaries:
Four Loma Prieta Earthquake Professional Papers, each containing multiple chapters, document the magnitude 6.9 earthquake that shook the San Francisco and Monterey Bay regions.- Professional Paper 1550: Earthquake Occurrence
- Professional Paper 1551: Strong Ground Motion and Ground Failure
- Professional Paper 1552: Performance of the Built Environment
- Professional Paper 1553: Societal Response
Faultline: Remembering Loma Prieta
A personal account of the events unfolding, by Mary K. Miller of the Exploratorium.1989 Earthquake Reports and Photographs
From the Virtual Museum of the City of San Francisco. - Multimedia
- Publications
Below are publications associated with this project.
Reported investments in earthquake mitigation top $73 to $80 billion in the San Francisco Bay Area, California, since the 1989 Loma Prieta earthquake
The purpose of this report is to provide a compilation of structural retrofits and replacements of older buildings and infrastructure in the San Francisco Bay Area that have either been completed since 1989 or that are in progress as of October 2018. For the purposes of this report, all or parts of nine Bay Area counties were included: Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo,AuthorsThomas M. Brocher, Kerri Gefeke, John Boatwright, Keith L. KnudsenThe October 17, 1989, Loma Prieta, California, earthquake: selected photographs
This CD-ROM contains 103 digitized color 35-mm images from Open-File Report 90-547 (Nakata and others, 1990). Our photographic coverage reflects the time and resources available immediately after the event and is not intended to portray the full extent of earthquake damage. This CD-ROM provides images for use by the interested public, multimedia producers, desktop publishers, and the high-end prinAuthorsJohn K. Nakata, C. E. Meyer, H. G. Wilshire, J. C. Tinsley, W.S. Updegrove, D.M. Peterson, S. D. Ellen, R. A. Haugerud, R. J. McLaughlin, G.R. Fisher, M. F. DigglesProgress toward a safer future since the 1989 Loma Prieta earthquake
AuthorsRobert A. Page, Peter H. Stauffer, James W. HendleyThe Loma Prieta, California, Earthquake of October 17, 1989: Earthquake occurrence
Professional Paper 1550 seeks to understand the M6.9 Loma Prieta earthquake itself. It examines how the fault that generated the earthquake ruptured, searches for and evaluates precursors that may have indicated an earthquake was coming, reviews forecasts of the earthquake, and describes the geology of the earthquake area and the crustal forces that affect this geology. Some significant findings wAuthorsWilliam H. Coordinated by Bakun, William H. PrescottThe Loma Prieta, California, Earthquake of October 17, 1989: Strong ground motion and ground failure
Professional Paper 1551 describes the effects at the land surface caused by the Loma Prieta earthquake. These effects: include the pattern and characteristics of strong ground shaking, liquefaction of both floodplain deposits along the Pajaro and Salinas Rivers in the Monterey Bay region and sandy artificial fills along the margins of San Francisco Bay, landslides in the epicentral region, and incAuthorsThomas L. Coordinated by HolzerThe Loma Prieta, California, Earthquake of October 17, 1989: Performance of the built environment
Professional Paper 1552 focuses on the response of buildings, lifelines, highway systems, and earth structures to the earthquake. Losses to these systems totaled approximated $5.9 billion. The earthquake displaced many residents from their homes and severely disrupted transportation systems. Some significant findings were: * Approximately 16,000 housing units were uninhabitable after the earthqAuthorsThomas L. Coordinated by HolzerThe Loma Prieta, California, Earthquake of October 17, 1989: Societal response
Professional Paper 1553 describes how people and organizations responded to the earthquake and how the earthquake impacted people and society. The investigations evaluate the tools available to the research community to measure the nature, extent, and causes of damage and losses. They describe human behavior during and immediately after the earthquake and how citizens participated in emergency resAuthorsDennis S. Coordinated by Mileti