Unified Interior Regions
California
The Southwest Region includes California, Nevada, and Arizona. The Regional Office, headquartered in Sacramento, provides Center oversight and support, facilitates internal and external collaborations, and works to further USGS strategic science directions.
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Topobathymetric Elevation Model of San Francisco Bay Area, California
Accurate, high-resolution elevation information is vital to understanding the natural hazards that can impact the highly populated San Francisco Bay area, such as sea-level rise, winter storms, cliff erosion, and other coastal hazards. The San Francisco Bay estuary three-dimensional (3D) topobathymetric digital elevation model (TBDEM) was developed in collaboration between ...
Earthquake Early Warning – Fine-Tuning for Best Alerts
The goal of an earthquake early warning (EEW) system is to provide an alert to people and automatic systems after an earthquake begins but before the shaking reaches their location. As the USGS and its partners are developing an EEW system, called ShakeAlert®, for the West Coast, the benefits, costs, capabilities, and limitations are being investigated. Two recent studies explored the...
Could the M7.1 Ridgecrest, CA Earthquake Sequence Trigger a Large Earthquake Nearby?
Release Date: SEPTEMBER 30, 2019
Two of the first questions that come to mind for anyone who just felt an earthquake are, “Will there be another one?” and “Will it be larger?”.
Loma Prieta Earthquake Professional Papers
The four Loma Prieta Earthquake Professional Papers, which were published as multiple chapters, comprehensively document the magnitude 6.9 earthquake in California that shook the San Francisco and Monterey Bay regions on October 17, 1989. They contain almost 3000 pages written by 401 investigators of the earthquake. The investigations were funded by a special Congressional appropriation to the...
Directions
Information to help you plan your visit to the Earthquake Science Center.
M7.9 1857 Fort Tejon Earthquake
The Last "Big One" in Southern California.
M6.9 October 17, 1989 Loma Prieta Earthquake
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.
M6.0 South Napa, California Earthquake – August 24, 2014
CoSMoS 3.0: Southern California
CoSMoS 3.0 for southern California provides detailed predictions of coastal flooding due to both future sea-level rise and storms, integrated with predictions of long-term coastal evolution (beach changes and coastal cliff retreat) for the Southern California region, from Point Conception (Santa Barbara County) to Imperial Beach (San Diego County).
CoSMoS 2.1: San Francisco Bay
With primary support from the National Estuarine Research Reserve (NERR), CoSMoS is set-up within the San Francisco Bay as part of Our Coast Our Future (OCOF).
CoSMoS 2.0: North-central California (outer coast)
Our Coast Our Future (OCOF) is a collaborative, user-driven project providing science-based decision-support tools to help coastal planners and emergency responders understand, visualize, and anticipate local impacts from sea-level rise (SLR) and storms in the San Francisco Bay region.
Western Basin & Range - Eastern California Shear Zone
The Eastern California Shear Zone (ECSZ) Mapping project, funded by the National Cooperative Geologic Mapping Program, combines surficial and bedrock geologic mapping, geophysical surveys, and high-resolution topographic data analysis with neotectonic, geomorphic, structural, volcanic, and geochronologic studies to better understand the tectonic framework and landscape...
2019 Santa Ana Reach Habitat Data
This dataset includes 2019 reach habitat data for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the Santa Ana River.
SAR 2019 Santa Ana River Reach Fish Data
This dataset contains the 2019 reach fish data for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the Santa Ana River, California.
Blank results for trace-element data collected for the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project, October 2009–October 2018
Groundwater samples have been collected in California as part of statewide investigations of groundwater quality conducted by the U.S. Geological Survey for the Groundwater Ambient Monitoring and Assessment (GAMA) Priority Basin Project (PBP). Quality-control samples are routinely collected as part of the GAMA-PBP quality assurance plan. Olsen and others (2010) and Davis and others %2
Minisparker and chirp seismic-reflection data of field activity 2014-645-FA; offshore Santa Barbara, southern California from 2014-11-12 to 2014-11-25
USGS collected high-resolution multichannel minisparker and single-channel chirp seismic-reflection data in November 2014, in the offshore Catalina and Santa Cruz basins, which are surrounded by several of the southern California Channel Islands. The survey was designed to image areas of the seafloor associated with movement on the numerous faults offshore of southern California.
2016 Zooplankton sampling in San Joaquin River and False River near Jersey Island in the Sacramento-San Joaquin River Delta of Contra Costa County, California, USA (ver. 2.0, April 2020)
This data set contains information on zooplankton and associated environmental parameters for sampling conducted in the San Joaquin River and False River near their confluence at Jersey Point (Contra Costa County, California), during February-March, 2016. Macrozooplankton were sampled with vertical tows (bottom to surface) of a 50 cm-diameter conical plankton net that was 150cm lon
Historical produced water chemistry data compiled for selected oil fields in Los Angeles and Orange Counties, southern California
This digital dataset contains historical geochemical and other information for 200 samples of produced water from 182 sites in 25 oil fields in Los Angeles and Orange Counties, southern California. Produced water is a term used in the oil industry to describe water that is produced as a byproduct along with the oil and gas. The locations from which these historical samples have been collected...
Multichannel minisparker and chirp seismic reflection data of USGS field activity 2016-616-FA collected in the Catalina Basin offshore southern California in February 2016
This data release contains 25 multichannel minisparker seismic reflection (MCS) profiles and 41 chirp sub-bottom profiles collected in February of 2016 from the Catalina Basin offshore southern California by PCMSC in cooperation with the University of Washington. We collected data on R/V Thompson on USGS cruise 2016-616-FA. We collected MCS profiles to image the fault and channel...
Multichannel minisparker seismic-reflection data of USGS field activity 2016-616-FA collected in the Catalina Basin offshore southern California in February 2016
This data release contains 25 multichannel minisparker seismic reflection (MCS) profiles that were collected in February of 2016 from the Catalina Basin offshore southern California by the U.S. Geological Survey Pacific and Coastal Marine Science Center in cooperation with the University of Washington. Data were collected aboard the University of Washington’s R/V Thomas G. Thompson
Chirp seismic-reflection data of USGS field activity 2016-616-FA collected in the Catalina Basin offshore southern California in February 2016
This data release contains 41 chirp sub-bottom profiles that were collected in February of 2016 from the Catalina Basin offshore southern California by the U.S. Geological Survey Pacific and Coastal Marine Science Center in cooperation with the University of Washington. Data were collected aboard the University of Washington’s R/V Thomas G. Thompson on USGS cruise 2016-616-FA. Chirp pro
Public-Supply Well Water Quality Results: Inorganic Data and Trends, 1974 - 2014 (California GAMA-PBP)
The GAMA-PBP Public-Supply Well Results data viewer allows the user to visualize and download California water-quality data and trends for1974 - 2014. Groundwater-quality data for 38 inorganic constituents are captured and can be downloaded for individual sites or by grid cell.
Electrical Resistivity Tomography in the Anza-Terwilliger Valley, Riverside County, California 2018
The Cahuilla Valley and Terwilliger Valley groundwater basins, 9-006 and 7-026 respectively (California Department of Water Resources 2016) located approximately 25 miles southwest of Palm Springs, are the sole-source for groundwater supply for the rural disadvantaged community and two Native American Tribes, the Ramona Band of Cahuilla and the Cahuilla. The characteristics and sustaina
Electrical Resistivity Tomography GIS Data near Anza, Riverside County, California, 2018
The Cahuilla Valley and Terwilliger Valley groundwater basins, 9-006 and 7-026 respectively (California Department of Water Resources 2016) located approximately 25 miles southwest of Palm Springs, are the sole-source for groundwater supply for the rural disadvantaged community and two Native American Tribes, the Ramona Band of Cahuilla and the Cahuilla. The characteristics and sustaina
Earthquake potential in California-Nevada implied by correlation of strain rate and seismicity
Rock mechanics studies and dynamic earthquake simulations show that patterns of seismicity evolve with time through (1) accumulation phase, (2) localization phase, and (3) rupture phase. We observe a similar pattern of changes in seismicity during the past century across California and Nevada. To quantify these changes, we correlate GPS strain...
Zeng, Yuehua; Petersen, Mark D.; Shen, Zheng-Kang Seafloor fluid seeps on Kimki Ridge, offshore southern California: Links to active strike-slip faulting
The Kimki Ridge fluid seeps are located in western Catalina Basin about 60 km southwest of the southern California mainland and at a water depth of approximately 1100 m. Multichannel seismic reflection profiles collected by the U.S. Geological Survey (USGS) in 2014 show acoustic transparency within the Kimki...
Conrad, James E.; Prouty, Nancy G.; Walton, Maureen A. L.; Kluesner, Jared W.; Maier, Katherine L.; McGann, Mary; Brothers, Daniel; Roland, Emily C.; Dartnell, Peter A prototype operational earthquake loss model for California based on UCERF3-ETAS – A first look at valuation
We present a prototype operational loss model based on UCERF3-ETAS, which is the third Uniform California Earthquake Rupture Forecast with an Epidemic Type Aftershock Sequence (ETAS) component. As such, UCERF3-ETAS represents the first earthquake forecast to relax fault segmentation assumptions and to include multi-fault ruptures, elastic-rebound...
Field, Edward H.; Porter, Keith; Milner, Kevn Reconstructing the evolution of the submarine Monterey Canyon System from Os, Nd, and Pb isotopes in hydrogenetic Fe-Mn crusts
The sources of terrestrial material delivered to the California margin over the past 7 Myr were assessed using 187Os/188Os, Nd, and Pb isotopes in hydrogenetic ferromanganese crusts from three seamounts along the central and southern California margin. From 6.8 to 4.5 (± 0.5) Ma, all three isotope systems show more radiogenic values at...
Conrad, T.A.; Nielsen, S.G.; Peucker-Ehrenbrink, Bernhard; Blusztajn, J.; Winslow, D.; Hein, James R.; Paytan, A. Seismic response of soft deposits due to landslide: The Mission Peak, California, landslide
The seismic response of active and intermittently active landslides is an important issue to resolve to determine if such landslides present an elevated hazard in future earthquakes. To study the response of landslide deposits, seismographs were placed on the Mission Peak landslide in the eastern San Francisco Bay region for a period of one year....
Hartzell, Stephen H.; Leeds, Alena L.; Jibson, Randall W. Science advancements key to increasing management value of life stage monitoring networks for endangered Sacramento River winter-run Chinook salmon in California
A robust monitoring network that provides quantitative information about the status of imperiled species at key life stages and geographic locations over time is fundamental for sustainable management of fisheries resources. For anadromous species, management actions in one geographic domain can substantially affect abundance of subsequent life...
Johnson, Rachel C.; Windell, Sean; Brandes, Patricia L.; Conrad, J. Louise; Ferguson, John; Goertler, Pascale A. L.; Harvey, Brett N.; Heublein, Joseph; Isreal, Joshua A.; Kratville, Daniel W.; Kirsch, Joseph E.; Perry, Russell W.; Pisciotto, Joseph; Poytress, William R.; Reece, Kevin; Swart, Brycen G. Refining fault slip rates using multiple displaced terrace risers—An example from the Honey Lake fault, NE California, USA
Faulted terrace risers are semi-planar features commonly used to constrain Quaternary slip rates along strike-slip faults. These landforms are difficult to date directly and therefore their ages are commonly bracketed by age estimates of the adjacent upper and lower terrace surfaces. However, substantial differences in the ages of the upper and...
Gold, Ryan D.; Briggs, Richard W.; Crone, Anthony J.; Duross, Christopher Refining fault slip rates using multiple displaced terrace risers—An example from the Honey Lake fault, NE California, USA
Faulted terrace risers are semi-planar features commonly used to constrain Quaternary slip rates along strike-slip faults. These landforms are difficult to date directly and therefore their ages are commonly bracketed by age estimates of the adjacent upper and lower terrace surfaces. However, substantial differences in the ages of the upper and...
Gold, Ryan D.; Briggs, Richard W.; Crone, Anthony J.; Duross, Christopher
Yolo Bypass Juvenile Salmon Utilization Study 2016—Summary of acoustically tagged juvenile salmon and study fish release, Sacramento River, California
The Yolo Bypass is a flood control bypass in Sacramento Valley, California. Flood plain habitats may be used for juvenile salmon rearing, however, the potential value of such habitats can be difficult to evaluate because of the intermittent nature of inundation events. The Yolo Bypass Juvenile Salmon Utilization Study (YBUS) used acoustic...
Liedtke, Theresa L.; Hurst, William R. A synoptic view of the Third Uniform California Earthquake Rupture Forecast (UCERF3)
Probabilistic forecasting of earthquake‐producing fault ruptures informs all major decisions aimed at reducing seismic risk and improving earthquake resilience. Earthquake forecasting models rely on two scales of hazard evolution: long‐term (decades to centuries) probabilities of fault rupture, constrained by stress renewal statistics, and short‐...
Field, Edward H.; Jordan, Thomas H.; Page, Morgan T.; Milner, Kevin R.; Shaw, Bruce E.; Dawson, Timothy E.; Biasi, Glenn; Parsons, Thomas E.; Hardebeck, Jeanne L.; Michael, Andrew J.; Weldon, Ray; Powers, Peter M.; Johnson, Kaj M.; Zeng, Yuehua; Bird, Peter; Felzer, Karen; van der Elst, Nicholas; Madden, Christopher; Arrowsmith, Ramon; Werner, Maximillan J.; Thatcher, Wayne R. The transtensional offshore portion of the northern San Andreas fault: Fault zone geometry, late Pleistocene to Holocene sediment deposition, shallow deformation patterns, and asymmetric basin growth
We mapped an ~120 km offshore portion of the northern San Andreas fault (SAF) between Point Arena and Point Delgada using closely spaced seismic reflection profiles (1605 km), high-resolution multibeam bathymetry (~1600 km2), and marine magnetic data. This new data set documents SAF location and continuity, associated tectonic...
Beeson, Jeffrey W.; Johnson, Samuel Y.; Goldfinger, Chris Investigation of late Pleistocene and Holocene activity in the San Gregorio fault zone on the continental slope north of Monterey Canyon, offshore central California
We provide an extensive high‐resolution geophysical, sediment core, and radiocarbon dataset to address late Pleistocene and Holocene fault activity of the San Gregorio fault zone (SGFZ), offshore central California. The SGFZ occurs primarily offshore in the San Andreas fault system and has been accommodating dextral strike‐slip motion between the...
Maier, Katherine L.; Paull, Charles K.; Brothers, Daniel; Caress, David W.; McGann, Mary; Lundsten, Eve M.; Anderson, Krystle; Gwiazda, Roberto
Lowering Chirp from R/V Bold Horizon
The crew of research vessel Bold Horizon with USGS science crew prepare to launch the Chirp sub-bottom profiler off the west coast near northern California and southern Oregon.
Jumbo piston corer with mud from the seafloor
After recovery, the jumbo piston corer sits on the deck of research vessel Bold Horizon in its launch and recovery system. This muddy collar is removed to reveal the removable length of the core, which sits within a stiff plastic tube inside the metal tube.
Prototype Earthquake Early Warning System (Interview)
Retired seismologist David Oppenheimer reflects on the first prototype earthquake early warning system used during the 1989 Loma Prieta earthquake. Scientists deployed an analog system to notify first responders of impending earthquake activity as they worked on rescue efforts at the Cypress Viaduct collapse in Oakland, CA.
GPS target
A global positioning system (GPS) sits on a tripod and is used to accurately pinpoint the center of a target that itself is used for photo rectification with aerial photos.
Santa Barbara survey
Goleta Beach in Santa Barbara experienced an unusual storm and large wave event in the Spring of 2014. Gaviota Pier, seen far off in the background, sustained heavy damage as did the restaurants on the pier and nearby. The USGS conducts seasonal surveys throught the year to see how the beaches are changing through time. Here, a USGS scientist navigates a personal
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PubTalk 09/2019 — Bats in the West
Title: Bats in the West: Discoveries, Questions, and Future Research
By Gabriel A. Reyes, USGS Biologist
- Learn about bat ecology, diversity, and the role they play in our ecosystem.
- See how scientists are using a variety of methods including capture, acoustic monitoring, and tracking, to learn more about local bat species.
- Find out how
Scott Lydeen at Strawberry Peak Seismic Station Tower
USGS technicial Scott Lydeen climbing the tower at the Strawberry Peak seismic station tower, part of the Southern California Seismic Network.
High-resolution Water Quality Mapping on California's Bay-Delta
Hydrologist Brian Bergamaschi is seen through the USGS California Water Science Center Biogeochemistry Group's underwater water quality mapping manifold. This maze of tygon tubing allows water to be pumped onto a boat while underway, splits the water into multiple flowpaths, and passes the water to various flow-through water quality instruments through a manifold that
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Quratulain Ahmed preserving samples in fume hood
Quratulain Ahmed preserving samples in fume hood
Sydney Berrios running samples on Aqualog
Sydney Berrios running samples on Aqualog
Horiba Aqaulog
Horiba Aqaulog - simultaneously measures absorbance spectra and fluorescence
Earlier this month, over 40 scientists from the California Water Science Center attended the 2019 Interagency Ecological Program (IEP) Workshop in Folsom, California.
New U.S. Geological Survey-led coastal modeling research presents state, federal, and commercial entities with varying storm and sea level-rise scenarios to assist with planning for future infrastructure and mitigation needs along the California coast.
The Mono Craters, a line of volcanic domes and craters south of Mono Lake in eastern California, represent the youngest rhyolitic volcanoes in the western United States.
Oceanographer Juliette Finzi Hart of the USGS Pacific Coastal and Marine Science Center was invited by the California Department of Transportation (Caltrans) to provide an overview of the USGS Coastal Storm Modeling System (CoSMoS) at the 2019 California Transportation Planning Conference in San Diego.
On Monday, February 25, 2019, research geologist Jonathan Warrick of the USGS Pacific Coastal and Marine Science Center spoke with ABC7 News about a February 22 landslide that injured one woman and buried another at San Francisco’s Fort Funston beach.
The potential for damaging earthquakes, landslides, floods, tsunamis, and wildfires is widely recognized in California.
Core players in “Expanding Pacific Research and Exploration of Submerged Systems” (EXPRESS) held a planning workshop at the USGS Pacific Coastal and Marine Science Center in Santa Cruz, California, November 29–30.
Great Lakes Phragmites programs served as a case study for the Delta Stewardship Council
During a tour of western USGS offices, Director James F. Reilly II visited the CalVO offices and operations center in Menlo Park, CA.
This month California Water Science Center Scientist Dr. Michelle Hladik and others published an article on water treatment processes and their effects on neonicotinoid pesticides and the potential health threats they pose.
Researchers from the USGS Pacific Coastal and Marine Science Center (PCMSC) participated in a research cruise to survey deep-water coral, sponge, and fish habitats off U.S. West Coast.
A low-flying helicopter under contract to the U.S. Geological Survey, in cooperation with the California State Water Resources Control Board, has begun collecting and recording geophysical measurements for purpose of groundwater salinity and aquifer mapping.
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Locations
Southwest Regional Director's Office
Phone: (916) 278-9551
Fax: (916) 278-9566
Pacific Coastal and Marine Science Center
Phone: 831-460-7401
Fax: 831-427-4748
Sacramento Projects Office (USGS California Water Science Center)
Phone: 916-278-3000
Fax: 916-278-3070
Western Ecological Research Center - Headquarters
Phone: (916) 278-9485
Fax: (916) 278-9475
Geology, Minerals, Energy and Geophysics Science Center
Phone: (650) 329-4881
Earthquake Science Center
Western Geographic Science Center - Main Office
San Diego Projects Office (USGS California Water Science Center)
Phone: 619-225-6100
Fax: 619-225-6101
Fort Collins Science Center
Phone: 970-226-9100
Fax: 970-226-9230
USGS California Volcano Observatory (CalVO package delivery)
askcalvo@usgs.gov
Phone: 650-329-5083
Poway Field Office (USGS California Water Science Center)
Phone: 858-679-4015
Fax: 858-679-4019
Truckee Field Office (USGS California Water Science Center)
Phone: 530-587-0910
Fax: 530-587-0914
Redding Field Office (USGS California Water Science Center)
Phone: 530-246-5282
Fax: 530-246-0717
Ukiah Field Office (USGS California Water Science Center)
Phone: 707-468-4040
Fax: 707-468-4022
Redlands Field Office (USGS California Water Science Center)
Phone: 909-798-3272
West Sacramento Projects Office (USGS California Water Science Center)
Phone: 916-617-2799
Eureka Satellite Office (USGS California Water Science Center)
Phone: 707-442-3169
Fax: 707-445-7860
Sacramento Field Office (USGS California Water Science Center)
Phone: 916-381-0207
Fax: 916-381-0556
Santa Cruz Field Office (USGS California Water Science Center)
Phone: 831-460-7494
Santa Maria Field Office (USGS California Water Science Center)
Phone: 805-928-9539
Fax: 805-928-9220
USGS Menlo Park Library
men_lib@usgs.gov
Phone: 650-329-5027
Fax: 650-329-5132