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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Evaluation of Groundwater Resources in the Adelaida Area of San Luis Obispo County, California
Stakeholders in San Luis Obispo County are concerned that the increased demand for water use has, and will continue to, affect groundwater levels and availability in the Adelaida area. To address stakeholder concerns, the County of San Luis Obispo Board of Supervisors has asked the USGS to conduct a comprehensive evaluation of groundwater resources of the Adelaida area.
Fourth Federal UAS Workshop
November 17 - 19, 2020 Virtual Workshop
Evaluation of groundwater resources of the Anza-Terwilliger area, Anza, California
Groundwater is the sole source for water use to the rural community and two Native American tribes in the Cahuilla Valley and Terwilliger Valley groundwater basins, which are located approximately 35 miles southwest of Palm Springs, California. The characteristics and sustainable yield of the basins are not well understood and are threatened by increasing water use and potential changes in...
Using Unmanned Aerial Systems (UAS) Capabilities to Help Identify Giant Salvinia (Salvinia molesta) and the effects of Salvinia weevil (Cyrtogagous salviniae)
USGS is collecting remotely sensed data to classify Salvinia molesta, a non-native aquatic species that reduces light and oxygen levels in water, making it unsuitable for fish and other aquatic plant life.
California Seafloor and Coastal Mapping Program
A Foundation for Characterizing Hazards, Monitoring Change, and Managing Resources
California Seafloor Mapping Program mapping progress
Table shows USGS California Seafloor Mapping Program progress by block number, as of August 2019.
Tsunami Record from the Great 1906 San Francisco Earthquake
Shortly after the Great San Francisco earthquake of April 18, 1906, a sea level disturbance (tsunami) was recorded at the Presidio tide gauge station in San Francisco (the station is now located nearby at Ft. Point). What type of mechanism (earthquake rupture, landslide, other) generated the tsunami...
Creating a Model to Predict Future Carbon Levels in Tidally-driven Marshes
Tidal marshes are important ecosystems in the San Francisco-Bay Delta. They remove carbon from the atmosphere, they build up soils that buffer our communities from sea level rise, they provide critical habitat and food resources for a diversity of species, and they reduce excessive nutrients which have a negative impact on water quality. As a result of land-use change and urbanization, the San...
Attending Seminars at PCMSC
Check our schedule for upcoming seminars and dates.
Earthquake Early Warning Seismic Station Adjustment Terms - Annemarie Baltay
Earthquake early warning, live in California, aims to send user alerts before ground shaking arrives at their location. Work directly with a USGS team in implementing a ground-motion based early warning algorithm, and develop novel station-specific adjustment factors to improve the accuracy of ground-shaking estimates, a critical step in sending the most useful user alerts.
San Francisco Bay Area – SF Peninsula (BALT4) Site near Pacifica, CA
Landslides in the San Francisco Bay area (SFBA) of California impact people, infrastructure, and the environment, and are commonly induced by intense or prolonged rainfall associated with strong winter storms...
San Francisco Bay Area – SF Peninsula (BALT3) Site near Brisbane, CA
Landslides in the San Francisco Bay area (SFBA) of California impact people, infrastructure, and the environment, and are commonly induced by intense or prolonged rainfall associated with strong winter storms...
CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood depth and duration projections: 20-year storm in Santa Cruz County
This data contains maximum depth of flooding (cm) in the region landward of the present-day shoreline for the sea-level rise (SLR) and storm condition indicated.
The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of kilometers) of storm-induced coastal flooding and erosion for both current and future sea-le
CoSMoS (Coastal Storm Modeling System) Central California v3.1 water-level projections: 20-year storm in Santa Cruz County
This data contains model-derived total water levels (in meters) for the sea-level rise (SLR) and storm condition indicated.
The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of kilometers) of storm-induced coastal flooding and erosion for both current and future sea-level rise (SLR) scenarios. Projecti
CoSMoS (Coastal Storm Modeling System) Central California v3.1 water-level projections: 100-year storm in Santa Cruz County
This data contains model-derived total water levels (in meters) for the sea-level rise (SLR) and storm condition indicated.
The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of kilometers) of storm-induced coastal flooding and erosion for both current and future sea-level rise (SLR) scenarios. Projecti
CoSMoS (Coastal Storm Modeling System) Central California v3.1 wave-hazard projections: 100-year storm in Santa Cruz County
This data contains maximum model-derived significant wave height (in meters) for the sea-level rise (SLR) and storm condition indicated.
The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of kilometers) of storm-induced coastal flooding and erosion for both current and future sea-level rise (SLR) scenar
CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood depth and duration projections: 1-year storm in Santa Cruz County
This data contains maximum depth of flooding (cm) in the region landward of the present-day shoreline for the sea-level rise (SLR) and storm condition indicated.
The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of kilometers) of storm-induced coastal flooding and erosion for both current and future sea-le
CoSMoS (Coastal Storm Modeling System) Central California v3.1 ocean-currents projections: average conditions in Santa Cruz County
This data contains maximum model-derived ocean currents (in meters per second) for the sea-level rise (SLR) and storm condition indicated.
The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of kilometers) of storm-induced coastal flooding and erosion for both current and future sea-level rise (SLR) scen
CoSMoS (Coastal Storm Modeling System) Central California v3.1 wave-hazard projections: 20-year storm in Santa Cruz County
This data contains maximum model-derived significant wave height (in meters) for the sea-level rise (SLR) and storm condition indicated.
The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of kilometers) of storm-induced coastal flooding and erosion for both current and future sea-level rise (SLR) scenar
Quaternary faults offshore of California
A comprehensive map of Quaternary faults has been generated for offshore of California. The Quaternary fault map includes mapped geometries and attribute information for offshore fault systems located in California State and Federal waters. The polyline shapefile has been compiled from previously published mapping where relatively dense, high-resolution marine geophysical data exist. The data...
Select borehole data for Anza Valley, Anza, CA
Borehole log number, State Well Number, location, construction information, and any wells tests performed on select wells from the Anza basin, Anza, CA. Also includes a lithologic data for a sub-set of borehole logs identified based on best coverage and representation of data within the study area.
Partitioning of six pyrethroid insecticides at varying salinities
To determine aqueous pyrethroid partitioning across a salinity gradient 20 mL Pyrex beakers were filled with 8 mL of deionized water at varying salinities (0, 0.5, 2, 6 ppt). Salinity was adjusted using a 10 ppt stock solution (made by diluting Instant Ocean into deionized water). The water samples were spiked with pyrethroids (bifenthrin, cyhalothrin, cyfluthrin, cypermethr
SmeltCam sampling in San Joaquin River and False River near Jersey Island in the Sacramento-San Joaquin River Delta, California, 2016
This dataset includes field data for fishes sampled using mid-water trawls and the SmeltCam during daylight hours in the Sacramento- San Joaquin Delta, California. Sampling took place between February 8, 2016 and March 1, 2016. This data release includes all measured environmental parameters and fish taxa collected during sampling event.
Otolith chemistry of fishes in Rodeo Lagoon, Marin County, California, 2016
The dataset includes multiple file types (CSV, ArcGIS shapefiles, and images), data relates to the elemental analysis of fish otoliths. Otoliths examined in this study were from randomly-sampled individual Tidewater Goby (Eucyclogobius newberryi) and Prickly Sculpin (Cottus asper) from the adult population of Rodeo Lagoon and Rodeo Creek, Marin County, California. The fish w
Geophysical and geologic maps of Mountain Pass and vicinity, California and Nevada
U.S. Geological Survey Scientific Investigations Map 3412 is a series of products that consists of geophysical and geologic maps of Mountain Pass and vicinity, California. Maps A and B (red outline in above map image) are gravity and aeromagnetic maps, respectively. The map series was begun as part of an effort to study regional crustal structures...
Ponce, David A.Improving earthquake rupture forecasts using California as a guide
This article discusses ways in which earthquake rupture forecast models might be improved. Because changes are most easily described in the context of specific models, the third Uniform California Earthquake Rupture Forecast (UCERF3) and its presumed successor, UCERF4, is used as a basis for discussion. Virtually all of the issues and possible...
Field, Edward H.2018 hurricane and wildfire supplemental funding: USGS recovery activities
The Additional Supplemental Appropriations for Disaster Relief Requirements Act, 2018 (P.L. 115-123), was signed by the President on February 9, 2018. This funding provided $42.2 million to the U.S. Geological Survey (USGS) for equipment repair and replacement, high-resolution elevation data collection in both hurricane- and wildfire-impacted...
Hinck, Jo Ellen; Stachyra, JosephIncreasing earthquake insurance coverage in California via parametric hedges
California has the highest earthquake risk of any state in the United States. The Federal Emergency Management Agency (FEMA) reported in 2017 that 73% of the nation’s annual losses to earthquakes were expected to be concentrated in California and the Pacific Northwest. California alone constitutes 61% ($3.7 billion out of an estimated $6.1 billion...
Franco, Guillermo; Tirabassi, G; Lopeman, M; Wald, David J.; Siembieda, W.J.State transportation agencies partner to deploy and enhance ShakeCast
The California Department of Transportation (Caltrans) is organizing and leading a three-year Transportation Pooled Fund (TPF) project, Connecting the Dots: Implementing ShakeCast Across Multiple State Departments of Transportation for Rapid Post-Earthquake Response. Ten state Departments of Transportation (DOT)—CA, ID, MO, MS, OK, OR, SC, TX, UT...
Turner, L.; Wald, David J.; Lin, Kuo-wan; Chiou, Brian; Slosky, DanielIdentifying physics‐based thresholds for rainfall‐induced landsliding
Most regional landslide warning systems utilize empirically derived rainfall thresholds that are difficult to improve without recalibration to additional landslide events. To address this limitation, we explored the use of synthetic rainfall to generate thousands of possible storm patterns and coupled them with a physics‐based hydrology and slope...
Thomas, Matthew A.; Mirus, Benjamin B.; Collins, Brian D.A physics-based earthquake simulator replicates seismic hazard statistics across California
Seismic hazard models are important for society, feeding into building codes and hazard mitigation efforts. These models, however, rest on many uncertain assumptions and are difficult to test observationally because of the long recurrence times of large earthquakes. Physics-based earthquake simulators offer a potentially helpful tool, but they...
Shaw, Bruce E.; Milner, Kevin R.; Field, Edward H.; Richards-Dinger, Keith B.; Gilchrist, Jacquelyn J.; Dieterich, James H.; Jordan, Thomas H.Flow-mediated effects on travel time, routing, and survival of juvenile Chinook salmon in a spatially complex, tidally forced river delta
We evaluated the interacting influences of river flows and tides on travel time, routing, and survival of juvenile late-fall Chinook salmon (Oncorhynchus tshawytscha) migrating through the Sacramento–San Joaquin River Delta. To quantify these effects, we jointly modeled the travel time, survival, and migration routing in relation to individual...
Perry, Russell W.; Pope, Adam C.; Romine, Jason G.; Brandes, Patricia L.; Burau, Jon R.; Blake, Aaron R.; Ammann, Arnold J.; Michel, Cyril J.Survival, travel time, and utilization of Yolo Bypass, California, by outmigrating acoustic-tagged late-fall Chinook salmon
Juvenile Chinook salmon (Oncorhynchus tshawytscha) migrating through California's Sacramento-San Joaquin River Delta toward the Pacific Ocean face numerous challenges to their survival. The Yolo Bypass is a broad floodplain of the Sacramento River that floods in about 70 percent of years in response to large, uncontrolled runoff events. As one of...
Pope, Adam C.; Perry, Russell W.; Hance, Dalton J.; Hansel, Hal C.Controls on submarine canyon head evolution: Monterey Canyon, offshore central California
The Monterey submarine canyon, incised across the continental shelf in Monterey Bay, California, provides a record of the link between onshore tectonism, fluvial transport, and deep-marine deposition. High-resolution seismic-reflection imaging in Monterey Bay reveals an extensive paleocanyon unit buried below the seafloor of the continental shelf...
Maier, Katherine L.; Johnson, Samuel Y.; Hart, Patrick E.Analysis of mean seismic ground motion and its uncertainty based on the UCERF3 geologic slip rate model with uncertainty for California
The Uniform California Earthquake Rupture Forecast v.3 (UCERF3) model (Field et al., 2014) considers epistemic uncertainty in fault‐slip rate via the inclusion of multiple rate models based on geologic and/or geodetic data. However, these slip rates are commonly clustered about their mean value and do not reflect the broader distribution of...
Zeng, YuehuaFaunal and stable isotopic analyses of benthic foraminifera from the Southeast Seep on Kimki Ridge offshore southern California, USA
We investigated the benthic foraminiferal faunal and stable carbon and oxygen isotopic composition of a 15-cm push core (NA075-092b) obtained on a Telepresence-Enabled cruise to the Southeast Seep on Kimki Ridge offshore southern California. The seep core was taken at a depth of 973 m in the vicinity of a Beggiatoa bacterial mat and vesicomyid...
McGann, Mary; Conrad, James E.California coastal erosion
This region of the California coastline is lined with coastal bluffs that have been shaped not only by runoff from rain, but also by wave- and wind-driven erosion. This photo from Pescadero State Beach displays an example of a bluff undergoing erosional processes. Water from the ocean, delivered in waves, can overtop some of these coastal bluffs. As water runs off the
...California coastline
The U.S. west coast is an area of complex coastal geography. This photograph depicts several examples of geological features along the California coastline that are shaped by varied coastal processes. The gently sloping beach, stark bluffs, and presence of smooth rocks suggests that the coastal processes shaping this coastline are complex.
A seasonal wetland engineered to have a deeper and shallow pool
A three year study was conducted in seasonal wetlands to determine if a deep and shallow water pool resulted in a reduction of methylmercury in caged fish and surface water.
Natural Recharge (1981 - 2010), Indian Wells Valley, CA
The USGS California Basin Characterization Model (BCM) was used to understand the rate and amounts of natural groundwater recharge in the Indian Wells Valley and to refine historical estimates of groundwater recharge in the valley. Results from this study provide validation of recharge estimates
...Southern Cascadia topography and bathymetry
Topography and bathymetry of southern Cascadia, which includes southern Oregon and northern California (seafloor depths between 200 and 3000 m are shown in the spectrum color scale from red (shallower) to purple (deeper). The land and continental shelf are shown in grayscale slope shading where darker colors represent steeper slopes. Green lines are locations of known
...USGS Menlo Park campus
Building 3 on the USGS Western Region campus in Menlo Park, California.
Building 1 and Credit Union on USGS Menlo Park campus
Building 1 formerly housed many different USGS groups, including the Western Coastal and Marine Geology team, but slowly has been leased out to other federal agencies like the Transportation Security Administration (TSA) and Veterans Affairs (VA). At the right is the Menlo Survey Federal Credit Union.
Thurston Lake and Mount Konocti, Clear Lake Volcanic Field
Thurston Lake and Mount Konocti, Clear Lake Volcanic Field, California.
Image of the Week - Fires Across California
Fires burned across California in late 2019. Fall is the state's most dangerous season for wildfires, propelled by dry and windy conditions. In recent years however, the fall fire season has been starting earlier and ending later. A series of images from the MODIS sensor on NASA's Terra and Aqua satellites show the Kincade Fire in northern California. This fire started on
Scientist adjusts equipment mounted on tower at the Suisun Marsh
USGS Research Scientist Ellen Goodrich-Stuart adjusts a CH4 (Methane) analyzer mounted on the eddy covariance flux tower at the Rush Ranch site at Suisun Marsh.
PubTalk 11/2019 —Sea-Level Rise, Extreme Water Levels, Coastal Erosion
Title: Sea-Level Rise, Extreme Water Levels, and Coastal Erosion ... How bad could it possibly be?
- Sea-level rise represents an unprecedented civil engineering challenge.
- Small amounts of sea-level rise can disproportionately increase the frequency of coastal flooding.
- One-third to two-thirds of the beaches in Southern California may disappear
Wintering Waterfowl at Sacramento National Wildlife Refuge
In this video, you can hear the honks and quacks of geese and ducks ring through the air, as birds fly in every direction above a wetland. This video was captured at Sacramento National Wildlife Refuge in November 2019, not long after geese and ducks began to arrive to spend the winter in the California Central Valley.

Effects from the two July 2019 Ridgecrest, CA earthquakes were observed in several USGS continuous groundwater-level monitoring sites in California, Nevada, and Arizona.

Two new publications underscore the role of wind in destructive California wildfires
Next week, USGS and the nation commemorate the 30th anniversary of one of the most destructive earthquake disasters in U.S. history – the 1989 Loma Prieta earthquake in northern California. The magnitude 6.9 quake struck on October 17 in the southern portion of the San Francisco Bay Area near Santa Cruz and was responsible for the deaths of 63 people and more than 3,500 injuries.

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?”.
Read Could the M7.1 Ridgecrest, CA Earthquake Sequence Trigger a Large Earthquake Nearby?

Do you get excited about working outdoors? Do you enjoy creative problem solving? Would you like to work part to full time in a challenging position that could lead to incredible career opportunities?
USGS researcher quoted in major news stories about the August 2 coastal cliff collapse that killed three people on a beach in Encinitas, California

GSA's news release on the recent USGS-authored publication from the Landslide Hazards Program: Inundation, flow dynamics, and damage in the 9 January 2018 Montecito debris-flow event, California, USA: Opportunities and challenges for post-wildfire risk assessment.
Dr. Nate Stephenson says the rules are changing for Sierra Nevada trees

For Dr. Kathryn McEachern, research and outreach go hand in hand

The seismic activity that started on the evening of July 5 at the southern margin of Coso Volcanic Field in Inyo County, California continues at a rate of about 600 M1.0 or greater earthquakes per day.

An earthquake swarm started on the evening of July 5 at the southern margin of Coso Volcanic Field in Inyo County, California.
Updated on July 19. Visit the USGS earthquake event page for more information.