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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Land Subsidence in California
Extensive groundwater withdrawals from aquifer systems have caused land subsidence in many California basins. Land subsidence can cause infrastructure damage, not only to buildings and roads but also to water conveyence systems. Groundwater-level and land-subsidence monitoring provide the information needed to guide mitigation efforts and management of future effects.
Characterizing the Influence of Fire on Hydrology in Southern California
The frequency of fire in southern California forests has steadily increased over time as a result of ignitions at the growing wildland-urban interface, as well as a result of warming due to climate change. Understanding the implications of increased wildfire on hydrologic conditions and water supply is particularly important given the increasing demands for water resources to satisfy growing...
Cheatgrass and Medusahead
Invasive annual grasses, such as cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae), are one of the most significant stressors to rangeland ecosystems in the western U.S. Their expansion and dominance across this area are the most damaging ecosystem agents on this iconic landscape.
San Diego Hydrogeology
This is the first comprehensive geologic and hydrologic study for the San Diego area. This study will provide the integrated hydrogeologic knowledge necessary in this important and highly visible area of the United States and will serve as a role model for similar coastal settings throughout the world that have modest rainfall and small aquifers. Locally, results will help...
Using Drone Imagery to Assess Impacts of the 2018 Carr Fire
USGS WERC’s Dr. Karen Thorne and her research team are using drone imagery to understand how the 2018 Carr Fire affected ecosystems and cultural resources. The study, a collaboration with the National Park Service (NPS), focuses on Whiskeytown National Recreation Area in northern California. The drone images will help the WERC researchers identify changes in topography, cultural sites, debris...
Groundwater Ambient Monitoring & Assessment (GAMA)
The Groundwater Ambient Monitoring and Assessment Program’s Priority Basin Project (GAMA-PBP) was established by the California State Water Resources Control Board (SWRCB) in response to the Ground-Water Quality Monitoring Act of 2001 (Sections 10780-10782.3 of the California Water Code). The USGS is the technical lead for the GAMA-PBP and between 2004-2012 focused on characterizing the...
Occurrence of natural and anthropogenic hexavalent chromium (Cr VI) in groundwater near a mapped plume, Hinkley, CA
Between 1952 and 1964, cooling water was treated with a compound containing chromium to prevent corrosion within the Pacific Gas and Electric Company (PG&E) Hinkley Compressor Station. This water was discharged to unlined ponds, resulting in contamination of soil and groundwater within the underlying alluvial aquifer. The purpose of this study is to evaluate the occurrence of natural and...
Regional Groundwater Availability Study of the California Coastal Basins
This study seeks to quantify water availability in the California Coastal Basins (CCBs). The CCBs vary greatly in their geologic, hydrologic, and climatic conditions; predominant water uses (agricultural, urban, or environmental); and how water availability changes in response to natural and anthropogenic stresses. Considering the complex dynamics of the CCBs and the history of managing water...
United States Assessments of Undiscovered Oil and Gas Resources
USGS Energy Resources Program provides periodic assessments of the oil and natural gas endowment of the United States and the World (click here for information about World Oil and Gas Assessments). This website provides access to new, prioritized, assessment results and supporting data for the United States, as part...
Forest health and drought response
Forests provide society with economically important and often irreplaceable goods and services, such as wood products, carbon sequestration, clean water, biodiversity, and recreational opportunities. Yet hotter droughts (droughts in which unusually high temperatures exacerbate the effects of low precipitation) are projected to increase in frequency and intensity in coming decades, potentially...
San Francisco Bay Basic Tide Model
This web page provides files that may be used to run a basic depth-averaged (2DH) Deltares Delft3D version 4.00.01 astronomic tide model for San Francisco Bay. It was developed with the primary aim of assessing water level fluctuations and flow conditions in the vicinity of the Golden Gate (Elias and Hansen 2013).
Soil Stratigraphy and Erosion Potential on the American and Sacramento Rivers
Much of the Sacramento region is protected from flooding by levees constructed on the American and Sacramento Rivers, which join near downtown Sacramento before flowing to the Sacramento-San Joaquin River Delta.
Historical produced water chemistry data compiled for the Orcutt and Oxnard oil fields, Santa Barbara and Ventura Counties, southern California
This digital dataset represents historical geochemical and other information for 58 sample results of produced water from 56 sites in the Orcutt and Oxnard oil fields in Santa Barbara and Ventura Counties, respectively, in 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 whic...
Success Dam spillway seismic refraction survey, Porterville, California, December 2018 and July 2019
Compressional- (P-) wave seismic refraction data were acquired in December 2018 and July 2019 along fourteen profiles within the spillway of Success Dam in Porterville, California. A new concrete ogee weir is planned for construction within the existing spillway, and the P-wave seismic velocity models will be used to inform further geotechnical investigations, including siting new geolo
Global Positioning System Survey data from 2015, Coachella Valley, Riverside County, California
Data collection: GPS measurements were taken at 24 geodetic monuments during September 27-October 2, 2015. The GPS surveys generally followed established guidelines (Zilkoski and others, 1997), except that the data were processed with single-baseline, rather than multi-baseline, software. GPS measurements were recorded at the monuments on at least 2 different days during 1-hour ob
Interferometric Synthetic Aperture Radar Data for 1995-2017
The data set consists of twenty-four individual interferograms and two stacked interferograms. Of the twenty-four individual interferograms, two interferograms were processed from synthetic aperture radar data acquired by the German Aerospace Center’s (DLR) TerraSAR-X satellite and twenty-two interferograms were processed from synthetic aperture radar data acquired by the European S
Physical and Biological Drivers of Fish Populations in the Sacramento Deep Water Shipping Channel, California, 2016-2018
This dataset includes field and lab data for fish, vegetation, zooplankton, phytoplankton, fish diets, and stable isotopes collected during daylight hours in the Sacramento Deep Water Shipping Channel in the Northern Sacramento-San Joaquin Delta, California, USA. This data release includes all measured environmental parameters, animal taxa, and isotope values included in the ana
Archive of boomer subbottom data collected offshore Eureka, California during USGS field activity W-1-96-NC from 1996-06-29 to 1996-07-07
This data release contains boomer subbottom data collected in June and July of 1996 on the shelf and slope offshore Eureka, California. Subbottom acoustic penetration spans up to several tens of meters, and is variable by location. This data release contains digital SEG-Y data. The data were collected aboard the R/V Wecoma using a Huntec Hydrosonde Deep-Tow system.
Airborne electromagnetic and magnetic survey, southwestern San Joaquin Valley near Lost Hills, California, 2016
Airborne electromagnetic (AEM) and magnetic survey data were collected during October 2016 along 1,443 line kilometers in the southwestern San Joaquin Valley near Lost Hills, California. These data were collected in support of groundwater salinity mapping and hydrogeologic framework development as part of the U.S. Geological Survey California Oil, Gas, and Groundwater program and the
Supporting groundwater salinity data used for salinity mapping adjacent to the Lost Hills and Belridge oil fields, Kern County, California
This dataset contains summarized historical groundwater salinity observations from wells near the Lost Hills and Belridge oil fields in the southwestern San Joaquin Valley, Kern County, California. Total dissolved solids (TDS) concentration, electrical fluid conductivity (EC), and well construction information were aggregated from public data sources and local water management age
Bathymetry, topography, and acoustic backscatter data, and a digital elevation model (DEM) of the Cache Slough Complex and Sacramento River Deep Water Ship Channel, Sacramento-San Joaquin Delta, California
This data release presents bathymetric and topographic data from surveys performed between 2017 and 2018 in the Cache Slough Complex and the Sacramento River Deep Water Ship Channel (DWSC), northern Sacramento-San Joaquin Delta, California. The shallow, highly vegetated aquatic habitats of this region necessitated a variety of survey platforms and techniques. In the deeper channels, swath...
Bathymetry, topography, and acoustic backscatter data, and a digital elevation model of the Cache Slough Complex and Sacramento River Deep Water Ship Channel, Sacramento-San Joaquin Delta, California
This data release presents bathymetric and topographic data from surveys performed between 2017 and 2018 in the Cache Slough Complex and the Sacramento River Deep Water Ship Channel (DWSC), northern Sacramento-San Joaquin Delta, California. The shallow, highly vegetated aquatic habitats of this region necessitated a variety of survey platforms and techniques. In the deeper channels, swath...
Digital elevation model (DEM) of the Sacramento River Deep Water Ship Channel (DWSC), Sacramento-San Joaquin Delta, California
This metadata describes a digital elevation model (DEM) created from bathymetric and topographic data collected between 2017 and 2019 in the Sacramento River Deep Water Ship Channel (DWSC), northern Sacramento-San Joaquin Delta, California.
We merged the newly collected bathymetric and topographic data presented in this data release (DOI:10.5066/P9AQSRVH) with 2019 surveys b
Digital elevation model (DEM) of the Cache Slough Complex, Sacramento-San Joaquin Delta, California
This metadata describes a digital elevation model (DEM) created from bathymetric and topographic data collected between 2004 and 2019 in the Cache Slough Complex (CSC), northern Sacramento-San Joaquin Delta, California.
We merged the newly collected bathymetric and topographic data presented in this data release (DOI:10.5066/P9AQSRVH) with 2019 surveys by the California Depa
High-resolution seismic-reflection data from offshore northern California — Bolinas to Sea Ranch
The U.S. Geological Survey collected high-resolution seismic-reflection data in September 2009, on survey S-8-09-NC, offshore of northern California between Bolinas and Sea Ranch.The survey area spans about 125 km of California’s coast and extends around Point Reyes. Data were collected aboard the U.S. Geological Survey R/V Parke Snavely....
Sliter, Ray W.; Johnson, Samuel Y.; Chin, John L.; Allwardt, Parker; Beeson, Jeffrey; Triezenberg, Peter J.
Annualized earthquake loss estimates for California and their sensitivity to site amplification
Input datasets for annualized earthquake loss (AEL) estimation for California were updated recently by the scientific community, and include the National Seismic Hazard Model (NSHM), site‐response model, and estimates of shear‐wave velocity. Additionally, the Federal Emergency Management Agency’s loss estimation tool, Hazus, was updated to include...
Chen, Rui; Jaiswal, Kishor; Bausch, D; Seligson, H; Wills, C.J. Constraining the relative importance of raindrop- and flow-driven sediment transport mechanisms in postwildfire environments and implications for recovery time scales
Mountain watersheds recently burned by wildfire often experience greater amounts of runoff and increased rates of sediment transport relative to similar unburned areas. Given the sedimentation and debris flow threats caused by increases in erosion, more work is needed to better understand the physical mechanisms responsible for the observed...
McGuire, Luke; Kean, Jason W.; Staley, Dennis M.; Rengers, Francis K.; Wasklewicz, Thad A.
California State Waters Map Series—Offshore of Monterey, California
IntroductionIn 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed...
Johnson, Samuel Y.; Cochran, Susan A.; Johnson, Samuel Y.; Dartnell, Peter; Hartwell, Stephen R.; Cochrane, Guy R.; Golden, Nadine E.; Watt, Janet T.; Davenport, Clifton W.; Kvitek, Rikk G.; Erdey, Mercedes D.; Krigsman, Lisa M.; Sliter, Ray W.; Maier, Katherine L. Model simulations of flood and debris flow timing in steep catchments after wildfire
Debris flows are a typical hazard on steep slopes after wildfire, but unlike debris flows that mobilize from landslides, most post-wildfire debris flows are generated from water runoff. The majority of existing debris-flow modeling has focused on landslide-triggered debris flows. In this study we explore the potential for using process-based...
Rengers, Francis K.; McGuire, Luke; Kean, Jason W.; Staley, Dennis M.; Hobley, D.E.J
Preliminary results from exploratory sampling of wells for the California oil, gas, and groundwater program, 2014–15
Introduction In 2014 and 2015, the U.S. Geological Survey (USGS) sampled water wells in the Los Angeles Basin and southern San Joaquin Valley, California, and oil wells in the San Joaquin Valley for analysis of multiple chemical, isotopic, and groundwater-age tracers. The purpose of this reconnaissance sampling...
McMahon, Peter B.; Kulongoski, Justin T.; Wright, Michael T.; Land, Michael T.; Landon, Matthew K.; Cozzarelli, Isabelle M.; Vengosh, Avner; Aiken, George R.
Relative distribution and abundance of fishes and crayfish in 2010 and 2014 prior to saltcedar (Tamarix ssp.) removal in the Amargosa River Canyon, southeastern California
The Amargosa River Canyon, located in the Mojave Desert of southeastern California, contains the longest perennial reach of the Amargosa River. Because of its diverse flora and fauna, it has been designated as an Area of Critical Environmental Concern and a Wild and Scenic River by the Bureau of Land Management. A survey of fishes conducted in...
Hereford, Mark E. Evaluation of a floating fish guidance structure at a hydrodynamically complex river junction in the Sacramento-San Joaquin River Delta, California, USA
Survival of out-migrating juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento–San Joaquin River delta, California, USA, varies by migration route. Survival of salmonids that enter the interior and southern Delta can be as low as half that of salmonids that remain in the main-stem Sacramento River. Reducing entrainment into...
Romine, Jason G.; Perry, Russell W.; Pope, Adam C.; Stumpner, Paul; Liedtke, Theresa L.; Kumagai, Kevin K.; Reeves, Ryan L. Anadromous salmonids in the Delta: New science 2006–2016
As juvenile salmon enter the Sacramento–SanJoaquin River Delta (“the Delta”) they disperse among its complex channel network where they are subject to channel-specific processes that affect their rate of migration, vulnerability to predation, feeding success, growth rates, and ultimately, survival. In the decades before 2006...
Perry, Russell W.; Buchanan, Rebecca A.; Brandes, Patricia L.; Burau, Jon R.; Israel, Joshua A
Estimating juvenile Chinook salmon (Oncorhynchus tshawytscha) abundance from beach seine data collected in the Sacramento–San Joaquin Delta and San Francisco Bay, California
Resource managers rely on abundance or density metrics derived from beach seine surveys to make vital decisions that affect fish population dynamics and assemblage structure. However, abundance and density metrics may be biased by imperfect capture and lack of geographic closure during sampling. Currently, there is considerable uncertainty about...
Perry, Russell W.; Kirsch, Joseph E.; Hendrix, A. Noble
Gravity and magnetic studies of the eastern Mojave Desert, California and Nevada
IntroductionFrom May 2011 to August 2014, the U.S. Geological Survey (USGS) collected gravity data at more than 2,300 stations and physical property measurements on more than 640 rock samples from outcrops in the eastern Mojave Desert, California and Nevada. Gravity, magnetic, and physical-property data are used to study and locate regional...
Denton, Kevin M.; Ponce, David A.
Historical files from Federal Government mineral exploration-assistance programs, 1950 to 1974
The Defense Minerals Administration (DMA), Defense Minerals Exploration Administration (DMEA), and Office of Minerals Exploration (OME) mineral exploration programs were active over the period 1950–1974. Under these programs, the Federal Government contributed financial assistance in the exploration for certain strategic and critical minerals. The...
Frank, David G.
PubTalk 08/2019 — Pliocene World
Title: Pliocene World: Earth's Climate 3 Million Years Ago and How it Relates to our Future
By Marci Robinson, USGS Research Geologist
- Three million years ago, during the late Pliocene, CO2 levels were similar to today, but global temperatures and sea level were much higher
- Find out how we use microfossils to reconstruct
Scott Lydeen on 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.
Animation of a Scenario M6.9 Earthquake on the Rose Canyon Fault
This video presents an animation of computer-simulated ground motions that might occur for a magnitude 6.9 earthquake rupturing the Rose Canyon fault in southern California. The scenario earthquake ruptures a 65-km-long section of the Rose Canyon fault that lies just offshore of San Diego, California, and Tijuana, Mexico. In this scenario, the rupture starts near the
Image of the Week - A Tear in the Mojave
Satellite imagery shows the rupture and shifting of land near Ridgecrest, CA from the July 2019 earthquakes.
PubTalk 07/2019 — Taking the Pulse of Our Planet
Title: Taking the Pulse of our Planet: A 10-year status report from the USA National Phenology Network
- Plants and animals in your backyard are sensitive indicators of climate variation and change
- Understanding and predicting plant and animal seasonal activity, a science called phenology, helps humans adapt to a changing world
- Learn about a
Navy Base Commander Commends USGS Work Following Earthquake Sequence
US Navy Captain Paul Dale discusses the collaborative efforts between the USGS and Naval Air Weapons Station, China Lake after the Ridgecrest earthquake sequence.
Streamgage Solar Panel Installation for Continuous Data Collection
Sierra Keller, Physical Science Technician, and Sharon Mulready, Student Trainee, both of the USGS California Water Science Center's Santa Cruz Field Office, install a solar panel on a rural streamgage station along the Arroyo Seco near Greenfield in Monterey County, California. Streamgaging stations require power to record and transmit data associated to flow conditions.
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Collecting Geophysical Data, Fort Irwin National Training Center
USGS Hydrologist, Krishangi Groover, lays wire in preparation for geophysical data collection at the U.S. Army's Fort Irwin National Training Center in California. The metal bits on this wire connect to metal stakes (one can be seen in the foreground), which allows for the transmission of electricity into the ground to measure sediment properties. This geophysical data
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Conducting a high tide waterbird survey on San Fransisco Bay
San Francisco Bay and the surrounding wetlands and ponds provide important habitat for waterfowl and shorebirds. To aid land and resource managers in tracking wildlife responses to habitat restoration efforts, Biological Science Technician, Aliya, conducts a high tide waterbird survey of a restored salt pond in the Napa-Sonoma Marshes Wildlife Area at the northern edge of
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Measuring a red fir tree in the Sierra Nevada
This is Teodora Rautu. She is a Biological Science Technician on the field crew for USGS Western Ecological Research Center's Sierra Nevada Forest Dynamics project. She is measuring the diameter of a red fir and trying to navigate the tape through the branches. All of the trees in the Sierra Nevada Forest Dynamics plots are measured every 5 years, not only for
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A new study by CalVO seismologists used a novel geophysical technique called "full waveform seismic tomography" to image the roots of Long Valley Caldera in eastern California.
Federal researchers used landscape genetics to evaluate the role that forest connectivity plays in determining genetic connectivity for the federally-threatened northern spotted owl.
Patrick Barnard and Li Erikson of the USGS Pacific Coastal and Marine Science Center in Santa Cruz, California are recognized for their leadership in developing the Coastal Storm Modeling System (CoSMoS).
With the development of the Central Valley (CVP) and State Water (SWP) projects, the natural flow of the Sacramento-San Joaquin Delta has been reengineered to provide water for California’s growing population and agricultural needs. These changes have drastically reduced natural wetlands, affecting the habitat of native fish species, including the threatened Delta Smelt. To address the situation, joint operations of the CVP and SWP must balance human water demands on the Delta with protection of its fragile ecosystem and species of concern, especially those listed as threatened or endangered under state and federal laws.
USGS scientists produced an animated GIF in coordination with the California Department of Transportation (Caltrans) re-opening of State Highway 1 through Big Sur on July 18, 2018.
The Cosumnes River watershed has seasonal, non-point source hotspots for total mercury and methylmercury production, which discharge to the Sacramento-San Joaquin River Delta in north-central California. To reduce mercury loads to the Delta, researchers created open-water deep cells at the downstream end of wetlands.
USGS scientists combined a series of computer models to forecast cliff erosion along the Southern California coast.
Coastal cliffs from Santa Barbara to San Diego might crumble at more than twice the historical rate by the year 2100 as sea levels rise.
In a study led by the USGS, researchers developed a framework to infer inbreeding rates of Northern Spotted Owls when incomplete parentage information exists.
Masayuki Banno is spending a year-long sabbatical with the USGS.
Remotely-sensed data key to response in tracking danger in areas like Montecito
A recently-published study co-authored by two CalVO scientists brings attention to the role that lava dams played in shaping Lake Tahoe.
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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