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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Coastal Storm Modeling System (CoSMoS)
The Coastal Storm Modeling System (CoSMoS) makes detailed predictions of storm-induced coastal flooding, erosion, and cliff failures over large geographic scales. CoSMoS was developed for hindcast studies, operational applications and future climate scenarios to provide emergency responders and coastal planners with critical storm-hazards information that can be used to increase public safety...
San Francisco Bay Area - Pacifica, CA (BALT4) Landslide Monitoring Site
Recent Monitoring Data
San Francisco Bay Area - Brisbane, CA (BALT3) Landslide Monitoring Site
Recent Monitoring Data
San Francisco Bay Area - Brisbane, CA (BALT3) Landslide Monitoring Site
Recent Monitoring Data
San Francisco Bay Area – Marin County (BALT2) Site near San Rafael, CA - Recent Conditions
Recent Monitoring Data
San Francisco Bay Area – East Bay (BALT1) Site near Castro Valley, CA - Recent Conditions
Recent Monitoring Data
2009 Station Fire, Dunsmore Canyon, Glendale, California
Recent Monitoring Data
2009 Station Fire, Arroyo Seco, Pasadena, CA Landslide Monitoring Site
Recent Monitoring Data
San Francisco Bay Area - Santa Cruz Mountains, CA (BALT-CZU)
Landslides in the San Francisco Bay Area of California impact people, infrastructure, and the environmnent, and are commonly induced by intense or prolonged rainfall associated with strong winter storms.
San Francisco Bay Area – Santa Cruz Mountains, CA (BALT-CZU) - Recent Conditions
Recent Monitoring Data
Marine Minerals Laboratory
In the Marine Minerals Laboratory Suite at the USGS Pacific Coastal and Marine Science Center in Santa Cruz, California, we have an X-ray diffractometer (XRD), Fourier transform infrared spectrophotometer, rock saw, shatterbox, and petrographic microscopes. Here we do mineral identification and classification, molecular identification
Multi-Sensor Core Logger Laboratory
The MSCL at the USGS Pacific Coastal and Marine Science Center (PCMSC) in Santa Cruz, California automatically measures P-wave velocity, magnetic susceptibility, electrical resistivity, and gamma density at intervals from 1 millimeter to 1 centimeter along cores up to 1.5 meters long. The device can also automatically line-scan photograph cores that have been split, at a resolution of 10...
Electron microprobe analyses of hydrothermal muscovite crystals from gold-bearing quartz veins of the Klamath Mountains, California, 2014 and 2019
This data release provides geochemical results of in situ electron probe microanalyses of hydrothermal muscovite associated with gold-bearing quartz veins from the Klamath Mountains, California. Samples were collected from eight different mines in the summer of 2013 and electron probe microanalyses were carried out May 27, 2014 and November 12, 2019.
Assessment of water-quality in the California Sacramento-San Joaquin Delta during a North Delta directed flow action: August - October 2018
This report documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta in the Sacramento-San Joaquin River Delta of California, USA. The data set includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, and chlorophyll . Data-collect
Southwestern Willow Flycatcher Habitat Viewer
The Flycatcher Habitat Viewer was developed to meet the needs of organizations by providing maps of predicted flycatcher breeding habitat throughout its range. Maps are provided from 2013 to present and cover 57 satellite scenes. Maps identify predicted flycatcher habitat based upon the amount of green vegetation within a 120-m radius of each cell, and the size of floodplain within a 360-m...
Discharge, nutrient, and suspended sediment data for selected streams in the Lake Tahoe watershed
A time series of nutrient and mean daily discharge data were used to create models of daily concentration and loads for selected streams of the Lake Tahoe watershed. A total of 15 sites have records ranging from as early as 1972 to 2017. Nutrients in the data set include nitrate, ammonium, Kjeldahl Nitrogen, orthophosphate, and total phosphorus. Total suspended sediment concentrations a
Scientific observations of fishes in tidal wetlands of the upper Sacramento San Joaquin Delta using imaging sonar devices, derived from 2018 field data
Major tidal wetland habitat restoration efforts are planned to benefit Delta Smelt and other imperiled species in the Sacramento-San-Joaquin Delta. However, successful implementation of habitat restoration is constrained by a paucity of information on the services and functions tidal wetlands provide for fishes. This knowledge gap is largely due to the difficulties of collecting ecological...
Geochemical data used in the tungsten skarn mineral resource assessment of the Great Basin region of western Nevada and eastern California
The U.S. Geological Survey (USGS) has undertaken a mineral resources assessment for tungsten for a portion of the Great Basin in parts of western Nevada and east-central California. This data release provides the Great Basin Tungsten Database: the geospatial and geologic data, and results of chemical analyses for 46,955 samples collected in the assessment area, extracted from the USGS
Daily Basin Characterization Model (BCM) archive for Humboldt Bay/Eel River
This data set includes: 1) A shapefile of the Humboldt Bay Eel River (HBER) 13 sub watersheds, 2) A shape file of the streamflow gages used in calibration, and 3) Daily Basin Characterization Model (BCM) model climate inputs (minimum and maximum air temperature, precipitation, and potential evapotranspiration) and outputs of recharge and runoff for the year 2010 used t
Underwater Videographic Observations of Cultured Delta Smelt in Field Enclosures: Video clips and Summary data
All data is part of a pilot study aimed to observe Delta Smelt behavior within enclosures deployed in the wild. The enclosures used were designed by The California Department of Water Resources and UC Davis as part of their ongoing Delta Smelt enclosure deployment studies. Study 1: This data includes 16 17:43 minute videos of observations of Delta Smelt behavior in a floating field enclosu...
Pesticide constituent data from the California Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP), August 2013 - May 2018, schedule 2437 constituents
This Data release presents results for pesticide constituents in 460 samples collected from domestic and public-supply wells in August 2013-May 2018 for the California Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP). The samples were analyzed for 225 pesticide constituents on USGS National Water Quality Laboratory analytical schedule 2437. Results from...
Aerial imagery and structure-from-motion derived data products from UAS survey of the Liberty Island Conservation Bank Wildlands restoration site, Sacramento-San Joaquin Delta, California, October 2018
Unmanned aerial systems were used to acquire high-resolution imagery of the Liberty Island Conservation Bank Wildlands restoration site in the Sacramento–San Joaquin Delta in California, with the goal of using structure-from-motion photogrammetric techniques to derive a digital surface model, orthomosaic imagery, and a topographic point cloud. The survey was conducted using two Department of...
Bay-Delta Regional Monitoring Program | Nutrient Mapping
Data visualization tool created for California's Bay-Delta Regional Monitoring Program. This web applicaton visualizes nutrients and phytoplankton spatially and temporally.
Projected responses of the coastal water table for California using present-day and future sea-level rise scenarios
Coastal groundwater levels (heads) can increase with sea level rise (SLR) where shallow groundwater floats on underlying seawater. In some areas coastal groundwater could rise almost as much as SLR, but where rising groundwater intersects surface drainage features, the increase will be less. Numerical modeling can provide insight into coastal areas that may be more or less vulnerable to...
A portal for easy access to USGS data collected during hydrogeologic research projects in Anza Valley, CA
Compares Anza Valley, CA land use data within the USGS study boundaries for 5 time periods between 1934 and 2005.
The GAMA program is a comprehensive statewide assessment designed to help better understand and identify risks to groundwater resources. Groundwater is sampled at many locations across California in order to characterize its constituents and identify trends in groundwater quality. The results of these tests provide information for water agencies to address a variety of water resource issues.
n 2012, the Groundwater Ambient Monitoring & Assessment Priority Basin Project (GAMA-PBP) began water-quality assessments of shallow aquifers, which are typically used for private domestic and small system drinking-water supplies. GAMA-PBP is designed to identify where and to what extent water quality of groundwater aquifers meets benchmarks that have been established for drinking water.
Coastal Basins of San Diego County, California, and Northern Baja California, Mexico. Local features include the San Dieguito River Basin, San Diego River Basin, Sweetwater River Basin, and Otay River Basin. Maps also display locations of groundwater-monitoring sites.
This map shows the provinces assessed by the USGS for undiscovered oil and gas resources.
The quality of groundwater in the Borrego Valley is a concern because it is the sole source of water for agricultural, recreational, and public supply. Explore this interactive water-quality data map for detailed information and to download data.
A geonarrative (Esri Story Map) describing what it might be like the next time the Hayward fault has a large earthquake. Scientists examined a hypothetical earthquake, the magnitude 7.0 HayWired earthquake scenario.
In order to understand the integrated hydrologic systems in the San Antonio Creek Valley, many different types of data are being gathered from both the surface water and groundwater system. Learn about these data types and explore them with the interactive map.
The Lower Colorado Monitoring Network is a series of groundwater-level and water-quality wells, as well as streamgages and micro-gravity sites. This interactive map displays the sites and provides links to the most current data.
In California, land subsidence—mostly from groundwater pumping—was first documented by the USGS in the early 20th century. Completion of State and Federal water projects that bring water from California's wet north to its dry south allowed some groundwater aquifers to recover, and subsidence decreased in these areas. Subsidence continues today, sometimes at high rates of more than 1 foot/year.
This interactive webmap plots water-quality data from domestic and public-supply wells sampled by the USGS for the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project (GAMA-PBP), and allows users to download datasets. The GAMA-PBP is a cooperative program between the California State Water Resources Control Board and the U.S. Geological Survey.
Evidence of previous faulting along the 2019 Ridgecrest, California earthquake ruptures
The July 2019 Ridgecrest earthquake sequence in southeastern California was characterized as surprising because only ~35% of the rupture occurred on previously mapped faults. Employing more detailed inspection of pre-event high-resolution topography and imagery in combination with field observations, we document evidence of active faulting in the...
Thompson Jobe, Jessica; Philibosian, Belle; Chupik, Colin; Dawson, Timothy E.; Bennett, Scott E. K.; Gold, Ryan D.; Duross, Christopher; Ladinsky, Tyler C.; Kendrick, Katherine; Haddon, Elizabeth; Pierce, Ian; Swanson, Brian J.; Seitz, Gordon G.Human behavioral response in the Ridgecrest earthquakes: Assessing immediate actions based on data from “Did You Feel It?”
Human behavioral response to earthquake ground motion has long been a subject of multidisciplinary interest and research. In most versions of seismic intensity scales, human perceptions and behavior are one component of the assignment of intensity. Public health research has shown that actions taken during earthquakes have a significant impact on...
Goltz, James D.; Park, Hyejeong; Quitoriano, Vince; Wald, David J.The predictive skills of elastic Coulomb rate-and-state aftershock forecasts during the 2019 Ridgecrest, California, earthquake sequence
Operational earthquake forecasting protocols commonly use statistical models for their recognized ease of implementation and robustness in describing the short-term spatiotemporal patterns of triggered seismicity. However, recent advances on physics-based aftershock forecasting reveal comparable performance to the standard statistical counterparts...
Mancini, Simone; Segou, Margarita; Werner, Maximillian J; Parsons, Thomas E.Surface displacement distributions for the July 2019 Ridgecrest, California earthquake ruptures
Surface rupture in the 2019 Ridgecrest, California, earthquake sequence occurred along two orthogonal cross faults and includes dominantly left‐lateral and northeast‐striking rupture in the Mw">Mw 6.4 foreshock and dominantly right‐lateral and northwest‐striking rupture in the Mw">Mw 7.1 mainshock. We present >...
Duross, Christopher; Gold, Ryan D.; Dawson, Timothy E.; Scharer, Katherine; Kendrick, Katherine; Akciz, Sinan; Angster, Stephen J.; Bachhuber, Jeffery; Bacon, Steven; Bennett, Scott E. K.; Blair, Luke; Brooks, Benjamin A.; Bullard, Thomas; Burgess, W. Paul; Chupik, Colin; DeFrisco, Michael; Delano, Jaime; Dolan, James D.; Frost, Erik; Graehl, Nick; Haddon, Elizabeth; Hatem, Alexandra Elise; Hernandez, Janis; Hitchcock, Christopher S.; Hudnut, Kennth; Thompson Jobe, Jessica; Koehler, Richard D; Kozaci, Ozgur; Ladinsky, Tyler C.; Madugo, Christopher; McPhillips, Devin; Milliner, Christopher; Morelan, Alexander; Olson, Brian; Patton, Jason; Philibosian, Belle; Pickering, Alexandra J.; Pierce, Ian; Ponti, Daniel J.; Seitz, Gordon G.; Spangler, Eleanor; Swanson, Brian J.; Thomas, Kate; Treiman, Jerome; Valencia, Francesca; Williams, Alana; Zinke, RobertPeak ground velocity spatial variability revealed by dense seismic array in southern California
Understanding and modeling variability of ground motion is essential for building accurate and precise ground motion prediction equations, which can net site‐specific characterization and reduced hazard levels. Here, we explore the spatial variability in peak ground velocity (PGV) at Sage Brush Flats along the San Jacinto Fault in southern...
Johnson, Christopher E; Kilb, Debi; Baltay, Annemarie S.; Vernon, FrankSubmarine canyons, slope failures and mass transport processes in southern Cascadia
The marine turbidite record along the southern Cascadia Subduction Zone has been used to interpret paleoseismicity and suggest a shorter recurrence interval for large (>M7) earthquakes along this portion of the margin; however, the sources and pathways of these turbidity flows are poorly constrained. We examine the spatial distribution of...
Hill, Jenna C.; Watt, Janet; Brothers, Daniel; Kluesner, Jared2018 U.S. Geological Survey–California Geological Survey fault-imaging surveys across the Hollywood and Santa Monica Faults, Los Angeles County, California
We acquired multiple types of seismic data across the Hollywood Fault in Hollywood, Calif., and the Santa Monica Fault in Beverly Hills, Calif., in May and June 2018. On the basis of our data, we infer near-surface locations of various traces of these faults.From two separate profiles across the Hollywood Fault, we evaluated multiple seismic...
Catchings, Rufus D.; Hernandez, Janis; Goldman, Mark R.; Chan, Joanne H.; Sickler, Robert R.; Olson, Brian; Criley, Coyn J.Airborne lidar and electro-optical imagery along surface ruptures of the 2019 Ridgecrest earthquake sequence, Southern California
Surface rupture from the 2019 Ridgecrest earthquake sequence, initially associated with the M 6.4 foreshock, occurred on July 4 on a ~17 km long, northeast-southwest oriented, left-lateral zone of faulting. Following the M 7.1 mainshock on July 5 (local time), extensive northwest-southeast-oriented, right-lateral faulting was then also mapped...
Brooks, Benjamin A.; Scharer, Katherine; Hernandez, Janis; Dawson, Timothy E.; Oskin, Mike; Arrowsmith, Ramon; Goulet, Christine A.; Blake, Kelly; Boggs, Matt; Bork, Stephan; Glennie, Craig; Fernandez-Diaz, J.C.; Singhania, Abhinav; Hauser, Darren L.; Sorhus, Sven; Hudnut, Kenneth W.; Brooks, Benjamin A.; Scharer, Katherine M.; Hernandez, Janis L.; Dawson, Timothy E.; Oskin, Michael E.; Arrowsmith, J. Ramon; Goulet, Christine A.; Blake, Kelly; Boggie, Matthew A.; Bork, Stephan; Craig L. Glennie; Fernandez-Diaz, J.C.; Singhania, Abhinav; Hauser, Darren; Sorhus, SvenScience plan for improving three-dimensional seismic velocity models in the San Francisco Bay region, 2019–24
This five-year science plan outlines short-term and long-term goals for improving three-dimensional seismic velocity models in the greater San Francisco Bay region as well as how to foster a community effort in reaching those goals. The short-term goals focus on improving the current U.S. Geological Survey San Francisco Bay region geologic and...
Aagaard, Brad T.; Graymer, Russell W.; Thurber, Clifford H.; Rodgers, Arthur J.; Taira, Taka'aki; Catchings, Rufus D.; Goulet, Christine A.; Plesch, AndreasOperational earthquake forecasting during the 2019 Ridgecrest, California, earthquake sequence with the UCERF3-ETAS model
The first Uniform California Earthquake Rupture Forecast, Version 3–epidemic‐type aftershock sequence (UCERF3‐ETAS) aftershock simulations were running on a high‐performance computing cluster within 33 min of the 4 July 2019 M 6.4 Searles Valley earthquake. UCERF3‐ETAS, an extension of the third Uniform California Earthquake Rupture Forecast (...
Milner, Kevin R.; Field, Edward H.; Savran, William H; Page, Morgan T.; Jordan, Thomas HClimate change vulnerability assessment for Pacific Lamprey in rivers of the Western United States
Pacific Lamprey (Entosphenus tridentatus) are a native anadromous species that, like salmon, historically returned to spawn in large numbers in watersheds along the west coast of the United States (U.S.). Lamprey play a vital role in river ecosystems and are one of the oldest vertebrates that have persisted over time likely influencing the...
Wang, Christina J; Shaller, Howard A; Coates, Kelly C.; Hayes, Michael C.; Rose, Robert KA high-resolution seismic catalog for the initial 2019 Ridgecrest Earthquake sequence: Foreshocks, aftershocks, and faulting complexity
I use template matching and precise relative relocation techniques to develop a high-resolution earthquake catalog for the initial portion of the 2019 Ridgecrest earthquake sequence, from July 4-16, encompassing the foreshock sequence and the first 10+ days of aftershocks following the Mw 7.1 mainshock. Using 13,525 routinely cataloged events as...
Shelly, David R.Sunset State Beach Variance Image
Far out, man... where science meets art
This is an image produced from one of two video cameras, which were installed to overlook the coast at Sunset State Beach in Watsonville, California. The cameras are part of the USGS Pacific Coastal and Marine Science Center’s
...Ready for nearshore survey
The USGS Pacific Coastal and Marine Science Center's new inflatable boat equipped with a portable, single beam, shallow-water echo sounder used for nearshore surveys. USGS scientists collect such data seasonally, to study sediment input and movement in and around Monterey Bay area beaches.
Portable single-beam echo sounder set-up
Marine engineering technician Pete Dal Ferro sets up a newly acquired, portable, single-beam echo sounder on the San Lorenzo River in Santa Cruz, California. The new device, called CEESCOPE, collects bathymetric (depth) data and also records features of the subsurface. All the components are easy for one person to set up and operate, with GPS and an LCD touch screen. This
...GeoDAWN: Geoscience Data Acquisition for Western Nevada
The USGS Earth Mapping Resources Initiative and USGS 3D Elevation Program (3DEP), Department of Energy Geothermal Technologies Office, Natural Resources Conservation Services, and Bureau of Land Management have partnered to conduct airborne geophysical and 3DEP lidar surveys over parts of Nevada and California to collect information on undiscovered geothermal, critical
...Image of the Week - Summer Fires Rage in California
As fire season continues in the western United States let's look back at a number of incidents tracked by officials across California in August. These fires were captured during the day by Landsats 7 and 8, in natural color bands of the visible spectrum. Landsat sensors also record infrared wavelengths revealing burn scars and active fires. Natural color images show smoke
Offshore northern California bathymetric map
Bathymetric map of offshore northern California reveals seafloor features and submarine canyons.
Cascadia megathrust fault map
Topo-bathymetric map of the Cascadia subduction zone. Cascadia megathrust fault (white line); approximate shelf break along 200-m isobath (yellow line); MTJ, Mendocino triple junction.
Cascadia fieldwork map
Index map of U.S. Cascadia margin showing where data have been collected since 2018 as part of the Subduction Zone Marine Geohazards Project. Details of each survey effort are provided on the Cascadia Subduction Zone Marine Geohazards project web site.
Remembering Ridgecrest
Reflections on the Ridgecrest earthquake sequence one year after from a few USGS employees. Employees discuss when they first heard about the magnitude 6.4 and notable professional experiences that happened afterwards.
Land Treatment Exploration Tool: A Quick Introduction
This is a quick introduction video to the Land Treatment Exploration Tool. This short video includes a summary of the tool with screen clips of the fact sheet, web tool, and an example Site Characterization Report.
These tutorial videos were created to aid in the use of the Land Treatment Exploration Tool (LTET). These videos
Land Treatment Exploration Tool—Step 1: Describe Proposed Treatment
This video describes Step 1 of the Land Treatment Exploration Tool. In Step 1 the user defines a name, the planned treatment/s, and a file name for exported items.
These tutorial videos were created to aid in the use of the Land Treatment Exploration Tool (LTET). These videos guide a user through the main steps of the tool.
Land Treatment Exploration Tool — Step 2: Select Treatment Boundary
This video describes Step 2 of the Land Treatment Exploration Tool. In Step 2 the user defines their planned treatment boundary. The user can load a zipped shapefile or on-screen digitize their boundary.
These tutorial videos were created to aid in the use of the Land Treatment Exploration Tool (LTET). These videos guide a
Residents should not be alarmed if they see a low-flying airplane over parts of northeastern California starting February 6, 2021.

Volunteers have already contributed over 400 edits to this challenge since it was launched last week - IMPRESSIVE!

USGS researchers respond to coastal hazards and wildfires: The intense storm that hit California’s coast between January 26 and 28, 2021, blew out a portion of Highway 1 near Big Sur. USGS works diligently to provide officials with science to help inform their decision making before, during, and after such events. Here, we present photos that describe this work.

TNMCorps Mapping Challenges continue along the Pacific Coast with a challenge for fire stations in California, Nevada, and Arizona!

This challenge is now complete! Thank you to everyone who contributed!

Volunteers continue to make headway on this challenge with another 40 points added since last week. However, there are a handful of communities in the metropolitan areas that still need a point. See our spatial analyses for tips on which communities these may be.

Volunteers jumped in feet first with almost 30 new points added since last week. That's pretty good, considering volunteers need to sift through what's already on the map versus what still needs to be collected. Keep up the good work!!

TNMCorps Mapping Challenges shift to the Pacific Coast with a new challenge for city/town halls in California and Nevada. Just in time to help fend off those winter blues, too!

A new geonarrative (Esri Story Map) summarizes the USGS response and findings after the M6.4 on July 4 and M7.1 on July 6, 2019 in Searles Valley, Southern California.

Learn more about the recent field activities completed by scientists in the Coastal and Marine Hazards and Resources Program at the USGS, and explore the Science Projects that guide this fieldwork.

In his regular job, EROS Scientist Kurtis Nelson manages post-fire mapping activities at EROS—the largest being Monitoring Trends in Burn Severity, and the Department of Interior’s (DOI) Burned Area Emergency Response (BAER) support. But for 21 days this past August and September, he did something more.

The U.S. Geological Survey (USGS) has 5 volcano observatories tasked with monitoring low to high threat volcanoes throughout the United States.