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.

States L2 Landing Page Tabs

Filter Total Items: 393
Date published: March 14, 2018
Status: Active

Babocomari - Managed Aquifer Recharge

We are working to investigate the most cost-efficient way to recharge the Sierra Vista sub-basin aquifer using rainwater harvesting in the tributaries of the San Pedro River using low-technology methods. Research is being conducted on the Babacomari Ranch, property of the Brophy family. The ...

Contacts: Laura M Norman
Date published: March 14, 2018
Status: Active

Aridland Water Harvesting Study

Most of western North America has been severely grazed by cattle, causing grasslands to deteriorate and desert scrub expansion. Climate in arid and semi-arid regions is often typified by short, intense rainfall events which contribute to short-term flooding and erosion. Associated arroyo cutting occurs when ephemeral creek beds are carved into the floodplain when erratic overland flow occurs;...

Date published: January 18, 2018
Status: Active

National Assessment of Coastal Vulnerability to Sea Level Rise

The original national coastal vulnerability index (CVI) assessment was motivated by expected accelerated sea-level rise (SLR) and the uncertainty in the response of the coastline to SLR. This research was conducted between 1999 and 2001, and is currently being updated using new data sources and methodology. This original study was part of the ...

Date published: January 18, 2018
Status: Active

Long-Term Coastal Change

Goals of this task include developing and improving coastal-change assessments and supporting long-term planning and decision making to ensure sustainable coastal economies, infrastructure, and ecosystems.

Date published: December 7, 2017
Status: Active

The Mud Creek landslide on California’s Big Sur coast

On May 20, 2017, the steep slopes at Mud Creek on California’s Big Sur coast, about 140 miles south of San Francisco, suffered a catastrophic collapse. USGS Scientists from the Pacific Coastal and Marine and the Geology, Minerals, Energy, and Geophysics Science Centers are monitoring this section of the coastline, in collaboration with the California Department of Transportation.

Date published: October 30, 2017
Status: Active

Ecology of Infectious Diseases

The public is most familiar with parasites' role in spreading infectious diseases to people and domestic animals. In tropical developing countries, malaria, schistosomiasis, and other infectious diseases cause significant human suffering. While most related studies focus on treating patients, Dr. Kevin Lafferty is studying how ecology of the local environment affects transmission of infectious...

Contacts: Kevin Lafferty
Date published: October 30, 2017
Status: Active

Desert Tortoise Ecology, Health, Habitat, and Conservation Biology

The desert tortoise is listed as “threatened” under the Endangered Species Act. USGS WERC scientists, along with project partners have been conducting long-term analyses on how changes in the southwestern deserts of the United States can affect desert tortoise populations. Dr. Todd Esque and his team are investigating how habitat disturbances and restoration projects influence tortoise...

Contacts: Todd Esque
Date published: October 30, 2017
Status: Active

Southwestern Desert Ecology of At-risk Species and their Habitats

The southwestern desert region is home to many sensitive species. Species are at-risk due to past, present, and future changes to the landscape. WERC’s Dr. Todd Esque, field researchers, and collaborators are using models, monitoring plans, and decision-support tools to provide land managers with the resources they need to answer questions about how environmental change influences plants,...

Contacts: Todd Esque
Date published: October 30, 2017
Status: Active

Ecological Stressors - Rocky Coastlines, Mangroves, Marshes, Droughts, and Storms

Coastal estuaries that contain marshes and mangroves are currently being reshaped by changing ocean and atmospheric conditions through prolong drought, sea-level rise and increased extreme storm events. Many projected increases in sea-level are expected to result in loss of tidal wetlands and their component species. In addition, changing sediment loads, extreme tide and storm events, and...

Date published: October 30, 2017
Status: Active

Supporting Informed Responses to Sea-Level Rise

To facilitate communication and outreach of sea level rise research results and implications, Dr. Karen Thorne and members of USGS WERC are hosting in-person workshops along the Pacific coast at different sites in Washington, Oregon, and California.

Date published: October 30, 2017
Status: Active

California Sea Otter Stranding Network

The California Sea Otter Stranding Network is part of the USGS effort to monitor southern sea otters (Enhydra lutris nereis) and provide data to the U.S. Fish and Wildlife Service. WERC's sea otter team works with multiple institutions and partners to report, recover, and examine stranded sea otters. In addition, instructions on how to report a stranded sea otter are included in this webpage...

Filter Total Items: 518
Date published: October 29, 2018

California Seafloor Mapping Program progress

Table showing California Seafloor Mapping Program map block mapping progress by block number, as of April 2018.

Date published: October 25, 2018

Beach topography and nearshore bathymetry of northern Monterey Bay, California

This data release presents beach topography and nearshore bathymetry data from repeated surveys in northern Monterey Bay, California to document changes in shoreline position and coastal morphology as they relate to episodic (storms), seasonal, and interannual and longer processes. Since October 2014, semi-annual surveys have been performed in late summer (September or October...

Date published: October 22, 2018

Grain size, mineralogic, and trace-element data from field samples near Hinkley, California

This data release is part of a study examining the occurrence of chromium and natural and anthropogenic hexavalent Chromium, Cr(VI) in groundwater. Data will be used to estimate naturally-occurring background Cr(VI) concentrations upgradient, near the plume margins, and downgradient from a mapped Cr(VI) contamination plume near Hinkley, CA (Izbicki and Groover, 2016).

Date published: October 4, 2018

Electrical Resistivity Tomography Data at Fort Irwin National Training Center, San Bernardino County, California, 2015 and 2017

The U.S. Army Fort Irwin National Training Center (NTC), approximately 35 mi north-northeast of Barstow, California, covers approximately 1,177 square miles, and is comprised of ten groundwater basins, three of which have been subdivided into subbasins on the basis of additional hydrologic testing. Since the early 1990s, the U.S. Geological Survey (USGS) has been studying water resources...

Date published: September 24, 2018

Bathymetry and acoustic backscatter data collected in 2007 from the San Miguel Passage in the Channel Islands, California

Bathymetry and acoustic backscatter data were collected in the San Miguel Passage, Channel Islands, California in August 2007. Data collection was conducted aboard the ship R/V Shearwater as part of the USGS research cruise S-2-07-SC. The San Miguel Passage is within the Channel Islands National Marine Sanctuary, and is the body of water between the two western-most islands of the...

Date published: August 28, 2018

USGS Domestic Continuous (Unconventional) Oil & Gas Assessments, 2000-Present

Interactively explore assessment summary information for continuous (unconventional) assessments conducted at the USGS from 2000-2018. The assessment results data used to generate this visualization can be downloaded here in Excel Format.  These data represent all assessment results...

Date published: August 24, 2018

GAMA-Priority Basin Project Groundwater-Quality Results: Assessment and Trends

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 Program (GAMA) Priority Basin Project, and allows users to download datasets.

Date published: July 5, 2018

In situ geochemical data related to the gold-quartz veins of Grass Valley, California, 2014-2015

In situ geochemical data were obtained for pyrite crystals and native gold from two distinct vein sets in the Grass Valley gold district, California. Samples of the N-S (north-south-trending) veins were collected underground at the Empire Mine State Historic Park and samples of the E-W (east-west-trending) veins were collected from drill core provided by the Idaho-Maryland Mining Corpor

Date published: June 19, 2018

Water Use Data for California

State water-use data are reported by source (surface water or groundwater, fresh and saline, and total), category, and area type (county). The water-use data presented here are the current best estimates, and may have been revised from previous publications. Data collection varied between the different compilations. Pre-1995 datasets have more data available than 2000 and later.

Date published: June 1, 2018

Historic Depth-to-Water, San Joaquin Valley, California, 1910

Mendenhall and others (1916) published depth-to-water data compiled in 1910 for all known wells in the San Joaquin Valley, California. Data for the 3,429 wells having depth-to-water of greater than zero feet were used to construct an interpolated depth-to-water surface for the entire SJV. This map represents groundwater levels in approximately 1910, prior to extensive development of the

Date published: May 13, 2018

Coastal Storm Modeling System (CoSMoS) for Southern California, v3.0, Phase 2

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. CoSMoS v3.0 for Southern California shows projections for future climate scenarios (sea-level rise and storms) to provide emergency responders and...

Date published: May 3, 2018

Land Treatment Exploration Tool

The Land Treatment Exploration Tool is designed for resource managers to use when planning land treatments. The tool provides useful summaries of environmental characteristics of planned treatment areas and facilitates adaptive management practices by comparing those characteristics to other similar treatments within a specified distance or area of interest. ...

Filter Total Items: 355
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Year Published: 2004

Reproductive status of western mosquitofish inhabiting selenium- contaminated waters in the Grassland Water District, Merced County, California

This study was implemented to determine if western mosquitofish (Gambusia affinis) populations in the Grassland Water District suffer from impaired reproduction because of seleniferous inflows of agricultural drainwater from the Grassland Bypass Project. During June to July 2001, laboratory trials with pregnant female fish collected from two...

Saiki, M. K.; Martin, B.A.; May, T.W.
Reproductive status of western mosquitofish inhabiting selenium- contaminated waters in the Grassland Water District, Merced County, California; 2004; Article; Journal; Archives of Environmental Contamination and Toxicology; Saiki, M. K.; Martin, B. A.; May, T. W.

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Year Published: 2004

Summary of total mercury concentrations in fillets of selected sport fishes collected during 2000-2003 from Lake Natoma, Sacramento County, California

This report summarizes results of total mercury measurements in skinless fillets of sport fishes collected during August 2000, September?October 2002, and July 2003 from Lake Natoma, a small (8,760 acre-feet) afterbay for Folsom Dam on the lower American River. The primary objective of the study was to determine if mercury concentrations in...

Saiki, Michael K.; Slotton, Darrell G.; May, Thomas W.; Ayers, Shaun M.; Alpers, Charles N.
Summary of total mercury concentrations in fillets of selected sport fishes collected during 2000-2003 from Lake Natoma, Sacramento County, California; 2004; DS; 103; Saiki, Michael K.; Slotton, Darrell G.; May, Thomas W.; Ayers, Shaun M.; Alpers, Charles N.

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Year Published: 2003

Signatures of the seismic source in EMD-based characterization of the 1994 Northridge, California, earthquake recordings

In this article we use empirical mode decomposition (EMD) to characterize the 1994 Northridge, California, earthquake records and investigate the signatures carried over from the source rupture process. Comparison of the current study results with existing source inverse solutions that use traditional data processing suggests that the EMD-based...

Zhang, R.R.; Ma, S.; Hartzell, S.
Signatures of the seismic source in EMD-based characterization of the 1994 Northridge, California, earthquake recordings; 2003; Article; Journal; Bulletin of the Seismological Society of America; Zhang, R. R.; Ma, S.; Hartzell, S.

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Year Published: 2003

Site response, shallow shear-wave velocity, and wave propagation at the San Jose, California, dense seismic array

Ground-motion records from a 52-element dense seismic array near San Jose, California, are analyzed to obtain site response, shallow shear-wave velocity, and plane-wave propagation characteristics. The array, located on the eastern side of the Santa Clara Valley south of the San Francisco Bay, is sited over the Evergreen basin, a 7-km-deep...

Hartzell, S.; Carver, D.; Williams, R.A.; Harmsen, S.; Zerva, A.
Site response, shallow shear-wave velocity, and wave propagation at the San Jose, California, dense seismic array; 2003; Article; Journal; Bulletin of the Seismological Society of America; Hartzell, S.; Carver, D.; Williams, R. A.; Harmsen, S.; Zerva, A.

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Year Published: 2002

Distribution and transport of suspended particulate matter in Monterey Canyon, California

From August 1993 to August 1994, six moorings that measure current, temperature, salinity, and water clarity were deployed along the axis of Monterey Canyon to study the circulation and transport of water and suspended particulate matter through the canyon system. The moorings occupied three sites that are morphologically different: a narrow...

Xu, J. P.; Noble, M.; Eittreim, S.L.; Rosenfeld, L.K.; Schwing, F.B.; Pilskaln, C.H.
Distribution and transport of suspended particulate matter in Monterey Canyon, California; 2002; Article; Journal; Marine Geology; Xu, J. P.; Noble, M.; Eittreim, S. L.; Rosenfeld, L. K.; Schwing, F. B.; Pilskaln, C. H.

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Year Published: 2000

A seismic landslide susceptibility rating of geologic units based on analysis of characterstics of landslides triggered by the 17 January, 1994 Northridge, California earthquake

One of the most significant effects of the 17 January, 1994 Northridge, California earthquake (M=6.7) was the triggering of thousands of landslides over a broad area. Some of these landslides damaged and destroyed homes and other structures, blocked roads, disrupted pipelines, and caused other serious damage. Analysis of the distribution and...

Parise, M.; Jibson, Randall W.

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Year Published: 1999

Maps Showing Locations of Damaging Landslides Caused by El Nino Rainstorms, Winter Season 1997-98, San Francisco Bay Region, California

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. Reports of landsliding began in early January 1998 and continued throughout the winter and spring. On February 9, President Clinton declared all 10 counties eligible for...

Godt, Jonathan W.
Maps Showing Locations of Damaging Landslides Caused by El Nino Rainstorms, Winter Season 1997-98, San Francisco Bay Region, California; 1999; MF; 2325; Godt, Jonathan W.

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Year Published: 1999

Map showing locations of damaging landslides in Alameda County, California, resulting from 1997-98 El Nino rainstorms

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. In Alameda County more than $20 million in damages were assessed. Debris flows occurred...

Coe, J.A.; Godt, J.W.; Brian, Dianne; Houdre, Nicolas
Map showing locations of damaging landslides in Alameda County, California, resulting from 1997-98 El Nino rainstorms; 1999; MF; 2325-B; Coe, J. A.; Godt, J. W.; Brian, Dianne; Houdre, Nicolas

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Year Published: 1999

Map showing locations of damaging landslides in Contra Costa County, California, resulting from 1997-98 El Nino rainstorms

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $27 million in damages were assessed in Contra Costa County.

Graymer, Russell W.; Godt, Jonathan W.
Map showing locations of damaging landslides in Contra Costa County, California, resulting from 1997-98 El Nino rainstorms; 1999; MF; 2325-E; Graymer, Russell W.; Godt, Jonathan W.

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Year Published: 1999

Map showing locations of damaging landslides in Marin County, California, resulting from 1997-98 El Nino rainstorms

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $2.5 million in damages were assessed in Marin County.

Morrissey, Meghan M.; Wieczorek, Gerald F.; Godt, Jonathan W.
Map showing locations of damaging landslides in Marin County, California, resulting from 1997-98 El Nino rainstorms; 1999; MF; 2325-C; Morrissey, Meghan M.; Wieczorek, Gerald F.; Godt, Jonathan W.

Filter Total Items: 994
January 25, 2018

PubTalk 1/2018 — ShakeAlert: Path to West Coast EQ Early Warning

Title: ShakeAlert: The Path to West Coast Earthquake Early Warning ... how a few seconds can save lives and property

  • The ShakeAlert earthquake early warning system will begin limited operations this year.
  • Alerts could save lives and properties but several challenges remain.
  • With millions at risk, why isn't full public alerting happening yet?
Photo of Staten Island in the Sacramento Delta
January 25, 2018

Staten Island, Sacramento Delta, CA.

Staten Island in the Sacramento Delta, CA.

Montecito after debris flow
January 14, 2018

Montecito after debris flow

The Dec. 4, 2017 Thomas fire, Southern California's largest wildfire on record, burned more than 280,000 acres across Ventura and Santa Barbara counties for nearly a month.

Boulder in debris flow
January 14, 2018

Geologists assess scene after debris flow

Geologists assess boulders displaced during the Montecito debris flow event on Jan. 9, 2018.  

Pool warning sign
January 14, 2018

Pool sign warns first responders

Swimming pool sign spray-painted to warn first responders and others to be careful around the potentially dangerous area. 

January 4, 2018

Image of the Week - Southern California Wildfires Update

After a month, the wildfires of Southern California are nearly contained. Landsat 8 imagery shows the dramatic burn scars left behind.

At the USGS EROS Center, we study land change, operate the Landsat satellites, and maintain the longest, continuously acquired collection of images of the Earth's land surface.

USGS EROS Center (

Map shows a coastal city with an airport and how, during a large storm, ocean water would flood around city features.
December 31, 2017

CoSMoS projection for San Diego

Example of CoSMoS projected flooding extents for a 1.5 meter sea level rise in combination with possible 100 year return period coastal storms.

USGS
December 31, 2017

Big Brown Bat (Eptesicus fuscus) Call

Bats produce a variety of vocalizations that are used for navigation, feeding, and social communication. Most vocalizations are pitched well above the range of human hearing and are referred to as ultrasonic. These calls are often known as echolocation calls since bats use the echoes produced when a sound bounces off a bug or a building to determine what is in the area. 

Map of Active Faults and Historic Earthquakes in California
December 31, 2017

California Seismicity

Map of historic seismicity, major faults, and paleoseismic summary of San Andreas Fault system.

USGS
December 31, 2017

California myotis (Myotis californicus) Call

Bats produce a variety of vocalizations that are used for navigation, feeding, and social communication. Most vocalizations are pitched well above the range of human hearing and are referred to as ultrasonic. These calls are often known as echolocation calls since bats use the echoes produced when a sound bounces off a bug or a building to determine what is in the area. 

USGS
December 31, 2017

Hoary Bat (Lasiurus cinereus) Echo Call

Bats produce a variety of vocalizations that are used for navigation, feeding, and social communication. Most vocalizations are pitched well above the range of human hearing and are referred to as ultrasonic. These calls are often known as echolocation calls since bats use the echoes produced when a sound bounces off a bug or a building to determine what is in the area. 

USGS
December 31, 2017

Hoary Bat (Lasiurus cinereus) Social Call

Bats produce a variety of vocalizations that are used for navigation, feeding, and social communication. Most vocalizations are pitched well above the range of human hearing and are referred to as ultrasonic. These calls are often known as echolocation calls since bats use the echoes produced when a sound bounces off a bug or a building to determine what is in the area. 

Filter Total Items: 938
WERC Sierra Nevadas
October 13, 2014

The USGS California Volcano Observatory (CalVO) is tracking an earthquake swarm in the Sierra Nevada range south of Long Valley Caldera, about 8 miles SW of Toms Place and 15 miles SE of the town of Mammoth Lakes.

Long Valley Caldera Earthquakes greater than M1.0 from 09/22 to 09/...
September 28, 2014

Over the past 42 hours, the earthquake swarm in California's Long Valley Caldera, which began last Friday (see September 26 post), has gradually diminished in terms of numbers of earthquakes and in earthquake magnitude.

Long Valley Caldera Earthquakes greater than M1.0 from 09/22 to 09/...
September 26, 2014

We have been closely tracking an earthquake swarm in California's Long Valley Caldera, which started yesterday at around 4AM PDT (September 25, 2014).

Mount Shasta looming over the town of Weed in the evening....
September 25, 2014

On the afternoon of September 20, a large volume of water surged down Mount Shasta's south flank into Mud Creek, entraining debris and inundating the drainage and roads near McCloud, California.

Image: Sea Otter Ready for a Nap
September 22, 2014

When sea otters want to rest, they wrap a piece of kelp around their body to hold themselves steady among the rolling waves. Likewise, California’s sea otter numbers are holding steady against the many forces pushing against their population recovery, according to the latest field survey led by federal, state, aquarium, and university scientists.

USGS
September 18, 2014

The U.S. Geological Survey will host an educational event for the news media focused on earthquakes on Wednesday September 24, 2014.

Landcover map (left) and pedestrian evacuation time estimate map (right) Ocean Shores, Washington.
September 16, 2014

Scientists at the U.S. Geological Survey have developed a new mapping tool, the Pedestrian Evacuation Analyst, for use by researchers and emergency managers to estimate how long it would take for someone to travel on foot out of a tsunami-hazard zone.

New 2014 US Topo quadrangle of the Three Fingered Jack, Oregon, area
September 15, 2014

Newly released US Topo maps for Oregon now feature segments of the Pacific Crest National Scenic Trail. Several of the 1,835 new US Topo quadrangles for the state now display parts of the Trail along with other improved data layers.

Overview of Klamath Mountains groundwater quality with pie charts showing concentrations of organic and inorganic constituents i
September 5, 2014

Naturally occurring trace elements were detected at high concentrations in less than 3 percent of raw groundwater sources used for public water supply in the Klamath Mountain area, according to the ongoing U.S. Geological Survey study of California groundwater quality.

USGS
September 3, 2014

Members of the news media are invited to attend a scientific briefing at the U.S. Geological Survey to summarize what has been learned about and from the August 24 magnitude 6 South Napa Earthquake

collage of scientists conducting science related to each mission are
August 25, 2014

Yesterday at 3:20 AM local time, the northern San Francisco Bay Area was struck by the largest earthquake to impact the Bay Area since the 1989 M6.9 Loma Prieta earthquake.

Thumbnail of report cover for water withdrawal by category in california
August 20, 2014

About 38 billion gallons per day (42,000,000 acre-feet per year) of water were withdrawn from groundwater and surface-water sources in California in 2010, according to a new U.S. Geological Survey dataset.