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: 417
Date published: October 31, 2018
Status: Active

Improved Lower South Bay suspended-sediment flux measurements

Tidal marshes provide animal habitats and prevent erosion. Expanding towns and cities have claimed major parts of San Francisco Bay’s marshland. Sediment deposits are essential to rebuilding tidal marshes and keeping existing marshes intact. In the southern part of the Bay, the largest tidal wetland restoration project on the west coast is underway. Sediment flux measurements are key in...

Date published: October 30, 2018
Status: Active

The influence of preferential flow on water and solute fluxes in the unsaturated zone- John Nimmo

Much unsaturated-zone water moves not as typically slow diffuse flow, but rapidly through preferential flow channels such as root holes and fractures. Impacts are profound and far-reaching for issues such as contaminant transport, ecohydrology, and aquifer recharge. Understanding is limited and accepted theory is lacking, making preferential flow a crucial and exciting area of earth science....

Date published: October 30, 2018
Status: Active

Regional attenuation in California in ground-motion modeling- Annemarie Baltay

The goal of this project is to contribute to our understanding of anelastic path attenuation in ground-motion prediction equations (GMPEs) by searching for correlations between seismic attenuation models constrained by 3D geophysical observations and \ ground motion measurements at individual stations.

Date published: October 30, 2018
Status: Active

California Seafloor Mapping Program data collection

Here we describe the data collection methods and techniques of the California Seaflor Mapping Program: mapping, video and photography ground-truthing, and seismic profiling data collection.

Date published: October 30, 2018
Status: Active

California Seafloor Mapping Program map-set production

USGS and the California Ocean Protection Council (COPC) are supporting development of peer-reviewed map sets for California’s mainland State Waters.

Date published: October 30, 2018
Status: Active

California State Waters Map Series: Map sheets and accompanying pamphlet

The map sheets display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. The total number of sheets varies by area but always includes a core of the same 10 sheets and may include specialty sheets depending on the region. The available sheet sets are listed by study...

Date published: October 30, 2018
Status: Active

California Seafloor Mapping Program applications

California Seafloor Mapping Program data and map publications have and will be used for a large range of applications in coastal zone management and research.

Date published: October 29, 2018
Status: Archived

National Water-Quality Assessment (NAWQA) Program

During the past 25 years, industry and government made large financial investments in pollution control that have resulted in better water quality across the Nation; however, many water-quality problems remain. To address the need for consistent and scientifically sound information for managing the Nation's water resources the U.S. Geological Survey began a full-scale ...

Date published: October 29, 2018
Status: Completed

Hydrogeologic Characterization of the Cox/San Andreas Oasis, California

The Bureau of Land Management (BLM) manages the Dos Palmas Oasis complex on the northeastern side of the Salton Sea for the maintainence of threatened and endangered species. This Oasis complex represents a rare area of riparian/wetland habitat in the midst of an extremely arid desert region. Anthropogenic development of water resources during the 1900s depleted natural groundwater supplies...

Date published: October 29, 2018
Status: Completed

Development of Numeric Flow Criteria to Support Freshwater Biological Objectives and Hydrologic Modification Management in California's Wadeable Streams

The State Water Resources Control Board (SWRCB) of California has initiated a process to develop numerical biological objectives for wadeable freshwater streams and rivers for the entire state. Use of biological endpoints for regulatory or compliance purposes requires the ability to relate specific stressors...

Contacts: Larry Brown
Date published: October 29, 2018
Status: Active

Monitoring the Impacts of the Rim Fire on Tuolumne River Water Quality

The Rim Fire has burned over 400 square miles of the Tuolumne River and Merced River watersheds in central California and is now the 3rd largest wildfire in state history. The burn area is largely on the Tuolumne between Hetch Hetchy Reservoir and Don Pedro Reservoir, both of which serve as critical sources of drinking water and irrigation water to San Francisco Bay area and Central Valley...

Contacts: Scott A Wright
Date published: October 26, 2018
Status: Completed

Depth-Dependent groundwater flow, age, and chemistry in relation to solvent contamination in a production well, Tulare Lake basin, California

The Tulare Lake basin in the southern Central Valley of California is heavily dependent upon groundwater for drinking water supply but groundwater in this basin is threatened by a wide array of issues. Groundwater aquifers in the alluvial fan sediments derived from the Sierra Nevada on the eastern side of the Tulare Lake basin are highly productive aquifers that are vulnerable to contamination...

Filter Total Items: 580
Date published: January 1, 2019

CoSMoS (Coastal Storm Modeling System) Central California v3.1 ocean-currents projections: 100-year storm in San Mateo 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

Date published: January 1, 2019

Groundwater-Quality Data in the Mojave Basin Shallow Aquifer Study Unit, 2018

The U.S. Geological Survey collected groundwater samples from 49 wells used for domestic and small system drinking water supplies and 10 monitoring wells in San Bernardino County, California in 2018. The wells were sampled for the Mojave Basin (MOBS) Shallow Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Prog

Date published: January 1, 2019

CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood depth and duration projections: 100-year storm in San Francisco 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

Date published: January 1, 2019

Structure-from-motion point cloud of Mud Creek, Big Sur, California, 2017-06-13

Presented here is a point cloud collected by the U.S. Geological Survey (USGS) using an oblique plane-mounted camera system, covering the area of the Mud Creek landslide on California State Route 1 (SR1), Mud Creek, Big Sur, California. The point cloud is referenced to previously published lidar data and contains RGB information as well as XYZ. Point cloud coordinates are in NAD83

Date published: January 1, 2019

Depth to Transition—Point Sur to Point Arguello, California

This part of DS 781 presents data for the depth-to-transition map of the Point Sur to Point Arguello, California, region. The raster data file is included in the “DepthToTransition_PointSurToPointArguello.zip,” which is accessible from https://doi.org/10.5066/P97CZ0T7.
As part of the USGS's California State Waters Mapping Project, a 50-m...

Date published: January 1, 2019

CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood depth and duration projections: 20-year storm in San Mateo 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

Date published: January 1, 2019

Isopachs—Point Sur to Point Arguello, California

This part of DS 781 presents data for the isopachs of the Point Sur to Point Arguello, California, region. The vector data file is included in the “Isopachs_PointSurToPointArguello.zip,” which is accessible from https://doi.org/10.5066/P97CZ0T7.
As part of the USGS's California State Waters Mapping Project, a 50-m grid of sediment thickness...

Date published: January 1, 2019

CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood depth and duration projections: 1-year storm in San Mateo 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

Date published: January 1, 2019

CoSMoS (Coastal Storm Modeling System) Central California v3.1 ocean-currents projections: 1-year storm in San Luis Obispo 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

Date published: January 1, 2019

Turbidity and water temperature profile data in Don Pedro Reservoir, California, 2015-2016

This dataset includes water temperature and turbidity profiles collected in Don Pedro Reservoir, California, during 2015-2016.

Date published: January 1, 2019

CoSMoS (Coastal Storm Modeling System) Central California v3.1 ocean-currents projections: 1-year storm in San Francisco 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

Date published: January 1, 2019

Time-series oceanographic data from the Monterey Canyon, CA October 2015 - March 2017

Time-series data of water depth, velocity, turbidity, and temperature were acquired between 5 October 2015 and 21 March 2017 within the Monterey Canyon off of Monterey, CA, USA.
In order to better understand the triggering, progression and evolution of turbidity currents in Monterey Submarine Canyon, an experiment was designed to directly measure velocity, suspended sediment an

Filter Total Items: 470
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Year Published: 2013

Low footwall accelerations and variable surface rupture behavior on the Fort Sage Mountains fault, northeast California

The Fort Sage Mountains fault zone is a normal fault in the Walker Lane of the western Basin and Range that produced a small surface rupture (<20  cm) during an ML 5.6 earthquake in 1950. We investigate the paleoseismic history of the Fort Sage fault and find evidence for two paleoearthquakes with surface displacements much larger than those...

Briggs, Richard W.; Wesnousky, Steven G.; Brune, James N.; Purvance, Matthew D.; Mahan, Shannon
Low footwall accelerations and variable surface rupture behavior on the Fort Sage Mountains fault, northeast California; 2013; Article; Journal; Bulletin of the Seismological Society of America; Briggs, Richard W.; Wesnousky, Steven G.; Brune, James N.; Purvance, Matthew D.; Mahan, Shannon A.

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Year Published: 2013

Adjusting survival estimates for premature transmitter failure: A case study from the Sacramento-San Joaquin Delta

In telemetry studies, premature tag failure causes negative bias in fish survival estimates because tag failure is interpreted as fish mortality. We used mark-recapture modeling to adjust estimates of fish survival for a previous study where premature tag failure was documented. High rates of tag failure occurred during the Vernalis Adaptive...

Holbrook, Christopher M.; Perry, Russell W.; Brandes, Patricia L.; Adams, Noah S.

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Year Published: 2013

Late quaternary slip-rate variations along the Warm Springs Valley fault system, northern Walker Lane, California-Nevada border

The extent to which faults exhibit temporally varying slip rates has important consequences for models of fault mechanics and probabilistic seismic hazard. Here, we explore the temporal behavior of the dextral‐slip Warm Springs Valley fault system, which is part of a network of closely spaced (10–20 km) faults in the northern Walker Lane (...

Gold, Ryan; dePolo, Craig; Briggs, Richard W.; Crone, Anthony; Goss, John

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Year Published: 2013

Assessment of juvenile coho salmon movement and behavior in relation to rehabilitation efforts in the Trinity River, California, using PIT tags and radiotelemetry

Coho salmon (Oncorhynchus kisutch) of the Southern Oregon/Northern California Coast (SONCC) Evolutionarily Significant Unit (ESU) is federally listed as a threatened species. The Trinity River Restoration Program (TRRP) is rehabilitating the Trinity River to restore coho salmon (coho) and other salmonid populations. In order to evaluate the...

Chase, Robert; Hemphill, Nina; Beeman, John; Juhnke, Steve; Hannon, John; Jenkins, Amy M.
Assessment of juvenile coho salmon movement and behavior in relation to rehabilitation efforts in the Trinity River, California, using PIT tags and radiotelemetry; 2013; Article; Journal; Environmental Biology of Fishes; Chase, Robert ; Hemphill, Nina ; Beeman, John ; Juhnke, Steve ; Hannon, John ; Jenkins, Amy M.

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Year Published: 2012

2011 Georgiana Slough non-physical barrier performance evaluation project report

<p>The Sacramento River and its tributaries support populations of anadromous fish species including winter-run, spring-run, fall-run, and late fall–run Chinook salmon (Oncorhynchus tshawytscha); and steelhead (O. mykiss). Several of these species are listed as threatened or endangered under the California Endangered Species Act (CESA...

Romine, Jason G.; Perry, Russell W.; Liedtke, Theresa L.

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Year Published: 2012

Effect of brook trout removal from a spawning stream on an adfluvial population of Lahontan cutthroat trout

Independence Lake (Nevada and Sierra counties, California) harbors the only extant native population of Lahontan cutthroat trout Oncorhynchus clarkii henshawi in the Truckee River system and one of two extant adfluvial populations in the Lahontan basin. The persistence of this population has been precarious for more than 50 years, with spawning...

Scoppettone, G. Gary; Rissler, Peter H.; Shea, Sean P.; Somer, William
Effect of brook trout removal from a spawning stream on an adfluvial population of Lahontan cutthroat trout; 2012; Article; Journal; North American Journal of Fisheries Management; Scoppettone, G. Gary; Rissler, Peter H.; Shea, Sean P.; Somer, William

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Year Published: 2012

Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California

Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader...

Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.

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Year Published: 2012

Using a non-physical behavioural barrier to alter migration routing of juvenile Chinook salmon in the Sacramento–San Joaquin River Delta

Anthropogenic alterations to river systems, such as irrigation and hydroelectric development, can negatively affect fish populations by reducing survival when fish are routed through potentially dangerous locations. Non-physical barriers using behavioural stimuli are one means of guiding fish away from such locations without obstructing water flow...

Perry, R.W.; Romine, J.G.; Adams, N.S.; Blake, A.R.; Burau, J.R.; Johnston, S.V.; Liedtke, T.L.

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Year Published: 2012

Trimming the UCERF2 hazard logic tree

The Uniform California Earthquake Rupture Forecast 2 (UCERF2) is a fully time‐dependent earthquake rupture forecast developed with sponsorship of the California Earthquake Authority (Working Group on California Earthquake Probabilities [WGCEP], 2007; Field et al., 2009). UCERF2 contains 480 logic‐tree branches reflecting choices among nine...

Porter, Keith A.; Field, Edward H.; Milner, Kevin

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Year Published: 2012

Survival and migration route probabilities of juvenile Chinook salmon in the Sacramento-San Joaquin River Delta during the winter of 2009-10

Juvenile Chinook salmon (Oncorhynchus tshawytscha) emigrating from natal tributaries of the Sacramento River may use a number of migration routes to negotiate the Sacramento-San Joaquin River Delta (hereafter, "the Delta"), each of which may influence their probability of surviving. We applied a mark-recapture model to data from acoustically...

Perry, Russell W.; Romine, Jason G.; Brewer, Scott J.; LaCivita, Peter E.; Brostoff, William N.; Chapman, Eric D.

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Year Published: 2012

2011 Georgiana Slough non-physical barrier performance evaluation project report

The Sacramento River and its tributaries support populations of anadromous fish species including winter-run, spring-run, fall-run, and late fall–run Chinook salmon (Oncorhynchus tshawytscha); and steelhead (O. mykiss). Several of these species are listed as threatened or endangered under the California Endangered Species Act (CESA), federal...

Reeves, Ryan R.; McQuirk, Jacob; Ameri, Khalid; Perry, Russell W.; Romine, Jason G.; Liedtke, Theresa L.; Burau, Jon R.; Blake, Aaron R.; Fitzer, Chris; Smith, Natalie; Pagliughi, Steve; Johnston, Sam; Kumagai, Kevin; Cash, Kenneth

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Year Published: 2012

Preliminary juvenile Lost River and shortnose sucker investigations in Clear Lake, California--2011 pilot study summary

Poor recruitment appears to limit the recovery of Lost River and shortnose sucker populations in Clear Lake Reservoir, California, but the cause is unknown. Adult suckers migrate up Willow Creek and its tributaries to spawn in some years, but low flow in Willow Creek may inhibit spawning migrations in other years. It is unclear whether spawning is...

Burdick, Summer M.; Rasmussen, Josh
Preliminary juvenile Lost River and shortnose sucker investigations in Clear Lake, California--2011 pilot study summary; 2012; OFR; 2012-1180; Burdick, Summer M.; Rasmussen, Josh

Filter Total Items: 1,109
Lineations on a vertical strand of the Soda-Avawatz Fault Zone exposed in Northern Soda Mountains, California.
December 17, 2018

Lineations on a strand of the Soda-Avawatz Fault Zone northern Soda Mt

Lineations on a vertical fault strand of the Soda-Avawatz Fault Zone, exposed in the northern Soda Mountains, Mojave Desert, southern California. The fault can be seen cutting both late Tertiary sand and gravel units, but is buried by an overlying mid-Pleistocene alluvial gravel deposit.

December 17, 2018

Burrowing Owl Regurgitating a Pellet

A burrowing owl regurgitates an owl pellet at the LAX Dunes Preserve caught by a wildlife camera.
 

A small boat sits at a dock.
December 15, 2018

PCMSC vessel San Lorenzo

USGS Pacific Coastal and Marine Science Center's research vessel R/V San Lorenzo.

Sunset in background on a body of water with a small boat in the foreground.
December 12, 2018

PCMSC vessel San Lorenzo at sunset

Sun sets on Whiskeytown Lake with PCMSC's vessel San Lorenzo in foreground.

View through the windshield of a boat on a calm bay looking out on calm waters, trees, and a mountain in distance.
November 30, 2018

What the skipper sees

Looking through the windshield of USGS Pacific Coastal and Marine Science Center's boat San Lorenzo under pristine field conditions.

Researcher in Mojave Desert
November 29, 2018

Researcher in Mojave Desert

One of 1,695 repeat photographs taken to provide context for the classification of the Central Mojave Desert into various vegetation classes.

November 29, 2018

PubTalk 11/2018 - California Birds

Title: The Least Bell's Vireo - A flagship species for riparian ecosystem conservation

The Least Bell's Vireo (Vireo bellii pusillus) is a songbird that is endangered in California:

  • What type of research is the USGS doing to help understand the threats these and other birds face?
  • How has our research during the last 30 years
Snow falls on USGS Hydrologist, Joe Nawikas, as he collects groundwater samples in Mammoth, California.
November 28, 2018

Collecting Groundwater Samples in Mammoth, CA

Snow falls on USGS Hydrologist, Joe Nawikas, as he collects groundwater samples in Mammoth, California.

November 16, 2018

Image of the Week - California Wildfires

Satellites have captured views of the numerous major fires burning in California.

An image acquired on November 9, 2018, from NASA’s MODIS sensor on the Terra satellite shows smoke pouring out of two major fires, the Camp Fire and the Woolsey Fire, which both ignited the day before.

In the north, the Camp Fire quickly became the deadliest wildfire in the

Scientist writing on clipboard, with small seismometer on the ground and mountains in the background
November 16, 2018

Collecting geophysics data at Pinnacles National Park

Research Hydrologist Paul Hsieh collects seismic data during a groundwater study at Pinnacles National Park in California. The red seismometer on the ground measures ambient seismic noise, which includes microtremors induced by wind, ocean waves, and human activity. The seismic data collected can be used to estimate unconsolidated sediment thickness, map the bedrock

...
Attribution: Water Resources
Image from an application that navigates users through USGS National Oil and Gas Assessment Provinces
November 14, 2018

National Oil and Gas Assessment Provinces

This is a graphic from the USGS National Oil and Gas Assessment Explorer application, which allows user to drill into 70 oil and gas assessment provinces throughout the United States.

Satellite picture showing the Woolsey fire in California
November 8, 2018

Fires Burning Across California

Satellites have captured views of the numerous major fires burning in California.

Filter Total Items: 985
Irrigation ditch alongside an agricultural field.
May 18, 2016

If past patterns of California land-use change continue, projected water needs by the year 2062 will increase beyond current supply.

Image shows gold-bearing veins of quartz
May 6, 2016

Happy Mother's Day from EarthWords!

USGS science for a changing world
May 4, 2016

Elevated levels of trace metals such as iron, lead, nickel and zinc were found in streams of the San Gabriel Mountains north of Los Angeles, California, at water-quality levels higher than the Environmental Protection Agency’s Aquatic Life Ambient Water Quality Criteria, according to a new U.S. Geological Survey study. 

Earth Day 2016 — USGS Graphic
April 21, 2016

Celebrate Earth Day on April 22! Learn about USGS science for a changing world.

USGS
April 11, 2016

Methane emissions from restored wetlands may offset the benefits of carbon sequestration a new study from the U.S. Geological Survey suggests. 

Earthquake preparedness flyer explaining what to do before, during and after an earthquake.
April 11, 2016

The U.S. Geological Survey (USGS) and Clear Channel Outdoor Americas (CCOA) today announced a new campaign to provide Southern Californians with critical earthquake preparedness information.

Shaded relief image of the Santa Rosa area showing active faults
April 4, 2016

For the first time, scientists at the U.S. Geological Survey have mapped the active surface trace of the Rodgers Creek Fault through the central part of the northern California city of Santa Rosa. Urban development has, until now, obscured its exact location.

Bathymetry of Monterey Canyon and the Soquel Canyon tributary
March 29, 2016

Six new sets of maps reveal the diverse and complex range of seafloor habitats along 130 kilometers (80 miles) of the central California coast from the Monterey Peninsula north to Pigeon Point. The publicly available maps can be used by a large stakeholder community to understand and manage California’s vast and valuable marine resources. 

Image: Scientists Collect Data on Yosemite Rock Erosion
March 28, 2016

After more than three years of monitoring the towering granite cliffs of Yosemite National Park, scientists have new insights into a potentially important mechanism that can trigger rockfalls in the park. Although many conditions can trigger rockfalls, some rockfalls are more likely to happen in the hottest part of the day, during the hottest part of the year.

This is a photo of Ubehebe Crater.
March 25, 2016

New research by scientists at CalVO indicates that Ubehebe Craters formed about 2100 years ago during a single eruptive event. Ubehebe Craters are a lone cluster of volcanic craters in the northern half of California's Death Valley National Park.

Picture of a ground water display
March 25, 2016

California Water Science Center scientist teach water quality issues to Orange County students