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: June 9, 2017
Status: Active

Role Nutrients Play in Fish Death Rates at Rodeo Lagoon

Scientists investigate excessive nutients levels in Rodeo Lagoon that are believed to be cause of dying fish

Date published: June 8, 2017
Status: Active

Delineation of Flood-Inundation Areas in Grapevine Canyon near Scotty’s Castle, Death Valley National Park, California

On October 18, 2015 an intense, nearly stationary, thunderstorm triggered flooding in Grapevine Canyon. Grapevine Canyon Road, power and water infrastructure, and several buildings at Scotty’s Castle were damaged by the flood water, necessitating closure of the area to the public. In response to the flood event, the National Park Service requested the USGS Nevada Water Science Center perform a...

Date published: June 1, 2017
Status: Completed

Back to the Future on the San Andreas Fault

Release Date: JUNE 1, 2017

Investigating Past Earthquakes to Inform the Future

What does the science say? Where does the information come from? And what does it mean? Investigating past earthquakes to inform the future. Maybe you’ve heard that the “Big One is overdue” on the San Andreas Fault. No one can predict earthquakes, so what does the science really say? Where...

Date published: May 26, 2017
Status: Active

Estimating Annual Groundwater Discharge by Evapotranspiration Along the Wild and Scenic Portion of the Amargosa River

The USGS Nevada Water Science Center is refining estimates of annual groundwater discharge along the Wild and Scenic portion of the Amargosa River (AWSR) and adjacent spring discharge areas. Discharge estimates will be based on evapotranspiration (ET) measurements made along the Amargosa River during a 2-year period, previous estimates of evapotranspiration rates, and remote sensing techniques...

Contacts: Michael Pavelko
Date published: April 27, 2017
Status: Completed

Evaluation of Groundwater Flow in the Southern Part of the Amargosa Desert, Nevada and California

Since the original publication of the Death Valley regional groundwater flow system (DVRFS) numerical model in 2004, more information on the regional groundwater flow system in the form of new data and interpretations has been compiled. Cooperators such as the Bureau of Land Management, National Park Service, U.S. Fish and Wildlife Service, the Department of Energy, and Nye County, Nevada,...

Contacts: Wayne Belcher
Date published: April 19, 2017
Status: Active

Epidemiology of Infectious and Other Diseases in Agassiz’s Desert Tortoise

Agassiz’s Desert Tortoise (Gopherus agassizii) was listed as threatened in 1990 under the Endangered Species Act. WERC’s Dr. Kristin Berry leads studies on the cause of diseases in populations of Agassiz’s Desert Tortoise across the Mojave and western Sonoran deserts in southern California.

Contacts: Kristin Berry
Date published: April 13, 2017

Integrated Wildland Fire Science

The size and number of large wildland fires in the western United States have grown dramatically over the past decade, with a contingent rise in damages and suppression costs. This trend will likely continue with further growth of the wildland urban interface (WUI) into fire prone ecosystems, hazardous fuel conditions from decades of fire suppression, and a potentially increasing effect from...

Date published: April 13, 2017
Status: Active

The Pacific Coastal Fog Project

Coastal marine fog is an important meteorological phenomenon for California.  A cloud—either stratus or stratocumulus—is called “fog” when it is low or touching the ground. Marine fog forms as a result of complex interactions between ocean evaporation, aerosols, atmospheric pressure, vertical air layering, onshore-offshore temperature gradients, and coastal mountain topography. The marine...

Date published: April 12, 2017
Status: Active

Land Use and Climate Change Team

We are a research team focusing on understanding the rates, causes, and consequences of land change across a range of geographic and temporal scales. Our emphasis is on developing alternative future projections and quantifying the impact on environmental systems, in particular, the role of land-use change on ecosystem carbon dynamics.

We are interested in how land-use and climate...

Date published: April 11, 2017
Status: Active

Hydrogeologic and Geothermal Conditions of the Northwest Volcanic Aquifers

Although sparsely populated, this area in southeastern Oregon, northeastern California, northwestern Nevada, and southeastern Idaho has high geothermal heat flow that may be used to generate large amounts of electricity.

Date published: March 9, 2017
Status: Active

Restoring Rare Plants on Public Lands

Ecosystems throughout the U.S. face threats from invasive species and rapid changes to the environment. Dr. Kathryn McEachern is studying the long-term effects of invasive plants and animals, and environmental change on the survival and recovery of rare plants across the 18 California Islands and in the Great Lakes.

Date published: March 3, 2017
Status: Active

Sequoia and Kings Canyon Field Station

The Sequoia and Kings Canyon Field Station is home to research programs that focus on wildfire patterns in Southern California, and the effects of drought on Sierra Nevada forests. Select the "Science" tab for a more comprehensive summary.

Filter Total Items: 580
Date published: April 12, 2018

The HayWired Scenario: An Urban Earthquake in a Connected World - A Geonarrative

What might it be like the next time the Hayward Fault has a large earthquake? A geonarrative and related imagery examines a hypothetical earthquake, the magnitude 7.0 HayWired earthquake scenario.”

Attribution: Natural Hazards
Date published: February 1, 2018

Electron microprobe data for monazite and xenotime used in consideration of gold deposit formation models

The genetic origin of many gold deposits, including Pogo in Alaska, remains controversial with questions as to whether they formed due to magmatic-hydrothermal or metamorphic-hydrothermal fluids. Gaining a better understanding of the formation mechanisms for these deposits is critical for defining proper exploration criteria in gold-bearing regions and production within these deposits. Monaz...

Date published: January 19, 2018

Oblique Aerial Photography Viewer

Obique photos offer a unique perspective of the coast. Features such as beach erosion or accretion, dune erosion and overwash can all be clearly characterized in this imagery. It also documents coastal infrastructure, as well as the damage that infrastructure may incur as the result of an impacting hurricane. 

Date published: January 18, 2018

Reanalysis of Selected Archived NURE-HSSR Sediment and Soil Samples from Arizona, California, Idaho, Montana, Nevada, New Mexico, and Utah

Beginning in November of 2015, the U.S. Geological Survey (USGS) undertook a project to reanalyze approximately 60,000 archived sample splits collected as part of the National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) project from selected areas in Arizona, California, Idaho, Montana, Nevada, New Mexico, and Utah. A s

Date published: January 1, 2018

High-Resolution Aeromagnetic Survey of Mountain Pass, California

A detailed aeromagnetic survey of Mountain Pass, California was flown by CGG Canada Services Ltd. (CGG) during November and December, 2016. The high-resolution helicopter survey was flown at a flightline spacing of 100 and 200 m, a flightline azimuthal direction of 70 degrees, a nominal flightline elevation above ground of 70 m, and consists of about 1,814 line-kilometers. Tie l

Date published: January 1, 2018

Water well data used for preliminary regional groundwater salinity mapping near selected oil fields in central and southern California

This digital dataset is comprised of three separate data files that contain total dissolved solids, well construction, and well identifying information for 3,546 water wells used to map salinity in and around 31 southern and central California oil fields. Salinity mapping was done for 27 fields located in the southern San Joaquin Valley of Kern County (North Belridge, South Belridge,

Date published: January 1, 2018

Study Boundary and Grid Cells for the North and South American, Cosumnes, and Mokelumne River Watersheds Shallow Aquifer Study Unit

The U.S. Geological Survey collected groundwater samples from 67 domestic wells and 1 spring used for domestic supply in Placer, El Dorado, Amador, and Calaveras Counties, California in 2016-2017. The sites were sampled for the Mokelumne, Cosumnes, and American River Watersheds (MCAW) Shallow Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambi

Date published: January 1, 2018

Magnetotelluric Data from the San Andreas Fault, Parkfield CA, 1990

The U.S. Geological Survey (USGS) Geology, Geophysics and Geochemistry Science Center (GGGSC) collaborated with the USGS Data at Risk (DaR) team to preserve and release a subset of magnetotelluric data from the San Andreas Fault in Parkfield, California. The San Andreas Fault data were collected by the Branch of Geophysics, a precursor to the now GGGSC, between 1989 and 1994.

Date published: January 1, 2018

River Channel Survey Data, Redwood Creek, California, 1953-2013

Dr. Richard Janda of the USGS began a channel monitoring program in Redwood Creek in northern coastal California in 1973. The USGS continued this work through 2013, when the Research Geologist, Dr. Mary Madej retired. This effort produced 40 years of channel change data in rivers that were disrupted by severe erosion following timber harvest of old-growth redwood forests, a portion of the p...

Date published: January 1, 2018

Marine magnetic data from Point Sur to Piedras Blancas, central California, 2011

This dataset includes marine magnetic data collected by the U.S. Geological Survey (USGS) in 2011 during field activity B-05-11-CC between Point Sur and Piedras Blancas, central California.

Date published: January 1, 2018

CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 flood-hazard depth and duration projections: 1-year storm in the Channel Islands

Maximum depth of flooding surface (in cm) in the region landward of the present day shoreline that is inundated for the storm condition and sea-level rise (SLR) scenario indicated. Note: Duration datasets may have occasional gaps in open-coast sections.
The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of k

Filter Total Items: 470
Publication Thumbnail
Year Published: 2008

The Uniform California Earthquake Rupture Forecast, version 2 (UCERF 2)

California?s 35 million people live among some of the most active earthquake faults in the United States. Public safety demands credible assessments of the earthquake hazard to maintain appropriate building codes for safe construction and earthquake insurance for loss protection. Seismic hazard analysis begins with an earthquake rupture forecast?a...

The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2); 2008; OFR; 2007-1437; 2007 Working Group on California Earthquake Probabilities

Publication Thumbnail
Year Published: 2008

Summary of Survival Data from Juvenile Coho Salmon in the Klamath River, Northern California, 2007

A study to estimate the effects of Iron Gate Dam discharge on ESA-listed juvenile coho salmon during their seaward migration to the ocean was begun in 2005. Estimates of survival through various reaches of river downstream from the dam were completed in 2006 and 2007 as part of this process. This report describes the estimates of survival during...

Beeman, John W.
Summary of Survival Data from Juvenile Coho Salmon in the Klamath River, Northern California, 2007; 2008; OFR; 2008-1022; Beeman, John W.

Publication Thumbnail
Year Published: 2008

Influence of plankton mercury dynamics and trophic pathways on mercury concentrations of top predator fish of a mining-impacted reservoir

Physical and biogeochemical characteristics of the aquatic environment that affect growth dynamics of phytoplankton and the zooplankton communities that depend on them may also affect uptake of methylmercury (MeHg) into the pelagic food web of oligotrophic reservoirs. We evaluated changes in the quality and quantity of suspended particulate...

Stewart, A.R.; Saiki, M. K.; Kuwabara, J.S.; Alpers, Charles N.; Marvin-DiPasquale, M.; Krabbenhoft, D.P.
Influence of plankton mercury dynamics and trophic pathways on mercury concentrations of top predator fish of a mining-impacted reservoir; 2008; Article; Journal; Canadian Journal of Fisheries and Aquatic Sciences; Stewart, A. R.; Saiki, M. K.; Kuwabara, J. S.; Alpers, C. N.; Marvin-DiPasquale, M.; Krabbenhoft, D. P.

Publication Thumbnail
Year Published: 2008

Relation between species assemblages of fishes and water quality in salt ponds and sloughs in South San Francisco Bay

This study was conducted to characterize fishery resources inhabiting salt-evaporation ponds and sloughs in South San Francisco Bay, and to identify key environmental variables that influence distribution of fishes. The ponds, which were originally constructed and operated for commercial production of salt, have undergone preliminary modifications...

Mejia, F.; Saiki, M. K.; Takekawa, John Y.
Relation between species assemblages of fishes and water quality in salt ponds and sloughs in South San Francisco Bay; 2008; Article; Journal; Southwestern Naturalist; Mejia, F.; Saiki, M. K.; Takekawa, J. Y.

Publication Thumbnail
Year Published: 2007

Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, April and July 2007

This report presents the results for two sampling periods during a 4-year monitoring survey to provide a characterization of selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species, and total suspended solids were determined in water samples, and total selenium was determined...

May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.
Total Selenium and Selenium Species in Irrigation Drain Inflows to the Salton Sea, California, April and July 2007; 2007; OFR; 2007-1347; May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

Publication Thumbnail
Year Published: 2007

Preliminary analytical results for ash and burned soils from the October 2007 southern California wildfires

The U.S. Geological Survey (USGS) collected ash and burned soils from about 28 sites in southern California wildfire areas (Harris, Witch, Ammo, Santiago, Canyon and Grass Valley) from Nov. 2 through 9, 2007 (table 1). USGS researchers are applying a wide variety of analytical methods to these samples, with the goal of helping identify...

Plumlee, Geoffrey S.; Martin, Deborah A.; Hoefen, Todd; Kokaly, Raymond F.; Hageman, Philip; Eckberg, Alison; Meeker, Gregory P.; Adams, Monique; Anthony, Michael; Lamothe, Paul J.
Preliminary Analytical Results for Ash and Burned Soils from the October 2007 Southern California Wildfires; 2007; OFR; 2007-1407; Plumlee, Geoffrey S.; Martin, Deborah A.; Hoefen, Todd; Kokaly, Raymond; Hageman, Philip; Eckberg, Alison; Meeker, Gregory P.; Adams, Monique; Anthony, Michael; Lamothe, Paul J.

Publication Thumbnail
Year Published: 2007

Data from theodolite measurements of creep rates on San Francisco Bay region faults, California: 1979-2007

Introduction Our purpose is to update with six additional years of data, our creep data archive on San Francisco Bay region active faults for use by the scientific research community. Earlier data (1979-2001) were reported in Galehouse (2002) and were analyzed and described in detail in a summary report (Galehouse and Lienkaemper, 2003). A...

McFarland, Forrest S.; Lienkaemper, James J.; Caskey, S. John; Grove, Karen
Data from Theodolite Measurements of Creep Rates on San Francisco Bay Region Faults, California: 1979-2007; 2007; OFR; 2007-1367; McFarland, Forrest S.; Lienkaemper, James J.; Caskey, S. John; Grove, Karen

Publication Thumbnail
Year Published: 2007

Simulations of potential runout and deposition of the Ferguson rockslide, Merced River Canyon, California

INTRODUCTION An active rockslide in Merced River Canyon was first noticed on April 29, 2006 when a few rocks rolled onto Highway 140 between mileposts 103 and 104, compromising traffic on this highway and signaling the onset of renewed activity of the Ferguson rockslide. State highway 140 is one of the main entrances to Yosemite National Park...

Denlinger, Roger P.
Simulations of Potential Runout and Deposition of the Ferguson Rockslide, Merced River Canyon, California; 2007; OFR; 2007-1275; Denlinger, Roger P.

Publication Thumbnail
Year Published: 2007

Dissolved solids in basin-fill aquifers and streams in the southwestern United States

The U.S. Geological Survey National Water-Quality Assessment Program performed a regional study in the Southwestern United States (Southwest) to describe the status and trends of dissolved solids in basin-fill aquifers and streams and to determine the natural and human factors that affect dissolved solids. Basin-fill aquifers, which include the...

Anning, David W.; Bauch, Nancy J.; Gerner, Steven J.; Flynn, Marilyn E.; Hamlin, Scott N.; Moore, Stephanie J.; Schaefer, Donald H.; Anderholm, Scott K.; Spangler, Lawrence E.
Dissolved Solids in Basin-Fill Aquifers and Streams in the Southwestern United States; 2007; SIR; 2006-5315; Anning, David W.; Bauch, Nancy J.; Gerner, Steven J.; Flynn, Marilyn E.; Hamlin, Scott N.; Moore, Stephanie J.; Schaefer, Donald H.; Anderholm, Scott K.; Spangler, Lawrence E.

Publication Thumbnail
Year Published: 2007

Using a remote sensing/GIS model to predict southwestern Willow Flycatcher breeding habitat along the Rio Grande, New Mexico

Introduction The Southwestern Willow Flycatcher (Empidonax traillii extimus; hereafter SWFL) is a federally endangered bird (USFWS 1995) that breeds in riparian areas in portions of New Mexico, Arizona, southwestern Colorado, extreme southern Utah and Nevada, and southern California (USFWS 2002). Across this range, it uses a variety of plant...

Hatten, James R.; Sogge, Mark K.
Using a Remote Sensing/GIS Model to Predict Southwestern Willow Flycatcher Breeding Habitat along the Rio Grande, New Mexico; 2007; OFR; 2007-1207; Hatten, James R.; Sogge, Mark K.

Publication Thumbnail
Year Published: 2007

Earthquake Rate Model 2.2 of the 2007 Working Group for California Earthquake Probabilities, Appendix D: Magnitude-Area Relationships

Summary To estimate the down-dip coseismic fault dimension, W, the Executive Committee has chosen the Nazareth and Hauksson (2004) method, which uses the 99% depth of background seismicity to assign W. For the predicted earthquake magnitude-fault area scaling used to estimate the maximum magnitude of an earthquake rupture from a fault's length...

Stein, Ross S.
Earthquake Rate Model 2.2 of the 2007 Working Group for California Earthquake Probabilities, Appendix D: Magnitude-Area Relationships; 2007; OFR; 2007-1162; Stein, Ross S.

Publication Thumbnail
Year Published: 2007

National assessment of shoreline change part 4: historical coastal cliff retreat along the California coast

Coastal cliff retreat, the landward migration of the cliff face, is a chronic problem along many rocky coastlines in the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information regarding trends and rates of coastal cliff retreat. There is...

Hapke, Cheryl J.; Reid, David
National assessment of shoreline change part 4: historical coastal cliff retreat along the California coast; 2007; OFR; 2007-1133; Hapke, Cheryl J.; Reid, David

Filter Total Items: 1,109
marsh
February 13, 2018

Egret Flyover, Petaluma River

While heading out to a survey plot off of San Pablo Bay, an egret flies over the Petaluma River in the early morning.

Female northern harrier gaze
February 9, 2018

Female Northern Harrier (Circus cyaneus) Gaze

A female northern harrier (Circus cyaneus) gazes into the camera at Suisun Marsh, CA.

In a pasture a white horse is standing in the foreground, in background is an apparatus that pumps oil from the ground.
February 2, 2018

Oil well pumping unit, Half Moon Bay oil field, California

The Half Moon Bay oil field is one of the oldest oil fields in California and was first developed during the 1880s. Since then, the field has produced an estimated 60,000 barrels of oil from about 19 wells. Most of the old wells have been plugged and abandoned, but this well was reworked in 1980 and produces small volumes of oil from thin sandstone layers of the Miocene

...
January 29, 2018

USGS Joins Efforts in Montecito to Assess Debris-Flow Aftermath

A team of USGS geologists provide science support following Montecito post-fire debris-flow event.
 

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.

Home damaged by post fire debris flow
January 16, 2018

Montecito home damaged by post-wildfire debrisflow.

Damage from a major post-wildfire landslide that occurred on 9 January 2018 near Montecito, Santa Barbara County as a result of the 2017 Thomas Fire.

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 (

Willow Creek detection station PIT tag system
January 3, 2018

Willow Creek detection station PIT tag systems

Passive Integrated Transponder (PIT) tag detection station on Willow Creek, California. Systems like this one are used to detect movements of endangered Lost River and shortnose suckers in remote locations.

Filter Total Items: 985
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.

Map showing outline of Cuyama Valley groundwater basin and sub-basins.
August 14, 2014

Groundwater is the sole source for agricultural, domestic and municipal water use in California’s Cuyama Valley, located primarily in Santa Barbara County.

Volcanic-gas "sniffer" installed at Mammoth Mountain, California me...
August 12, 2014

In July 2014, USGS Scientists Peter Kelly (Cascades Volcano Observatory) and Stuart Wilkinson (California Volcano Observatory) installed an automated volcanic-gas monitoring station on Mammoth Mountain, located on the SW rim of Long Valley Caldera (CA).

Public lecture flyer for The Ecological Value of Coastal Fog
July 29, 2014

Fog is more than just nature’s air conditioning keeping Bay Area residents cool while others in California bake in the summer’s heat; it is also extremely valuable for the local economy for everything from wine production to tourism.

CalVO geologist Mae Marcaida examines thin layers of volcanic ash s...
July 3, 2014

CalVO geologist Mae Marcaida examines thin layers of volcanic ash sandwiched between thick beds of sediment deposited by ancestral Mono Lake in eastern California.

Mammoth Lakes Basin including the treekill area next to Horseshoe L...
June 27, 2014

A swarm of small earthquakes (magnitudes less than 2) occurred at a depth of 6-7 km (about 4 miles) beneath Highway 203 in Mammoth Lakes, California midway between the water treatment plant and the Highway 395-203 junction, June 27, 2014.

June 2014 flyer
June 24, 2014

June is recognized as National Oceans Month in the United States. Join USGS Oceanographer Dr. Nancy Prouty to hear about scientific studies of deep-sea corals that show how these long-living creatures provide our oceans with a healthy ecosystem.

USGS science for a changing world logo
June 10, 2014

While most of the Coachella Valley was relatively stable, land surfaces declined about nine inches to two feet in some areas of Palm Desert, Indian Wells, and La Quinta, between 1995 and 2010.

USGS science for a changing world logo
June 10, 2014

While most of the Coachella Valley was relatively stable, land surfaces declined about nine inches to two feet in some areas of Palm Desert, Indian Wells, and La Quinta, between 1995 and 2010.

Flyer for May presentation
May 28, 2014

Can better understanding fish diseases help to create much sought-after cures for human diseases such as Hepatitis C?

Image: Mud and Peat Deposits from Point Reyes Marsh
May 20, 2014

An extensive sedimentary deposit formed by a tsunami in 1946 was recently discovered at Pillar Point Marsh near Half Moon Bay, California. While there were photos and eyewitness accounts of the tsunami and resulting damage at the time, finding the tangible evidence in the geologic record is an important part of assessing the long-term hazard of tsunamis on California coastal communities.