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: 418
Date published: June 22, 2017
Status: Active

Land use and carbon modeling in the Sierra Nevada Mountains

The goal of this study was to develop an integrated, regional-scale terrestrial carbon model, which can project changes in ecosystem carbon dynamics resulting from both changing biophysical conditions (e.g. CO2 fertilization, changes in climate) and land-change processes (e.g. urbanization, agricultural intensification, wildfire, harvest).

Our objective was to develop a modeling...

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.

Filter Total Items: 577
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

Date published: January 1, 2018

Repeat high-resolution acoustic-backscatter datasets collected between 2014 and 2016 of a field of crescent-shaped rippled scour depressions in northern Monterey Bay, California

Between November 2014 and June 2016 the U.S. Geological Survey, Pacific Coastal and Marine Science Center (PCMSC) conducted eight repeat, high-resolution bathymetry and acoustic-backscatter surveys of a small patch of seafloor offshore Santa Cruz in northern Monterey Bay, California. PCMSC also collected oceanographic time-series data over the same two-year period. This metadata file de

Date published: January 1, 2018

Central California CoSMoS v3.1 projections of coastal cliff retreat due to 21st century sea-level rise

This dataset contains spatial projections of coastal cliff retreat (and associated uncertainty) for future scenarios of sea-level rise (SLR) in Central California. Present-day cliff-edge positions used as the baseline for projections are also included. Projections were made using numerical models and field observations such as historical cliff retreat rate, nearshore slope, coastal cl

Date published: January 1, 2018

CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 wave-hazard projections: average conditions in Channel Islands

Model-derived significant wave height (in meters) for the given storm condition and sea-level rise (SLR) scenario.
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 So

Filter Total Items: 450
Publication Thumbnail
Year Published: 2006

Physical properties of two core samples from Well 34-9RD2 at the Coso geothermal field, California

The Coso geothermal field, located along the Eastern California Shear Zone, is composed of fractured granitic rocks above a shallow heat source. Temperatures exceed 640 ?F (~338 ?C) at a depth of less than 10000 feet (3 km). Permeability varies throughout the geothermal field due to the competing processes of alteration and mineral precipitation,...

Morrow, C.A.; Lockner, D.A.
Physical properties of two core samples from Well 34-9RD2 at the Coso geothermal field, California; 2006; OFR; 2006-1230; Morrow, C. A.; Lockner, D. A.

Publication Thumbnail
Year Published: 2006

Subsurface structure of the East Bay Plain ground-water basin: San Francisco Bay to the Hayward fault, Alameda County, California

The area of California between the San Francisco Bay, San Pablo Bay, Santa Clara Valley, and the Diablo Ranges (East Bay Hills), commonly referred to as the 'East Bay', contains the East Bay Plain and Niles Cone ground-water basins. The area has a population of 1.46 million (2003 US Census), largely distributed among several cities, including...

Catchings, R.D.; Borchers, J.W.; Goldman, M.R.; Gandhok, G.; Ponce, D.A.; Steedman, C.E.
Subsurface structure of the East Bay Plain ground-water basin: San Francisco Bay to the Hayward fault, Alameda County, California; 2006; OFR; 2006-1084; Catchings, R. D.; Borchers, J. W.; Goldman, M. R.; Gandhok, G.; Ponce, D. A.; Steedman, C. E.

Publication Thumbnail
Year Published: 2006

Seismic constraints and coulomb stress changes of a blind thrust fault system, 2: Northridge, California

We review seismicity, surface faulting, and Coulomb stress changes associated with the 1994 Northridge, California, earthquake. All of the observed surface faulting is shallow, extending meters to tens of meters below the surface. Relocated aftershocks reveal no seismicity shallower than 2 km depth. Although many of the aftershocks lie along the...

Stein, Ross S.; Lin, Jian
Seismic constraints and coulomb stress changes of a blind thrust fault system, 2: Northridge, California; 2006; OFR; 2006-1158; Stein, Ross S.; Lin, Jian

Publication Thumbnail
Year Published: 2006

Seismic constraints and coulomb stress changes of a blind thrust fault system, 1: Coalinga and Kettleman hills, California

This report reviews the seismicity and surface ruptures associated with the 1982-1985 earthquake sequence in the Coalinga region in California, and the role of Coulomb stress in triggering the mainshock sequence and aftershocks. The 1982-1985 New Idria, Coalinga, and Kettleman Hills earthquakes struck on a series of west-dipping, en echelon blind...

Lin, Jian; Stein, Ross S.
Seismic constraints and coulomb stress changes of a blind thrust fault system, 1: Coalinga and Kettleman hills, California; 2006; OFR; 2006-1149; Lin, Jian; Stein, Ross S.

Publication Thumbnail
Year Published: 2006

Digital database of recently active traces of the Hayward Fault, California

The purpose of this map is to show the location of and evidence for recent movement on active fault traces within the Hayward Fault Zone, California. The mapped traces represent the integration of the following three different types of data: (1) geomorphic expression, (2) creep (aseismic fault slip),and (3) trench exposures. This publication is...

Lienkaemper, James J.
Lienkaemper, J.J., 2006, Digital Database of Recently Active Traces of the Hayward Fault, California (ver. 1.1, November 2008): U.S Geological Survey Data Series 177, https://doi.org/10.3133/ds177.

Publication Thumbnail
Year Published: 2006

Maps of quaternary deposits and liquefaction susceptibility in the Central San Francisco Bay Region, California

This report presents a map and database of Quaternary deposits and liquefaction susceptibility for the urban core of the San Francisco Bay region. It supercedes the equivalent area of U.S. Geological Survey Open-File Report 00-444 (Knudsen and others, 2000), which covers the larger 9-county San Francisco Bay region. The report consists of (1) a...

Witter, Robert C.; Knudsen, Keith L.; Sowers, Janet M.; Wentworth, Carl M.; Koehler, Richard D.; Randolph, Carolyn E.; Brooks, Suzanna K.; Gans, Kathleen D.
Maps of Quaternary Deposits and Liquefaction Susceptibility in the Central San Francisco Bay Region, California; 2006; OFR; 2006-1037; Witter, Robert C.; Knudsen, Keith L.; Sowers, Janet M.; Wentworth, Carl M.; Koehler, Richard D.; Randolph, Carolyn E.; Brooks, Suzanna K.; Gans, Kathleen D.

Publication Thumbnail
Year Published: 2006

USGS science in Menlo Park -- a science strategy for the U.S. Geological Survey Menlo Park Science Center, 2005-2015

In the spring of 2004, the U.S. Geological Survey (USGS) Menlo Park Center Council commissioned an interdisciplinary working group to develop a forward-looking science strategy for the USGS Menlo Park Science Center in California (hereafter also referred to as "the Center"). The Center has been the flagship research center for the USGS in the...

Brocher, Thomas M.; Carr, Michael D.; Halsing, David L.; John, David A.; Langenheim, Victoria E.; Mangan, Margaret T.; Marvin-DiPasquale, Mark C.; Takekawa, John Y.; Tiedeman, Claire

Publication Thumbnail
Year Published: 2006

Coastal landslide material loss rates associated with severe climatic events

Deep-seated landslides along the California coast deliver large amounts of material to the nearshore littoral environment. Landslide movement, a combined result of slope base undercutting by waves and ground saturation, is highly episodic. Movement occurs primarily during periods of high rainfall and large waves, such as those associated with El...

Hapke, C.J.; Green, K.R.
Coastal landslide material loss rates associated with severe climatic events; 2006; Article; Journal; Geology; Hapke, C. J.; Green, K. R.

Publication Thumbnail
Year Published: 2006

Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary

Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans to...

Takekawa, John Y.; Miles, A.K.; Schoellhamer, D.H.; Athearn, N.D.; Saiki, M.K.; Duffy, W.D.; Kleinschmidt, S.; Shellenbarger, G.G.; Jannusch, C.A.
Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary; 2006; Conference Paper; Hydrobiologia; Takekawa, J. Y.; Miles, A. K.; Schoellhamer, D. H.; Athearn, N. D.; Saiki, M. K.; Duffy, W. D.; Kleinschmidt, S.; Shellenbarger, G. G.; Jannusch, C. A.

Publication Thumbnail
Year Published: 2006

Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary

Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans...

Takekawa, John Y.; Miles, A.K.; Schoellhamer, D.H.; Athearn, N.D.; Saiki, M. K.; Duffy, W.D.; Kleinschmidt, S.; Shellenbarger, G.G.; Jannusch, C.A.

Filter Total Items: 1,111
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.

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. 

Photo of a laboratory with various equipment and tables to work on.
December 31, 2017

PCMSC Marine Minerals Laboratory

A look into the USGS Pacific Coastal and Marine Science Center’s Marine Minerals Laboratory Suite.

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. 

Photo of a laboratory with various equipment and tables to work on.
December 31, 2017

PCMSC Marine Minerals Laboratory

A look into the USGS Pacific Coastal and Marine Science Center’s Marine Minerals Laboratory Suite.

Filter Total Items: 980
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.

USGS science for a changing world logo
May 19, 2014

Contaminated groundwater found at shallow depths in southern Los Angeles County has the potential to migrate to deeper aquifers, according to a scientific study just published by the U.S. Geological Survey and the Water Replenishment District of Southern California.

USGS science for a changing world logo
May 14, 2014

Nitrate was detected at high concentrations in about 14 percent of untreated groundwater sources used for public water supply in the Livermore, Gilroy-Hollister, and Cuyama valleys of the Southern Coast Ranges, according to an ongoing U.S. Geological Survey study of the state's groundwater quality.

Lidar image showing the upper parts of the landslide that occurred in northwest Washington on March 22, 2014.
May 14, 2014

Want to know how elevation will benefit your state? The USGS National Geospatial Program is advancing the 3D Elevation Program, known as 3DEP, in response to the growing need for high-quality three-dimensional representations of the Nation’s natural and constructed features.

USGS science for a changing world logo
May 7, 2014

Results of a new hydrologic model show a decrease in groundwater levels in response to pumping, which in turn causes a reduction in groundwater discharge to streams, a reduction in groundwater evapotranspiration, and a reduction in groundwater storage in the Santa Rosa Plain watershed.