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: 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...

Date published: October 26, 2018
Status: Active

Determination of the geohydrologic characteristics of the boundary between the Mojave River and Antelope Valley groundwater basins, California

The Mojave Basin Area was adjudicated in 1993 and the Mojave Water Agency (MWA) was appointed as Watermaster to ensure that water rights are allocated according to the Court Judgment (Riverside County Superior Court, 1996). Established in 1960, the southwestern boundary of MWA’s management area is not a hydrologic boundary but instead coincides roughly with the boundary between San Bernardino...

Date published: October 26, 2018
Status: Active

Coordinated Pesticide Reconnaissance Study of Surface Waters in California

Pesticides are used throughout the State of California in both urban and agricultural settings and are routinely detected in surface water. Each year, new pesticides are introduced to the market and often become detected in surface water. It can take several years or more for routine monitoring programs to acquire the capability to detect new and understudied pesticides of concern because...

Contacts: James Orlando
Date published: October 26, 2018
Status: Completed

Atmospheric Deposition Contributions to Mercury Yields in Select Watersheds in the Western United States and Canada

The atmosphere plays an important role in the delivery to and cycling of mercury (Hg) in the environment and it can be a major source of Hg contamination to surface waters. Globally, atmospheric deposition of Hg is the primary source of Hg related concerns for human and ecosystem health (Fitzgerald and others, 1998). In California and other areas in the United States, Hg use in gold and silver...

Filter Total Items: 518
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

Annual streamflow, runoff and baseflow, estimated for the period of record using six hydrograph-separation methods, for 312 gaged basins in the Northwest Volcanic Aquifer Study Area, USA, 1904-2015.

The U.S. Geological Survey’s Water Availability and Use Study Program (WAUSP) (https://water.usgs.gov/ogw/gwrp/activities/regional.html) supports quantitative assessments of groundwater availability in areas of critical importance. As part of a WAUSP study in the arid to semi-arid Northwest Volcanic Aquifer Study Area (...

Date published: January 1, 2019

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

This data contains model-derived total water levels (in meters) 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) scenarios. Projecti

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

Atmospheric-loading frequency response functions and groundwater-levels filtered for the effects of atmospheric loading and solid Earth tides for three monitoring wells near Mammoth Lakes, California, 2015 - 2017.

The data include atmospheric-loading frequency response functions (table 1) and filtered detrended and reconstructed (trends restored) groundwater-levels (tables 2 to 4) computed for selected, parsed time series for three USGS monitoring wells [28A-25-1 (373904118570701); 28A-25-2 (373904118570702); and 14A-25-1 (373927118571701)], and the associated hourly res

Date published: January 1, 2019

CoSMoS (Coastal Storm Modeling System) Central California v3.1 water-level projections: average conditions in Santa Barbara County

This data contains model-derived total water levels (in meters) 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) scenarios. Projecti

Date published: January 1, 2019

CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood depth and duration projections: 1-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

CoSMoS (Coastal Storm Modeling System) Central California v3.1 ocean-currents projections: 20-year storm in Santa Barbara 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

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

CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood-hazard projections: average conditions in San Mateo County

This data contains geographic extents of projected coastal flooding, low-lying vulnerable areas, and maximum/minimum flood potential (flood uncertainty) associated with 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-ind

Date published: January 1, 2019

CoSMoS (Coastal Storm Modeling System) Central California v3.1 wave-hazard projections: average conditions in San Francisco County

This data contains maximum model-derived significant wave height (in meters) 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) scenar

Date published: January 1, 2019

CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood-hazard projections: 100-year storm in Santa Barbara County

This data contains geographic extents of projected coastal flooding, low-lying vulnerable areas, and maximum/minimum flood potential (flood uncertainty) associated with 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-ind

Filter Total Items: 355
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Year Published: 2008

The ShakeOut Earthquake Scenario: A story that southern Californians are writing

The question is not if but when southern California will be hit by a major earthquake - one so damaging that it will permanently change lives and livelihoods in the region. How severe the changes will be depends on the actions that individuals, schools, businesses, organizations, communities, and governments take to get ready. To help prepare for...

Perry, Suzanne; Cox, Dale; Jones, Lucile; Bernknopf, Richard; Goltz, James; Hudnut, Kenneth; Mileti, Dennis; Ponti, Daniel; Porter, Keith; Reichle, Michael; Seligson, Hope; Shoaf, Kimberley; Treiman, Jerry; Wein, Anne
The ShakeOut Earthquake Scenario - A Story That Southern Californians Are Writing; 2008; CIR; 1324; Perry, Suzanne; Cox, Dale; Jones, Lucile; Bernknopf, Richard; Goltz, James; Hudnut, Kenneth; Mileti, Dennis; Ponti, Daniel; Porter, Keith; Reichle, Michael; Seligson, Hope; Shoaf, Kimberley; Treiman, Jerry; Wein, Anne

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Year Published: 2008

The ShakeOut Scenario

This is the initial publication of the results of a cooperative project to examine the implications of a major earthquake in southern California. The study comprised eight counties: Imperial, Kern, Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura. Its results will be used as the basis of an emergency response and preparedness...

Jones, Lucile M.; Bernknopf, Richard; Cox, Dale; Goltz, James; Hudnut, Kenneth; Mileti, Dennis; Perry, Suzanne; Ponti, Daniel; Porter, Keith; Reichle, Michael; Seligson, Hope; Shoaf, Kimberley; Treiman, Jerry; Wein, Anne
The ShakeOut Scenario; 2008; OFR; 2008-1150; Jones, Lucile M.; Bernknopf, Richard; Cox, Dale; Goltz, James; Hudnut, Kenneth; Mileti, Dennis; Perry, Suzanne; Ponti, Daniel; Porter, Keith; Reichle, Michael; Seligson, Hope; Shoaf, Kimberley; Treiman, Jerry; Wein, Anne

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Year Published: 2008

Leachate Geochemical Results for Ash and Burned Soil Samples from the October 2007 Southern California Wildfires

This report is the second release of leachate geochemical data included as part of a multidisciplinary study of ash and burned soil samples from the October 2007 wildfires in southern California. Geochemical data for the first set of samples were released in an Open-File Report (Plumlee and others, 2007). This study is a continuation of that work...

Hageman, Philip L.; Plumlee, Geoffrey S.; Martin, Deborah A.; Hoefen, Todd M.; Meeker, Gregory P.; Adams, Monique; Lamothe, Paul J.; Anthony, Michael W.
Leachate Geochemical Results for Ash and Burned Soil Samples from the October 2007 Southern California Wildfires; 2008; OFR; 2008-1139; Hageman, Philip L.; Plumlee, Geoffrey S.; Martin, Deborah A.; Hoefen, Todd M.; Meeker, Gregory P.; Adams, Monique; Lamothe, Paul J.; Anthony, Michael W.

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Year Published: 2008

A-priori rupture models for Northern California Type-A faults

This appendix describes how a-priori rupture models were developed for the northern California Type-A faults. As described in the main body of this report, and in Appendix G, “a-priori” models represent an initial estimate of the rate of single and multi-segment surface ruptures on each fault. Whether or not a given model is moment balanced (i.e...

Wills, Chris J.; Weldon, Ray J.; Field, Edward H.
A-Priori Rupture Models for Northern California Type-A Faults; 2008; OFR; 2007-1437-K; Appendix K in The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2); Wills, Chris J.; Weldon, Ray J., II; Field, Edward H.

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Year Published: 2008

Compilation of surface creep on California faults and comparison of WGCEP 2007 deformation model to Pacific-North American plate Mmtion

This Appendix contains 3 sections that 1) documents published observations of surface creep on California faults, 2) constructs line integrals across the WG-07 deformation model to compare to the Pacific - North America plate motion, and 3) constructs strain tensors of volumes across the WG-07 deformation model to compare to the Pacific - North...

Wisely, Beth A.; Schmidt, David A.; Weldon, Ray J.
Compilation of Surface Creep on California Faults and Comparison of WGCEP 2007 Deformation Model to Pacific-North American Plate Motion; 2008; OFR; 2007-1437-P; Appendix P in The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2); Wisely, Beth A.; Schmidt, David A.; Weldon, Ray J., II

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Year Published: 2008

Conditional, time-dependent probabilities for segmented Type-A faults in the WGCEP UCERF 2

This appendix presents elastic-rebound-theory (ERT) motivated time-dependent probabilities, conditioned on the date of last earthquake, for the segmented type-A fault models of the 2007 Working Group on California Earthquake Probabilities (WGCEP). These probabilities are included as one option in the WGCEP?s Uniform California Earthquake Rupture...

Field, Edward H.; Gupta, Vipin
Conditional, Time-Dependent Probabilities for Segmented Type-A Faults in the WGCEP UCERF 2; 2008; OFR; 2007-1437-N; Appendix N in The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2); Field, Edward H.; Gupta, Vipin

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Year Published: 2008

Paleoseismic Investigations of the Walnut Site on the San Jacinto Fault

The Walnut paleoseismic site is located along the northern San Jacinto fault about 3 km southeast of the San Bernardino, California city center (Figures 1, 2). More than 340 meters of trenches were excavated across the fault zone at this site as part of an Alquist-Priolo fault study (Figure 3). We photographed and logged the SE wall and most of...

Fumal, T.E.; Kendrick, K.J.
Paleoseismic Investigations of the Walnut Site on the San Jacinto Fault; 2008; OFR; 2007-1437-O; Appendix O in The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2); Fumal, T. E.; Kendrick, K. J.

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Year Published: 2008

Calculating California seismicity rates

Empirically the rate of earthquakes = magnitude M is well fit by the Gutenberg-Richter relationship, logN=a-bM (1) where N is the number of earthquakes = M over a given time period, a is the number of M = 0 earthquakes over the same period, and b is a parameter that determines the ratio of larger to smaller earthquakes (Ishimoto and Iida 1939;...

Felzer, Karen R.
Calculating California Seismicity Rates; 2008; OFR; 2007-1437-I; Appendix I in The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2); Felzer, Karen R.

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Year Published: 2008

California fault parameters for the National Seismic Hazard Maps and Working Group on California Earthquake Probabilities 2007

This report describes development of fault parameters for the 2007 update of the National Seismic Hazard Maps and the Working Group on California Earthquake Probabilities (WGCEP, 2007). These reference parameters are contained within a database intended to be a source of values for use by scientists interested in producing either seismic hazard or...

Wills, Chris J.; Weldon, Ray J.; Bryant, W.A.
California Fault Parameters for the National Seismic Hazard Maps and Working Group on California Earthquake Probabilities 2007; 2008; OFR; 2007-1437-A; Appendix A in The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2); Wills, Chris J.; Weldon, Ray J., II; Bryant, W. A.

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Year Published: 2008

Development of final a-fault rupture models for WGCEP/ NSHMP Earthquake Rate Model 2

This appendix discusses how we compute the magnitude and rate of earthquake ruptures for the seven Type-A faults (Elsinore, Garlock, San Jacinto, S. San Andreas, N. San Andreas, Hayward-Rodgers Creek, and Calaveras) in the WGCEP/NSHMP Earthquake Rate Model 2 (referred to as ERM 2. hereafter). By definition, Type-A faults are those that have...

Field, Edward H.; Weldon, Ray J.; Parsons, Thomas; Wills, Chris J.; Dawson, Timothy E.; Stein, Ross S.; Petersen, Mark D.
Development of Final A-Fault Rupture Models for WGCEP/ NSHMP Earthquake Rate Model 2; 2008; OFR; 2007-1437-G; Appendix G in The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2); Field, Edward H.; Weldon, Ray J., II; Parsons, Thomas; Wills, Chris J.; Dawson, Timothy E.; Stein, Ross S.; Petersen, Mark D.

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Year Published: 2008

Earthquake Rate Model 2 of the 2007 working group for California earthquake probabilities, magnitude-area relationships

The Working Group for California Earthquake Probabilities must transform fault lengths and their slip rates into earthquake moment-magnitudes. First, the down-dip coseismic fault dimension, W, must be inferred. We have chosen the Nazareth and Hauksson (2004) method, which uses the depth above which 99% of the background seismicity occurs to assign...

Stein, Ross S.
Earthquake Rate Model 2 of the 2007 Working Group for California Earthquake Probabilities, Magnitude-Area Relationships; 2008; OFR; 2007-1437-D; Appendix D in The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2); Stein, Ross S.

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Year Published: 2008

Monte Carlo method for determining earthquake recurrence parameters from short paleoseismic catalogs: Example calculations for California

Paleoearthquake observations often lack enough events at a given site to directly define a probability density function (PDF) for earthquake recurrence. Sites with fewer than 10-15 intervals do not provide enough information to reliably determine the shape of the PDF using standard maximum-likelihood techniques [e.g., Ellsworth et al., 1999]. In...

Parsons, Tom
Monte Carlo Method for Determining Earthquake Recurrence Parameters from Short Paleoseismic Catalogs: Example Calculations for California; 2008; OFR; 2007-1437-C; Appendix C in The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2); Parsons, Tom

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city skyline with tall buildings lit up at night and bridge in left foreground
August 15, 2018

The Bay Bridge and the Oakland city skyline

The nighttime Oakland city skyline as seen from San Francisco with the Bay Bridge in the foreground

August 14, 2018

Image of the Week - Mendocino Fire

Landsat 8 captured satellite views of California’s largest wildfire on record in the summer of 2018. The Mendocino Complex Fire in northern California is a combination of two fires: the Ranch Fire and the River Fire. 

Both fires started July 27, and hot, dry, windy conditions caused them to spread rapidly. Landsat 8 imaged the area the day before the fires broke out

Satellite image of fire destruction.
August 11, 2018

Mendocino Complex Fire Scorches Northern California

Landsat 8 captured satellite views of California's largest wildfire on record in the summer of 2018. The Mendocino Complex fire in northern California is a combination of two fires: the Ranch Fire and the River Fire.

Three people stand at the base of a grassless, rocky, steep slope looking up at landslides caused by an extreme rain event.
August 2, 2018

Tuolumne watershed landslides

USGS scientists examining landslides in the Tuolumne watershed, California, caused by an extreme rain event in 2018.

Map highlighting sampling locations of 339 Northern Spotted Owls used in Miller, et al, 2018
August 2, 2018

Figure 1 from Miller, et al, 2018

Map highlighting sampling locations of 339 Northern Spotted Owls used in Miller, et al, 2018

July 26, 2018

PubTalk 7/2018— Extreme acid mine drainage at Iron Mountain California

Title: Iron Mountain, California: An Extreme Acid Mine Drainage Environment

  • "The world's most acid water" — explaining negative pH
  • Colorful mineral salts that store metals and acidity in underground mine workings
  • Microbial iron oxidation and formation of pipe scale in the water treatment system
  • Challenges and successes of
View from the sky of a jagged coastline with many roads, houses, a park, and other buildings nearby.
July 25, 2018

Natural Bridges

Natural Bridges State Beach, shown here in the middle of the photo, is nestled amongst coastal neighborhoods in the southwestern part of Santa Cruz, California. View is looking south. The offices of the USGS Pacific Coastal and Marine Science Center are just a few hundred feet north, outside the bottom portion of the photograph.

View from the sky of a large estuary with large and small waterways surrounded by villages and agriculture, hills in background.
July 25, 2018

Elkhorn Slough

Elkhorn Slough is a tidal river delta, salt marsh, and estuary in Monterey County, California. It is near the community of Moss Landing and is fed by Carneros Creek.

Animation is looking at an angle at a coastal cliff region with a newly cut road running across it, showing how it has changed.
July 18, 2018

Mud Creek landslide changes March 2017-June 2018

Time-lapse view of California Highway 1 reconstruction after 2017 landslide

USGS scientists produced an animated GIF in coordination with the California Department of Transportation (Caltrans) re-opening of State Highway 1 through Big Sur on July 18, 2018. In 2017, the massive Mud Creek landslide buried a quarter-mile of the famous coastal route

...
adult male harrier
July 13, 2018

Adult Male Northern Harrier (Circus cyaneus)

An adult male Northern Harrier (Circus cyaneus) surveys Suisun Marsh, CA. Males are known for their beautiful, steel-gray plumage.

Salt marsh harvest mouse
July 13, 2018

Endangered Salt Marsh Harvest Mouse (Reithrodontomys raviventris)

A Federally endangered salt marsh harvest mouse (Reithrodontomys raviventris) climbs a branch.

Female northern harrier
July 13, 2018

Adult Female Northern Harrier (Circus cyaneus)

An adult, female northern harrier (Circus cyaneus) flies overhead in Suisun Marsh, CA. Before habitat loss drove declines in the bird's populations, Suisun Marsh hosted the state's largest population of northern harriers.

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Geologic field-trip guide to Lassen Volcanic National Park and vici...
November 16, 2015

USGS geologists Patrick Muffler and Michael Clynne published a new geologic field-trip guide for areas in and around Lassen Volcanic National Park in northern California.

Conceptual geologic model of partially crystallized magma (C1, C3) ...
November 4, 2015

USGS CalVO scientists have developed a new 3D conceptual model of the magma system below Mono Lake and Mono Craters in eastern California to give scientists a more detailed understanding of volcanic processes at depth.

Image: Mono Lake and Mono Craters Landscape Overview
October 29, 2015

A new conceptual model of the magma system below Mono Lake and Mono Craters in eastern California gives scientists a more detailed understanding of volcanic processes at depth, and a better model for forecasting volcanic unrest.

USGS science for a changing world logo
October 26, 2015

The rate of earthquakes has increased sharply since 2009 in the central and eastern United States, with growing evidence confirming that these earthquakes are primarily caused by human activity, namely the injection of wastewater in deep disposal wells.

USGS
October 22, 2015

Joint Venture Silicon Valley and the U.S. Geological Survey today jointly announced a partnership to address regional challenges from natural hazards, climate and land use change, and continued availability of clean air and water resources.

USGS
October 14, 2015

MENLO PARK, Calif. — U.S. Geological Survey employees in Menlo Park, Calif. will participate in an earthquake safety drill, and test their emergency response plan as part of the Great ShakeOut on Oct. 15, an annual day of action to practice how to protect yourself from an earthquake.

Map of San Joaquin Basin Province
October 6, 2015

The Monterey Formation in the deepest parts of California’s San Joaquin Basin contains an estimated mean volumes of 21 million barrels of oil, 27 billion cubic feet of gas, and 1 million barrels of natural gas liquids, according to the first USGS assessment of continuous (unconventional), technically recoverable resources in the Monterey Formation.

USGS
October 1, 2015

This year, groundwater levels in many wells in California’s Central Valley are at or below historical low levels. In addition, from 2007 through 2015, land subsidence that correlates to areas with large groundwater level declines has strongly increased in two large agricultural areas near the towns of El Nido and Pixley, according to a new article by the U.S. Geological Survey.

A picture of low water levels of the American River
September 23, 2015

The rising temperatures in many of California's rivers have become potentially lethal to anadromous fish, and other fish species. Even in rivers controlled by reservoirs, where operators have traditionally been able to help control river temperature by timed releases, the combination of low flows, reduced cold-water pools in reservoirs and high air temps has resulted in elevated river temps.

Image: Severe Coastal Erosion During an El Niño Storm
September 21, 2015

SANTA CRUZ, Calif. — The projected upsurge of severe El Niño and La Niña events will cause an increase in storm events leading to extreme coastal flooding and erosion in populated regions across the Pacific Ocean, according to a multi-agency study published today in Nature Geoscience.

Image: Sea Otter Ready for a Nap
September 17, 2015

SANTA CRUZ, Calif. — The recovery of southern sea otters appears to have taken an upturn, according to results from the annual California sea otter survey released by the U.S. Geological Survey today. Yet despite an overall increase in sea otter abundance, sharks have been “taking a bite” out of the portion of the population that could fuel expansion into new areas.

Illustration: Study area showing boundaries of each of the seven greater sage-grouse management zones
September 10, 2015

OAKHURST, Calif. -- Overall fire threats to greater sage-grouse habitat are much higher in the western part of the species’ range than in the eastern part, according to a U.S. Geological Survey fire threats assessment study published today.

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