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.

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Filter Total Items: 580
Date published: January 1, 2017

Bathymetric DEM of the Sacramento River, from the Feather River to Knights Landing, California in February 2011

This part of the data release presents a digital elevation model (DEM) created from bathymetry data collected on February 1, 2011, in the Sacramento River from the confluence of the Feather River to Knights Landing. The data were collected by the USGS Pacific Coastal and Marine Science Center (PCMSC) team with collaboration and funding from the U.S. Army Corps of Engineers. This proje

Date published: January 1, 2017

CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 ocean-currents projections: average conditions in Orange County

Model-derived ocean current velocities (in meters per second) 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

Date published: January 1, 2017

CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 flood-hazard projections: average conditions in Ventura County

Geographic extent of projected coastal flooding, low-lying vulnerable areas, and maxium/minimum flood potential (flood uncertainty) associated with the sea-level rise 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 erosi

Date published: January 1, 2017

CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 wave-hazard projections: 20-year storm in Orange County

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

Date published: January 1, 2017

1992 pruned digital surface model Malakoff Diggins State Historic Park, California

One of the largest hydraulic mines (1.6 km2) is located in California’s Sierra Nevada within the Humbug Creek watershed and Malakoff Diggins State Historic Park (MDSHP). MDSHP’s denuded and dissected landscape is composed of weathered Eocene auriferous sediments susceptible to chronic rill and gully erosion whereas block failures and debris flows occur in more cohesive ter

Date published: January 1, 2017

CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 wave-hazard projections: 1-year storm in Ventura County

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

Date published: January 1, 2017

CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 flood-hazard projections: 20-year storm in Orange County

Geographic extent of projected coastal flooding, low-lying vulnerable areas, and maxium/minimum flood potential (flood uncertainty) associated with the sea-level rise 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 erosi

Date published: January 1, 2017

CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 water-level projections: average conditions in Orange County

Model-derived total water levels (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 Souther

Date published: January 1, 2017

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

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

Date published: January 1, 2017

Water pressure/depth and turbidity time-series data from CHC13 Marsh and mudflat stations in San Pablo Bay and China Camp Marsh, California

Files contain hydrodynamic and sediment transport data for the location and deployment indicated. Time-series data of water depth, velocity, turbidity, and temperature were collected in San Pablo Bay and China Camp Marsh as part of the San Francisco Bay Marsh Sediment Experiments. Several instruments were deployed in tidal creek, marsh, mudflat, and Bay locations, gathering data on

Date published: January 1, 2017

Water pressure/depth and turbidity time-series data from CHC14 Marsh and mudflat stations in San Pablo Bay and China Camp Marsh, California

Files contain hydrodynamic and sediment transport data for the location and deployment indicated. Time-series data of water depth, velocity, turbidity, and temperature were collected in San Pablo Bay and China Camp Marsh as part of the San Francisco Bay Marsh Sediment Experiments. Several instruments were deployed in tidal creek, marsh, mudflat, and Bay locations, gathering data on

Date published: January 1, 2017

Groundwater-Quality Data in the Tulare Shallow Aquifer Study Unit, 2014-2015: Results from the California GAMA Priority Basin Project

The U.S. Geological Survey collected groundwater samples from 95 domestic wells in Tulare and Kings Counties, California in 2014-2015. The wells were sampled for the Tulare Shallow Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project’s assessment of the quality of groundwater reso

Filter Total Items: 470
Publication Thumbnail
Year Published: 1973

Geohydrology of the Yuma area, Arizona and California

Olmsted, F.H.; Loeltz, Omar J.; Irelan, Burdge
Geohydrology of the Yuma area, Arizona and California; 1973; PP; 486-H; USGS NUMBERED SERIES; Water resources of Lower Colorado River-Salton Sea area; Olmsted, F. H.; Loeltz, O. J.; Irelan, Burdge

Publication Thumbnail
Year Published: 1970

Physiographic diagrams of parts of the continental borderlands of California and Alaska: 12 physiographic diagrams: Southern California Borderland; Eastern Murray Fracture Zone and Transverse Ranges; Southern Monterey Bay; Monterey Canyon; Central San

Alpha, Tau Rho
Physiographic diagrams of parts of the continental borderlands of California and Alaska: 12 physiographic diagrams: Southern California Borderland; Eastern Murray Fracture Zone and Transverse Ranges; Southern Monterey Bay; Monterey Canyon; Central San; 1970; OFR; 70-5; Alpha, Tau Rho

Filter Total Items: 1,108
A woman in a lab coat stands in front of an apparatus with a thin cylindrical glass tube attached to flexible plastic tubing.
March 16, 2017

Total inorganic carbon content analyzer

The UIC CM5230/CM5015 analyzes total inorganic carbon content. It's less automated than other analyzers, but often easier to use.

A woman wearing a lab coat walks into a laboratory with sinks and machinery, she is carrying a bag.
March 16, 2017

PCMSC Sediment Prep Lab

This is the Pacific Coastal and Marine Science Center's Sediment Prep Lab, where sediment samples and core subsamples are prepared for analyses.

A woman in a lab coat stands in a lab opening the doors of a cabinet filled with glass beakers.
March 16, 2017

Fume hood lab

Our fume hood lab allows for sample preparation in safe conditions.

View of hands in rubber gloves scooping a small amount of mud from a plastic bag and about to place it in a beaker in a lab.
March 16, 2017

Preparing sediment for particle size analysis

We add about 20 grams of sediment from a sample to distilled water for particle size analysis. Then we add strong hydrogen peroxide to break down organic matter that makes clay particles stick together. Digestion takes place overnight.

A woman in a lab coat reaches into a machine with a see-through window into a space with receptacles to hold bottles.
March 16, 2017

Accelerated solvent extractor

This Dionex ASE 350 accelerated solvent extractor automatically extracts hydrocarbons for further analysis. We also have a Zymark TurboVap II for sample preparation (not shown).

A woman wearing a lab coat stands in front of a machine with 6 cylindrical holders, she is placing a bottle in a cylinder.
March 16, 2017

Centrifuge in the sediment prep lab

We spin down a sample of sediment that's mixed with distilled water in a centrifuge. This separates the sediment from the water at the bottom of the sample bottle, and we pour off most of the water. This process removes dissolved salts.

A person wearing a lab coat and rubber gloves holds clear plastic tube with water running into a cylindrical metal pan.
March 16, 2017

Sieving sediment

Washing a sediment sample through two sieves with distilled water lets us measure the fractions of gravel (bigger than 2 millimeters or -1 phi) and sand (2 millimeters to 63 microns, -1 phi to 4 phi). Smaller sediment passes through the sieves into a standard 1-liter graduated cylinder.

A woman in a lab coat holds a tall plastic cylinder with murky water in it, and a plunger to carefully stir the water.
March 16, 2017

Sediment suspension preparation

After adding a little sodium hexametaphosphate dispersant, we use a plunger to carefully stir the cylinder then let it settle, to ensure good mixing and standardized suspension of the sediment.

A woman wearing a lab coat pushes a cart with a tube of sediment through a large metal door.
March 16, 2017

Refrigerated sample storage

We take most cores and samples straight from the loading dock into a large walk-in refrigerator (about 780 square feet), kept at the international core curation standard of 4° C plus or minus 2° C. Each core and sample must be labeled with an identifier and metadata, which follows the material through processing and analysis.

A woman in a lab coat holds a tall plastic cylinder with murky water in it, and a sampling device to take a small amount out.
March 16, 2017

Subsampling the suspended sediment sample

Lab technician Angela Tan takes a sample of the sediment suspended in liquid, for analysis in one of several ways.

A woman, wearing a lab coat and protective equipment in a laboratory, holds a core in a device that will split the core in half.
March 16, 2017

Geotek core splitter

In the core lab, the Geotek core splitter cuts sediment cores in half lengthwise using oscillating saws and a wire cutter.

A woman in a lab coat holds a small stack of metal sediment sieves, with an enlarged photo of the sieves to show detail.
March 16, 2017

Sediment sieves

We can use the tried-and-true method of washing samples through finer and finer sieves, then weighing the sediment trapped in each sieve, to determine sediment size fractions.

Filter Total Items: 985
USGS science for a changing world logo
August 12, 2011

The public is invited to the Loomis Museum in Lassen Volcanic National Park on Wednesday, August 17 from 10:30 a.m. to 11:30 a.m. for the unveiling of a spectacular new map and booklet that interprets the detailed geology of the park. The U.S. Geological Survey and the Park are pleased to announce a special public presentation by USGS scientists to unveil their new landmark publication, the "

Screenshot Location of Lassen Volcanic Center
August 12, 2011

The U.S. Geological Survey and Lassen Volcanic National Park are pleased to announce a special public presentation by USGS scientists to unveil, the "Geologic Map of Lassen Volcanic National Park and Vicinity," a map and booklet that interprets the detailed geology of the park.

USGS science for a changing world logo
August 11, 2011

Science papers, posters, and other types of information used to inform and update Klamath Basin public and private sector stakeholders at the 2010 Klamath Basic Science Conference have been published by the USGS in an Open File Report that is now available online.

USGS science for a changing world logo
August 9, 2011

This July, researchers from the U.S. Geological Survey and National Park Service discovered that California Common Murre (Uria aalge californica) chicks had hatched on the Channel Islands for the first time since 1912.

USGS science for a changing world logo
August 1, 2011

Marine biologists are setting up camp in Forks this week, and sea otters will be their quarry on a three-week expedition. Researchers from the U.S. Geological Survey, Seattle Aquarium, Monterey Bay Aquarium and other institutions are studying the health of local sea otters to assess the condition of Washington’s nearshore ecosystem. 

CalVO staff assembled in the Rambo Auditorium, Menlo Park, CA...
August 1, 2011

Inquiries have come to the USGS regarding a potential eruption in the vicinity of Lavic Lake Volcanic Field (LLVF) in Southern California.

USGS science for a changing world logo
July 12, 2011

Knowing that the U.S. west coast was battered during the winter before last by a climatic pattern expected more often in the future, scientists have now pieced together a San Diego-to-Seattle assessment of the damage wrought by that winter's extreme waves and higher-than-usual water levels. 

USGS science for a changing world logo
July 5, 2011

Scientists detected low concentrations of pharmaceutical compounds in groundwater samples from 2.3 percent of tested aquifers used for drinking water in California.  Pharmaceuticals were detected more frequently in urban areas according to results of a U.S. Geological Survey study published in the journal, Science of the Total Environment.

USGS science for a changing world logo
June 23, 2011

 A new U.S. Geological Survey documentary, Turbid Bay: Sediment in Motion, describes ongoing research into the transport of sediment at the margins of San Francisco Bay. 

USGS science for a changing world logo
May 16, 2011

Marine biologists are gathering in Alaska this week to kick off a three-week expedition studying sea otters, as part of a joint U.S.-Canadian project to investigate the ecological health of the Pacific coastline.

The "Pacific Nearshore Project" is a multinational, multiagency project investigating sea otters as health indicators of coastal waters and marine resources from California nort

USGS science for a changing world logo
May 13, 2011

Fecal indicator bacteria, or FIB, sometimes found in the Malibu Lagoon and the near-shore ocean water in Malibu, California, may not be the result of human waste contamination according to preliminary results of a new U.S. Geological Survey study.

USGS science for a changing world logo
April 27, 2011

High concentrations of naturally occurring elements, including arsenic and boron as well as human-introduced compounds such as nitrate, were found in three aquifers studied in the Sacramento Valley. Scientists determined that concentrations of these substances in untreated water exceed state and federal health standards for drinking water.