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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Hazards Societal Consequences and Risk Communication
The Hazards Societal Consequences and Risk Communication project is led by Anne Wein at the Western Geographic Science Center (WGSC).
The umbrella project is Science Application for Risk Reduction (SAFRR), which estimates consequences of natural hazard disaster scenarios as a strategy to engage decision-makers in increasing a community’s ability to cope with the effects of a disaster....
Land use and tsunami hazards in the Pacific Northwest
Tsunamis have the potential to cause considerable damage to communities along the U.S. Pacific Northwest coastline. As coastal communities expand over time, the potential societal impact of tsunami inundation changes.
To understand how community exposure to tsunami hazards may change in coming decades, we projected future development (i.e. urban, residential, and rural), households, and...
California land-change projections
This dataset consists of modeled projections of land use and land cover and population for the State of California for the period 1970-2101. For the 1970-2001 period, we used the USGS's LUCAS model to "backcast" LULC, beginning with the 2001 initial conditions and ending with 1970. For future projections, the model was initialized in 2001 and run forward on an annual time step to 2100. In...
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...
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
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...
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...
Big Sur Landslide
On May 20, 2017, the steep slopes at Mud Creek on California’s Big Sur coast, about 140 miles south of San Francisco, suffered a catastrophic collapse. USGS Scientists from the Pacific Coastal and Marine and the Geology, Minerals, Energy, and Geophysics Science Centers are monitoring this section of the coastline, in collaboration with the California Department of Transportation.
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...
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,...
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.
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...
Acoustic backscatter data collected in 2007 from the San Miguel Passage in the Channel Islands, California
This portion of the data release presents acoustic backscatter data from the San Miguel Passage, in the Channel Islands, California. The data were collected in August 2007 by the U.S. Geological Survey, Pacific Coastal and Marine Science Center (USGS, PCMSC) using a 234.5 kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonar mounted on the NOAA, Channel Islands Nationa
Geochemical and geophysical data for wells in the Rosedale Ranch oil and gas field
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board compiled and analyzed data for the purpose of mapping groundwater salinity in selected oil and gas fields in California. The data for the Rosedale Ranch oil field include well construction data, digitized borehole geophysical data, geochemical analyses of water samples from oil and gas
All Wells, District Boundaries, and Field Boundaries from the California Division of Oil, Gas, and Geothermal Resources (DOGGR)
There are 487 onshore oil and gas fields in California encompassing 3,392 square miles of aggregated area. The California State Water Resources Control Board (State Water Board) initiated a Regional Monitoring Program (RMP) in July 2015, intended to determine where and to what degree groundwater quality may be at potential risk to contamination related to oil and gas development activ
Water chemistry data for samples collected at groundwater and surface-water sites near the Lost Hills and Belridge oil fields, November 2016-September 2017, Kern County, California
An investigation was done by the U.S. Geological Survey, in cooperation with the California State Water Resources Control Board's Program of Regional Groundwater Monitoring of Water Quality in Areas of Oil and Gas Production, to assess the effects of oil and gas production activities on nearby groundwater resources. During November 2016–September 2017, 30 samples were collected at
Water chemistry data for samples collected at groundwater sites near the Fruitvale oil field, September 2016–February 2017, Kern County, California
As part of the California State Water Resources Control Board’s Regional Groundwater Monitoring Program of Water Quality in Areas of Oil and Gas Production, during September 2016–February 2017, the U.S. Geological Survey collected and analyzed groundwater and associated quality-control (QC) samples from 14 water-production wells located within a three mile buffer zone of a
Grain size and bulk density of sediment cores from Little Holland Tract and Liberty Island, Sacramento-San Joaquin Delta, California, 2014
Grain size distribution and bulk density are reported for sediment push cores from two flooded agricultural tracts, Little Holland Tract and Liberty Island, in the Sacramento-San Joaquin Delta, California. Push core samples were collected from 14 sites by the U.S Geological Survey in August, 2014. Each core was analyzed at multiple depths to investigate variations in particle sizes with d
Structure-from-Motion (SfM) surface models derived from seafloor video from the Channel Islands, California
Structure-from-Motion (SfM) surface models were created using seafloor video collected over a visible fault scarp in the Channel Islands, California, during a 2016 U.S. Geological Survey (USGS) field activity. Four SfM surface models were created, each with a different combination of locating, scaling, and optimizing methods. Video imagery was collected using the USGS Pacific Co
Photographs and video clips of Clear Lake Hitch (Lavinia exilicauda chi)
This data release includes a collection of photographs and video clips. Above water observations were taken with with a Nikon D5300 digital camera and underwater observations were taken with a SOOCOO S100Pro digital camera. All observations were made on April 1, 2018 in Kelsey, Creek, Lake County, California. Further details can be found in: Feyrer, F. 2018. Rapid potamodromy int
California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project Study Areas and grid cells for assessment of groundwater resources used for public drinking-water supply.
The California Groundwater Ambient Monitoring and Assessment Program (GAMA) is a statewide, comprehensive assessment of groundwater quality designed to help better understand and identify risks to groundwater resources. GAMA is being implemented by the California State Water Resources Control Board. The USGS is the technical lead for the Priority Basin Project (PBP), one of the compon
Central Mojave Desert Vegetation Mapping Project, California, 1997-1999
The U.S. Geological Survey (USGS) Data at Risk (DaR) team partnered with the USGS Southwest Biological Science Center (SBSC) to preserve and release tabular data, shapefiles and field photographs of the Central Mojave Desert from 1997-1999. The data were originally collected as part of an effort through the Desert Managers Group (DMG) to develop scientific information on the dis
Hydrodynamic and sediment transport data from San Pablo Bay and China Camp marsh (northern San Francisco Bay), 2013-2016
The USGS Pacific Coastal and Marine Science Center collected data to investigate sediment dynamics in the shallows of San Pablo Bay (SP) and sediment exchange between bay shallows and the tidal salt marsh in China Camp State Park (CMC) in a series of deployments between December 2013 and June 2016. This data release includes two related groups of data sets, one for SP and one for CMC.
River-channel topography, grain size, and turbidity records from the Carmel River, California, before, during, and after removal of San Clemente Dam
The San Clemente Dam, built in the 1920s on the Carmel River in Monterey County, California, was removed during 2014 and 2015. The dam-removal project was the largest in California to date, and one of the largest in the U.S. The USGS collected data before, during, and after the removal of the dam to study how the river channel's topographic profiles and sediment distributions changed...
Drainage-return, surface-water withdrawal, and land-use data for the Sacramento-San Joaquin Delta, with emphasis on Twitchell Island, California
Partial data on drainage returns and surface-water withdrawals are presented for areas of the Sacramento-San Joaquin Delta, California, for March 1994 through February 1996. These areas cover most of the delta. Data are also presented for all drainage returns and some surface-water withdrawals for Twitchell Island, which is in the western part of...
Templin, William E.; Cherry, Daniel E.Chapter D. The Loma Prieta, California, Earthquake of October 17, 1989 - Aftershocks and postseismic effects
While the damaging effects of the earthquake represent a significant social setback and economic loss, the geophysical effects have produced a wealth of data that have provided important insights into the structure and mechanics of the San Andreas Fault system. Generally, the period after a large earthquake is vitally important to monitor. During...
Reasenberg, Paul A.Chapter A. The Loma Prieta, California, Earthquake of October 17, 1989 - Main shock characteristics
The October 17, 1989, Loma Prieta, Calif., earthquake (0004:15.2 G.m.t. October 18; lat 37.036? N., long 121.883? W.; 19-km depth) had a local magnitude (ML) of about 6.7, a surface-wave magnitude (MS) of 7.1, a seismic moment of 2.2x1019 N-m to 3.5x1019 N-m, a source duration of 6 to 15 s, and an average stress drop of at least 50 bars. Slip...
Spudich, PaulRiparian vegetation and its water use during 1995 along the Mojave River, Southern California
The extent and areal density of riparian vegetation, including both phreatophytes and hydrophytes, were mapped along the 100-mile main stem of the Mojave River during 1995. Mapping was aided by vertical false-color infrared and low-level oblique photographs. However, positive identification of plant species and plant physiological stress required...
Lines, Gregory C.; Bilhorn, Thomas W.Water-resources data network evaluation for Monterey County, California; Phase 2, northern and coastal areas of Monterey County
This report presents an evaluation of water- resources data-collection networks in the northern and coastal areas of Monterey County, California. This evaluation was done by the U.S. Geological Survey in cooperation with the Monterey County Flood Control and Water Conservation District to evaluate precipitation, surface water, and ground water...
Templin, W.E.; Smith, P.E.; DeBortoli, M.L.; Schluter, R.C.Land use and water use in the Antelope Valley, California
Urban land use and water use in the Antelope Valley, California, have increased significantly since development of the valley began in the late 1800's.. Ground water has been a major source of water in this area because of limited local surface-water resources. Ground-water pumpage is reported to have increased from about 29,000 acre-feet in 1919...
Templin, William E.; Phillips, Steven P.; Cherry, Daniel E.; DeBortoli, Myrna L.; Haltom, T.C.; McPherson, Kelly R.; Mrozek, C.A.Look before you build; geologic studies for safer land development in the San Francisco Bay area
This Circular provides a general description of the types of geologic hazards that exist throughout the United States. In nontechnical language this book describes how geologic information can be incorporated in the land-use development process and contains useful discussion of several examples from the San Francisco Bay area and elsewhere in the...
Blair-Tyler, MarthaAccounting for Consumptive Use of Lower Colorado River Water in Arizona, California, Nevada, and Utah
In the Colorado River valley between the east end of Lake Mead and the international boundary with Mexico (see figure), the river is the principal source of water for agricultural, domestic, municipal, industrial, hydroelectric-power generation, and recreational purposes. Water is stored in surface reservoirs and in the river aquifer---permeable...
Owen-Joyce, Sandra J.; Wilson, Richard P.Chapter A. The Loma Prieta, California, Earthquake of October 17, 1989 - Loss estimation and procedures
This Professional Paper includes a collection of papers on subjects ranging from evaluation of building safety, to human injuries, to correlation of ground deformation with building damage. What these papers share is a common goal to improve the tools available to the research community to measure the nature, extent, and causes of damage and...
Tubbesing, Susan K.Chapter A. The Loma Prieta, California, Earthquake of October 17, 1989 - Strong ground motion
Strong ground motion generated by the Loma Prieta, Calif., earthquake (MS~7.1) of October 17, 1989, resulted in at least 63 deaths, more than 3,757 injuries, and damage estimated to exceed $5.9 billion. Strong ground motion severely damaged critical lifelines (freeway overpasses, bridges, and pipelines), caused severe damage to poorly constructed...
Borcherdt, Roger D.Chapter C. The Loma Prieta, California, Earthquake of October 17, 1989 - Fire, police, transportation and hazardous materials
The papers in this chapter discuss some of the failures and successes that resulted from the societal response by a multitude of agencies to the Loma Prieta earthquake. Some of the lessons learned were old ones relearned. Other lessons were obvious ones which had gone unnoticed. Still, knowledge gained from past earthquakes spawned planning and...
Van Anne, Craig; Scawthorn, Charles R.Chapter E. The Loma Prieta, California, Earthquake of October 17, 1989 - Hydrologic disturbances
Seismic events have long been known to cause changes in the level of oceans, streams, lakes, and the water table. The great San Francisco earthquake of 1906 induced significant hydrologic changes that were qualitatively similar to those changes observed for the Loma Prieta earthquake. What is different is that the hydrologic data sets collected...
Rojstaczer, Stuart A.TV camera records scene at Open House
Emma Kelsey (right) explained seabird biology to visitors as a TV camera recorded the scene.
Sharing information on the screen
Visitors watched closely as Alicia Balster-Gee (in green vest) presented our research on marine geohazards in Alaska.
USGS Open House discussions
Members of the PCMSC Marine Minerals Team, including physical science technician Kira Mizell (center), took turns describing the importance of seafloor minerals.
Talking about seafloor mineral deposits
Research geologist Jim Hein (right) gave a hands-on explanation of seafloor mineral deposits.
Try these on for size
Li Erikson (right) helped a young visitor try on the tall boots needed for Alaskan coastal research.
Drone discussion
The drone on the table helped map a giant Big Sur landslide that closed California’s Highway 1. Josh Logan (right) described the process to visitors.
Colorful handouts from USGS
Our handouts were very popular with both kids and adults.
Discussing exhibit at open house
Patrick Barnard (left) explained detailed computer forecasts of coastal flooding and erosion driven by climate change.
Scientist spreading moss fragments
A USGS scientist spreads moss fragments for a study to test the restoration potential of moss, an important component of biological soil crust. A jute net, foreground, helps stabilize the moss fragments as they adhere to the soil.
Upper terrace of Mud Creek slide
Mud Creek slide from south side of north upper terrace (above north and south berms). Note tension cracks and offset on the terrace to the north.
2017 Nov. Pub. Lecture—Sea Otters: Confessions of a Keystone Carnivore
- Sea otters are perhaps the best-known example of a "keystone predator".
- Sea otter behavior -- in particular diet specialization and limited mobility -- can mediate their effects on ecosystem dynamics.
- Other predators, especially large sea stars, can complement and reinforce the keystone role of sea otters: this became apparent with the loss of all
Secretary of the Interior Sally Jewell announced today that Interior’s Southwest Climate Science Center is awarding nearly $1.2 million to universities and other partners for research to guide managers of parks, refuges and other cultural and natural resources in planning how to help species and ecosystems adapt to climate change.
Drought conditions are linked to declines in a protected desert tortoise population in part of the Sonoran Desert, according to a U.S. Geological Survey study.
The U.S. Geological Survey participates in the American Geophysical Union's fall meeting with hundreds of technical presentations. Below are some highlights of USGS science at AGU this year. Highlights about the technical sessions are presented in chronological order with session numbers, and room numbers in San Francisco's Moscone Convention Center...
Extensive groundwater pumping from San Joaquin Valley aquifers is increasing the rate of land subsidence, or sinking, that could result in serious operational and structural challenges and repairs to water infrastructure, according to a new report by the U.S. Geological Survey.
Although dousing the flames was foremost in people's minds during the recent Rim Fire in Stanislaus National Forest and Yosemite National Park, U.S. Geological Survey scientific work continues well after the fire is out. USGS scientists are continuing their critical research characterizing the hidden dangers faced after large wildfires.
A new cooperative study by the U.S. Geological Survey and the Hi-Desert Water District indicates that the artificial replenishment of the groundwater aquifer system in the west hydrogeologic unit of the Warren groundwater basin in San Bernardino County’s Yucca Valley resulted in a decrease of nitrate concentrations in groundwater samples and a rise in water levels.

On October 6, 2013 the California Office of Emergency Services (CalOES) published its 2013 State of California Multi-Hazard Mitigation Plan complete with a chapter from the USGS on volcano hazard mitigation.

A magnitude 3.8 earthquake occurred on October 21, 2013 at 10:04 PDT 18 km (11 miles) SE of the town of Mammoth Lakes in eastern California.
Nitrate was detected at high concentrations in 10 percent of the aquifer system used for public supply in coastal areas of Santa Barbara and San Luis Obispo counties, according to a new U.S. Geological Survey report.
California’s Sea Otter Numbers Continue Slow Climb

The fearsome aftermath of a tsunami striking California might cost at least $3.4 billion to repair, but neither of the state's nuclear power plants would be damaged, suggests a new analysis that could help officials and the public prepare for a tsunami and reduce risks before any such disasters happen.
While scientists can't predict when a great earthquake producing a pan-Pacific tsunami will occur, thanks to new tools being developed by federal and state officials, scientists can now offer more accurate insight into the likely impacts when tsunamis occur. This knowledge can lead officials and the public to reduce the risk of the future tsunamis that will impact California.