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: 519
Date published: September 20, 2011

1:1,000,000-scale estimated outer extent of areas of groundwater discharge as evapotranspiration for the Great Basin carbonate and alluvial aquifer system of Nevada, Utah, and parts of adjacent states

This dataset was created in support of a study focusing on groundwater resources in the Great Basin carbonate and alluvial aquifer system (GBCAAS). The GBCAAS is a complex aquifer system comprised of both unconsolidated and bedrock formations covering an area of approximately 110,000 square miles. The aquifer system is situated in the eastern portion of the Great Basin Province of the western...

Date published: January 1, 2009

1:1,000,000-scale Hydrographic Areas of the Great Basin

This data set consists of hydrographic area and major flow system boundaries and polygons delineated at 1:1,000,000-scale for the Great Basin.

Date published: November 8, 2004

1:250,000-scale geology of the Dry Valley Hydrographic Area, Nevada and California

This dataset consists of digital geologic data for the Dry Valley Hydrographic area, Nevada and California. It was compiled from individual 1:250,000-scale geologic data for Washoe County, Nevada, 1:62,500-scale geologic data for the Chilcoot and Doyle 15' quadrangles in California and the results of field mapping within the study area in 2004. 

Filter Total Items: 994
March 26, 2015

PubTalk 3/2015 — The Environmental Legacy of California's Gold Rush

by Andrea Foster, USGS Research Geologist & Christopher Kim, Associate Professor, Chapman University

  • Why are arsenic and mercury associated with California's gold mines?
  • What types of arsenic and mercury contamination can be directly related to historic mining?
  • How are geochemists studying the distribution and
USGS Research Geologist uses a field meter to measure magnetic susceptibility of basalt flows in the Mojave Desert.
March 12, 2015

Measuring magnetic susceptibility in the field

Research Geologist Geoff Phelps measuring basalt flow thickness and magnetic susceptibility of individual basalt flows of the Broadwell Mesa Basalt in the central Mojave Desert near Ludlow, CA. 

Research geologist using satellite imagery on tablet computers to conduct geologic mapping on a mule pack train.
March 10, 2015

Digital mapping supported by mule team

Research Geologist Kevin Schmidt and Geoff Phelps examine satellite imagery on tablet computers during geologic mapping field work near Broadwell Mesa while supported by mule pack train.  

Tubes used for collecting groundwater samples protruding from a nested groundwater well
March 8, 2015

Groundwater Sampling

A groundwater well that is outfitted with equipment to collect samples to test for several water quality parameters.

USGS hydrologists collects a groundwater sample pumped through a hose into a bottle
March 2, 2015

Groundwater Sampling in Hinkley, CA

USGS hydrologist, Carmen Burton, collects a groundwater sample from a well in Hinkley, CA. The samples are being collected as part of a study analysing the occurrance of hexavalent chromium in groundwater. 

February 26, 2015

PubTalk 2/2015 — Undamming Washington's Elwha River

by Amy East USGS Research Geologist

  • Hear about river response to the largest dam removal in history.
  • Causing disturbance as a means of restoration: how well does it work?
  • Will legendary salmon runs return?
A man stands near a tripod with an instrument on it, he is wearing field gear like hip waders, steel toed boots, field vest.
January 31, 2015

Surveying position and elevation of instruments

Josh Logan (USGS PCMSC) surveys position and elevation of instrumentation to measure water level and suspended-sediment concentration in the marsh at China Camp State Park in Marin County CA, adjacent to San Pablo Bay (northern San Francisco Bay).

Bottom of a soil pit showing the different colored soils
January 26, 2015

Marine Terrace Soil at Wilder Ranch State Park

Marine terrace soil at Wilder Ranch State Park near Santa Cruz, California. Here at the bottom of the pit, 64 inches (160cm), the colors have different mineralogy and chemistry from one another, these changes have been formed by root processes over 90,000 years of soil development.

Lassen Volcanic Center, California simplified hazards map showing p...
December 31, 2014

Lassen Volcanic Center, CA simplified hazards map

Lassen Volcanic Center, California simplified hazards map showing potential impact area for ground-based hazards during a volcanic event.

USGS scientist inspecting a buckled portion of the Delta-Mendota canal lining
December 31, 2014

Delta-Mendota Canal: Land Subidence Damage

Reduced surface-water availability (associated with droughts) during 1976-77, 1986-92, 2007-09, and 2012-2016 caused groundwater-pumping increases, water-level declines to near or beyond historic lows, and renewed aquifer compaction. The resulting land subsidence has canal buckling and reduced flow capacity of the Delta-Mendota Canal (pictured), the California Aqueduct,

...
Diagram showing the relation between surface and subsurface processes with linkage to land subsidence.
December 31, 2014

Landscape and Subsurface After Land Subsidence (MODFLOW-OWHM)

Post-subsidence diagram showing the relation between surface and subsurface processes with linkage to land subsidence. The linkages to subsidence deformation are briefly summarized for surface-water, landscape and groundwater flow processes. The potential changes in movement of water before and after the linked effects of subsidence result in redirected or

...
Computer-generated diagram from lidar data shows beach, amusement park, river, and cliff with houses in a stippled pattern.
December 31, 2014

Lidar point cloud with digital still image overlay

A digital still image can be overlaid onto the lidar “point cloud” data to give it a realistic 3D look.

Filter Total Items: 938
USGS science for a changing world logo
January 21, 2009

Tree death rates have more than doubled over the last few decades in old-growth forests of the western United States, and the most probable cause of the worrisome trend is regional warming, according to a U.S. Geological Survey-led (USGS) study published in Science on January 23.
The study found that the increase in dying trees has been pervasive. 

USGS
December 19, 2008

Now Planning for 2009 

Los Angeles - It's working! On November 13, 2008 more than 5.47 million people in southern California participated in The Great Southern California ShakeOut, now officially the largest earthquake drill in the Nation's history - and according to some community leaders, a success that should be practiced every year. 

USGS science for a changing world logo
December 18, 2008

Dr. Julio Betancourt, a U.S. Geological Survey senior scientist, was recently awarded a prestigious 2008 Presidential Rank Award. Betancourt, who has conducted groundbreaking research in how climate variability affects ecosystems, is also an adjunct professor at the University of Arizona, where he received his graduate degrees.

 

USGS
November 14, 2008

Earthquakes are far more than just geological phenomena-they can greatly alter the way people live by damaging whole communities.

USGS
November 12, 2008

New 3-D animations of the magnitude 7.8 earthquake scenario are now available to the public

USGS
November 10, 2008

You can now view video interviews, see earthquake animations and impacts, download high-resolution imagery and much more, all related to the USGS science behind the Great Southern California ShakeOut, all in one place:

USGS
November 6, 2008

A great earthquake along the southern San Andreas Fault could cause many tall buildings to collapse in Los Angeles, explains USGS earthquake expert Dr. Ken Hudnut in a new video interview.

USGS
October 29, 2008

The Indian Ocean tsunami that claimed a quarter million lives was not the first nor last of its kind, according to reports in the October 30 issue of the scientific journal Nature.

USGS
October 28, 2008

What if you knew that a magnitude 7.8 earthquake would happen in less than three weeks? In a new video interview, USGS earthquake scientist Dr. Lucy Jones explains that millions of Southern Californians will be preparing as if they do know, thanks to the Great Southern California ShakeOut.

USGS
October 21, 2008

Bay Area Schools, Businesses, Governments Practice Readiness for Next Big Quake

A special ceremony will be held at Mission San Jose on Tuesday, October 21st, to commemorate the moment a magnitude 7 earthquake struck on the Hayward Fault in 1868. This 140th Anniversary is especially significant since the last five major earthquakes on the Hayward Fault have occurred at approximately 140-year interva

USGS
October 21, 2008

Conference on Earthquake Hazards in the East San Francisco Bay Over 200 earthquake professionals are expected to attend this three day technical conference on earthquake hazard and risk in the East Bay. A full program including presentations, posters, and field trips is online.

USGS
October 17, 2008

Bay Area Schools, Businesses, Governments Practice Readiness for Next Big Quake

A special ceremony will be held at Mission San Jose on Tuesday, October 21st, to commemorate the moment a magnitude 7 earthquake struck on the Hayward Fault in 1868.  This 140th Anniversary is especially significant since the last five major earthquakes on the Hayward Fault have occurred at approximately 140-year interv