Unified Interior Regions


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

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Tamarisk growing along a river
April 22, 2006

A single species stand of nonnative tamarisk

Single species stand of nonnative tamarisk on the Lower Colorado River at Cibola National Wildlife Refuge, California

Small tress re-growing after a fire
April 22, 2006

Nonnative tamarisk re-grows following a wildfire

Nonnative tamarisk is resistant to wildfire, in part because of its ablity to re-sprout.

Shrubs re-sprout after a wildfire
April 22, 2006

Nonnative tamarisk re-sprouts after wildfire

Nonnative tamarisk is resistant to wildfire, in part due to its ability to resprout

A tamarisk plant with many pink flowers
April 22, 2006

Tamarisk plants can make many flowers

Tamarisk plants have been sucessful in southwestern US river- and stream-side habitats, in part because of its ablity to make many flowers and, therefore, seeds.

Picture of a valley in California depicting residential housing
April 1, 2006

A valley shot with residential housing in California

Photograph taken during a Land Cover Trends Project field trip in California of a valley with residential housing.

A picture of a wind farm in California
April 1, 2006

A wind farm in California

A wind farm with many wind mills on a hiil in California. The picture was taken during a field trip for the Land Cover Trends project.

March 30, 2006

PubTalk 3/2006 — The Great 1906 Earthquake

Lessons learned, lessons forgotten, and future directions in earthquake science

By Mary Lou Zoback, Seismologist (and Chair of the Steering Committee, 1906 Earthquake Centennial Alliance)

  • The 1906 California disaster taught us that--
    • the San Andreas Fault is a continuous feature extending nearly the length of the State
Photo of a postfire landscape that was previously blackbrush scrub in the Mojave Desert
February 28, 2006

Winter, Postfire Landscape in the Mojave Desert

Picture taken February, 2006, Beaver Dam mountains, UT. Postfire landscape taken after a summer 2005 fire in what was previously blackbrush scrub. 

February 23, 2006

PubTalk 2/2006 — Science and Natural Resources along La Frontera

By Floyd Gray, Geologist

  • Natural systems-water, geology, and wildlife-tend to cross the 1,900- mile-long arbitrary political border between Mexico and the U.S.
  • Rapid population growth on the U.S. side and in Mexican border cities is creating a variety of environmental, ecological, and human health problems
  • The San Pedro River
Satellite image showing fire in California.
February 12, 2006

Southern California Wildfires, USA - 2006

These images show the nearly 11,000 acres affected by the Sierra fire in Orange County, California, in February 2006.

Andrew Schwartz and Dan Hanes hold a current profiler for a study of surf-zone hydrodynamics at Ocean Beach, San Francisco.
January 30, 2006

Studying Surf-Zone Hydrodynamics

USGS scientists Andrew Schwartz and Dan Hanes maneuver a current profiler for a study of surf-zone hydrodynamics at Ocean Beach, on the west side of San Francisco, California. Beach erosion has been a continuing problem in this area. This fieldwork is part of an effort to document, analyze, and simulate the processes that control sand transport and sedimentation patterns

January 26, 2006

PubTalk 1/2006 — Serving California's Needs


By George J. Saucedo and Keith L. Knudson, Geologists

  • Hear about the rich and productive 125-year history of the California Geological Survey (CGS)
  • Major emphases of CGS work are mapping
Filter Total Items: 973
December 16, 1999

The U.S. Geological Survey still needs a few good back yards. Beginning in January 2000, the USGS Earthquake Hazards Team, in cooperation the seismographic Station at UC Berkeley, will begin installing 60-70 seismograph stations in the core urban areas of San Francisco, Oakland and Berkeley.

December 9, 1999

Holocene muds that cover the Santa Cruz, Calif., continental shelf have enough breaks to reveal traces of the San Gregorio fault, according to scientists with the U.S. Geological Survey, who will present several papers relating to the side-scan sonar images that were obtained earlier this year.

December 8, 1999

The Moscone convention center will be alive with the sound of music, Thursday, Dec. 16, as U.S. Geological Survey geophysicist Andrew Michael presents, "The Music of Earthquakes -- Waveforms of Sound and Seismology."

November 22, 1999

All offices of the U.S. Geological Survey, at 345 Middlefield Road in Menlo Park, will close at 2 p.m., Wednesday, November 24, but will be open to serve the public Friday, November 26. This includes the map sales office and the USGS library.

October 22, 1999

Southern California’s deserts have been profoundly altered since the arrival of modern civilization and it may take centuries for the harsh but fragile ecosystem to recover even with vigorous intervention to restore natural habitats, according to an article in the current issue of the journal Environmental Management.

October 21, 1999

Recent devastating earthquakes have impacted Turkey, Taiwan, and Mexico. If the epicenter of last weeks 7.1 Hector earthquake in the Mojave Desert had occurred 100 miles to the east or to the west, Las Vegas or Los Angeles would still be picking up the pieces.

October 19, 1999

White abalone - 1,000 to 5,000 per acre - were easy to find in the early 1970s around the Channel Islands off California’s southern coast. But by the late 1970s, intense commercial and recreational harvesting made the abalone as difficult to locate a needle in an ocean-sized haystack.

October 14, 1999

There is a 70 percent probability that one or more damaging earthquakes of magnitude 6.7 or larger will strike the San Francisco Bay area during the next 30 years, according to a report released today (Oct. 14, 1999) by the U.S. Geological Survey. A magnitude 6.7 earthquake is equivalent to the 1994 Northridge earthquake which killed 57 people and caused $20 billion in damage.

October 8, 1999

A new set of maps from the U.S. Geological Survey explains in depth, literally, more than 30,000 earthquakes that occurred in north-central California between 1967 and 1993. That time frame, of course, includes the largest earthquake to occur in the area since 1906, the 1989, 6.9 Loma Prieta earthquake.

October 8, 1999

When is a badly damaged, but stable building safe to enter after an earthquake? That is a question that safety-response and building-department officials have to answer in order to let occupants retrieve important possessions and business records, and to let contractors begin emergency repairs

October 5, 1999

When their offices and homes began shaking at 5:04 p.m., Oct. 17, 1989, earthquake scientists at the U.S. Geological Survey in Menlo Park, Calif., were as surprised as anyone.

October 5, 1999

With a press run of more than three million copies, "The Next Big Earthquake In The Bay Area May Come Sooner Than You Think-- Are You Prepared?" is the most widely distributed publication ever prepared by the U.S. Geological Survey. Nine years after it’s publication, it is still available from the USGS, and still helpful as a preparedness guide for Bay Area residents.