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: 1,119
3-D angular view of a bay inlet with a bridge spanning the inlet, the floor of the bay is shown as if the water is drained out.
December 31, 2005

Sand waves at mouth of San Francisco Bay

A field of giant sand waves, among the largest in the world, at the mouth of San Francisco Bay in California. This massive bed form field covers an area of approximately four square kilometers in water depths ranging from 30 to 106 meters, featuring more than 40 distinct sand waves with crests aligned approximately perpendicular to the dominant tidally generated cross-

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long fissure in the dry Mojave Desert with the mountains in the background
December 31, 2005

Fissure in the Mojave Desert

Fissure near Lucerne Lake along State Route 247 (visible in background), Mojave Desert, California. The localized subsidence in five areas near dry lake beds was caused by declining water levels in fine-grained (clay and silt) sediments. In the Mojave River and Morongo Groundwater Basins (fig. 2), the combination of variable climatic conditions, tectonic activity, and

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Map of the known ash-fall boundaries for several U.S. eruptions
December 31, 2005

Map of the known ash-fall boundaries for several U.S. eruptions

Eruptions of the Yellowstone volcanic system have included the two largest volcanic eruptions in North America in the past few million years; the third largest was at Long Valley in California and produced the Bishop ash bed. The biggest of the Yellowstone eruptions occurred 2.1 million years ago, depositing the Huckleberry Ridge ash bed. These eruptions left behind huge

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Map of land subsidence in the Sacramento-San Joaquin Delta, shaded by feet below sea level
December 31, 2005

Sacramento-San Joaquin Delta Land Subsidence

A map of subsidence in the Delta based on the leveling and observations of transmission-line foundations, circa 1930s-1990s. The subsidence increases stresses on the levee system, and failure of levees would cause salt water to move further up the Delta system by disrupting favorable gradients. This would degrade the quality of water that is the heart of water supply

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Poster laid out with photos, images, and text.
December 31, 2005

Should Englebright Dam Be Removed?

Large-scale poster describing USGS work.

The USGS, in cooperation with the Upper Yuba River Studies Program and the California Bay–Delta Authority (CALFED), studied Englebright Lake. Englebright Dam was built in 1941 to trap sediment washed downstream by hydraulic gold mining.

We used sonar to map the lake and took sediment cores from the lake bottom. By

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Image: Pacific Coast of California
December 31, 2005

Pacific Coast of California

Waves crashing against rocks off the Pacific coast of California.

Attribution: Water Resources
Image: Pacific Coast of California
December 31, 2005

Pacific Coast of California

Waves crashing against rocks off the Pacific coast of California.

Attribution: Water Resources
December 8, 2005

PubTalk 12/2005 — Frozen in Time

How Ice Cores Are Revealing the Composition and Temperature of Earth's Atmosphere During the Past Million Years

by Todd Hinkley, Geologist

 

  • Scientifically invaluable ice cores taken from Antarctic and Arctic ice are stored and safe guarded at the U.S. National Ice Core Laboratory, operated by the U.S. Geological Su rvey
November 17, 2005

PubTalk 11/2005 — Shifting Shoals and Shattered Rocks

HOW MAN HAS CHANGED THE FLOOR OF SAN FRANCISCO BAY

by John Chin and Florence Wong, Geologists

 

  • San Francisco Bay is one of the world's finest natural harbors and a major center of maritime trade
  • All ships visiting bay ports are funneled through the central bay
  • Bedrock knobs that rise from the central
October 27, 2005

PubTalk 10/2005 – Earthquake Storms

The Very Long Reach of Very Large Earthquakes

by Susan Hough, Seismologist

 

  • How did the 1992 Landers quake in the remote Mojave Desert change scientists' thinking about earthquake sequences?
  • What is the explanation for "aftershocks" of the 1906 San Francisco earthquake reported in Arizona?
  • How do large
Image: Greater Roadrunner (Geococcyx californianus)
October 24, 2005

Greater Roadrunner (Geococcyx californianus)

A roadrunner at the base of a old volcanic rock, near a trail in Petroglyph National Monument.

Attribution: Ecosystems
October 21, 2005

PubTalk 10/2005 — A Crack in the Edge of the World

America and the Great California Earthquake of 1906

by Simon Winchester

 

  • The international bestselling author of The Professor and the Madman and Kra katoa vividly brings to life the 1906 San Francisco Earthquake that leveled a city symbolic of America's relentless western expansion. Simon Winchester
Filter Total Items: 979
USGS
May 12, 1999

Maps and other products of the U.S. Geological Survey will be on display,for sale and as free handouts, at the USGS booth at the Sunset Magazine open house, this weekend, May 15 and 16.

USGS
April 30, 1999

The source of tarballs in the Monterey Bay National Marine Sanctuary, new views of the seafloor of Monterey Bay and new data on the San Gregorio fault are the focus of three presentations by U.S. Geological Survey scientists at the Pacific Section Meeting of the American Association of Petroleum Geologists, in Monterey.

USGS
April 23, 1999

As United States Geological Survey (USGS) researchers skim the surface of the ocean in a small boat near Long Beach, a new never-before-seen view of Los Angeles is revealed.

USGS
March 26, 1999

U.S. Geological Survey scientists of the Western Ecological Research Center will report on the effects of exotic animals on native plants in Channel Islands National Park at the 5th California Islands Symposium, in Santa Barbara, Calif., Mar. 29-Apr. 1.

USGS
March 11, 1999

Chemical contamination in San Francisco Bay has decreased since enactment of the Clean Water Act in 1970, but the bay is still suffering from "contaminant stress," according to a a U.S. Geological Survey chemist who has been analyzing the bay’s waters for 30 years.

USGS
January 21, 1999

From the Gold Rush of 1849 through the 1960’s, California produced about 3,300 tons of gold, or about one-third of all U.S. gold production, but it left a legacy of detrimental environmental effects whose damage may never be fully determined, according to Roger Ashley of the U.S. Geological Survey in Menlo Park, Calif.

USGS
January 21, 1999

The environmental effects of the California gold rush and the effects of earthquakes on the urban environment are two of the topics that will be covered by scientists from the U.S. Geological Survey at this week’s annual meeting of the American Association for the Advancement of Science (AAAS) at the Anaheim Convention Center, Anaheim, Calif., Jan. 21-26, 1999.

USGS
January 19, 1999

On January 23, 1999, U.S. Geological Survey scientists Gladys Cotter, Charles van Riper III, and Henry J. Moore II will be inducted as Fellows by the American Association for the Advancement of Science (AAAS) during its annual meeting in Anaheim, California.

USGS
December 17, 1998

Sitting in the darkened cab of a pick-up truck on a California Central Valley back road, research biologist Joe Fleskes of the USGS Western Ecological Research Center strained to hear the faint "beep beep beep" from his radio-tracking receiver. Somewhere out in the foggy night, the radio signal was emanating from a small transmitter worn by one of 320 ducks and geese fitted with these monitoring d

USGS
December 4, 1998

A thirty-foot-long exhibit, and several presentations will focus on changes along the west coast of the US during the 1997-98 El Nino at the Fall Meeting of the American Geophysical Union, scheduled for Dec. 6-10 at the Moscone Convention Center in San Francisco, California.

USGS
October 25, 1998

Observers of last winter’s El Nino storms along the Pacific Coast who might have compared the intense rainfall to a monsoon were not far off the mark.

USGS
October 15, 1998

Because of a lack of Steller sea lions and harbor seals, large numbers of sea otters are being eaten by hungry killer whales in western Alaska waters, according to findings in the October 16 issue of the journal Science.