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: 418
Date published: March 3, 2017
Status: Active

Sequoia and Kings Canyon Field Station

The Sequoia and Kings Canyon Field Station is home to research programs that focus on wildfire patterns in Southern California, and the effects of drought on Sierra Nevada forests. Select the "Science" tab for a more comprehensive summary.

Date published: March 3, 2017
Status: Active

Santa Monica Mountains Field Station

Update: The Santa Monica Mountains Field Station is no longer an active USGS field station.

Contacts: Erin Boydston
Date published: February 24, 2017
Status: Active

Santa Cruz Field Station

Scientists at the Santa Cruz Field Station study sea otters and seabirds in their environment. The USGS Western Ecological Research Center has two research missions based in the Santa Cruz region:

Date published: February 23, 2017
Status: Active

San Francisco Bay Estuary Field Station

The San Francisco Bay Field Station is the center of studies on recovering tidal wetland ecosystems and ongoing efforts to balance the restoration of local marshes and the needs of seabirds. Click on the "Science" tab for a comprehensive summary of this station and its research.

Date published: February 21, 2017
Status: Active

San Diego Field Station

The San Diego Field Station is the site of research on golden eagles, endangered amphibians and reptiles, and more. Click on the "Science" tab for a comprehensive summary of this study site's projects.

Date published: February 21, 2017
Status: Active

Temecula Hydrogeology

This site provides hydrologic data collected or compiled by the USGS for the Temecula area; some additional data may be available from the USGS database National Water Information System (NWIS).

Contacts: Wesley Danskin
Date published: February 21, 2017
Status: Active

Redwood Field Station

The Redwood Field Station is located in Arcata, CA. Click on the following tab to learn more.

Date published: February 21, 2017
Status: Active

Yosemite Field Station

The Yosemite Field Station is comprised of a main office located on the west side of the Sierra Nevada. 

Contacts: Matthew Brooks
Date published: February 7, 2017
Status: Completed

San Bernardino Optimal Basin Management

The San Bernardino area of southern California has complex water-management issues. As an aid to local water managers, this report provides an integrated analysis of the surface-water and ground-water systems, documents ground-water flow and constrained optimization models, and provides seven examples using the models to better understand and manage water resources of the area. As an aid to...

Contacts: Wesley Danskin
Date published: January 17, 2017
Status: Active

Ecological Drought in Riparian Ecosystems

Drought is killing riparian trees along many rivers in the western United States. The cause can be increasing temperature or decreasing precipitation, flow or water-table elevation. At multiple locations we are relating water availability to physiological measurements of tree survival and water stress, such as ring width, carbon stable isotope ratio and branch hydraulic conductivity. These...

Date published: December 29, 2016
Status: Completed

Injection, storage, and extraction of water, Roseville, California

The purpose of this study is evaluate how vertical variations in aquifer properties and well hydraulics may affect the injection, storage, and extraction of water and the transport of associated disinfection by-products in the Mehrten Formation underlying the City of Roseville.

Date published: December 29, 2016
Status: Completed

Whiskeytown Aquatic Inventory Assessment

The project focuses on the assessment of aquatic biology, habitat, and water quality conditions of the major WHIS watersheds

Filter Total Items: 581
Date published: January 1, 2018

CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 flood-hazard depth and duration projections: 1-year storm in the Channel Islands

Maximum depth of flooding surface (in cm) in the region landward of the present day shoreline that is inundated for the storm condition and sea-level rise (SLR) scenario indicated. Note: Duration datasets may have occasional gaps in open-coast sections.
The Coastal Storm Modeling System (CoSMoS) makes detailed predictions (meter-scale) over large geographic scales (100s of k

Date published: January 1, 2018

Repeat high-resolution acoustic-backscatter datasets collected between 2014 and 2016 of a field of crescent-shaped rippled scour depressions in northern Monterey Bay, California

Between November 2014 and June 2016 the U.S. Geological Survey, Pacific Coastal and Marine Science Center (PCMSC) conducted eight repeat, high-resolution bathymetry and acoustic-backscatter surveys of a small patch of seafloor offshore Santa Cruz in northern Monterey Bay, California. PCMSC also collected oceanographic time-series data over the same two-year period. This metadata file de

Date published: January 1, 2018

Central California CoSMoS v3.1 projections of shoreline change due to 21st century sea-level rise

This dataset contains projections of shoreline positions and uncertainty bands for future scenarios of sea-level rise. Projections were made using the Coastal Storm Modeling System - Coastal One-line Assimilated Simulation Tool (CoSMoS-COAST), a numerical model forced with global-to-local nested wave models and assimilated with lidar-derived shoreline vectors. Read metadata carefully.
De...

Date published: January 1, 2018

Recent historical and projected (years 2006–99) areas (km2) of managed, flooded habitats used by waterbirds overwintering in Central Valley, California basins for 17 climate, urbanization, and water management scenarios.

Matchett and Fleskes (2018) evaluated availability of wetland and agricultural habitats used by waterbirds overwintering in the Central Valley of California under 17 scenarios of projected climate, urbanization, and water supply management (for more information about scenarios see scenario description and Table 1 in Matchett and Fleskes [2018]). Central Valley waterbird habitats investigated...

Date published: January 1, 2018

Central California CoSMoS v3.1 projections of coastal cliff retreat due to 21st century sea-level rise

This dataset contains spatial projections of coastal cliff retreat (and associated uncertainty) for future scenarios of sea-level rise (SLR) in Central California. Present-day cliff-edge positions used as the baseline for projections are also included. Projections were made using numerical models and field observations such as historical cliff retreat rate, nearshore slope, coastal cl

Date published: January 1, 2018

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

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, 2018

Recent historical and projected (years 2006–99) areas (km2) of managed, flooded habitats used by waterbirds overwintering in Central Valley, California basins for 17 climate, urbanization, and water management scenarios.

Matchett and Fleskes (2018) evaluated availability of wetland and agricultural habitats used by waterbirds overwintering in the Central Valley of California under 17 scenarios of projected climate, urbanization, and water supply management (for more information about scenarios see scenario description and Table 1 in Matchett and Fleskes [2018]). Central Valley waterbird habitats investigated...

Date published: January 1, 2018

Repeat high-resolution bathymetry datasets collected between 2014 and 2016 of a field of crescent-shaped rippled scour depressions in northern Monterey Bay, California

Between November 2014 and June 2016 the U.S. Geological Survey, Pacific Coastal and Marine Science Center (PCMSC) conducted eight repeat, high-resolution bathymetry and acoustic-backscatter surveys of a small patch of seafloor offshore Santa Cruz in northern Monterey Bay, California. PCMSC also collected oceanographic time-series data over the same two-year period. This metadata file de

Date published: January 1, 2018

Geophysical and geochemical data for salinity mapping in the Midway-Sunset oil field area

The U.S. Geological Survey (USGS) and California State University-Sacramento, in cooperation with the California State Water Resources Control Board and U.S. Bureau of Land Management, compiled and analyzed data for mapping groundwater salinity in selected oil and gas fields in California. The data for the Midway-Sunset (MWSS) oil field includes digitized borehole geophysical data,

Date published: January 1, 2018

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

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, 2018

Bathymetry data collected in 2007 from the San Miguel Passage in the Channel Islands, California

This portion of the data release presents bathymetry data from the San Miguel Passage, in the Channel Islands, California. Bathymetry data were collected in the San Miguel Passage, Channel Islands, California in August 2007 by the U.S. Geological Survey, Pacific Coastal and Marine Science Center (USGS, PCMSC). Collection was accomplished using a 234.5 kHz SEA (AP) Ltd. SWATHpl

Date published: January 1, 2018

CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 wave-hazard projections: 100-year storm in Channel Islands

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

Filter Total Items: 471
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Year Published: 2007

National assessment of shoreline change part 4: historical coastal cliff retreat along the California coast

Coastal cliff retreat, the landward migration of the cliff face, is a chronic problem along many rocky coastlines in the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information regarding trends and rates of coastal cliff retreat. There is...

Hapke, Cheryl J.; Reid, David
National assessment of shoreline change part 4: historical coastal cliff retreat along the California coast; 2007; OFR; 2007-1133; Hapke, Cheryl J.; Reid, David

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Year Published: 2007

Near-Surface Structure and Velocities of the Northeastern Santa Cruz Mountains and the Western Santa Clara Valley, California, From Seismic Imaging

Introduction The Santa Clara Valley (SCV) is located in the southern San Francisco Bay area of California and is bounded by the Santa Cruz Mountains to the southwest, the Diablo Ranges to the northeast, and the San Francisco Bay to the north (Fig. 1). The SCV, which includes the City of San Jose, numerous smaller cities, and much of the high-...

Catchings, R.D.; Gandhok, G.; Goldman, M.R.; Steedman, Clare
Near-Surface Structure and Velocities of the Northeastern Santa Cruz Mountains and the Western Santa Clara Valley, California, From Seismic Imaging; 2007; OFR; 2007-1039; Catchings, R. D.; Gandhok, G.; Goldman, M. R.; Steedman, Clare

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Year Published: 2007

Riding the storm--landslide danger in the San Francisco Bay Area

Movie Synopsis: --A catastrophic 1982 rainstorm triggered 18,000 landslides in the Bay Area, claiming 25 lives and causing $66 million in property damage. --The combination of steep slopes, weak rocks, and intense winter storms make Bay Area uplands an ideal setting for landslides. --Landslides include both swift, potentially deadly...

Adams, Karen
Riding the storm--landslide danger in the San Francisco Bay Area; 2007; GIP; 48; Producer/Director/Editor Adams, Karen

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Year Published: 2007

Summary of Survival Data from Juvenile Coho Salmon in the Klamath River, Northern California, 2006

Little is known about the survival of ESA-listed juvenile coho salmon during their seaward migration in the lower Klamath River. In 2006, the Bureau of Reclamation funded a study to estimate the survival of radio-tagged juvenile coho salmon in the Klamath River downstream of Iron Gate Dam. A series of models were evaluated to determine if survival...

Beeman, John W.
Summary of Survival Data from Juvenile Coho Salmon in the Klamath River, Northern California, 2006; 2007; OFR; 2007-1023; Beeman, John W.

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Year Published: 2007

Genetic diversity of infectious hematopoietic necrosis virus from Feather River and Lake Oroville, California, and virulence of selected isolates for Chinook salmon and rainbow trout

Infectious hematopoietic necrosis virus (IHNV) is a significant pathogen of young salmonid fishes worldwide but particularly within the historical range of the Pacific Northwest and California. In the Sacramento and San Joaquin River drainages of California, IHNV outbreaks in juvenile Chinook salmon Oncorhynchus tshawytscha have been observed...

Bendorf, C.M.; Kelley, G.O.; Yun, S.C.; Kurath, Gael; Andree, K.B.; Hedrick, R.P.
Genetic diversity of infectious hematopoietic necrosis virus from Feather River and Lake Oroville, California, and virulence of selected isolates for Chinook salmon and rainbow trout; 2007; Article; Journal; Journal of Aquatic Animal Health; Bendorf, C. M.; Kelley, G. O.; Yun, S. C.; Kurath, G.; Andree, K. B.; Hedrick, R. P.

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Year Published: 2007

Genotypes and phylogeographical relationships of infectious hematopoietic necrosis virus in California, USA

Infectious hematopoietic necrosis virus (IHNV) contains 3 major genogroups in North America with discreet geographic ranges designated as upper (U), middle (M), and lower (L). A comprehensive genotyping of 237 IHNV isolates from hatchery and wild salmonids in California revealed 25 different sequence types (a to y) all in the L genogroup;...

Kelley, G.O.; Bendorf, C.M.; Yun, S.C.; Kurath, Gael; Hedrick, R.P.
Genotypes and phylogeographical relationships of infectious hematopoietic necrosis virus in California, USA; 2007; Article; Journal; Diseases of Aquatic Organisms; Kelley, G. O.; Bendorf, C. M.; Yun, S. C.; Kurath, G.; Hedrick, R. P.

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Year Published: 2007

Life history and ecological characteristics of the Santa Ana sucker, Catostomus santaanae

This study was conducted to document the life history and ecological characteristics of the Santa Ana sucker, Catostomus santaanae, within its native range in southern California. Electrofishing surveys were conducted at 3-month intervals from December 1998 to December 1999 at one site on the San Gabriel River and two sites on...

Saiki, Michael K.; Martin, Barbara A.; Knowles, Glen W.; Tennant, Patrick W.

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Year Published: 2007

Relation between mortality of prickly sculpin and diurnal extremes in water quality at Rodeo Lagoon, Marin County, California

[No abstract available]

Martin, B.A.; Saiki, M. K.; Fong, D.
Relation between mortality of prickly sculpin and diurnal extremes in water quality at Rodeo Lagoon, Marin County, California; 2007; Article; Journal; California Fish and Game; Martin, B. A.; Saiki, M. K.; Fong, D.

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Year Published: 2006

Mineralogy and Morphology of Amphiboles Observed in Soils and Rocks in El Dorado Hills, California

From the Executive Summary: At the request of the U.S. Environmental Protection Agency (USEPA), the U.S. Geological Survey (USGS) has conducted an independent study of amphiboles in rocks and soils in the El Dorado Hills, California, area. The purpose of this study is to investigate specific issues regarding the presence of 'naturally occurring...

Meeker, G.P.; Lowers, H.A.; Swayze, G.A.; Van Gosen, B. S.; Sutley, S. J.; Brownfield, I.K.
Mineralogy and Morphology of Amphiboles Observed in Soils and Rocks in El Dorado Hills, California; 2006; OFR; 2006-1362; Meeker, G. P.; Lowers, H. A.; Swayze, G. A.; Van Gosen, B. S.; Sutley, S. J.; Brownfield, I. K.

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Year Published: 2006

Physical properties of two core samples from Well 34-9RD2 at the Coso geothermal field, California

The Coso geothermal field, located along the Eastern California Shear Zone, is composed of fractured granitic rocks above a shallow heat source. Temperatures exceed 640 ?F (~338 ?C) at a depth of less than 10000 feet (3 km). Permeability varies throughout the geothermal field due to the competing processes of alteration and mineral precipitation,...

Morrow, C.A.; Lockner, D.A.
Physical properties of two core samples from Well 34-9RD2 at the Coso geothermal field, California; 2006; OFR; 2006-1230; Morrow, C. A.; Lockner, D. A.

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Year Published: 2006

Subsurface structure of the East Bay Plain ground-water basin: San Francisco Bay to the Hayward fault, Alameda County, California

The area of California between the San Francisco Bay, San Pablo Bay, Santa Clara Valley, and the Diablo Ranges (East Bay Hills), commonly referred to as the 'East Bay', contains the East Bay Plain and Niles Cone ground-water basins. The area has a population of 1.46 million (2003 US Census), largely distributed among several cities, including...

Catchings, R.D.; Borchers, J.W.; Goldman, M.R.; Gandhok, G.; Ponce, D. A.; Steedman, C.E.
Subsurface structure of the East Bay Plain ground-water basin: San Francisco Bay to the Hayward fault, Alameda County, California; 2006; OFR; 2006-1084; Catchings, R. D.; Borchers, J. W.; Goldman, M. R.; Gandhok, G.; Ponce, D. A.; Steedman, C. E.

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Year Published: 2006

Seismic constraints and coulomb stress changes of a blind thrust fault system, 2: Northridge, California

We review seismicity, surface faulting, and Coulomb stress changes associated with the 1994 Northridge, California, earthquake. All of the observed surface faulting is shallow, extending meters to tens of meters below the surface. Relocated aftershocks reveal no seismicity shallower than 2 km depth. Although many of the aftershocks lie along the...

Stein, Ross S.; Lin, Jian
Seismic constraints and coulomb stress changes of a blind thrust fault system, 2: Northridge, California; 2006; OFR; 2006-1158; Stein, Ross S.; Lin, Jian

Filter Total Items: 1,110
Willow Creek detection station PIT tag system
January 3, 2018

Willow Creek detection station PIT tag systems

Passive Integrated Transponder (PIT) tag detection station on Willow Creek, California. Systems like this one are used to detect movements of endangered Lost River and shortnose suckers in remote locations.

Map shows a coastal city with an airport and how, during a large storm, ocean water would flood around city features.
December 31, 2017

CoSMoS projection for San Diego

Example of CoSMoS projected flooding extents for a 1.5 meter sea level rise in combination with possible 100 year return period coastal storms.

USGS
December 31, 2017

Big Brown Bat (Eptesicus fuscus) Call

Bats produce a variety of vocalizations that are used for navigation, feeding, and social communication. Most vocalizations are pitched well above the range of human hearing and are referred to as ultrasonic. These calls are often known as echolocation calls since bats use the echoes produced when a sound bounces off a bug or a building to determine what is in the area. 

Map of Active Faults and Historic Earthquakes in California
December 31, 2017

California Seismicity

Map of historic seismicity, major faults, and paleoseismic summary of San Andreas Fault system.

USGS
December 31, 2017

California myotis (Myotis californicus) Call

Bats produce a variety of vocalizations that are used for navigation, feeding, and social communication. Most vocalizations are pitched well above the range of human hearing and are referred to as ultrasonic. These calls are often known as echolocation calls since bats use the echoes produced when a sound bounces off a bug or a building to determine what is in the area. 

USGS
December 31, 2017

Hoary Bat (Lasiurus cinereus) Echo Call

Bats produce a variety of vocalizations that are used for navigation, feeding, and social communication. Most vocalizations are pitched well above the range of human hearing and are referred to as ultrasonic. These calls are often known as echolocation calls since bats use the echoes produced when a sound bounces off a bug or a building to determine what is in the area. 

3 close-up views of the toe of the Mud Creek landslide created from air photos after the landslide
December 31, 2017

3 close-up views of the toe of the Mud Creek landslide

Close-up views of the toe of the Mud Creek landslide created from air photos taken May 27 (top), June 13 (middle), and June 26 (bottom). Caltrans built roads on top of the slide for assessment and monitoring activities.

USGS
December 31, 2017

Hoary Bat (Lasiurus cinereus) Social Call

Bats produce a variety of vocalizations that are used for navigation, feeding, and social communication. Most vocalizations are pitched well above the range of human hearing and are referred to as ultrasonic. These calls are often known as echolocation calls since bats use the echoes produced when a sound bounces off a bug or a building to determine what is in the area. 

Topographic-change image produced by comparing 3D map derived from May 27 air photos with that derived from June 13 air photos
December 31, 2017

Topographic-change image produced by comparing subsequent 3D maps

Topographic-change image produced by comparing 3D map derived from May 27 air photos with that derived from June 13 air photos. Note that material has eroded from the seaward edge of the toe (yellow and orange tones), and material has built up on beaches to either side of the slide (blue tones).

USGS
December 31, 2017

Yuma myotis (Myotis yumanensis) Call

Bats produce a variety of vocalizations that are used for navigation, feeding, and social communication. Most vocalizations are pitched well above the range of human hearing and are referred to as ultrasonic. These calls are often known as echolocation calls since bats use the echoes produced when a sound bounces off a bug or a building to determine what is in the area. 

Pollen samples from various plants collected from hedgerows
December 31, 2017

Pollen samples from various plants collected from hedgerows

Organic Chemistry Research Laboratory -- Sacramento, California. Small sample bottles with pollen inside

erry Hatcher with the system he designed to record the precise time and geographic location of each air photo Van Wagenen shoots
December 31, 2017

Scientist with the system he designed to record precise photo data

Gerry Hatcher with the system he designed to record the precise time and geographic location of each air photo Van Wagenen shoots.

Filter Total Items: 985
USGS science for a changing world logo
May 19, 2014

Contaminated groundwater found at shallow depths in southern Los Angeles County has the potential to migrate to deeper aquifers, according to a scientific study just published by the U.S. Geological Survey and the Water Replenishment District of Southern California.

USGS science for a changing world logo
May 14, 2014

Nitrate was detected at high concentrations in about 14 percent of untreated groundwater sources used for public water supply in the Livermore, Gilroy-Hollister, and Cuyama valleys of the Southern Coast Ranges, according to an ongoing U.S. Geological Survey study of the state's groundwater quality.

Lidar image showing the upper parts of the landslide that occurred in northwest Washington on March 22, 2014.
May 14, 2014

Want to know how elevation will benefit your state? The USGS National Geospatial Program is advancing the 3D Elevation Program, known as 3DEP, in response to the growing need for high-quality three-dimensional representations of the Nation’s natural and constructed features.

USGS science for a changing world logo
May 7, 2014

Results of a new hydrologic model show a decrease in groundwater levels in response to pumping, which in turn causes a reduction in groundwater discharge to streams, a reduction in groundwater evapotranspiration, and a reduction in groundwater storage in the Santa Rosa Plain watershed.

USGS science for a changing world logo
April 30, 2014

The coastal geology of Simeonof Island, the southeastern-most island in the Shumagin archipelago of the Aleutian Islands, suggests the region has not experienced a great megathrust earthquake in at least the past 3,400 years.

Catastrophic Earthquakes – In a Crowded World Public Lecture Flyer
April 22, 2014

Why have there been so many catastrophic earthquakes at the beginning of the 21stcentury? On April 24th, USGS Research Geologist Thomas Holzer will tell us the history and future of earthquake death tolls, and the urbanization of the planet. Find out what makes modern megacities vulnerable to natural hazards.

USGS science for a changing world logo
April 22, 2014

Inorganic trace elements – fluoride, arsenic, molybdenum and boron – were detected at high concentrations in 42 percent of groundwater used for public supply in the Borrego Valley, and southern desert areas of California, according to a recent study by the U.S. Geological Survey. The USGS evaluated the quality of untreated groundwater for this study – not treated tap water.

Image:  Desert Perchlorate Field Work
April 3, 2014

Newly published research is the first to characterize the distribution and interactions of natural perchlorate in a terrestrial ecosystem. The study results are important in assessing risks associated with ecological and human health and with potential movement of natural perchlorate contamination into groundwater.

Lecture flyer thumbnail
March 24, 2014

How much will California's climate warm in future decades and what are the greatest vulnerabilities to climate change? On March 27th, USGS Climate Researcher Dan Cayan will explain about how scientists are investigating the way climate change might impact resources that are crucial to the state, including the Sierra Nevada snowpack, California coastal sea levels and the San Francisco Bay and Delta

USGS science for a changing world logo
March 20, 2014

Why does the 1964 Great Alaska Earthquake Matter 50 Years Later? Scientific experts will talk about a half-century of scientific and monitoring advances triggered by the 1964 events.

USGS science for a changing world logo
March 17, 2014

How does drought affect California's water supply? Does it impact the surface water only, or what about groundwater? How does it impact water quality? What about streamflow? How is the water shortage affecting ecosystems? How is the drought related to climate change?