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: 406
Date published: October 18, 2018
Status: Active

Genomic Mechanisms that Underlie Lack of Recovery of Prince William Sound Herring Following the 1990s Collapse

In the decades following the Exxon Valdez Oil Spill (EVOS), it has become increasingly apparent that oil can be toxic at extremely low concentrations to developing fish embryos including herring, where some toxic phenotypes may be apparent during embryogenesis, but some are delayed until later in life. Therefore, acute and lingering oil may act as an insidious selective force within...

Contacts: Paul Hershberger, Ph.D., Jacob Gregg, Ashley MacKenzie, William Richards, Andrew Whitehead, John Incardona, Nat Scholtz
Date published: October 17, 2018
Status: Active

Land Subsidence in the San Joaquin Valley

The San Joaquin Valley is one of the most productive agricultural regions in the nation. Beginning around the 1920's, farmers relied upon groundwater for water supply. Over time, overpumping caused groundwater-level declines and associated aquifer-system compaction and land subsidence that resulted in permanent aquifer-system storage loss.

Contacts: Michelle Sneed
Date published: October 15, 2018
Status: Completed

Debris-Flow Forecasts Before Wildfires

Release Date: OCTOBER 15, 2018

USGS scientists have been pursuing a way to assess debris-flow hazards before a fire occurs.

Date published: October 3, 2018
Status: Active

Implementing New Acoustic Monitoring Techniques in the Trinity River

Accurate river-sediment data is fundamental to planning and managing river restoration efforts on the Trinity River, and throughout the world’s waterways. The USGS has developed a “hydrophone” that enables scientists to listen to sediment particles as they move along the riverbed in order to inexpensively and reliably record near-continuous sediment-bedload-transport data. For this study,...

Date published: August 30, 2018
Status: Active

Yucaipa Subbasin Integrated Hydrologic Model

The USGS is developing a hydrologic model of the Yucaipa Subbasin to aid in evaluating and managing the groundwater resources in the area. The study results will provide a greater understanding of the geohydrology of the subbasin, and aid in the development of a groundwater-monitoring plan, as well as in the evaluation of potential hydrologic effects of future groundwater development and...

Contacts: Geoff Cromwell
Date published: August 28, 2018
Status: Active

Microbial Biogeochemistry Laboratory

Microbiologists at the Microbial Biogeochemistry Laboratory develop and apply innovative methods to measure key microbial processes. These methods are used to better understand how major biogeochemical cycles (carbon, nitrogen, sulfur, and iron) interact with and control the speciation and fate of metals like mercury and selenium which can impact the health of humans and other organisms.

Date published: August 28, 2018
Status: Active

Organic Chemistry Research Laboratory — Sacramento, California

About the Laboratory

Chemists and hydrologists at the Organic Chemistry Research Laboratory (OCRL) develop targeted analytical methods for the quantitation of chemicals that can impact the health of organisms and humans. They have developed methods in a wide variety of environmental media; in addition to water and sediment, they also analyze a variety of tissue matrices...

Date published: August 27, 2018
Status: Completed

Increasing Soil Organic Carbon to Mitigate Greenhouse Gases and Increase Climate Resiliency for California

Rising air temperatures are projected to continue to drive up urban, agricultural, and rangeland water use, straining both surface and groundwater resources. Scientific studies have shown that managing farms, ranches, and public lands to increase soil carbon can increase soil waterholding capacity and increase hydrologic benefits such as increased baseflows and aquifer recharge, reduced...

Contacts: Michelle Stern
Date published: August 24, 2018
Status: Active

Yucaipa Valley Hydrogeology

This study assesses the quality of water in the Yucaipa area, primarily in the Yucaipa plain. This hydrogeology study will aid local water purveyors in understanding and evaluating local resources and using those resources effectively in combination with water imported from northern California and from the adjacent San Bernardino area.

Contacts: Gregory Mendez
Date published: August 5, 2018
Status: Active

Global Hyperspectral Imaging Spectroscopy of Agricultural-Crops & Vegetation (GHISA)

This webpage showcases the key research advances made in hyperspectral remote sensing of agricultural crops and vegetation over the last 50 years. There are three focus areas:

Date published: July 18, 2018
Status: Active

A Critical Assessment of Recent Soil Dating Methods in Coastal Wetlands- Judith Drexler

Are you interested in coastal wetlands and how they form in the landscape? In this internship you will learn about wetland formation and how carbon accumulates in wetland soils over time. In addition, you will learn to learn how to critically evaluate soil dating methods that are currently being used to report carbon accumulation to the US EPA and the Intergovernmental Panel on Climate Change...

Date published: July 17, 2018
Status: Active

A tale of two coasts: tidal marsh persistence with changing climate and sea-level rise- Karen Thorne

The overall goal of this project is to improve our understanding of the combined effects of inundation, due to sea-level rise and storm surges, and other climate factor on tidal marsh physical and biological processes to provide guidance to natural resource managers to reduce these threats and increase resilience.

Filter Total Items: 520
Date published: December 21, 2018

California Flood Activity Alerts

USGS Project Alert Notices RSS feed includes response summaries of USGS streamgaging network activity during storm events in California. These Notices are produced by USGS Streamgaging Programs nationally and can be found on the USGS Current Floods Website.

Date published: December 19, 2018

Drought & Groundwater in California

Long-term groundwater-level data are fundamental to the resolution of problems dealing with groundwater availability and sustainability. Significant periods of time typically are required to collect water-level data needed to assess the effects of climate variability, to monitor the effects of regional aquifer development, or to obtain data sufficient for analysis of water-level trends.

Date published: December 19, 2018

Runoff Estimates for California

Streams, rivers, lakes and reservoirs are important natural resources for irrigation, public supply, wetlands and wildlife.  Excess precipitation that flows into these sources is called runoff, and it's an important drought indicator.  The California Water Science Center tracks both monthly and annual runoff. 

Date published: December 18, 2018

Mojave River and Morongo Groundwater Basins Data

Interactive map of the Mojave and Morongo groundwater basins.  Data layers include sites and data for groundwater levels, water quality, and land subsidence.  Groundwater data spans 1992 to the present.

Date published: December 18, 2018

Drought & Surface Water in California

Careful observation and analysis of the movement and condition of surface water is essential for understanding this resource, especially during times of drought. The California Water Science Center uses a network of more than 500 streamgages to collect real-time data on surface water at locations across the state.

Date published: December 18, 2018

San Antonio Creek Valley Hydrologic Monitoring

In order to understand the integrated hydrologic systems in the San Antonio Creek Valley, many different types of data are being gathered from both the surface water and groundwater system. Learn about these data types and explore them with the interactive map.

Date published: December 17, 2018

Central Valley: Drought Indicators

During the recent droughts of 2007-2010 and 2012-2017, groundwater pumping has increased from the combined effects of the drought and land-use changes, re-initiating land subsidence. In order to document historical subsidence and monitor continued changes, the USGS has gathered and interpreted data from a variety of sources.

Date published: December 17, 2018

Benchmark Site Data | San Joaquin Valley, CA

These 5 northern benchmarks in the San Joaquin Valley are where the largest magnitude of subsidence was recently measured using repeat surveys. That doesn't mean these locations are where the largest magnitude of subsidence occurred, just where it's been measured. The southernmost benchmark in this set is where the largest magnitude was historically measured using repeat surveys.

Date published: December 17, 2018

Compaction | Data from Central Valley, CA Extensometers

Aquifer-system compaction has been monitored at selected locations for various periods with borehole extensometers by different agencies, including the USGS, DWR, SLDMWA, and CCID, and by Luhdorff and Scalmanini Consulting Engineers.  This dataset contains compaction data for 23 extensometers across California's Central Valley.

Date published: December 17, 2018

Continuous Global Positioning System (CGPS) Stations

The CGPS data were obtained from the UNAVCO Plate Boundary Observatory (PBO) network of continuously operating GPS stations. The PBO is the geodetic component of UNAVCO, a consortium of research institutions whose focus is measuring vertical and horizontal plate boundary deformation across the North American and Pacific Plates in the western U.S. using high-precision measurement techniques....

Date published: December 17, 2018

InSAR | Central Valley Areas of Interest

The InSAR technique uses two SAR scenes of the same area taken at different times which are then processed together to produce maps called interferograms that show relative land-surface-elevation change between the two SAR acquisition dates. This Areas of Interest dataset is where InSAR data has been interpreted to produce a time-history of subsidence in the Central Valley, CA.

Date published: December 14, 2018

Water Quality Sites, San Bernardino County, CA

List of USGS sites in San Bernardino County, CA that have water quality data samples.  Data is on the USGS National Water Information System database.

Filter Total Items: 360
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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

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Year Published: 2006

Seismic constraints and coulomb stress changes of a blind thrust fault system, 1: Coalinga and Kettleman hills, California

This report reviews the seismicity and surface ruptures associated with the 1982-1985 earthquake sequence in the Coalinga region in California, and the role of Coulomb stress in triggering the mainshock sequence and aftershocks. The 1982-1985 New Idria, Coalinga, and Kettleman Hills earthquakes struck on a series of west-dipping, en echelon blind...

Lin, Jian; Stein, Ross S.
Seismic constraints and coulomb stress changes of a blind thrust fault system, 1: Coalinga and Kettleman hills, California; 2006; OFR; 2006-1149; Lin, Jian; Stein, Ross S.

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Year Published: 2006

Digital database of recently active traces of the Hayward Fault, California

The purpose of this map is to show the location of and evidence for recent movement on active fault traces within the Hayward Fault Zone, California. The mapped traces represent the integration of the following three different types of data: (1) geomorphic expression, (2) creep (aseismic fault slip),and (3) trench exposures. This publication is...

Lienkaemper, James J.
Lienkaemper, J.J., 2006, Digital Database of Recently Active Traces of the Hayward Fault, California (ver. 1.1, November 2008): U.S Geological Survey Data Series 177, https://doi.org/10.3133/ds177.

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Year Published: 2006

Maps of quaternary deposits and liquefaction susceptibility in the Central San Francisco Bay Region, California

This report presents a map and database of Quaternary deposits and liquefaction susceptibility for the urban core of the San Francisco Bay region. It supercedes the equivalent area of U.S. Geological Survey Open-File Report 00-444 (Knudsen and others, 2000), which covers the larger 9-county San Francisco Bay region. The report consists of (1) a...

Witter, Robert C.; Knudsen, Keith L.; Sowers, Janet M.; Wentworth, Carl M.; Koehler, Richard D.; Randolph, Carolyn E.; Brooks, Suzanna K.; Gans, Kathleen D.
Maps of Quaternary Deposits and Liquefaction Susceptibility in the Central San Francisco Bay Region, California; 2006; OFR; 2006-1037; Witter, Robert C.; Knudsen, Keith L.; Sowers, Janet M.; Wentworth, Carl M.; Koehler, Richard D.; Randolph, Carolyn E.; Brooks, Suzanna K.; Gans, Kathleen D.

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Year Published: 2006

USGS science in Menlo Park -- a science strategy for the U.S. Geological Survey Menlo Park Science Center, 2005-2015

In the spring of 2004, the U.S. Geological Survey (USGS) Menlo Park Center Council commissioned an interdisciplinary working group to develop a forward-looking science strategy for the USGS Menlo Park Science Center in California (hereafter also referred to as "the Center"). The Center has been the flagship research center for the USGS in the...

Brocher, Thomas M.; Carr, Michael D.; Halsing, David L.; John, David A.; Langenheim, Victoria E.; Mangan, Margaret T.; Marvin-DiPasquale, Mark C.; Takekawa, John Y.; Tiedeman, Claire

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Year Published: 2006

Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary

Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans to...

Takekawa, John Y.; Miles, A.K.; Schoellhamer, D.H.; Athearn, N.D.; Saiki, M.K.; Duffy, W.D.; Kleinschmidt, S.; Shellenbarger, G.G.; Jannusch, C.A.
Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary; 2006; Conference Paper; Hydrobiologia; Takekawa, J. Y.; Miles, A. K.; Schoellhamer, D. H.; Athearn, N. D.; Saiki, M. K.; Duffy, W. D.; Kleinschmidt, S.; Shellenbarger, G. G.; Jannusch, C. A.

Filter Total Items: 1,043
Photo of absolute-gravity meter next to a groundwater well in the field
April 25, 2018

Changes in Earth's Gravity Reveal Changes in Groundwater Storage

Did you know that changes in the amount of water in aquifers cause small changes in Earth’s gravitational field? When the amount of groundwater in an aquifer changes, either by recharge or by discharge to surface water or wells, the gravitational acceleration at the land surface also changes. In this photo, USGS Research Hydrologist Jeff Kennedy is making measurements of

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Attribution: Water Resources
April 20, 2018

MODIS and VIIRS Observe Snowpack in the Sierra Nevada Mountain Range

The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor is located onboard NASA’s Terra and Aqua satellites. The Visible Infrared Imaging Radiometer Suite (VIIRS) sensor is located onboard the joint NASA/NOAA Suomi National Polar-Orbiting Partnership (S-NPP) and data products created by NASA provide a continuation of the MODIS data heritage. These data are crucial

View from a rooftop looking down into a cove with gentle ocean waves, coastal bluffs, surfers and anchored boat in distance.
April 19, 2018

Cowells Beach Snapshot

Snapshot, or first frame of from a 10-minute video taken on April 19, 2018, in Santa Cruz, California. View is from atop a hotel looking down on Cowells Beach, a popular surf spot. Researchers at the USGS are using these and other video images to improve understanding and computer modeling of beach processes, especially those that change the coast. 

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April 18, 2018

HayWired Scenario - Movie

The HayWired earthquake scenario, led by the U.S. Geological Survey (USGS), anticipates the impacts of a hypothetical magnitude-7.0 earthquake on the Hayward Fault. The fault is along the east side of California’s San Francisco Bay and is among the most active and dangerous in the United States, because it runs through a densely urbanized and interconnected region. 

Gas chromatograph-mass spectrometer (GCMS) used for pesticide analysis
April 4, 2018

Gas chromatograph-mass spectrometer (GCMS) used for pesticide analysis

Organic Chemistry Research Laboratory — Sacramento, California. Gas chromatograph-mass spectrometer - GCMS

Map of California showing the sections of the coast where the USGS has generated computer models of storm impacts.
April 2, 2018

CoSMoS Implementation versions

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 SLR scenarios, as well as long-term shoreline change and cliff retreat.  Resulting projections for future climate scenarios (sea-level rise and storms) provide

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View from the sky of a marsh labeled with sample locations.
April 2, 2018

Little Holland Tract and Liberty Island sample locations, 2014-2017

Sediment sampling locations in the Sacramento-San Joaquin Delta, California near Little Holland Tract and Liberty Island, 2014 to 2017

Comparison maps indicating short or long times available for earthquake shaking arrival times
March 31, 2018

Earthquake Alerts: Early and Often? Or Possibly Late?

The choice when issuing earthquake warnings is to: 1) issue alerts for weak shaking and potentially provide long warning times, but risk sending alerts for the many events that do not go on to produce damaging ground shaking, or 2) issue alerts only when ground shaking is expected to be damaging, with the tradeoff that the alert will be sent much later, reducing the

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A coastline with trees on the beach berm on left, two people looking out at two jet skis, waves are gentle, sun is gleaming.
March 28, 2018

Nearshore survey of San Ysidro Creek

Two USGS scientists operate personal watercraft equipped with sonar and GPS along the beachfront off San Ysidro Creek, near Fernald Point in Montecito, California. They will use the data collected to create bathymetric (depth) maps. Collecting these data on a seasonal basis over many years provides a detailed picture of how the coastline reacts to changes in waves and

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Two women stand together smiling on a boat wearing life jackets and sun hats with other safety gear.
March 27, 2018

Fieldwork in the Delta

Shruti Khanna (left, California Department of Fish and Wildlife) and Judy Drexler (USGS California Water Science Center) on the USGS Pacific Coastal and Marine Science Center’s research vessel Parke Snavely during fieldwork in the Sacramento-San Joaquin River Delta.

An object of two circular pieces of mixed materials are partially covered with mud and plant debris.
March 27, 2018

Instrument package for river data collection

Patches of dark sand cling to an instrument package that collected data for approximately two weeks at the Mokelumne River site—evidence that currents at the site were strong enough to carry sand, which is heavier than mud, probably during elevated river flows following two storms in the watershed.

A woman and a man stand on the stern of a boat wearing safety gear, man is pressing on a piece of equipment.
March 19, 2018

Gomex sediment corer preparation

Dan Powers (USGS PCMSC) and Rachel Marcuson (USGS PCMSC) prepare to deploy a Gomex sediment corer from the R/V Snavely in the Mokulumne River near confluence of San Joaquin River in the Sacramento-San Joaquin Delta, CA.

Filter Total Items: 942
Flyer thumbnail
April 22, 2015

Everyone knows that California is “earthquake country,” but it is also “volcano country.” The most recent large volcanic eruption in California was 100 years ago at Lassen Peak, in what is now Lassen Volcanic National Park. California is much different today than it was 100 years ago; in 1915 there were no deaths, no injuries, and minimal economic losses due to the eruption.

USGS
April 14, 2015

The U.S. Geological Survey and Clear Channel Outdoor today announced a partnership to provide the public with critical earthquake safety information during April.

Image: Tsunami Evacuation Sign
April 13, 2015

Tens of thousands of people along the U.S. Pacific Northwest coastline may not have enough time to evacuate low-lying areas before tsunami waves arrive, according to a new publication by researchers at the U.S. Geological Survey, University of Colorado Boulder, and California State University, Sacramento.

Image: Female Golden Eagle with GPS-GSM Transmitter
April 8, 2015

Golden eagles in the Mojave Desert travel farther, to different areas, and at different times of the year than previously understood, according to research by the U.S. Geological Survey and partners from other federal agencies, academia and the private sector. 

Screenshot of the Upper Klamath Basin Collaborative Groundwater Monitoring website.
April 3, 2015

The U.S. Geological Survey recently launched the Upper Klamath Basin Collaborative Groundwater Monitoring  website to provide information on groundwater conditions in the upper Klamath Basin.

Plot of earthquakes in Mount Shasta region greater than M1.0 from A...
April 3, 2015

Since February 19, 2015 an ongoing series of small earthquakes has been occurring approximately 5 miles southeast of the summit of Mount Shasta, near the Clear Creek Trailhead on a regional, unnamed fault at about 3-5 miles depth.

Updated 2015 version of the El Capitan, California quadrangle with orthoimage turned off
April 1, 2015

Several of the 2,798 new US Topo quadrangles for California now display public trails along with segments of the Pacific Crest National Scenic Trail. Also the new maps now show improved data layers such as public land survey information, map symbol redesign, enhanced railroad information and new road source data.

Image: Happy Cows in Happy Flowers
March 25, 2015

Grassland habitats on rangelands in California’s Central Valley and surrounding foothills could decline by as much as 37 percent by 2100 due to changes in land use and climate, according to new scientific projections by the U.S. Geological Survey.

Image: San Jose Earthquakes' Avaya Stadium
March 20, 2015

Where better to install a new earthquake sensor than in the new home of the San Jose Earthquakes Major League Soccer team? 

3D perspective view of the likelihood that each region of California will experience a magnitude 6.7 within 30 years
March 10, 2015

A new California earthquake forecast by the U.S. Geological Survey and partners revises scientific estimates for the chances of having large earthquakes over the next several decades.