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: 415
Date published: April 8, 2020
Status: Active

Evaluation of Groundwater Resources in the Adelaida Area of San Luis Obispo County, California

Stakeholders in San Luis Obispo County are concerned that the increased demand for water use has, and will continue to, affect groundwater levels and availability in the Adelaida area. To address stakeholder concerns, the County of San Luis Obispo Board of Supervisors has asked the USGS to conduct a comprehensive evaluation of groundwater resources of the Adelaida area. 

Date published: March 6, 2020
Status: Active

Fourth Federal UAS Workshop

November 17 - 19, 2020 Virtual Workshop

Contacts: Jonathan Stock, Bruce Quirk, Matthew Fladeland
Date published: February 18, 2020
Status: Active

Evaluation of groundwater resources of the Anza-Terwilliger area, Anza, California

Groundwater is the sole source for water use to the rural community and two Native American tribes in the Cahuilla Valley and Terwilliger Valley groundwater basins, which are located approximately 35 miles southwest of Palm Springs, California. The characteristics and sustainable yield of the basins are not well understood and are threatened by increasing water use and potential changes in...

Date published: January 22, 2020
Status: Active

Using Unmanned Aerial Systems (UAS) Capabilities to Help Identify Giant Salvinia (Salvinia molesta) and the effects of Salvinia weevil (Cyrtogagous salviniae)

USGS is collecting remotely sensed data to classify Salvinia molesta, a non-native aquatic species that reduces light and oxygen levels in water, making it unsuitable for fish and other aquatic plant life.

Date published: January 2, 2020
Status: Active

California Seafloor and Coastal Mapping Program

A Foundation for Characterizing Hazards, Monitoring Change, and Managing Resources

Date published: December 31, 2019
Status: Active

California Seafloor Mapping Program mapping progress

Table shows USGS California Seafloor Mapping Program progress by block number, as of August 2019.

Date published: December 11, 2019
Status: Completed

Tsunami Record from the Great 1906 San Francisco Earthquake

Shortly after the Great San Francisco earthquake of April 18, 1906, a sea level disturbance (tsunami) was recorded at the Presidio tide gauge station in San Francisco (the station is now located nearby at Ft. Point). What type of mechanism (earthquake rupture, landslide, other) generated the tsunami...

Contacts: Eric Geist
Date published: November 22, 2019
Status: Active

Creating a Model to Predict Future Carbon Levels in Tidally-driven Marshes

Tidal marshes are important ecosystems in the San Francisco-Bay Delta. They remove carbon from the atmosphere, they build up soils that buffer our communities from sea level rise, they provide critical habitat and food resources for a diversity of species, and they reduce excessive nutrients which have a negative impact on water quality. As a result of land-use change and urbanization, the San...

Date published: November 14, 2019
Status: Active

Attending Seminars at PCMSC

Check our schedule for upcoming seminars and dates.

Date published: November 13, 2019
Status: Active

Earthquake Early Warning Seismic Station Adjustment Terms - Annemarie Baltay

Earthquake early warning, live in California, aims to send user alerts before ground shaking arrives at their location. Work directly with a USGS team in implementing a ground-motion based early warning algorithm, and develop novel station-specific adjustment factors to improve the accuracy of ground-shaking estimates, a critical step in sending the most useful user alerts.

Date published: October 23, 2019
Status: Active

San Francisco Bay Area – SF Peninsula (BALT4) Site near Pacifica, CA

Landslides in the San Francisco Bay area (SFBA) of California impact people, infrastructure, and the environment, and are commonly induced by intense or prolonged rainfall associated with strong winter storms...

Contacts: Brian Collins
Date published: October 23, 2019
Status: Active

San Francisco Bay Area – SF Peninsula (BALT3) Site near Brisbane, CA

Landslides in the San Francisco Bay area (SFBA) of California impact people, infrastructure, and the environment, and are commonly induced by intense or prolonged rainfall associated with strong winter storms...

Contacts: Brian Collins
Filter Total Items: 542
Date published: May 4, 2020

CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood depth and duration projections: 20-year storm in Santa Cruz County

This data contains maximum depth of flooding (cm) in the region landward of the present-day shoreline for the sea-level rise (SLR) and storm condition indicated.
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-le

Date published: May 4, 2020

CoSMoS (Coastal Storm Modeling System) Central California v3.1 water-level projections: 20-year storm in Santa Cruz County

This data contains model-derived total water levels (in meters) for the sea-level rise (SLR) and storm condition indicated.
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. Projecti

Date published: May 4, 2020

CoSMoS (Coastal Storm Modeling System) Central California v3.1 water-level projections: 100-year storm in Santa Cruz County

This data contains model-derived total water levels (in meters) for the sea-level rise (SLR) and storm condition indicated.
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. Projecti

Date published: May 4, 2020

CoSMoS (Coastal Storm Modeling System) Central California v3.1 wave-hazard projections: 100-year storm in Santa Cruz County

This data contains maximum model-derived significant wave height (in meters) for the sea-level rise (SLR) and storm condition indicated.
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) scenar

Date published: May 4, 2020

CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood depth and duration projections: 1-year storm in Santa Cruz County

This data contains maximum depth of flooding (cm) in the region landward of the present-day shoreline for the sea-level rise (SLR) and storm condition indicated.
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-le

Date published: May 4, 2020

CoSMoS (Coastal Storm Modeling System) Central California v3.1 ocean-currents projections: average conditions in Santa Cruz County

This data contains maximum model-derived ocean currents (in meters per second) for the sea-level rise (SLR) and storm condition indicated.
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) scen

Date published: May 4, 2020

CoSMoS (Coastal Storm Modeling System) Central California v3.1 wave-hazard projections: 20-year storm in Santa Cruz County

This data contains maximum model-derived significant wave height (in meters) for the sea-level rise (SLR) and storm condition indicated.
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) scenar

Date published: April 30, 2020

Quaternary faults offshore of California

A comprehensive map of Quaternary faults has been generated for offshore of California. The Quaternary fault map includes mapped geometries and attribute information for offshore fault systems located in California State and Federal waters. The polyline shapefile has been compiled from previously published mapping where relatively dense, high-resolution marine geophysical data exist. The data...

Date published: April 30, 2020

Select borehole data for Anza Valley, Anza, CA

Borehole log number, State Well Number, location, construction information, and any wells tests performed on select wells from the Anza basin, Anza, CA. Also includes a lithologic data for a sub-set of borehole logs identified based on best coverage and representation of data within the study area.

Date published: April 29, 2020

Partitioning of six pyrethroid insecticides at varying salinities

To determine aqueous pyrethroid partitioning across a salinity gradient 20 mL Pyrex beakers were filled with 8 mL of deionized water at varying salinities (0, 0.5, 2, 6 ppt). Salinity was adjusted using a 10 ppt stock solution (made by diluting Instant Ocean into deionized water). The water samples were spiked with pyrethroids (bifenthrin, cyhalothrin, cyfluthrin, cypermethr

Date published: April 29, 2020

SmeltCam sampling in San Joaquin River and False River near Jersey Island in the Sacramento-San Joaquin River Delta, California, 2016

This dataset includes field data for fishes sampled using mid-water trawls and the SmeltCam during daylight hours in the Sacramento- San Joaquin Delta, California. Sampling took place between February 8, 2016 and March 1, 2016. This data release includes all measured environmental parameters and fish taxa collected during sampling event.

Date published: April 28, 2020

Otolith chemistry of fishes in Rodeo Lagoon, Marin County, California, 2016

The dataset includes multiple file types (CSV, ArcGIS shapefiles, and images), data relates to the elemental analysis of fish otoliths. Otoliths examined in this study were from randomly-sampled individual Tidewater Goby (Eucyclogobius newberryi) and Prickly Sculpin (Cottus asper) from the adult population of Rodeo Lagoon and Rodeo Creek, Marin County, California. The fish w

Filter Total Items: 414
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Year Published: 2018

Geophysical and geologic maps of Mountain Pass and vicinity, California and Nevada

U.S. Geological Survey Scientific Investigations Map 3412 is a series of products that consists of geophysical and geologic maps of Mountain Pass and vicinity, California. Maps A and B (red outline in above map image) are gravity and aeromagnetic maps, respectively. The map series was begun as part of an effort to study regional crustal structures...

Ponce, David A.

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Year Published: 2018

Improving earthquake rupture forecasts using California as a guide

This article discusses ways in which earthquake rupture forecast models might be improved. Because changes are most easily described in the context of specific models, the third Uniform California Earthquake Rupture Forecast (UCERF3) and its presumed successor, UCERF4, is used as a basis for discussion. Virtually all of the issues and possible...

Field, Edward H.
Field, E. H. (2018). Improving Earthquake Rupture Forecasts Using California as a Guide, Seismological Research Letters, https://doi.org/10.1785/0220180151.

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Year Published: 2018

2018 hurricane and wildfire supplemental funding: USGS recovery activities

The Additional Supplemental Appropriations for Disaster Relief Requirements Act, 2018 (P.L. 115-123), was signed by the President on February 9, 2018. This funding provided $42.2 million to the U.S. Geological Survey (USGS) for equipment repair and replacement, high-resolution elevation data collection in both hurricane- and wildfire-impacted...

Hinck, Jo Ellen; Stachyra, Joseph
Hinck, J.E., and Stachyra, J., 2018, 2018 hurricane and wildfire supplemental funding—USGS recovery activities: U.S. Geological Survey Fact Sheet 2018–3063, 4 p., https://doi.org/10.3133/fs20183063.

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Year Published: 2018

Increasing earthquake insurance coverage in California via parametric hedges

California has the highest earthquake risk of any state in the United States. The Federal Emergency Management Agency (FEMA) reported in 2017 that 73% of the nation’s annual losses to earthquakes were expected to be concentrated in California and the Pacific Northwest. California alone constitutes 61% ($3.7 billion out of an estimated $6.1 billion...

Franco, Guillermo; Tirabassi, G; Lopeman, M; Wald, David J.; Siembieda, W.J.

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Year Published: 2018

State transportation agencies partner to deploy and enhance ShakeCast

The California Department of Transportation (Caltrans) is organizing and leading a three-year Transportation Pooled Fund (TPF) project, Connecting the Dots: Implementing ShakeCast Across Multiple State Departments of Transportation for Rapid Post-Earthquake Response. Ten state Departments of Transportation (DOT)—CA, ID, MO, MS, OK, OR, SC, TX, UT...

Turner, L.; Wald, David J.; Lin, Kuo-wan; Chiou, Brian; Slosky, Daniel

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Year Published: 2018

Identifying physics‐based thresholds for rainfall‐induced landsliding

Most regional landslide warning systems utilize empirically derived rainfall thresholds that are difficult to improve without recalibration to additional landslide events. To address this limitation, we explored the use of synthetic rainfall to generate thousands of possible storm patterns and coupled them with a physics‐based hydrology and slope...

Thomas, Matthew A.; Mirus, Benjamin B.; Collins, Brian D.
Thomas, M. A., Mirus, B. B., & Collins, B. D. (2018). Identifying physics‐based thresholds for rainfall‐induced landsliding. Geophysical Research Letters. https://doi.org/10.1029/2018GL079662

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Year Published: 2018

A physics-based earthquake simulator replicates seismic hazard statistics across California

Seismic hazard models are important for society, feeding into building codes and hazard mitigation efforts. These models, however, rest on many uncertain assumptions and are difficult to test observationally because of the long recurrence times of large earthquakes. Physics-based earthquake simulators offer a potentially helpful tool, but they...

Shaw, Bruce E.; Milner, Kevin R.; Field, Edward H.; Richards-Dinger, Keith B.; Gilchrist, Jacquelyn J.; Dieterich, James H.; Jordan, Thomas H.
B. E. Shaw, K. R. Milner, E. H. Field, K. Richards-Dinger, J. J. Gilchrist, J. H. Dieterich, T. H. Jordan, A physics-based earthquake simulator replicates seismic hazard statistics across California. Sci. Adv. 4, eaau0688 (2018).

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Year Published: 2018

Flow-mediated effects on travel time, routing, and survival of juvenile Chinook salmon in a spatially complex, tidally forced river delta

We evaluated the interacting influences of river flows and tides on travel time, routing, and survival of juvenile late-fall Chinook salmon (Oncorhynchus tshawytscha) migrating through the Sacramento–San Joaquin River Delta. To quantify these effects, we jointly modeled the travel time, survival, and migration routing in relation to individual...

Perry, Russell W.; Pope, Adam C.; Romine, Jason G.; Brandes, Patricia L.; Burau, Jon R.; Blake, Aaron R.; Ammann, Arnold J.; Michel, Cyril J.

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Year Published: 2018

Survival, travel time, and utilization of Yolo Bypass, California, by outmigrating acoustic-tagged late-fall Chinook salmon

Juvenile Chinook salmon (Oncorhynchus tshawytscha) migrating through California's Sacramento-San Joaquin River Delta toward the Pacific Ocean face numerous challenges to their survival. The Yolo Bypass is a broad floodplain of the Sacramento River that floods in about 70 percent of years in response to large, uncontrolled runoff events. As one of...

Pope, Adam C.; Perry, Russell W.; Hance, Dalton J.; Hansel, Hal C.
Pope, A.C., Perry, R.W., Hance, D.J., and Hansel, H.C., 2018, Survival, travel time, and utilization of Yolo Bypass, California, by outmigrating acoustic-tagged late-fall Chinook salmon: U.S. Geological Survey Open-File Report 2018-1118, 33 p., https://doi.org/10.3133/ofr20181118.

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Year Published: 2018

Controls on submarine canyon head evolution: Monterey Canyon, offshore central California

The Monterey submarine canyon, incised across the continental shelf in Monterey Bay, California, provides a record of the link between onshore tectonism, fluvial transport, and deep-marine deposition. High-resolution seismic-reflection imaging in Monterey Bay reveals an extensive paleocanyon unit buried below the seafloor of the continental shelf...

Maier, Katherine L.; Johnson, Samuel Y.; Hart, Patrick E.
Maier, K.L., Johnson, S.Y., and Hart, P., 2018, Controls on submarine canyon head evolution—Monterey Canyon, offshore central California: Marine Geology, v. 404, p. 24-40.

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Year Published: 2018

Analysis of mean seismic ground motion and its uncertainty based on the UCERF3 geologic slip rate model with uncertainty for California

The Uniform California Earthquake Rupture Forecast v.3 (UCERF3) model (Field et al., 2014) considers epistemic uncertainty in fault‐slip rate via the inclusion of multiple rate models based on geologic and/or geodetic data. However, these slip rates are commonly clustered about their mean value and do not reflect the broader distribution of...

Zeng, Yuehua
Zeng, Y. (2018). Analysis of Mean Seismic Ground Motion and Its Uncertainty Based on the UCERF3 Geologic Slip Rate Model with Uncertainty for California, SRL, doi: 10.1785/0220170114.

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Year Published: 2018

Faunal and stable isotopic analyses of benthic foraminifera from the Southeast Seep on Kimki Ridge offshore southern California, USA

We investigated the benthic foraminiferal faunal and stable carbon and oxygen isotopic composition of a 15-cm push core (NA075-092b) obtained on a Telepresence-Enabled cruise to the Southeast Seep on Kimki Ridge offshore southern California. The seep core was taken at a depth of 973 m in the vicinity of a Beggiatoa bacterial mat and vesicomyid...

McGann, Mary; Conrad, James E.
McGann, M., Conrad, J.E., 2018, Faunal and stable isotopic analyses of benthic foraminifera from the Southeast Seep on Kimki Ridge offshore southern California, USA: Deep Sea Research Part II: Topical Studies in Oceanography, https://doi.org/10.1016/j.dsr2.2018.01.011

Filter Total Items: 1,114
Photo of a coastline where sections of bluff have eroded into a network of small gullies in a dendritic pattern.
January 16, 2020

California coastal erosion

This region of the California coastline is lined with coastal bluffs that have been shaped not only by runoff from rain, but also by wave- and wind-driven erosion. This photo from Pescadero State Beach displays an example of a bluff undergoing erosional processes. Water from the ocean, delivered in waves, can overtop some of these coastal bluffs. As water runs off the

...
Photo of a rugged coastline with bluffs, gentle waves, and rocks jutting out from the sand.
January 16, 2020

California coastline

The U.S. west coast is an area of complex coastal geography. This photograph depicts several examples of geological features along the California coastline that are shaped by varied coastal processes. The gently sloping beach, stark bluffs, and presence of smooth rocks suggests that the coastal processes shaping this coastline are complex.

constructed wetland montage
December 31, 2019

A seasonal wetland engineered to have a deeper and shallow pool

A three year study was conducted in seasonal wetlands to determine if a deep and shallow water pool resulted in a reduction of methylmercury in caged fish and surface water.

map of Indian Wells Valley displaying subbasin boundaries and shaded by recharge in mm/year
December 31, 2019

Natural Recharge (1981 - 2010), Indian Wells Valley, CA

The USGS California Basin Characterization Model (BCM) was used to understand the rate and amounts of natural groundwater recharge in the Indian Wells Valley and to refine historical estimates of groundwater recharge in the valley. Results from this study provide validation of recharge estimates

...
Illustration helps visualize the seafloor character showing canyons and and the rivers that form them.
December 31, 2019

Southern Cascadia topography and bathymetry

Topography and bathymetry of southern Cascadia, which includes southern Oregon and northern California (seafloor depths between 200 and 3000 m are shown in the spectrum color scale from red (shallower) to purple (deeper). The land and continental shelf are shown in grayscale slope shading where darker colors represent steeper slopes. Green lines are locations of known

...
Photograph of a building in the distance with a flagpole in front of it, trees, cars parked, and grassy lawn in the foreground.
December 27, 2019

USGS Menlo Park campus

Building 3 on the USGS Western Region campus in Menlo Park, California.

Two men walk along a path near one building towards another building with trees and a grassy lawn.
December 27, 2019

Building 1 and Credit Union on USGS Menlo Park campus

Building 1 formerly housed many different USGS groups, including the Western Coastal and Marine Geology team, but slowly has been leased out to other federal agencies like the Transportation Security Administration (TSA) and Veterans Affairs (VA). At the right is the Menlo Survey Federal Credit Union.

Thurston Lake and Mount Konocti, Clear Lake Volcanic Field
December 16, 2019

Thurston Lake and Mount Konocti, Clear Lake Volcanic Field

Thurston Lake and Mount Konocti, Clear Lake Volcanic Field, California.

December 11, 2019

Image of the Week - Fires Across California

Fires burned across California in late 2019. Fall is the state's most dangerous season for wildfires, propelled by dry and windy conditions. In recent years however, the fall fire season has been starting earlier and ending later. A series of images from the MODIS sensor on NASA's Terra and Aqua satellites show the Kincade Fire in northern California. This fire started on

Scientist adjusts equipment mounted on tower at the Suisun Marsh in California.
November 22, 2019

Scientist adjusts equipment mounted on tower at the Suisun Marsh

USGS Research Scientist Ellen Goodrich-Stuart adjusts a CH4 (Methane) analyzer mounted on the eddy covariance flux tower at the Rush Ranch site at Suisun Marsh. 

November 21, 2019

PubTalk 11/2019 —Sea-Level Rise, Extreme Water Levels, Coastal Erosion

Title: Sea-Level Rise, Extreme Water Levels, and Coastal Erosion ... How bad could it possibly be?

  • Sea-level rise represents an unprecedented civil engineering challenge.
  • Small amounts of sea-level rise can disproportionately increase the frequency of coastal flooding.
  • One-third to two-thirds of the beaches in Southern California may disappear
November 14, 2019

Wintering Waterfowl at Sacramento National Wildlife Refuge

In this video, you can hear the honks and quacks of geese and ducks ring through the air, as birds fly in every direction above a wetland. This video was captured at Sacramento National Wildlife Refuge in November 2019, not long after geese and ducks began to arrive to spend the winter in the California Central Valley.

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aerial view of road damage after the Ridgecrest, CA earthquake
October 15, 2019

Effects from the two July 2019 Ridgecrest, CA earthquakes were observed in several USGS continuous groundwater-level monitoring sites in California, Nevada, and Arizona.

satellite image of wildfires in Southern California, featuring big smoke plumes extending out from the coast
October 10, 2019

Two new publications underscore the role of wind in destructive California wildfires

Ground view of collapsed building and burned area, Beach and Divisadero Sts., Marina District.
October 7, 2019

Next week, USGS and the nation commemorate the 30th anniversary of one of the most destructive earthquake disasters in U.S. history – the 1989 Loma Prieta earthquake in northern California. The magnitude 6.9 quake struck on October 17 in the southern portion of the San Francisco Bay Area near Santa Cruz and was responsible for the deaths of 63 people and more than 3,500 injuries.

gray-scale map with black dots and colored lines
September 20, 2019

Two of the first questions that come to mind for anyone who just felt an earthquake are, “Will there be another one?” and “Will it be larger?”.

Read Could the M7.1 Ridgecrest, CA Earthquake Sequence Trigger a Large Earthquake Nearby?

6 USGS crew members on a silver metal boat on a river with yellow bridge scaffolding in the background
September 10, 2019

 

Do you get excited about working outdoors? Do you enjoy creative problem solving? Would you like to work part to full time in a challenging position that could lead to incredible career opportunities?

Photograph shows eroding cliff in Isla Vista, California, with parts of houses hanging over edge.
August 14, 2019

USGS researcher quoted in major news stories about the August 2 coastal cliff collapse that killed three people on a beach in Encinitas, California

mud around house and car upside down
August 1, 2019

GSA's news release on the recent USGS-authored publication from the Landslide Hazards Program: Inundation, flow dynamics, and damage in the 9 January 2018 Montecito debris-flow event, California, USA: Opportunities and challenges for post-wildfire risk assessment.

A forested mountainside with patches of dead trees
July 18, 2019

Dr. Nate Stephenson says the rules are changing for Sierra Nevada trees

Screenshot Location of Coso volcanic field
July 10, 2019

The seismic activity that started on the evening of July 5 at the southern margin of Coso Volcanic Field in Inyo County, California continues at a rate of about 600 M1.0 or greater earthquakes per day.

Screenshot Location of Coso volcanic field
July 6, 2019

An earthquake swarm started on the evening of July 5 at the southern margin of Coso Volcanic Field in Inyo County, California.

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