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: 377
Date published: August 5, 2019
Status: Completed

M6.0 South Napa, California Earthquake – August 24, 2014

  

Date published: July 26, 2019
Status: Active

CoSMoS 3.0: Southern California

CoSMoS 3.0 for southern California provides detailed predictions of coastal flooding due to both future sea-level rise and storms, integrated with predictions of long-term coastal evolution (beach changes and coastal cliff retreat) for the Southern California region, from Point Conception (Santa Barbara County) to Imperial Beach (San Diego County).

Date published: July 26, 2019
Status: Active

CoSMoS 2.1: San Francisco Bay

With primary support from the National Estuarine Research Reserve (NERR), CoSMoS is set-up within the San Francisco Bay as part of Our Coast, Our Future (OCOF).

Date published: July 26, 2019
Status: Active

CoSMoS 2.0: North-central California (outer coast)

Our Coast, Our Future (OCOF) is a collaborative, user-driven project providing science-based decision-support tools to help coastal planners and emergency responders understand, visualize, and anticipate local impacts from sea-level rise (SLR) and storms...

Date published: July 18, 2019
Status: Active

Western Basin & Range - Eastern California Shear Zone

 

The Eastern California Shear Zone (ECSZ) Mapping project, funded by the National Cooperative Geologic Mapping Program, combines surficial and bedrock geologic mapping, geophysical surveys, and high-resolution topographic data analysis with neotectonic, geomorphic, structural, volcanic, and geochronologic studies to better understand the tectonic framework and landscape...

Contacts: Andrew Cyr
Date published: July 15, 2019
Status: Active

Dynamic coastlines along the western U.S.

The west coast of the United States is extremely complex and changeable because of tectonic activity, mountain building, and land subsidence. These active environments pose a major challenge for accurately assessing climate change impacts, since models were historically developed for more passive sandy coasts.

Date published: July 11, 2019
Status: Completed

Comparing Shaking Intensity from Two Bay Area Earthquakes

The 1989 Loma Prieta earthquake caused billions of dollars in damage and claimed more than sixty lives. But was it "the big one"? Take a look at the comparison between the images below for the 1989 Loma Prieta and the 1906 San Francisco earthquakes, and decide for yourself.

The colors on the map indicate Modified Mercalli Shaking Intensity (MMI) at each point, which is usually (but not...

Date published: June 28, 2019
Status: Completed

Paleoseismology and the Hayward Fault

A large, widely damaging earthquake will occur on the Hayward fault in the future. That much we know.
What we don't know is when.

Date published: June 26, 2019
Status: Active

Information by Region- California

  

Date published: June 20, 2019
Status: Active

Aerial Seabird and Marine Mammal Surveys

The Seabird Studies Team at the USGS Western Ecological Research Center is conducting aerial photographic surveys of the ocean off central and southern California to create comprehensive maps of seabird and marine mammal distributions. The project is supported by the Bureau of Ocean Energy Management and will inform planning in advance of potential offshore wind energy development along the...

Date published: June 17, 2019
Status: Active

California Seafloor and Coastal Mapping Program

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

Date published: June 17, 2019
Status: Active

The Coastal Storm Modeling System

The Coastal Storm Modeling System (CoSMoS) provides emergency responders and coastal planners with critical storm-hazard information such as flood extent, flood depth, duration of flooding, wave height, and currents that can be used to increase public safety, mitigate physical damages, and more effectively manage complex coastal settings....

Filter Total Items: 501
Date published: April 23, 2020

Domestic Wells in the United States

Domestic wells provide drinking water supply for approximately 40 million people in the United States. Knowing the location of these wells, and the populations they serve, is important for identifying heavily used aquifers, locations susceptible to contamination, and populations potentially impacted by poor-quality groundwater. 

Date published: April 23, 2020

Boundaries and Grid Cells of the Redding-Red Bluff Shallow Aquifer Study Unit, 2018-2019

The U.S. Geological Survey collected groundwater samples from 50 wells used for domestic and small-system drinking water supplies in Shasta and Tehama Counties, California in 2018-2019. The wells were sampled for the Redding-Red Bluff Shallow Aquifer study unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin P...

Date published: April 23, 2020

Groundwater-Quality Data in the Redding-Red Bluff Shallow Aquifer Study Unit, 2018-2019: Tables

The U.S. Geological Survey collected groundwater samples from 50 wells used for domestic and small system drinking water supplies in Shasta and Tehama Counties, California in 2018-2019. The wells were sampled for the Redding-Red Bluff Shallow Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin P...

Date published: April 23, 2020

2019 Santa Ana Reach Location Information

This dataset includes the 2019 latitude and longitude information for habitat and fish reach locations on the Santa Ana River.

Date published: April 23, 2020

SAR 2018 San Gabriel Reach Fish Data

This dataset contains the 2018 reach fish data for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the San Gabriel River.

Date published: April 23, 2020

SAR 2018 SAR and SGR_Latitude_Longitude Data

This dataset includes the 2018 latitude and longitude information for habitat and fish reach locations on the Santa Ana and San Gabriel Rivers.

Date published: April 23, 2020

SAR 2018 Santa Ana River Reach Fish Data

This dataset contains the 2018 reach fish data for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the Santa Ana River, California.

Date published: April 23, 2020

SAR 2019 Santa Ana River Reach Fish Data

This dataset contains the 2019 reach fish data for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the Santa Ana River, California.

Date published: April 23, 2020

2018 San Gabriel Reach Habitat Data

This dataset includes reach habitat data for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the San Gabriel River.

Date published: April 23, 2020

Groundwater-quality data in the Redding-Red Bluff Shallow Aquifer Study Unit, 2018-2019: Results from the California GAMA Priority Basin Project

The U.S. Geological Survey collected groundwater samples from 50 wells used for domestic and small system drinking water supplies in Shasta and Tehama Counties, California in 2018-2019. The wells were sampled for the Redding-Red Bluff Shallow Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin P...

Date published: April 23, 2020

2019 Santa Ana Reach Habitat Data

This dataset includes 2019 reach habitat data for the Santa Ana Sucker (Catostomus santaanae) and the Arroyo Chub (Gila orcutti) in the Santa Ana River.

Date published: April 16, 2020

Blank results for trace-element data collected for the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project, October 2009–October 2018

Groundwater samples have been collected in California as part of statewide investigations of groundwater quality conducted by the U.S. Geological Survey for the Groundwater Ambient Monitoring and Assessment (GAMA) Priority Basin Project (PBP). Quality-control samples are routinely collected as part of the GAMA-PBP quality assurance plan. Olsen and others (2010) and Davis and others %2

Filter Total Items: 351
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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

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

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Year Published: 2018

Effects of the proposed California WaterFix North Delta Diversion on survival of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento-San Joaquin River Delta, northern California

The California Department of Water Resources and Bureau of Reclamation propose new water intake facilities on the Sacramento River in northern California that would convey some of the water for export to areas south of the Sacramento-San Joaquin River Delta (hereinafter referred to as the Delta) through tunnels rather than through the Delta. The...

Perry, Russell W.; Pope, Adam C.
Perry, R.W., and Pope, A.C., 2018, Effects of the proposed California WaterFix North Delta Diversion on survival of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento-San Joaquin River Delta, northern California: U.S. Geological Survey Open-File Report 2018-1078, 94 p. plus appendixes, https://doi.org/10.3133/ofr20181078.

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Year Published: 2018

Estimating fluvial discharges coincident with 21st century coastal storms modeled with CoSMoS

On the open coast, flooding is largely driven by tides, storm surge, waves, and in areas near coastal inlets, the magnitude and co-occurrence of high fluvial discharges. Statistical methods are typically used to estimate the individual probability of coastal storm and fluvial discharge occurrences for use in sophisticated flood hazard models. A...

Erikson, Li H.; O'Neill, Andrea C.; Barnard, Patrick L.
Erikson, L.H., O’Neill, A.C., and Barnard, P.L., 2018. Estimating fluvial discharges coincident with 21st century coastal storms modeled with CoSMoS. In: Shim, J.S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). J. of Coastal Research, Special Issue No. 85, pp. 1–5. Coconut Creek (Florida), ISSN 0749-0208.

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Year Published: 2018

Juvenile Lost River and shortnose sucker year class strength, survival, and growth in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California—2016 Monitoring Report

Executive SummaryThe largest populations of federally endangered Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) exist in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California. Upper Klamath Lake populations are decreasing because adult mortality, which is relatively low, is not being balanced by...

Burdick, Summer M.; Ostberg, Carl O.; Hoy, Marshal S.
Burdick, S.M., Ostberg, C.O., and Hoy, M.S., 2018, Juvenile Lost River and shortnose sucker year class strength, survival, and growth in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California—2016 Monitoring Report: U.S. Geological Survey Open-File Report 2018–1066, 43 p., https://doi.org/10.3133/ofr20181066.

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Year Published: 2018

Effects of the proposed California WaterFix North Delta Diversion on flow reversals and entrainment of juvenile Chinook salmon (Oncorhynchus tshawytscha) into Georgiana Slough and the Delta Cross Channel, northern California

The California Department of Water Resources and Bureau of Reclamation propose new water intake facilities on the Sacramento River in northern California that would convey some of the water for export to areas south of the Sacramento-San Joaquin River Delta (hereinafter referred to as the Delta) through tunnels rather than through the Delta. The...

Perry, Russell W.; Romine, Jason G.; Pope, Adam C.; Evans, Scott D.
Perry, R.W., Romine, J.G., Pope, A.C., and Evans, S.D., 2018, Effects of the proposed California WaterFix North Delta Diversion on flow reversals and entrainment of juvenile Chinook salmon (Oncorhynchus tshawytscha) into Georgiana Slough and the Delta Cross Channel, northern California: U.S. Geological Survey Open File Report 2018-1028, 46 p., https://doi.org/10.3133/ofr20181028.

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Year Published: 2018

Clayey landslide initiation and acceleration strongly modulated by soil swelling

Largely unknown mechanisms restrain motion of clay-rich, slow-moving landslides that are widespread worldwide and rarely accelerate catastrophically. We studied a clayey, slow-moving landslide typical of thousands in northern California, USA, to decipher hydrologic-mechanical interactions that modulate landslide dynamics. Similar to some other...

Schulz, William; Smith, Joel B.; Wang, Gonghui; Jiang, Yao; Roering, Joshua J.

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Year Published: 2018

Variability in soil-water retention properties and implications for physics-based simulation of landslide early warning criteria

Rainfall-induced shallow landsliding is a persistent hazard to human life and property. Despite the observed connection between infiltration through the unsaturated zone and shallow landslide initiation, there is considerable uncertainty in how estimates of unsaturated soil-water retention properties affect slope stability assessment. This source...

Thomas, Matthew A.; Mirus, Benjamin B.; Collins, Brian D.; Lu, Ning; Godt, Jonathan W.
Thomas MA, Mirus BB, Collins BD, Lu N, and Godt JW (2018) Variability in soil-water retention properties and implications for physics-based simulation of landslide early warning criteria, Landslides. https://doi.org/10.1007/s10346-018-0950-z

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October 10, 2019

PubTalk 10/2019 — Remembering Loma Prieta Earthquake 30 Years Later

Remembering the Loma Prieta Earthquake 30 Years Late: Looking back to see how far we've come.
By: Tom Holzer, David Schwartz, Jessica Murray, and Annemarie Baltay

  • The Loma Prieta earthquake ended decades of seismic tranquility in the Bay Area - Is the earthquake threat in the Bay Area real and imminent?
  • Up to $80 billion in earthquake mitigation
October 10, 2019

October 17, 1989 (Part 1)

On October 17, 1989, at 5:04 pm a magnitude M6.9 earthquake struck near Loma Prieta, California. It was a tragic reminder of the destructive power of earthquakes. However, it was also a watershed moment in seismic research. 30 years later, we revisit the earthquake through the eyes of the scientists who experienced it. And studied it. These are their stories. In Part 1 (of

October 10, 2019

October 17, 1989 (Part 2)

On October 17, 1989, at 5:04 pm a magnitude M6.9 earthquake struck near Loma Prieta, California. It was a tragic reminder of the destructive power of earthquakes. However, it was also a watershed moment in seismic research. 30 years later, we revisit the earthquake through the eyes of the scientists who experienced it. And studied it. These are their stories. In Part 2 (of

October 10, 2019

October 17, 1989 (Part 3)

On October 17, 1989, at 5:04 pm a magnitude M6.9 earthquake struck near Loma Prieta, California. It was a tragic reminder of the destructive power of earthquakes. However, it was also a watershed moment in seismic research. 30 years later, we revisit the earthquake through the eyes of the scientists who experienced it. And studied it. These are their stories. In Part 3 (of

A group of people help guide a yellow instrument, suspended from a cabling system, off a boat and into the ocean.
October 2, 2019

Lowering Chirp from R/V Bold Horizon

The crew of research vessel Bold Horizon with USGS science crew prepare to launch the Chirp sub-bottom profiler off the west coast near northern California and southern Oregon.

Photo looks at the very end of a metal coring device with mud in it, sitting on the deck of a ship in its metal launch.
October 1, 2019

Jumbo piston corer with mud from the seafloor

After recovery, the jumbo piston corer sits on the deck of research vessel Bold Horizon in its launch and recovery system. This muddy collar is removed to reveal the removable length of the core, which sits within a stiff plastic tube inside the metal tube.

A small device sits on a tripod which rests on a square tarp pinned down on a flat area of grass.
September 30, 2019

GPS target

A global positioning system (GPS) sits on a tripod and is used to accurately pinpoint the center of a target that itself is used for photo rectification with aerial photos. 

September 30, 2019

Prototype Earthquake Early Warning System (Interview)

Retired seismologist David Oppenheimer reflects on the first prototype earthquake early warning system used during the 1989 Loma Prieta earthquake. Scientists deployed an analog system to notify first responders of impending earthquake activity as they worked on rescue efforts at the Cypress Viaduct collapse in Oakland, CA.
 

A person on a personal watercraft navigates through waters near a coast with low cliffs and hills way off in background.
September 30, 2019

Santa Barbara survey

Goleta Beach in Santa Barbara experienced an unusual storm and large wave event in the Spring of 2014. Gaviota Pier, seen far off in the background, sustained heavy damage as did the restaurants on the pier and nearby. The USGS conducts seasonal surveys throught the year to see how the beaches are changing through time. Here, a USGS scientist navigates a personal

...
September 26, 2019

PubTalk 09/2019 — Bats in the West

Title: Bats in the West: Discoveries, Questions, and Future Research
By Gabriel A. Reyes, USGS Biologist

  • Learn about bat ecology, diversity, and the role they play in our ecosystem.
  • See how scientists are using a variety of methods including capture, acoustic monitoring, and tracking, to learn more about local bat species.
  • Find out how
person with yellow top and red hardhat
September 11, 2019

Scott Lydeen at Strawberry Peak Seismic Station Tower

USGS technicial Scott Lydeen climbing the tower at the Strawberry Peak seismic station tower, part of the Southern California Seismic Network.

man in the background of a view between clear tubing
September 11, 2019

High-resolution Water Quality Mapping on California's Bay-Delta

Hydrologist Brian Bergamaschi is seen through the USGS California Water Science Center Biogeochemistry Group's underwater water quality mapping manifold. This maze of tygon tubing allows water to be pumped onto a boat while underway, splits the water into multiple flowpaths, and passes the water to various flow-through water quality instruments through a manifold that

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research boat on delta
March 15, 2019

Earlier this month, over 40 scientists from the California Water Science Center attended the 2019 Interagency Ecological Program (IEP) Workshop in Folsom, California. 

Flooding in California
March 13, 2019

New U.S. Geological Survey-led coastal modeling research presents state, federal, and commercial entities with varying storm and sea level-rise scenarios to assist with planning for future infrastructure and mitigation needs along the California coast. 

View of the Mono Lake-Long Valley volcanic region
March 7, 2019

The Mono Craters, a line of volcanic domes and craters south of Mono Lake in eastern California, represent the youngest rhyolitic volcanoes in the western United States.

Application window with parameter settings down the left, map showing results of parameter settings, and legend on right.
March 1, 2019

Oceanographer Juliette Finzi Hart of the USGS Pacific Coastal and Marine Science Center was invited by the California Department of Transportation (Caltrans) to provide an overview of the USGS Coastal Storm Modeling System (CoSMoS) at the 2019 California Transportation Planning Conference in San Diego.

Three illustrations to show location of a study site, each labeled with distinctive areas, where there are high coastal cliffs.
March 1, 2019

On Monday, February 25, 2019, research geologist Jonathan Warrick of the USGS Pacific Coastal and Marine Science Center spoke with ABC7 News about a February 22 landslide that injured one woman and buried another at San Francisco’s Fort Funston beach.

Infographic about the 2019 report "California's Exposure to Volcanic Hazards"
February 25, 2019

The potential for damaging earthquakes, landslides, floods, tsunamis, and wildfires is widely recognized in California.

USGS
February 14, 2019

Great Lakes Phragmites programs served as a case study for the Delta Stewardship Council

USGS Director Jim Reilly being given a tour of the CalVO Ops room by Emily Montgomery-Brown
February 7, 2019

During a tour of western USGS offices, Director James F. Reilly II visited the CalVO offices and operations center in Menlo Park, CA.

A picture of a river in the neonicotionoid insecticide study
January 14, 2019

This month California Water Science Center Scientist Dr. Michelle Hladik and others published an article on water treatment processes and their effects on neonicotinoid pesticides and the potential health threats they pose.

Underwater photo of a rocky outcrop with many multicolored corals growing on it.
November 29, 2018

Researchers from the USGS Pacific Coastal and Marine Science Center (PCMSC) participated in a research cruise to survey deep-water coral, sponge, and fish habitats off U.S. West Coast.

A low-flying helicopter towing a geophysical device collects scientific data for salinity and aquifer mapping.
November 20, 2018

A low-flying helicopter under contract to the U.S. Geological Survey, in cooperation with the California State Water Resources Control Board, has begun collecting and recording geophysical measurements for purpose of groundwater salinity and aquifer mapping.

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