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: 412
Date published: June 11, 2020
Status: Active

PCMSC vessel San Lorenzo

Above, the view through the windshield of San Lorenzo reveals a perfect work day on the Sacramento-San Joaquin Delta near Rio Vista, California.

Date published: June 8, 2020
Status: Active

PCMSC MarFac Team

Meet our team of fieldwork specialists at PCMSC's MarFac

Date published: June 2, 2020
Status: Active

PCMSC vessel Jewell

Above, Jewell is prepared for a day of sampling on Grizzly Bay

Date published: June 2, 2020
Status: Active

PCMSC Marine Facility (MarFac)

Learn about the USGS Pacific Coastal and Marine Science Center Marine Facility, or MarFac

Contacts: Timothy Elfers
Date published: May 29, 2020
Status: Completed

The Blind Zone of Earthquake Early Warning

Residents in California, Oregon, and Washington have been told that earthquake early warning (EEW) is at their doorstep and will alert them to the shaking from an earthquake before it arrives. Some media reports have said there will be “up to a minute of warning”. The problem is, for onshore earthquakes these claims are exaggerated, and under some conditions a warning is not scientifically or...

Date published: May 8, 2020
Status: Active

Nutrient Source Identification in Groundwater and Periphyton Along the Nearshore of Lake Tahoe

High concentrations of phosphorus (P) and nitrogen (N) are responsible for excessive, or nuisance algal blooms in many ecosystems world-wide, and climate change is predicted to exacerbate the problem1,2. Excessive nutrients supplied to the nearshore zone of Lake Tahoe may have significant consequences to ecological communities, water clarity, and water quality. The nearshore zone...

Contacts: Ramon C Naranjo
Date published: May 1, 2020
Status: Active

Offshore Faults along Central and Northern California

From Point Conception to Cape Mendocino, seafloor faults have been, in the past, mapped in varying ways and without enough detail to assess their earthquake potential. To provide this important information, USGS uses advanced technology to image offshore faults that could trigger devastating earthquakes near densely populated areas and a nuclear power plant.

Contacts: Janet Watt
Date published: April 29, 2020
Status: Active

LCMAP Change Stories: Building a Boomtown, Block by Block

The desert outpost of Palm Springs, California and the surrounding Thousand Palms region has experienced explosive population growth over the past four decades, with tract after tract of development filling in previously barren landscapes along Interstate 10.

Date published: April 17, 2020
Status: Active

The Response of Coastal Wetlands to Sea-level Rise: Understanding how Macroscale Drivers Influence Local Processes and Feedbacks

The purpose of this work is to advance our understanding of how coastal wetland responses to sea-level rise (SLR) within the conterminous United States are likely to vary as a function of local, regional, and macroscale drivers, including climate. Based on our interactions with managers and decision makers, as well as our knowledge of the current state of the science, we propose to: (a)...

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...

Filter Total Items: 533
Date published: May 4, 2020

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

This data contains geographic extents of projected coastal flooding, low-lying vulnerable areas, and maximum/minimum flood potential (flood uncertainty) associated with 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-ind

Date published: May 4, 2020

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

This data contains geographic extents of projected coastal flooding, low-lying vulnerable areas, and maximum/minimum flood potential (flood uncertainty) associated with 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-ind

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.

Filter Total Items: 399
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Year Published: 2018

Emigration and transportation stress of juvenile Chinook salmon relative to their reintroduction upriver of Shasta Dam, California, 2017–18

The Bureau of Reclamation supports the Shasta Dam Fish Passage Evaluation (SDFPE; Yip, 2015) program, and in 2016 set out to determine the feasibility of reintroducing winter-run and spring-run Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) to tributaries upstream of Shasta Dam. Ideally, reintroduction strategy includes...

Adams, Noah S.; Liedtke, Theresa L.; Plumb, John M.; Weiland, Lisa K.; Hansen, Amy C.; Evans, Scott D.
Adams, N.S., Liedtke, T.L., Plumb, J.M., Hansen, A.C., Evans, S.D., and Weiland., L.K., 2018, Emigration and transportation stress of juvenile Chinook salmon relative to their reintroduction upriver of Shasta Dam, California, 2017–18: U.S. Geological Survey Open-File Report 2018-1144, 60 p., https://doi.org/10.3133/ofr20181144.

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Year Published: 2018

Reported investments in earthquake mitigation top $73 to $80 billion in the San Francisco Bay Area, California, since the 1989 Loma Prieta earthquake

The purpose of this report is to provide a compilation of structural retrofits and replacements of older buildings and infrastructure in the San Francisco Bay Area that have either been completed since 1989 or that are in progress as of October 2018. For the purposes of this report, all or parts of nine Bay Area counties were included:...

Brocher, Thomas M.; Gefeke, Kerri; Boatwright, John; Knudsen, Keith L.
Brocher, T.M., Gefeke, K., Boatwright, J., and Knudsen, K.L., 2018, Reported investments in earthquake mitigation top \$73 to \$80 billion in the San Francisco Bay Area, California, since the 1989 Loma Prieta earthquake: U.S. Geological Survey Open-File Report 2018–1168, 18 p., https://doi.org/10.3133/ofr20181168.

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Year Published: 2018

Aeromagnetic map of Mountain Pass and vicinity, California and Nevada

Magnetic investigations of Mountain Pass and vicinity were begun as part of an effort to study regional crustal structures as an aid to understanding the geologic framework and mineral resources of the eastern Mojave Desert. The study area, which straddles the state boundary between southeastern California and southern Nevada, encompasses Mountain...

Ponce, David A.; Ponce, David A.; Denton, Kevin M.
Ponce, D.A., and Denton, K.M. (D.A. Ponce, ed.), 2018, Aeromagnetic map of Mountain Pass and vicinity, California and Nevada: U.S. Geological Survey Scientific Investigations Map 3412–B, scale 1:62,500, https://doi.org/10.3133/sim3412B.

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Year Published: 2018

Isostatic gravity map of Mountain Pass and vicinity, California and Nevada

Gravity investigations of Mountain Pass and vicinity were begun as part of an effort to study regional crustal structures as an aid to understanding the geologic framework and mineral resources of the eastern Mojave Desert. The study area, which straddles the state boundary between southeastern California and southern Nevada, encompasses Mountain...

Ponce, David A.; Ponce, David A.; Denton, Kevin M.
Ponce, D.A., and Denton, K.M. (D.A. Ponce, ed.), 2018, Isostatic gravity map of Mountain Pass and vicinity, California and Nevada: U.S. Geological Survey Scientific Investigations Map 3412–A, scale 1:62,500, https://doi.org/10.3133/sim3412A.

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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.

Filter Total Items: 1,077
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.

Flyer with images of sea-level rise with ocean waves
November 6, 2019

2019 November Public Lecture

2019 November Public Lecture Flyer

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

By Sean Vitousek, USGS Research Oceanographer

  • Sea-level rise represents an unprecedented civil engineering challenge.
  • Small amounts of sea-level rise can disproportionately increase the frequency
...
A smiling woman in a hard hat and life jacket gives two-thumbs-up on the deck of a ship standing next to a sediment core tube.
October 31, 2019

Hooray for sediment cores!

Dr. Nora Nieminski is a research geologist and Mendenhall Fellow at the USGS Pacific Coastal and Marine Science Center in Santa Cruz, California. She is pictured here, on board Marine Vessel Bold Horizon, with a piston core sample collected from the southern Cascadia subduction zone offshore of northern California/southern Oregon. The 

...
An instrument rests on the deck of a ship, its cables suspended above it, while a scientist looks on.
October 22, 2019

Chirp rests on the deck of R/V Bold Horizon

This instrument, the Edgetech SB-516 or "chirp", emits acoustic signals that penetrate the sediment on the seafloor. The reflected sound is recorded and is used to create a cross-section image, or profile, of the sub-bottom.

View from up high on a coastal cliff looking down along a beach where a river meets the ocean.
October 17, 2019

Klamath River mouth

A view of the mouth of the Klamath River where it meets the Pacific Ocean in northern California. The river runs from Oregon to California. Four dams along the Klamath are pending removal. USGS is studying coastal watershed response to dam removal, including long-term before-after/control-impact (BACI) studies.

October 17, 2019

Initial Observations of Cypress Structure Collapse, Oakland, CA 1989

Retrospective interview with USGS Geophysicist Susan Hough about the collapse of the Nimitz Freeway (known as the Cypress Structure) in Oakland, CA, during the October 17, 1989 Loma Prieta Earthquake and how the first responders reacted to the event.
 

October 17, 2019

Sight Response and Cypress Structure Collapse, Oakland, CA 1989

Retrospective interview with USGS Geophysicist Susan Hough about her early earthquake work during the 1989 Loma Prieta earthquake. The interview covers how the Cypress Structure collapse in Oakland, CA, served as a site response study for seismic research.
 

Filter Total Items: 965
Deep-sea organisms
October 16, 2019

Keep up to speed with the latest USGS deep-sea research cruise with this seafloor syntax.

ROV control room
October 16, 2019

Keep up to speed with our EXPRESS research cruise with this latest seafloor syntax!

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

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