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California

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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.

News

Date published: October 7, 2019

USGS ShakeAlert Earthquake Early Warning System

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.

Date published: September 20, 2019

New Earthquake Science for Everyone Web Article

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?

Date published: September 10, 2019

The CAWSC is Hiring a Hydrologic Field Assistant!

 

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?

Filter Total Items: 353
Topobathymetric elevation model of San Francisco Bay Area, California
Date Published: October 14, 2019
Status: Completed

Topobathymetric Elevation Model of San Francisco Bay Area, California

Accurate, high-resolution elevation information is vital to understanding the natural hazards that can impact the highly populated San Francisco Bay area, such as sea-level rise, winter storms, cliff erosion, and other coastal hazards. The San Francisco Bay estuary three-dimensional (3D) topobathymetric digital elevation model (TBDEM) was developed in collaboration between ...

Two panels showing California map and red line for rupture of fault
Date Published: October 8, 2019
Status: Completed

Earthquake Early Warning – Fine-Tuning for Best Alerts

The goal of an earthquake early warning (EEW) system is to provide an alert to people and automatic systems after an earthquake begins but before the shaking reaches their location. As the USGS and its partners are developing an EEW system, called ShakeAlert®, for the West Coast, the benefits, costs, capabilities, and limitations are being investigated. Two recent studies explored the...

An ad for an upcoming seminar with the title at top, image in middle, and speaker name and information at bottom.
Date Published: October 8, 2019
Status: Active

Science Seminar Series

Upcoming public seminars at the Pacific Coastal and Marine Science Center in Santa Cruz, California will be listed here. Also check out a list of our past seminars.

Map showing regional faults and Coso field near Ridgecrest
Date Published: September 30, 2019
Status: Completed

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

Release Date: SEPTEMBER 30, 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?”.

Coastal flowers in foreground up on a beach bluff above flat beach with waves gently lapping, sky is cloudy in the distance.
Date Published: September 19, 2019
Status: Active

Using Video Imagery to Study Coastal Change: Sunset State Beach

Two video cameras overlook the coast at Sunset State Beach in Watsonville, California. Camera 1 looks northwest while Camera 2 looks north. The cameras are part of the Remote Sensing Coastal Change project.

USGS
Date Published: August 26, 2019
Status: Completed

Loma Prieta Earthquake Professional Papers

The four Loma Prieta Earthquake Professional Papers, which were published as multiple chapters, comprehensively document the magnitude 6.9 earthquake in California that shook the San Francisco and Monterey Bay regions on October 17, 1989. They contain almost 3000 pages written by 401 investigators of the earthquake. The investigations were funded by a special Congressional appropriation to the...

map
Date Published: August 21, 2019
Status: Active

Directions

Information to help you plan your visit to the Earthquake Science Center.

Fort Tejon Earthquake
Date Published: August 5, 2019
Status: Completed

The Great M7.9 1857 Fort Tejon Earthquake

The Last "Big One"

Image: Damaged Building
Date Published: August 5, 2019
Status: Completed

M6.9 October 17, 1989 Loma Prieta Earthquake

On October 17, 1989, at 5:04:15 p.m. (PDT), a magnitude 6.9 earthquake severely shook the San Francisco and Monterey Bay regions. The epicenter was located near Loma Prieta peak in the Santa Cruz Mountains, approximately 14 km (9 mi) northeast of Santa Cruz and 96 km (60 mi) south-southeast of San Francisco.

Mapped Faults and Seismicity- South Napa
Date Published: August 5, 2019
Status: Completed

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

  

Map of a western coastline with stretches of the coast labeled to identify data set regions.
Date Published: July 29, 2019
Status: Active

CoSMoS 3.1: Central California

CoSMoS v3.1 for central California shows projections for future climate scenarios (sea-level rise and storms)

Fish on seafloor, Offshore Northern California
Date Published: July 29, 2019
Status: Active

California Seafloor Mapping Program

The California Seafloor Mapping Program (CSMP) is a cooperative program to create a comprehensive coastal/marine geologic and habitat base map series for all of California's State waters. The California Ocean Protection Council (COPC) authorized funds to establish the CSMP in 2007 (...

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USGS
October 4, 2019

This data release documents 155 sets of dissolved noble gas analyses (neon, argon, krypton, xenon) and 153 modeled recharge temperatures for groundwater sampled from domestic water supply wells and springs throughout the northern Sierra Nevada foothills as part of the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment (GAMA) Program in 2015-2017.

USGS
October 1, 2019

Beginning in November of 2015, a project was undertaken to reanalyze approximately 60,000 archived sample splits collected as part of the National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) project from selected areas in Arizona, California, Idaho, Montana, Nevada, New Mexico, and Utah. A small amount (approximately 0.25 g) of sieved -75 micron s

Map of a western coastline with stretches of the coast labeled to identify data set regions.
August 14, 2019

This dataset contains spatial projections of coastal cliff retreat (and associated uncertainty) for future scenarios of sea-level rise (SLR) in Central California. Present-day cliff-edge positions used as the baseline for projections are also included. Projections were made using numerical models and field observations as part of Coastal Storm Modeling System (CoSMoS). Read metadata carefully.

Long thin colorful shape, a map of a strip of coastline whose colors correspond to varying offshore sediment thicknesses.
July 22, 2019

Each GIS data file is listed with a brief description, a small image, and links to the metadata files and the downloadable data files. The data were compiled in ArcMap. Raster data layers are registered TIFF images and are in the UTM Zone 10 coordinate system. Line features are in shapefile format and are projected in UTM Zone 10 coordinates.

A series of dots with capital letters near them and words beneath.
July 1, 2019

Our Coast, Our Future (OCOF) is a collaborative, user-driven project focused on providing California coastal resource managers and planners locally relevant, online maps and tools to help understand, visualize, and anticipate vulnerabilities to sea level rise and storms.

map of USGS installed wells in San Diego County, CA
May 16, 2019

Summary tables of data for USGS installed wells in San Diego County, CA.  Included are links to data sets, including well construction, geophysical logs, lithologic logs, groundwater levels, water quality, and streamgages.

tablet showing data
April 26, 2019

The annual review by USGS personnel of furnished records is designed to ensure that furnished records are collected in accordance with USGS standards. Furnished records are provided to the USGS by Federal Energy Regulatory Commission (FERC) licensees and other cooperating agencies as a method for reviewing and quality assuring their records so that the data are collected using methods that result

Graphic illustrating location of Land Change Monitoring, Assessment, and Projection sample data
March 28, 2019

USGS LCMAP is the foundation for an integrated land change science framework. This new generation of land change and land cover data are provided to the science community as a suite of products. The products are developed from 30-m Landsat TM, ETM+, and OLI for the years 1985 to 2017. The provisional product suite includes five land cover products and five spectral change products.

Mpa shows areas along the California coast where coastal storm modeling system implementations are completed
March 26, 2019

CoSMoS makes detailed predictions over large geographic scales of storm-induced coastal flooding and erosion for both current and future SLR scenarios, as well as long-term shoreline change and cliff retreat. Several versions of CoSMoS have been implemented for areas of the California coast, including Southern California, Central California, and San Francisco Bay.

3D flyover view of Mud Creek slide
March 18, 2019

This data release contains structure-from-motion (SfM) point-cloud data from aerial surveys conducted over the Mud Creek landslide on Big Sur from 1967-2018. Data sources include scanned aerial photographs, digital images collected from fixed-wing aircraft, and digital images collected from multirotor UAS.

NWIS Mapper screenshot
March 5, 2019

The NWIS mapper provides access to over 1.5 million sites contained in the USGS National Water Information System (NWIS), including sites where current and historical surface-water, groundwater, springs, and atmospheric data has been collected. Users can search by site type, data type, site number, or place.

Filter Total Items: 27
map of California shaded by GAMA deep aquifer study units
June 18, 2019

The GAMA program is a comprehensive statewide assessment designed to help better understand and identify risks to groundwater resources. Groundwater is sampled at many locations across California in order to characterize its constituents and identify trends in groundwater quality. The results of these tests provide information for water agencies to address a variety of water resource issues.

map of California shaded by GAMA shallow aquifer study units
June 18, 2019

n 2012, the Groundwater Ambient Monitoring & Assessment Priority Basin Project (GAMA-PBP) began water-quality assessments of shallow aquifers, which are typically used for private domestic and small system drinking-water supplies. GAMA-PBP is designed to identify where and to what extent water quality of groundwater aquifers meets benchmarks that have been established for drinking water.

maps of the 5 coastal drainage basins in San Diego County
May 16, 2019

Coastal Basins of San Diego County, California, and Northern Baja California, Mexico.  Local features include the San Dieguito River Basin, San Diego River Basin, Sweetwater River Basin, and Otay River Basin.  Maps also display locations of groundwater-monitoring sites. 

Application to explore US Oil and Gas Assessments
March 19, 2019

This map shows the provinces assessed by the USGS for undiscovered oil and gas resources. 

Screenshot of the Borrego Valley groundwater quality data map
January 30, 2019

The quality of groundwater in the Borrego Valley is a concern because it is the sole source of water for agricultural, recreational, and public supply. Explore this interactive water-quality data map for detailed information and to download data.

screenshot of interactive data map displaying  USGS wells in the San Antonio Creek groundwater basin
December 18, 2018

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.

screenshot of interactive map displaying groundwater, water quality, streamgage, and microgravity sites
December 10, 2018

The Lower Colorado Monitoring Network is a series of groundwater-level and water-quality wells, as well as streamgages and micro-gravity sites. This interactive map displays the sites and provides links to the most current data.

Map of California with areas of subsidence shaded by cause
December 7, 2018

In California, land subsidence—mostly from groundwater pumping—was first documented by the USGS in the early 20th century. Completion of State and Federal water projects that bring water from California's wet north to its dry south allowed some groundwater aquifers to recover, and subsidence decreased in these areas. Subsidence continues today, sometimes at high rates of more than 1 foot/year.

screenshot of the user interface
November 13, 2018

This interactive webmap plots water-quality data from domestic and public-supply wells sampled by the USGS for the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project (GAMA-PBP), and allows users to download datasets. The GAMA-PBP is a cooperative program between the California State Water Resources Control Board and the U.S. Geological Survey. 

screenshot of an interactive map of groundwater data in the Mojave region.  Well sites and water-level contours are displayed.
November 7, 2018

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 1994 to the present.

Map displaying areas in California where the USGS has built groundwater models
August 30, 2018

The USGS models shown on this site are in the public domain, and are freely available. They are based on MODFLOW and other public-domain USGS software. Links to publications and web resources associated with each model are shown in the table next to the model map. The associated model files for some of these models are currently available via download.

Thumbnail image of the cover of USGS Fact Sheet 2016-3020
April 16, 2018

Using information from recent earthquakes, improved mapping of active faults, and a new model for estimating earthquake probabilities, the 2014 Working Group on California Earthquake Probabilities updated the 30-year earthquake forecast for California. They concluded that there is a 72 percent probability (or likelihood) of at least one earthquake of magnitude 6.7 or greater striking somewhere in

Filter Total Items: 310
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Year Published: 2019

Sediment and organic carbon transport and deposition driven by internal tides along Monterey Canyon, offshore California

Submarine canyons provide globally important conduits for sediment and organic carbon transport into the deep-sea. Using a novel dataset from Monterey Canyon, offshore central California, that includes an extensive array of water column sampling devices, we address how fine-grained sediment and organic carbon are transported, mixed, fractionated,...

Maier, Katherine L.; Rosenberger, Kurt J.; Paull, Charles K.; Gwiazda, Roberto; Gales, Jenny; Lorenson, Thomas; Barry, James P.; Talling, Peter J.; McGann, Mary; Xu, Jingping; Lundsten, Eve M.; Anderson, Krystle; Litvin, Steven; Parsons, Daniel; Clare, Michael; Simmons, Stephen; Sumner, Esther J; Cartigny, Matthieu J.B.

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Year Published: 2019

Santa Rosa's past and future earthquakes

Santa Rosa is no stranger to earthquakes. This northern California city was damaged several times in the late 19th and early 20th centuries by shaking from earthquakes, culminating in the devastating earthquake of 1906, whose rupture passed 20 miles to the west of the city on the San Andreas Fault. Then in 1969, Santa Rosa was again strongly...

Hecker, Suzanne; McPhee, Darcy K.; Langenheim, Victoria E.; Watt, Janet T.
Hecker, S., McPhee, D.K., Langenheim, V.E., and Watt, J.T., 2019, Santa Rosa's past and future earthquakes: U.S. Geological Survey Fact Sheet 2019–3035, 4 p., https://doi.org/10.3133/fs20193035.

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Year Published: 2019

Offshore shallow structure and sediment distribution, Punta Gorda to Point Arena, Northern California

This publication consists of two map sheets that display shallow geologic structure, along with sediment distribution and thickness, for an approximately 150-km-long offshore section of the northern California coast between Punta Gorda and Point Arena. Each map sheet includes three maps at scales of either 1:100,000 or 1:200,000, and together the...

Beeson, Jeffrey W.; Johnson, Samuel Y.
Beeson, J.W., and Johnson, S.Y., 2019, Offshore shallow structure and sediment distribution, Punta Gorda to Point Arena, northern California: U.S. Geological Survey Open-File Report 2019–1072, 2 sheets, scales 1:100,000 and 1:200,000, https://doi.org/10.3133/ofr20191072.

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Year Published: 2019

Airborne radiometric maps of Mountain Pass, California

Geophysical 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 encompasses Mountain Pass, host to one of the world’s largest rare earth element carbonatite deposits. The...

Ponce, David A.; Ponce, David A.; Denton, Kevin M.
Ponce, D.A., and Denton, K.M. (D.A. Ponce, ed.), 2019, Airborne radiometric maps of Mountain Pass, California: U.S. Geological Survey Scientific Investigations Map 3412–C, scale 1:62,500, https://doi.org/10.3133/sim3412C.

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Year Published: 2019

Occurrence and sources of radium in groundwater associated with oil fields in the southern San Joaquin Valley, California

Geochemical data from 40 water wells were used to examine the occurrence and sources of radium (Ra) in groundwater associated with three oil fields in California (Fruitvale, Lost Hills, South Belridge). 226Ra+228Ra activities (range=0.010-0.51 Bq/L) exceeded the 0.185 Bq/L drinking-water standard in 18% of the wells (not drinking-water wells)....

McMahon, Peter B.; Avner Vengosh; Davis, Tracy; Landon, Matthew K.; Rebecca L. Tyne; Wright, Michael; Kulongoski, Justin T.; Hunt, Andrew G.; Peter H. Barry; A.J. Kondash; Z. Wang; Christopher J. Ballentine
McMahon, P.B., A. Vengosh, T.A. Davis, M.K. Landon, R.L. Tyne, M.T. Wright, J.T. Kulongoski, A.G. Hunt, P.H. Barry, A.J. Kondash, Z. Wang, C.J. Ballentine, 2019. Occurrence and sources of radium in groundwater associated with oil fields in the southern San Joaquin Valley, California. Environmental Science & Technology, 53, 9398-9406.

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Year Published: 2019

Preliminary report on engineering and geological effects of the July 2019 Ridgecrest earthquake sequence

The Ridgecrest Earthquake sequence included a foreshock event on July 4 2019 (M6.4) and a M7.1 mainshock event on July 5 2019. These events occurred in the Eastern California Shear Zone, near Indian Wells Valley, south of China Lake and west of Searles Valley. GEER has partnered with several organizations to collect perishable data and document...

Stewart, Jonathan P.; Brandenberg, Scott J; Wang, Pengfei; Nweke, Chukwuebuka C; Hudson, Kenneth; Mazzoni, Silvia; Bozorgnia, Yousef; Hudnut, Kenneth W.; Davis, Craig A.; Ahdi, Sean K; Zareian, Farzin; Fayaz, Jawad; Koehler, Richard D; Chupik, Colin; Pierce, Ian; Williams, Alana; Akciz, Sinan; Hudson, Martin B; Kishida, Tadahiro; Brooks, Benjamin A.; Gold, Ryan D.; Ponti, Daniel J.; Scharer, Katherine; McPhillips, Devin; Duross, Christopher; Ericksen, Todd; Hernandez, Janis .; Patton, Jay; Olson, Brian; Dawson, Timothy E.; Treiman, Jerome; Blake, Kelly; Buchhuber, Jeffrey; Madugo, Chris L M; Sun, Joseph; Donnellan, Andrea; Lyzenga, Greg; Conway, Erik
Stewart, J.P. (ed.), Brandenberg, S.J., Wang, Pengfei, N., Chukwuebuka C., Hudson, K., Mazzoni, S., Bozorgnia, Y., Hudnut, K.W., Davis, C.A., Ahdi, S.K., Zareian, F., Fayaz, J., Koehler, R.D., Chupik, C., Pierce, I., Williams, A., Akciz, S., Hudson, M.B., Kishida, T., Brooks, B.A., Gold, R.D., Ponti, D.J., Scharer, K.M., McPhillips, D.F., Ericksen, T.., Hernandez, J., Patton, J., Olson, B., Dawson, T., Treiman, J., Duross, C.B., Blake, K., Buchhuber, J., Madugo, C., Sun, J., Donnellan, A., Lyzenga, G., and Conway, E., 2019, Preliminary report on engineering and geological effects of the July 2019 Ridgecrest Earthquake sequence: Geotechnical Extreme Event Reconnaissance Association Report GEER-064, https://doi.org/10.18118/G6H66K.

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Year Published: 2019

Offshore shallow structure and sediment distribution, Point Sur to Point Arguello, central California

This publication consists of three map sheets that display shallow geologic structure, along with sediment distribution and thickness, for an about 225-km-long offshore section of the central California coast between Point Sur and Point Arguello. Each map sheet includes three maps, at scales of either 1:150,000 or 1:200,000, as well as a set of...

Johnson, Samuel Y.; Hartwell, Stephen R.; Watt, Janet T.; Beeson, Jeffrey W.; Dartnell, Peter
Johnson, S.Y., Hartwell, S.R., Watt, J.T., Beeson, J.W., and Dartnell, P., 2019, Offshore shallow structure and sediment distribution, Point Sur to Point Arguello, central California: U.S. Geological Survey Open-File Report 2018–1158, 3 sheets, scales 1:150,000 and 1:200,000, https://doi.org/10.3133/ofr20181158.

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Year Published: 2019

Widespread initiation, reactivation, and acceleration of landslides in the northern California Coast Ranges due to extreme rainfall

Episodically to continuously active slow-moving landslides are driven by precipitation. Climate change, which is altering both the frequency and magnitude of precipitation world21 wide, is therefore predicted to have a major impact on landslides. Here we examine the behavior of hundreds of slow-moving landslides in northern California in...

Handwerger, Alexander L.; Fielding, Eric J.; Huang, Mong-Han; Bennett, Georgina L.; Liang, Cunren; Schulz, William

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Year Published: 2019

Event detection performance of the PLUM earthquake early warning algorithm in southern California

We test the Japanese ground‐motion‐based earthquake early warning (EEW) algorithm, propagation of local undamped motion (PLUM), in southern California with application to the U.S. ShakeAlert system. In late 2018, ShakeAlert began limited public alerting in Los Angeles to areas of expected modified Mercalli intensity (⁠IMMI⁠) 4.0+ for magnitude 5.0...

Cochran, Elizabeth S.; Bunn, Julian; Minson, Sarah E.; Baltay, Annemarie S.; Kilb, Deborah L.; Kodera, Y.; Hoshiba, Mitsuyuki

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Year Published: 2019

An evaluation of debris-flow runout model accuracy and complexity in Montecito, CA: Towards a framework for regional inundation-hazard forecasting

Numerous debris-flow inundation models have been applied retroactively to noteworthy events around the world. While such studies can be useful in identifying controlling factors, calibrating model parameters, and assessing future hazards in specific study areas, model parameters tailored to individual events can be difficult to apply regionally....

Bessette-Kirton, Erin; Kean, Jason W.; Coe, Jeffrey A.; Rengers, Francis K.; Staley, Dennis M.
Bessette-Kirton, E.K., Kean, J.W., Coe, J.A., Rengers, F.K., Staley, D.M., 2019, An evaluation of debris-flow runout model accuracy and complexity in Montecito, California: Towards a framework for regional inundation-hazard forecasting, in Kean, J.W., Coe, J.A., Santi, P.M., and Guillen, B.K., eds., Debris-Flow Hazards Mitigation: Mechanics, Monitoring, Modeling, and Assessment, Proceedings of the 7th International Conference on Debris Flow Hazards Mitigation, Golden, Colorado p. 257-264.

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Year Published: 2019

Taking the pulse of debris flows: Extracting debris-flow dynamics from good vibrations in southern California and central Colorado

The destructive nature of debris flows makes it difficult to quantify flow dynamics with direct instrumentation. For this reason, seismic sensors placed safely away from the flow path are often used to identify the timing and speed of debris flows. While seismic sensors have proven to be a valuable tool for event detection and early warning, their...

Michel, A.; Kean, Jason W.; Smith, Joel B.; Allstadt, Kate E.; Coe, Jeffrey A.
Michel, A., Kean, J.W., Smith, J.B., Allstadt, K., and Coe, J.A. (2019), Taking the pulse of debris flows: extracting debris-flow dynamics from good vibrations in southern California and central Colorado, in Debris-Flow Hazards Mitigation: Mechanics, Monitoring, Modeling, and Assessment, edited by Kean, J.W., Coe, J.A., Santi, P.M., and Guillen, B.K., Association of Environmental and Engineering Geologists, Special Publication #28, p. 154-161.

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Year Published: 2019

Inundation, flow dynamics, and damage in the 9 January 2018 Montecito Debris-Flow Event, California, USA: Opportunities and challenges for post-wildfire risk assessment

Shortly before the beginning of the winter rainy season, one of the largest fires in California history (Thomas Fire) substantially increased the susceptibility of steep slopes in Santa Barbara and Ventura Counties to debris flows. On January 9, 2018, before the fire was fully contained, an intense burst of rain fell on the portion of the burn...

Kean, Jason W.; Staley, Dennis M.; Lancaster, Jeremy T.; Rengers, Francis K.; Swanson, Brian J.; Coe, Jeffrey A.; Hernandez, Janis .; Sigman, Aaron; Allstadt, Kate E.; Lindsay, Donald N.

Filter Total Items: 6
multicolored map of Ocean Shores, Washington
April 13, 2017

The Pedestrian Evacuation Analyst is an ArcGIS extension that estimates how long it would take for someone to travel on foot out of a hazardous area that was threatened by a sudden event such as a tsunami, flash flood, or volcanic lahar. It takes into account the elevation changes and the different types of landcover that a person would encounter along the way.

schematic one water hydrologic model
November 5, 2014

The One-Water Hydrologic Flow Model (MF-OWHM) (Hanson and others, 2014) is a MODFLOW-based integrated hydrologic flow model (IHM) that is the most complete version, to date, of the MODFLOW family of hydrologic simulators needed for the analysis of a broad range of conjunctive-use issues. 

MODPATH-OBS_distance-direction-observations_USGS-hydrologic-modelling
April 26, 2013

The MODPATH-OBS (Hanson and others, 2013) computer program is designed to calculate simulated equivalents for observations related to advective groundwater transport that can be represented in a quantitative way by using simulated particle-tracking data. 

map of the central valley with the CVHM grid cells overlaid, and a cross section of the subsurface
August 27, 2012

The Central Valley Hydrologic Model (CVHM) is an extensive, detailed three-dimensional (3D) computer model of the hydrologic system of the Central Valley (Faunt, 2009). The Central Valley Hydrologic Model (CVHM) simultaneously accounts for changing water supply and demand across the landscape, and simulates surface water and groundwater flow across the entire Central Valley.

subsurface grid showing relationship surface water and groundwater recharge
June 19, 2008

A Grid-Based, Distributed-Parameter Watershed Model to Estimate Net Infiltration Below the Root Zone

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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

...
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

...
October 10, 2019

October 17, 1989 (Part 4)

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 4 (of

...
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.
 

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

...
Quratulain Ahmed preserving samples in fume hood
September 9, 2019

Quratulain Ahmed preserving samples in fume hood

Quratulain Ahmed preserving samples in fume hood

Sydney Berrios running samples on Aqualog
September 8, 2019

Sydney Berrios running samples on Aqualog

Sydney Berrios running samples on Aqualog

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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.

Giant gartersnake (Thamnophis gigas)
June 24, 2019

SACRAMENTO – A new study shows how giant gartersnakes use Central Valley rice fields

USGS Scientists taking sediment core at Six Gill Slough restored marsh.
June 6, 2019

California Water Science Center Research Hydrologist Dr. Judith Drexler and others have published an article in the journal Restoration Ecology, observing the progress of a restored salt marsh in southern Puget Sound, Washington.

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