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: 421
Date published: December 7, 2018
Status: Completed

Sedimentation in the Lower Laguna-Mark West Drainage

The Sonoma County Water Agency (SCWA) and the San Francisco District office of the U.S. Army Corps of Engineers (CORPS) have identified issues associated with sedimentation in the lower Laguna de Santa Rosa and Mark West Creek in Sonoma County. Human activities in the watershed over the last 200 years have accelerated erosion and sediment delivery to the Laguna reducing the water storage...

Date published: December 6, 2018
Status: Active

Subsidence in the Sacramento-San Joaquin Delta

The Sacramento-San Joaquin Delta is part of the San Francisco Estuary, home to a diverse flora and fauna, including several threatened and endangered species, has a large area of prime farmland, and serves as the hub of California's freshwater-delivery system that moves water from the wet north to the dry southern part of the State.

Date published: December 6, 2018
Status: Active

Western Great Basin Oil and Gas Assessments

The U.S. Geological Survey completed the following assessments of undiscovered continuous oil and gas resources of the Western Great Basin Province 5018.

Date published: December 6, 2018
Status: Active

Assessment of environmental impacts of mercury treatability test using suction dredging, South Yuba River

The goals of the BLM suction dredging treatability study are to (1) assess the effectiveness of suction dredging in removing mercury from the environment and (2) assess potential impacts of suction dredging with regard to discharging mercury-contaminated suspended sediment to the aquatic environment.

Contacts: Jacob A Fleck
Date published: December 6, 2018
Status: Completed

Mercury and Dissolved Organic Matter in Delta Wetlands

Between 1860 and 1914, hydraulic mining activities sent more than 800,000,000 cubic yards of mercury-laden sediment into the Delta altering the landscape, water flows, and contributing to the leveeing and reclamation of the Delta's marshes. Transport of mercury from historic mining areas continues today. The sedimentary supply of mercury to the Delta and in Delta sediments (cinnabar,...

Date published: December 4, 2018
Status: Completed

Management Tools For The Hydrologic Model Of Santa Clara Valley, California

Groundwater flow model of the Santa Clara Valley.

Date published: December 4, 2018
Status: Completed

Scoping Study of Los Angeles River-Arroyo Seco Confluence Park

The Mountains Recreation and Conservation Authority (MRCA) is considering plans for developing a new park at the confluence of the Los Angeles River and the Arroyo Seco. These plans include removing channel lining and creating a temporary lake using an inflatable rubber dam. Before implementing the plan, a wide array of scientific and engineering issues must be addressed. The U.S. Geological...

Contacts: Michael T Land
Date published: December 4, 2018
Status: Active

Biogeochemistry of the Critical Zone: Origin and Fate of Organic Matter

Changing temperature, precipitation, and land use intensification has resulted in global soil degradation. The accompanying loss of soil organic matter (SOM) decreases important soil health services. Soil organic matter is a major global pool of carbon; if SOM can be increased, soils can mitigate elevated atmospheric CO2. However, there are major knowledge gaps in SOM persistence....

Date published: December 3, 2018
Status: Active

A Non-Point Source Of Contaminants To The Estuarine Food Web: Mobilized Particles From The Intertidal Zone

The San Francisco Bay and Sacramento-San Joaquin Delta (Bay-Delta) region is a highly urbanized and contaminated estuary with a valuable commercial and recreational fishery (Nichlos et al., 1986; SFEI, 2004). Many fish and birds in the San Francisco Estuary exhibit high levels of contaminants (metals and organic pollutants), which have been shown to affect their behavior and reproductive...

Contacts: Jacob A Fleck
Date published: November 30, 2018
Status: Active

Extensometers and Compaction

Extensometers measure the compaction and expansion of the aquifer system, providing depth-specific data that can help CAWSC scientists better understand the rate, extent, and at what depths in the system subsidence is occurring. 

Contacts: Michelle Sneed
Date published: November 30, 2018
Status: Active

Los Angeles Basin Oil and Gas Assessments

The U.S. Geological Survey completed the following assessments of technically recoverable continuous petroleum resources of the Los Angeles Basin Province 5014.

     

    Date published: November 30, 2018
    Status: Active

    Santa Maria Basin Oil and Gas Assessments

    The U.S. Geological Survey completed the following assessments of the Santa Maria Basin Province 5012.

    Filter Total Items: 588
    Date published: March 18, 2019

    Topographic point clouds for the Mud Creek landslide, Big Sur, California from structure-from-motion photogrammetry from aerial photographs

    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.

    Date published: February 21, 2019

    Yucaipa Valley Hydrologic Monitoring

    This site provides hydrologic data collected or compiled by the USGS in the Yucaipa area; some additional data may be available from the USGS database National Water Information System (NWIS).

    Date published: February 13, 2019

    San Antonio Creek Monitoring Networks

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

    Date published: February 11, 2019

    Electromagnetic induction (EMI) geophysical data collected at the Bicycle Basin, U.S. Army Fort Irwin National Training Center, California

    This data release presents raw (.csv) and processed (.csv) data files from land-based, frequency-domain electromagnetic induction (EMI) data collected at Bicycle Basin, U.S. Army Fort Irwin National Training Center, California. Data were collected during three distinct time periods: March 19, 2008 (1 survey), December 1 to December 5, 2014 (46 surveys) and Dece

    Date published: February 1, 2019

    Groundwater Levels and Water Quality | Borrego Valley

    Table of groundwater well sites in the Borrego Valley that were sampled for groundwater quality and groundwater level measurements.  Provides links to data as well as archvied well documents.

    Date published: January 31, 2019

    Assessment of Groundwater Quality in the Borrego Valley

    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 the interactive water-quality data map for detailed information and to download data.

    Date published: January 1, 2019

    CoSMoS (Coastal Storm Modeling System) Central California v3.1 flood-hazard projections: 1-year storm in San Luis Obispo 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: January 1, 2019

    Structure-from-motion point cloud of Mud Creek, Big Sur, California, 2018-01-29

    Presented here is a point cloud collected by the U.S. Geological Survey (USGS) using an oblique plane-mounted camera system, covering the area of the Mud Creek landslide on California State Route 1 (SR1), Mud Creek, Big Sur, California. Point cloud is referenced to previously published lidar data and contains RGB information as well as XYZ. Point cloud coordinates are in NAD83 UT

    Date published: January 1, 2019

    CoSMoS (Coastal Storm Modeling System) Central California v3.1 water-level projections: 100-year storm in San Luis Obispo 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: January 1, 2019

    Faults--Punta Gorda to Point Arena, California

    This part of DS 781 presents data for the faults of the Punta Gorda to Point Arena, California, region. The vector data file is included in the "Faults_PuntaGordaToPointArena.zip," which is accessible from https://doi.org/10.5066/P9PNNI9H.
    Faults in the Punta Gorda and Point Arena region are identified on seismic-reflection data based on...

    Date published: January 1, 2019

    Sediment Thickness—Point Sur to Point Arguello, California

    This part of DS 781 presents data for the sediment-thickness map of the Point Sur to Point Arguello, California, region. The raster data file is included in the “SedimentThickness_PointSurToPointArguello.zip,” which is accessible from https://doi.org/10.5066/P97CZ0T7.
    As part of the USGS's California State Waters Mapping Project, a 50-m grid...

    Filter Total Items: 485
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    Year Published: 2016

    A satellite model of Southwestern Willow Flycatcher (Empidonax traillii extimus) breeding habitat and a simulation of potential effects of tamarisk leaf beetles (Diorhabda spp.), southwestern United States

    Executive Summary The study described in this report represents the first time that a satellite model has been used to identify potential Southwestern Willow Flycatcher (Empidonax traillii extimus) (hereinafter referred to as “flycatcher”) breeding habitat rangewide for 2013–15. Fifty-seven Landsat scenes were required to map the...

    Hatten, James R.
    Hatten, J.R., 2016, A satellite model of Southwestern Willow Flycatcher (Empidonax traillii extimus) breeding habitat and a simulation of potential effects of tamarisk leaf beetles (Diorhabda spp.), Southwestern United States: U.S. Geological Survey Open-File Report 2016–1120, 88 p., http://dx.doi.org/10.3133/ofr20161120.

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    Year Published: 2016

    Preliminary results from exploratory sampling of wells for the California oil, gas, and groundwater program, 2014–15

    Introduction In 2014 and 2015, the U.S. Geological Survey (USGS) sampled water wells in the Los Angeles Basin and southern San Joaquin Valley, California, and oil wells in the San Joaquin Valley for analysis of multiple chemical, isotopic, and groundwater-age tracers. The purpose of this reconnaissance sampling...

    McMahon, Peter B.; Kulongoski, Justin T.; Wright, Michael T.; Land, Michael T.; Landon, Matthew K.; Cozzarelli, Isabelle M.; Vengosh, Avner; Aiken, George R.
    McMahon, P.B., Kulongoski, J.T., Wright, M.T., Land, M.T., Landon, M.K., Cozzarelli, I.M., Vengosh, Avner, and Aiken, G.R., 2017, Preliminary results from exploratory sampling of wells for the California oil, gas, and groundwater program, 2014–15 (ver 1.1, January 2017): U.S. Geological Survey Open-File Report 2016–1100, 8 p., http://dx.doi.org/10.3133/ofr20161100.

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    Year Published: 2016

    Relative distribution and abundance of fishes and crayfish in 2010 and 2014 prior to saltcedar (Tamarix ssp.) removal in the Amargosa River Canyon, southeastern California

    The Amargosa River Canyon, located in the Mojave Desert of southeastern California, contains the longest perennial reach of the Amargosa River. Because of its diverse flora and fauna, it has been designated as an Area of Critical Environmental Concern and a Wild and Scenic River by the Bureau of Land Management. A survey of fishes conducted in...

    Hereford, Mark E.
    Hereford, M.E., 2016, Relative distribution and abundance of fishes and crayfish in 2010 and 2014 prior to saltcedar (Tamarix ssp.) removal in the Amargosa River Canyon, southeastern California: U.S. Geological Survey Open-File Report 2016–1112, 18 p., http://dx.doi.org/10.3133/ofr20161112.

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    Year Published: 2016

    Evaluation of a floating fish guidance structure at a hydrodynamically complex river junction in the Sacramento-San Joaquin River Delta, California, USA

    Survival of out-migrating juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento–San Joaquin River delta, California, USA, varies by migration route. Survival of salmonids that enter the interior and southern Delta can be as low as half that of salmonids that remain in the main-stem Sacramento River. Reducing entrainment into...

    Romine, Jason G.; Perry, Russell W.; Pope, Adam C.; Stumpner, Paul; Liedtke, Theresa L.; Kumagai, Kevin K.; Reeves, Ryan L.
    Romine, J.G., R.W. Perry, A.C. Pope, P. Stumpner, T.L. Liedtke, K.K. Kumagai, and R.L. Reeves. 2016. Evaluation of a floating fish guidance structure at a hydrodynamically complex river junction in the Sacramento–San Joaquin River Delta, California, USA. Mar. Freshwater Res. (Online Early).

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    Year Published: 2016

    Anadromous salmonids in the Delta: New science 2006–2016

    As juvenile salmon enter the Sacramento–SanJoaquin River Delta (“the Delta”) they disperse among its complex channel network where they are subject to channel-specific processes that affect their rate of migration, vulnerability to predation, feeding success, growth rates, and ultimately, survival. In the decades before 2006...

    Perry, Russell W.; Buchanan, Rebecca A.; Brandes, Patricia L.; Burau, Jon R.; Israel, Joshua A

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    Year Published: 2016

    Estimating juvenile Chinook salmon (Oncorhynchus tshawytscha) abundance from beach seine data collected in the Sacramento–San Joaquin Delta and San Francisco Bay, California

    Resource managers rely on abundance or density metrics derived from beach seine surveys to make vital decisions that affect fish population dynamics and assemblage structure. However, abundance and density metrics may be biased by imperfect capture and lack of geographic closure during sampling. Currently, there is considerable uncertainty about...

    Perry, Russell W.; Kirsch, Joseph E.; Hendrix, A. Noble
    Perry, R.W., Kirsch, J.E., and Hendrix, A.N., 2016, Estimating juvenile Chinook salmon (Oncorhynchus tshawytscha) abundance from beach seine data collected in the Sacramento–San Joaquin Delta and San Francisco Bay, California: U.S. Geological Survey Open-File Report 2016–1099, 21 p., http://dx.doi.org/10.3133/ofr20161099.

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    Year Published: 2016

    Gravity and magnetic studies of the eastern Mojave Desert, California and Nevada

    IntroductionFrom May 2011 to August 2014, the U.S. Geological Survey (USGS) collected gravity data at more than 2,300 stations and physical property measurements on more than 640 rock samples from outcrops in the eastern Mojave Desert, California and Nevada. Gravity, magnetic, and physical-property data are used to study and locate regional...

    Denton, Kevin M.; Ponce, David A.
    Denton, K.M., and Ponce, D.A., 2018, Gravity and magnetic studies of the eastern Mojave Desert, California and Nevada (ver 1.1, August 2018): U.S. Geological Survey Open-File Report 2016-1070, 20 p., https://doi.org/10.3133/ofr20161070.

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    Year Published: 2016

    Historical files from Federal Government mineral exploration-assistance programs, 1950 to 1974

    The Defense Minerals Administration (DMA), Defense Minerals Exploration Administration (DMEA), and Office of Minerals Exploration (OME) mineral exploration programs were active over the period 1950–1974. Under these programs, the Federal Government contributed financial assistance in the exploration for certain strategic and critical minerals. The...

    Frank, David G.
    Frank, D.G., 2016, Historical files from Federal Government mineral exploration-assistance programs, 1950 to 1974: U.S. Geological Survey Data Series 1004, http://dx.doi.org/10.3133/ds1004.

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    Year Published: 2016

    California State Waters Map Series—Monterey Canyon and vicinity, California

    IntroductionIn 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed...

    Dartnell, Peter; Cochran, Susan A.; Dartnell, Peter; Maier, Katherine L.; Erdey, Mercedes D.; Dieter, Bryan E.; Golden, Nadine E.; Johnson, Samuel Y.; Hartwell, Stephen R.; Cochrane, Guy R.; Ritchie, Andrew C.; Finlayson, David P.; Kvitek, Rikk G.; Sliter, Ray W.; Greene, H. Gary; Davenport, Clifton W.; Endris, Charles A.; Krigsman, Lisa M.
    Dartnell, P., Maier, K.L., Erdey, M.D., Dieter, B.E., Golden, N.E., Johnson, S.Y., Hartwell, S.R., Cochrane, G.R., Ritchie, A.C., Finlayson, D.P., Kvitek, R.G., Sliter, R.W., Greene, H.G., Davenport, C.W., Endris, C.A., and Krigsman, L.M. (P. Dartnell and S.A. Cochran, eds.), 2016, California State Waters Map Series—Monterey Canyon and Vicinity, California: U.S. Geological Survey Open-File Report 2016–1072, 48 p., 10 sheets, scale 1:24,000, http://dx.doi.org/10.3133/ofr20161072.

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    Year Published: 2016

    A fault-based model for crustal deformation, fault slip-rates and off-fault strain rate in California

    We invert Global Positioning System (GPS) velocity data to estimate fault slip rates in California using a fault‐based crustal deformation model with geologic constraints. The model assumes buried elastic dislocations across the region using Uniform California Earthquake Rupture Forecast Version 3 (UCERF3) fault geometries. New GPS velocity and...

    Zeng, Yuehua; Shen, Zheng-Kang

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    Year Published: 2016

    Enhancing drought resilience with conjunctive use and managed aquifer recharge in California and Arizona

    Projected longer‐term droughts and intense floods underscore the need to store more water to manage climate extremes. Here we show how depleted aquifers have been used to store water by substituting surface water use for groundwater pumpage (conjunctive use, CU) or recharging groundwater with surface water (Managed Aquifer Recharge, MAR). Unique...

    Scanlon, Bridget R.; Reedy, Robert C.; Faunt, Claudia C.; Pool, Donald R.; Uhlman, Kristine;

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    Year Published: 2016

    Late Holocene volcanism at Medicine Lake Volcano, northern California Cascades

    Late Holocene volcanism at Medicine Lake volcano in the southern Cascades arc exhibited widespread and compositionally diverse magmatism ranging from basalt to rhyolite. Nine well-characterized eruptions have taken place at this very large rear-arc volcano since 5,200 years ago, an eruptive frequency greater than nearly all other Cascade volcanoes...

    Donnelly-Nolan, Julie M.; Champion, Duane E.; Grove, Timothy L.
    Donnelly-Nolan, J.M., Champion, D.E., and Grove, T.L., 2016, Late Holocene volcanism at Medicine Lake volcano, northern California Cascades: U.S. Geological Survey Professional Paper 1822, 59 p., http://dx.doi.org/10.3133/pp1822.

    Filter Total Items: 1,119
    fault rupture
    July 7, 2019

    Searles Valley Earthquake field photo #5

    USGS geophysicist Ken Hudnut demonstrating Drop Cover and Hold Technique during the foreshock sequence to the M7.1 Searles Valley earthquake.

    fault rupture
    July 7, 2019

    Searles Valley Earthquake field photo #6

    Aerial view shot from Blackhawk helicopter overflight on July 6 of the zone of high surface displacement.

    fault rupture
    July 7, 2019

    Searles Valley Earthquake field photo #7

    USGS geologist Josie Nevitt and geodesist Todd Ericksen collect a sample from the fault zone of the main rupture.

    fault rupture
    July 7, 2019

    Searles Valley Earthquake field photo #8

    Truck scanning road offset on the base with USGS geologist Josie Nevitt walking along side.

    fault rupture
    July 7, 2019

    Searles Valley Earthquake field photo #9

    Vertical fault rupture on road with truck.

    Image shows a road with damage from an earthquake
    July 6, 2019

    Damage to Access Road from Searles Valley Earthquake

    Fault scarp at offset access road site. Center line has been offset up and to the right as one looks across the fault towards the east.

    Image shows a group of people standing on a road surrounded by desert
    July 6, 2019

    Planning for Surveying for Earthquake Damage

    Team discussion among CGS and USGS earthquake scientists at the location of the primary surface fault rupture where is has disrupted and offset an access road at the NAWS China Lake. The fault runs NW to SE across the road, which runs from west to east. The east side of the road is uplifted relative to the west side. The west side has shifted permanently towards the NW

    ...
    Image shows an aerial view of a road with surrounding desert
    July 6, 2019

    Railroad Track Offsets from Searles Valley Earthquake

    Railroad tracks offset right-laterally by about 3 feet; southeast of Hwy. 178.

    Image shows an aerial view of desert
    July 6, 2019

    Right-Lateral Fractures from Searles Valley Earthquake

    Right-lateral slip across fractures on a hillside, with shattered ground along the surface fault rupture near Ridgecrest, CA.

    Image shows several people standing next to a helicopter
    July 6, 2019

    Preparing for a Helicopter Overflight

    CGS and USGS geologists and geophysicists with National Guard and Navy personnel plan next phase of helicopter-supported field investigations on Sat., July 6, 2019 at China Lake NAWS.

    Image shows several people standing on the desert
    July 6, 2019

    Preparing to Survey Searles Earthquake Scarp

    USGS scientists and partners review objectives and group assignments  at fault scarp site. The team will deploy seismic instruments to better observe aftershock activity from close in, and to document surface faulting.

    Image shows people silhouetted by the sun working in the desert
    July 6, 2019

    Surveying the Searles Valley Earthquake Scarp

    USGS Seismologists Alan Yong and Elizabeth Cohcran conduct field work near the main rupture between Trona and Ridgecrest California.

    Filter Total Items: 992
    2014 South Napa Earthquake in California
    May 15, 2017

    Early on the morning of August 24, 2014, Loren Turner was awoken by clattering window blinds, a moving bed, and the sound of water splashing out of his backyard pool. He experienced what is now named the “South Napa Earthquake.” 

    A radio-tracked adult desert tortoise basks in the sun among the wind turbines at a wind energy facility
    May 3, 2017

    How a wind energy facility is designed can influence the behavior of animal predators and their prey, according to a recent study published in The Journal of Wildlife Management by researchers at the University of California, Davis, and the U.S. Geological Survey.

    Image shows a map of U.S. states colored based on the value of their mineral industry
    April 14, 2017

    In 2016, these five states led the pack in mineral production, accounting for about one third of the total mineral production value for the entire country.

    BART
    April 6, 2017

    Although no one can reliably predict earthquakes, today’s technology is advanced enough to rapidly detect seismic waves as an earthquake begins, calculate the maximum expected shaking, and send alerts to surrounding areas before damage can occur. This technology is known as “earthquake early warning” (EEW).

    Earthquake Early Warning: Vital for City Transit
    April 6, 2017

    The U.S. Geological Survey along with university, state and private-sector partners will highlight the rollout of Version 1.2 of the USGS ShakeAlert earthquake early warning system on April 10, 2017.

    Field-trip guides to selected volcanoes and volcanic landscapes of ...
    April 5, 2017

    California is well-known for its frequent earthquakes, but less so for its volcanic history – despite the fact that the most recent eruption in the state occurred just 100 years ago.

    CalVO geologists Duane Champion and Drew Downs collect paleomagneti...
    April 3, 2017

    New research on the ages of the most recent lava flows at Eagle Lake Volcanic Field, California suggest they are much older than once thought, minimizing the possibility of future eruption.

    house perched at the top of cliff edge above beach.
    March 27, 2017

    Using a newly-developed computer model called “CoSMoS-COAST” (Coastal Storm Modeling System – Coastal One-line Assimilated Simulation Tool) scientists predict that with limited human intervention, 31 to 67 percent of Southern California beaches may become completely eroded (up to existing coastal infrastructure or sea-cliffs) by the year 2100 under scenarios of sea-level rise of one to two meters.

    USGS
    March 20, 2017

    Seal Beach, Calif.— A new collaborative study shows evidence of prior abrupt sinking of the wetlands near Seal Beach, caused by ancient earthquakes that shook the area at least three times in the past 2,000 years, according to researchers.

    A picture of a restored extensometer
    March 16, 2017

    San Joaquin Valley: the final frontier. These are the voyages of the U.S. Geological Survey. Its weeklong mission: to explore strange new locations, to seek out abandoned scientific technologies, to boldly go where no scientist has gone before (at least in a few decades).

    Wes Hildreth at Long Valley Caldera...
    March 15, 2017

    Two new journal articles about California Volcanoes in the eastern part of the state, the Long Valley Caldera and Ubehebe Craters, are headed to press.

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