American Canyon Sanitary Landfill Operation Regulatory Permit Application, Napa County, California, Public Notice 9297-29R.

DTIC Science & Technology

1982-03-01

control and containment levees on land located along the east bank of the Napa River in southern Napa County, California. 2. In response to the National...approximately 60 acres with construction of flood protection and containment levees around these areas. The estimated refuse and earthwork volumes are...of flood control and containment levees) of restorable wetland being permanently converted to upland. f. provide nuisance factors associated with

Seismo-Lineament Analysis Method (SLAM) Applied to the South Napa Earthquake

NASA Astrophysics Data System (ADS)

Worrell, V. E.; Cronin, V. S.

2014-12-01

We used the seismo-lineament analysis method (SLAM; http://bearspace.baylor.edu/Vince_Cronin/www/SLAM/) to "predict" the location of the fault that produced the M 6.0 South Napa earthquake of 24 August 2014, using hypocenter and focal mechanism data from NCEDC (http://www.ncedc.org/ncedc/catalog-search.html) and a digital elevation model from the USGS National Elevation Dataset (http://viewer.nationalmap.gov/viewer/). The ground-surface trace of the causative fault (i.e., the Browns Valley strand of the West Napa fault zone; Bryant, 2000, 1982) and virtually all of the ground-rupture sites reported by the USGS and California Geological Survey (http://www.eqclearinghouse.org/2014-08-24-south-napa/) were located within the north-striking seismo-lineament. We also used moment tensors published online by the USGS and GCMT (http://comcat.cr.usgs.gov/earthquakes/eventpage/nc72282711#scientific_moment-tensor) as inputs to SLAM and found that their northwest-striking seismo-lineaments correlated spatially with the causative fault. We concluded that SLAM could have been used as soon as these mechanism solutions were available to help direct the search for the trace of the causative fault and possible rupture-related damage. We then considered whether the seismogenic fault could have been identified using SLAM prior to the 24 August event, based on the focal mechanisms of smaller prior earthquakes reported by the NCEDC or ISC (http://www.isc.ac.uk). Seismo-lineaments from three M~3.5 events from 1990 and 2012, located in the Vallejo-Crockett area, correlate spatially with the Napa County Airport strand of the West Napa fault and extend along strike toward the Browns Valley strand (Bryant, 2000, 1982). Hence, we might have used focal mechanisms from smaller earthquakes to establish that the West Napa fault is likely seismogenic prior to the South Napa earthquake. Early recognition that a fault with a mapped ground-surface trace is seismogenic, based on smaller earthquakes

Napa Earthquake impact on water systems

NASA Astrophysics Data System (ADS)

Wang, J.

2014-12-01

South Napa earthquake occurred in Napa, California on August 24 at 3am, local time, and the magnitude is 6.0. The earthquake was the largest in SF Bay Area since the 1989 Loma Prieta earthquake. Economic loss topped $ 1 billion. Wine makers cleaning up and estimated the damage on tourism. Around 15,000 cases of lovely cabernet were pouring into the garden at the Hess Collection. Earthquake potentially raise water pollution risks, could cause water crisis. CA suffered water shortage recent years, and it could be helpful on how to prevent underground/surface water pollution from earthquake. This research gives a clear view on drinking water system in CA, pollution on river systems, as well as estimation on earthquake impact on water supply. The Sacramento-San Joaquin River delta (close to Napa), is the center of the state's water distribution system, delivering fresh water to more than 25 million residents and 3 million acres of farmland. Delta water conveyed through a network of levees is crucial to Southern California. The drought has significantly curtailed water export, and salt water intrusion reduced fresh water outflows. Strong shaking from a nearby earthquake can cause saturated, loose, sandy soils liquefaction, and could potentially damage major delta levee systems near Napa. Napa earthquake is a wake-up call for Southern California. It could potentially damage freshwater supply system.

Comparative Study of Vocational Nursing Curriculum and Employer Requirements. Update. Napa Valley College, October 1991-June 1992.

ERIC Educational Resources Information Center

Zylinski, Doris; And Others

In 1991-92, a project was undertaken at Napa Valley College to update the college's 1990 Comparative Study of Vocational Nursing Curriculum and Employer Requirements, to develop a model articulation program for licensed nurses pursuing associate degrees, and to produce a guide for recruiting and retaining underrepresented groups in vocational…

Employment Trends from 1984 to 1995 and Their Implications for Napa Valley College. Planning Report Number 1.

ERIC Educational Resources Information Center

Friedlander, Jack

Designed to assist staff at Napa Valley College (NVC) in their efforts to develop short- and long-range plans for the institution, this report reviews recent reports by the Bureau of Labor Statistics regarding trends in the labor force. Following introductory material, the report looks at occupations with the largest job growth, the 20 fastest…

Recruiting and Retaining Underrepresented Groups and Special Populations in Nursing Programs. Napa Valley College, October 1991-June 1992.

ERIC Educational Resources Information Center

Zylinski, Doris; Metson, Elena

In 1991-92, Napa Valley College participated in a statewide project to develop and publish this guide for recruiting and retaining underrepresented groups and special populations in vocational nursing. Among the highlighted recommendations presented in the guide are the following: (1) disseminate information on nursing education and job…

Ground motion observations of the 2014 South Napa earthquake

USGS Publications Warehouse

Baltay, Annemarie S.; Boatwright, John

2015-01-01

Using the ground‐motion data compiled and reported by ShakeMap (Wald et al., 2000), we examine the peak ground acceleration (PGA) and peak ground velocity (PGV), as well as the pseudospectral acceleration (PSA) at periods of 0.3, 1.0, and 3.0 s. At the higher frequencies, especially PGA, data recorded at close distances (within ∼20  km) are very consistent with the GMPEs, implying a stress drop for this event similar to the median for California, that is, 5 MPa (Baltay and Hanks, 2014). At all frequencies, the attenuation with distance is stronger than the GMPEs would predict, which suggests the attenuation in the Napa and San Francisco Bay delta region is stronger than the average attenuation in California. The spatial plot of the ground‐motion residuals is positive to the north, in both Napa and Sonoma Valleys, consistent with increases in amplitude expected from both the directivity and basin effects. More interestingly, perhaps, there is strong ground motion to the south in the along‐strike direction, particularly for PSA at 1.0 s. These strongly positive residuals align with an older, Quaternary fault structure associated with the Franklin or Southampton fault, potentially indicating a fault‐zone‐guided wave.

Geodetic constraints on the 2014 M 6.0 South Napa earthquake

USGS Publications Warehouse

Barnhart, William D.; Murray, Jessica R.; Yun, S H; Svarc, Jerry L.; Samsonov, SV; Fielding, EJ; Brooks, Benjamin A.; Milillo, Pietro

2014-01-01

On 24 August 2014, the M 6.0 South Napa earthquake shook much of the San Francisco Bay area, leading to significant damage in the Napa Valley. The earthquake occurred in the vicinity of the West Napa fault (122.313° W, 38.22° N, 11.3 km), a mapped structure located between the Rodger’s Creek and Green Valley faults, with nearly pure right‐lateral strike‐slip motion (strike 157°, dip 77°, rake –169°; http://comcat.cr.usgs.gov/earthquakes/eventpage/nc72282711#summary, last accessed December 2014) (Fig. 1). The West Napa fault previously experienced an M 5 strike‐slip event in 2000 but otherwise exhibited no previous definitive evidence of historic earthquake rupture (Rodgers et al., 2008; Wesling and Hanson, 2008). Evans et al. (2012) found slip rates of ∼9.5  mm/yr along the West Napa fault, with most slip rate models for the Bay area placing higher slip rates and greater earthquake potential on the Rodger’s Creek and Green Valley faults, respectively (e.g., Savage et al., 1999; d’Alessio et al., 2005; Funning et al., 2007).

Aftershocks of the 2014 South Napa, California, Earthquake: Complex faulting on secondary faults

USGS Publications Warehouse

Hardebeck, Jeanne L.; Shelly, David R.

2016-01-01

We investigate the aftershock sequence of the 2014 MW6.0 South Napa, California, earthquake. Low-magnitude aftershocks missing from the network catalog are detected by applying a matched-filter approach to continuous seismic data, with the catalog earthquakes serving as the waveform templates. We measure precise differential arrival times between events, which we use for double-difference event relocation in a 3D seismic velocity model. Most aftershocks are deeper than the mainshock slip, and most occur west of the mapped surface rupture. While the mainshock coseismic and postseismic slip appears to have occurred on the near-vertical, strike-slip West Napa fault, many of the aftershocks occur in a complex zone of secondary faulting. Earthquake locations in the main aftershock zone, near the mainshock hypocenter, delineate multiple dipping secondary faults. Composite focal mechanisms indicate strike-slip and oblique-reverse faulting on the secondary features. The secondary faults were moved towards failure by Coulomb stress changes from the mainshock slip. Clusters of aftershocks north and south of the main aftershock zone exhibit vertical strike-slip faulting more consistent with the West Napa Fault. The northern aftershocks correspond to the area of largest mainshock coseismic slip, while the main aftershock zone is adjacent to the fault area that has primarily slipped postseismically. Unlike most creeping faults, the zone of postseismic slip does not appear to contain embedded stick-slip patches that would have produced on-fault aftershocks. The lack of stick-slip patches along this portion of the fault may contribute to the low productivity of the South Napa aftershock sequence.

Seismogeodesy of the 2014 Mw6.1 Napa earthquake, California: Rapid response and modeling of fast rupture on a dipping strike-slip fault

NASA Astrophysics Data System (ADS)

Melgar, Diego; Geng, Jianghui; Crowell, Brendan W.; Haase, Jennifer S.; Bock, Yehuda; Hammond, William C.; Allen, Richard M.

2015-07-01

Real-time high-rate geodetic data have been shown to be useful for rapid earthquake response systems during medium to large events. The 2014 Mw6.1 Napa, California earthquake is important because it provides an opportunity to study an event at the lower threshold of what can be detected with GPS. We show the results of GPS-only earthquake source products such as peak ground displacement magnitude scaling, centroid moment tensor (CMT) solution, and static slip inversion. We also highlight the retrospective real-time combination of GPS and strong motion data to produce seismogeodetic waveforms that have higher precision and longer period information than GPS-only or seismic-only measurements of ground motion. We show their utility for rapid kinematic slip inversion and conclude that it would have been possible, with current real-time infrastructure, to determine the basic features of the earthquake source. We supplement the analysis with strong motion data collected close to the source to obtain an improved postevent image of the source process. The model reveals unilateral fast propagation of slip to the north of the hypocenter with a delayed onset of shallow slip. The source model suggests that the multiple strands of observed surface rupture are controlled by the shallow soft sediments of Napa Valley and do not necessarily represent the intersection of the main faulting surface and the free surface. We conclude that the main dislocation plane is westward dipping and should intersect the surface to the east, either where the easternmost strand of surface rupture is observed or at the location where the West Napa fault has been mapped in the past.

Rates and patterns of surface deformation from laser scanning following the South Napa earthquake, California

USGS Publications Warehouse

DeLong, Stephen B.; Lienkaemper, James J.; Pickering, Alexandra J; Avdievitch, Nikita N.

2015-01-01

The A.D. 2014 M6.0 South Napa earthquake, despite its moderate magnitude, caused significant damage to the Napa Valley in northern California (USA). Surface rupture occurred along several mapped and unmapped faults. Field observations following the earthquake indicated that the magnitude of postseismic surface slip was likely to approach or exceed the maximum coseismic surface slip and as such presented ongoing hazard to infrastructure. Using a laser scanner, we monitored postseismic deformation in three dimensions through time along 0.5 km of the main surface rupture. A key component of this study is the demonstration of proper alignment of repeat surveys using point cloud–based methods that minimize error imposed by both local survey errors and global navigation satellite system georeferencing errors. Using solid modeling of natural and cultural features, we quantify dextral postseismic displacement at several hundred points near the main fault trace. We also quantify total dextral displacement of initially straight cultural features. Total dextral displacement from both coseismic displacement and the first 2.5 d of postseismic displacement ranges from 0.22 to 0.29 m. This range increased to 0.33–0.42 m at 59 d post-earthquake. Furthermore, we estimate up to 0.15 m of vertical deformation during the first 2.5 d post-earthquake, which then increased by ∼0.02 m at 59 d post-earthquake. This vertical deformation is not expressed as a distinct step or scarp at the fault trace but rather as a broad up-to-the-west zone of increasing elevation change spanning the fault trace over several tens of meters, challenging common notions about fault scarp development in strike-slip systems. Integrating these analyses provides three-dimensional mapping of surface deformation and identifies spatial variability in slip along the main fault trace that we attribute to distributed slip via subtle block rotation. These results indicate the benefits of laser scanner surveys along

Seismic site characterization of an urban dedimentary basin, Livermore Valley, California: Site tesponse, basin-edge-induced surface waves, and 3D simulations

USGS Publications Warehouse

Hartzell, Stephen; Leeds, Alena L.; Ramirez-Guzman, Leonardo; Allen, James P.; Schmitt, Robert G.

2016-01-01

Thirty‐two accelerometers were deployed in the Livermore Valley, California, for approximately one year to study sedimentary basin effects. Many local and near‐regional earthquakes were recorded, including the 24 August 2014 Mw 6.0 Napa, California, earthquake. The resulting ground‐motion data set is used to quantify the seismic response of the Livermore basin, a major structural depression in the California Coast Range Province bounded by active faults. Site response is calculated by two methods: the reference‐site spectral ratio method and a source‐site spectral inversion method. Longer‐period (≥1  s) amplification factors follow the same general pattern as Bouguer gravity anomaly contours. Site response spectra are inverted for shallow shear‐wave velocity profiles, which are consistent with independent information. Frequency–wavenumber analysis is used to analyze plane‐wave propagation across the Livermore Valley and to identify basin‐edge‐induced surface waves with back azimuths different from the source back azimuth. Finite‐element simulations in a 3D velocity model of the region illustrate the generation of basin‐edge‐induced surface waves and point out strips of elevated ground velocities along the margins of the basin.

Co- and post-seismic deformation for the 2014 Napa Valley Earthquake from Sentinel-1A interferometry

NASA Astrophysics Data System (ADS)

Elliott, J. R.; Wright, T. J.; Elliott, A. J.; González, P. J.; Hooper, A. J.; Larsen, Y.; Marinkovic, P.; Plain, M.; Walters, R. J.

2014-12-01

Here we present analysis of co- and post-seismic deformation for the 24 August 2014 Napa Valley Earthquake derived from Sentinel-1A interferometry. We use these to derive the co-seismic slip distribution and map the evolution of post-seismic afterslip. The 24 August 2014 Napa Valley earthquake was the first earthquake for which surface deformation was measured by Sentinel-1A, a new radar satellite launched by the European Space Agency on 3 April 2014, and operated by the European Commission's Copernicus program. Sentinel-1A reached its final operational orbit on 7 August, and fortuitously acquired a pre-earthquake image of the San Francisco Bay area on that day in StripMap mode. By comparing it with an image acquired on 31 August, we formed a co-seismic interferogram, which reveals the surface deformation that occurred during the earthquake and the first 7 days of the post-seismic period. We use this to constrain a simple elastic model of the co-seismic slip distribution; preliminary inversion results show that the slip at depth reached a peak of >1.5 m at a depth of ~4 km. Following the earthquake, Sentinel-1A has acquired further acquisitions in both StripMap and Interferometric Wide Swath modes. The first 12-day post-seismic StripMap interferogram shows a sharp discontinuity along the entire fault rupture, consistent with field observations of rapid afterslip. We will use the full time series from August to December to measure the spatio-temporal behaviour of the afterslip, and discuss the implications for the frictional properties of the fault. The results from Napa point to an exciting and impactful future for the Sentinel-1 radar constellation. By mid-2014, Sentinel-1A will be acquiring data systematically over all the seismic belts, and the launch of Sentinel-1B in 2016 will increase the temporal frequency of acquisitions. The data will be available free of charge and will transform our ability to conduct tectonic geodesy, particularly in remote areas of the

33 CFR 117.169 - Mare Island Strait and the Napa River.

Code of Federal Regulations, 2012 CFR

2012-07-01

... SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.169 Mare Island Strait and the Napa River. (a) The draw of the Mare Island Drawbridge, mile 2.8, at Vallejo shall open on... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Mare Island Strait and the Napa...

33 CFR 117.169 - Mare Island Strait and the Napa River.

Code of Federal Regulations, 2013 CFR

2013-07-01

... SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.169 Mare Island Strait and the Napa River. (a) The draw of the Mare Island Drawbridge, mile 2.8, at Vallejo shall open on... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Mare Island Strait and the Napa...

33 CFR 117.169 - Mare Island Strait and the Napa River.

Code of Federal Regulations, 2014 CFR

2014-07-01

... SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.169 Mare Island Strait and the Napa River. (a) The draw of the Mare Island Drawbridge, mile 2.8, at Vallejo shall open on... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Mare Island Strait and the Napa...

33 CFR 117.169 - Mare Island Strait and the Napa River.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.169 Mare Island Strait and the Napa River. (a) The draw of the Mare Island Drawbridge, mile 2.8, at Vallejo shall open on... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Mare Island Strait and the Napa...

33 CFR 117.169 - Mare Island Strait and the Napa River.

Code of Federal Regulations, 2011 CFR

2011-07-01

... SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.169 Mare Island Strait and the Napa River. (a) The draw of the Mare Island Drawbridge, mile 2.8, at Vallejo shall open on... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Mare Island Strait and the Napa...

California: Diamond Valley

Atmospheric Science Data Center

2014-05-15

... article title:  Watching the Creation of Southern California's Largest Reservoir     ... Valley Lake is designed to provide protection against drought and a six-month emergency supply in the event of earthquake damage to a ...

Comparison of Earthquake Damage Patterns and Shallow-Depth Vs Structure Across the Napa Valley, Inferred From Multichannel Analysis of Surface Waves (MASW) and Multichannel Analysis of Love Waves (MALW) Modeling of Basin-Wide Seismic Profiles

NASA Astrophysics Data System (ADS)

Chan, J. H.; Catchings, R.; Strayer, L. M.; Goldman, M.; Criley, C.; Sickler, R. R.; Boatwright, J.

2017-12-01

We conducted an active-source seismic investigation across the Napa Valley (Napa Valley Seismic Investigation-16) in September of 2016 consisting of two basin-wide seismic profiles; one profile was 20 km long and N-S-trending (338°), and the other 15 km long and E-W-trending (80°) (see Catchings et al., 2017). Data from the NVSI-16 seismic investigation were recorded using a total of 666 vertical- and horizontal-component seismographs, spaced 100 m apart on both seismic profiles. Seismic sources were generated by a total of 36 buried explosions spaced 1 km apart. The two seismic profiles intersected in downtown Napa, where a large number of buildings were red-tagged by the City following the 24 August 2014 Mw 6.0 South Napa earthquake. From the recorded Rayleigh and Love waves, we developed 2-Dimensional S-wave velocity models to depths of about 0.5 km using the multichannel analysis of surface waves (MASW) method. Our MASW (Rayleigh) and MALW (Love) models show two prominent low-velocity (Vs = 350 to 1300 m/s) sub-basins that were also previously identified from gravity studies (Langenheim et al., 2010). These basins trend N-W and also coincide with the locations of more than 1500 red- and yellow-tagged buildings within the City of Napa that were tagged after the 2014 South Napa earthquake. The observed correlation between low-Vs, deep basins, and the red-and yellow-tagged buildings in Napa suggests similar large-scale seismic investigations can be performed. These correlations provide insights into the likely locations of significant structural damage resulting from future earthquakes that occur adjacent to or within sedimentary basins.

Transformations, transport, and potential unintended consequences of high sulfur inputs to Napa Valley vineyards

PubMed Central

Hinckley, Eve-Lyn S.; Matson, Pamela A.

2011-01-01

Unintended anthropogenic deposition of sulfur (S) to forest ecosystems has a range of negative consequences, identified through decades of research. There has been far less study of purposeful S use in agricultural systems around the world, including the application of elemental sulfur (S0) as a quick-reacting fungicide to prevent damage to crops. Here we report results from a three-year study of the transformations and flows of applied S0 in soils, vegetation, and hydrologic export pathways of Napa Valley, CA vineyards, documenting that all applied S is lost from the vineyard ecosystem on an annual basis. We found that S0 oxidizes rapidly to sulfate () on the soil surface where it then accumulates over the course of the growing season. Leaf and grape tissues accounted for only 7–13% of applied S whereas dormant season cover crops accounted for 4–10% of applications. Soil S inventories were largely and ester-bonded sulfates; they decreased from 1,623 ± 354 kg ha-1 during the dry growing season to 981 ± 526 kg ha-1 (0–0.5 m) during the dormant wet season. Nearly all S applied to the vineyard soils is transported offsite in dissolved oxidized forms during dormant season rainstorms. Thus, the residence time of reactive S is brief in these systems, and largely driven by hydrology. Our results provide new insight into how S use in vineyards constitutes a substantial perturbation of the S cycle in Northern California winegrowing regions and points to the unintended consequences that agricultural S use may have at larger scales. PMID:21825150

The Napa Project: 02 Year Annual Drug Survey.

ERIC Educational Resources Information Center

Moskowitz, Joel M.; And Others

The results of a survey administered to junior and senior high students in the Napa Valley (CA) Unified School District in 1980 are summarized. The questionnaire administered was the Drug and Alcohol Survey, a group administered, self-report instrument. The questionnaire assesses: (1) drug knowledge; (2) general drug attitudes; (3) perceived…

Multi-sensor Integration of Space and Ground Observations of Pre-earthquake Anomalies Associated with M6.0, August 24, 2014 Napa, California

NASA Astrophysics Data System (ADS)

Ouzounov, Dimitar; Tramutoli, Valerio; Pulinets, Sergey; Liu, Tiger; Filizzola, Carolina; Genzano, Nicola; Lisi, Mariano; Petrov, Leonid; Kafatos, Menas

2015-04-01

We integrate multiple space-born and ground sensors for monitoring pre-earthquake geophysical anomalies that can provide significant early notification for earthquakes higher than M5.5 worldwide. The latest M6.0 event of August 24, 2014 in South Napa, California generated pre-earthquake signatures during our outgoing tests for California, and an experimental warning was documented about 17 days in advance. We process in controlled environment different satellite and ground data for California (and several other test areas) by using: a) data from the NPOES sensors recording OLR (Outgoing Longwave Radiation) in the infrared; b) 2/GNSS, FORMOSAT (GPS/TEC); c) Earth Observing System assimilation models from NASA; d) ground-based gas observations and meteorological data; e) TIR (Thermal Infrared) data from geostationary satellite (GOES). On Aug 4th, we detected (prospectively) a large anomaly of OLR transient field at the TOA over Northern California. The location was shifted in the northeast direction about 150 km from the Aug 23rd epicentral area. Compared to the reference field of August 2004 to 2014 the hotspot anomaly was the largest energy flux anomaly over the entire continental United States at this time. Based on the temporal and spatial estimates of the anomaly, on August 4th we issued an internal warning for a M5.5+ earthquake in Northern California within the next 1-4 weeks. TIR retrospective analysis showed significant (spatially extended and temporally persistent) sequences of TIR anomalies starting August 1st just in the future epicenter area and approximately in the same area affected by OLR anomalies in the following days. GPS/TEC retrospective analysis based on GIM and TGIM products show anomalies TEC variations 1-3 days, over region north form the Napa earthquake epicenter. The calculated index of atmospheric chemical potential based on the NASA numerical Assimilation weather model GEOS5 indicates for abnormal variations near the epicentral area days

Key recovery factors for the August 24, 2014, South Napa Earthquake

USGS Publications Warehouse

Hudnut, Kenneth W.; Brocher, Thomas M.; Prentice, Carol S.; Boatwright, John; Brooks, Benjamin A.; Aagaard, Brad T.; Blair, James Luke; Fletcher, Jon Peter B.; Erdem, Jemile; Wicks, Chuck; Murray, Jessica R.; Pollitz, Fred F.; Langbein, John O.; Svarc, Jerry L.; Schwartz, David P.; Ponti, Daniel J.; Hecker, Suzanne; DeLong, Stephen B.; Rosa, Carla M.; Jones, Brenda; Lamb, Rynn M.; Rosinski, Anne M.; McCrink, Timothy P.; Dawson, Timothy E.; Seitz, Gordon G.; Glennie, Craig; Hauser, Darren; Ericksen, Todd; Mardock, Dan; Hoirup, Don F.; Bray, Jonathan D.; Rubin, Ron S.

2014-01-01

Through discussions between the Federal Emergency Management Agency (FEMA) and the U.S. Geological Survey (USGS) following the South Napa earthquake, it was determined that several key decision points would be faced by FEMA for which additional information should be sought and provided by USGS and its partners. This report addresses the four tasks that were agreed to. These tasks are (1) assessment of ongoing fault movement (called afterslip) especially in the Browns Valley residential neighborhood, (2) assessment of the shaking pattern in the downtown area of the City of Napa, (3) improvement of information on the fault hazards posed by the West Napa Fault System (record of past earthquakes and slip rate, for example), and (4) imagery acquisition and data processing to provide overall geospatial information support to FEMA.

Forecasting the (un)productivity of the 2014 M 6.0 South Napa aftershock sequence

USGS Publications Warehouse

Llenos, Andrea L.; Michael, Andrew J.

2017-01-01

The 24 August 2014 Mw 6.0 South Napa mainshock produced fewer aftershocks than expected for a California earthquake of its magnitude. In the first 4.5 days, only 59 M≥1.8 aftershocks occurred, the largest of which was an M 3.9 that happened a little over two days after the mainshock. We investigate the aftershock productivity of the South Napa sequence and compare it with other M≥5.5 California strike‐slip mainshock–aftershock sequences. While the productivity of the South Napa sequence is among the lowest, northern California mainshocks generally have fewer aftershocks than mainshocks further south, although the productivities vary widely in both regions. An epidemic‐type aftershock sequence (ETAS) model (Ogata, 1988) fit to Napa seismicity from 1980 to 23 August 2014 fits the sequence well and suggests that low‐productivity sequences are typical of this area. Utilizing regional variations in productivity could improve operational earthquake forecasting (OEF) by improving the model used immediately after the mainshock. We show this by comparing the daily rate of M≥2 aftershocks to forecasts made with the generic California model (Reasenberg and Jones, 1989; hereafter, RJ89), RJ89 models with productivity updated daily, a generic California ETAS model, an ETAS model based on premainshock seismicity, and ETAS models updated daily following the mainshock. RJ89 models for which only the productivity is updated provide better forecasts than the generic RJ89 California model, and the Napa‐specific ETAS models forecast the aftershock rates more accurately than either generic model. Therefore, forecasts that use localized initial parameters and that rapidly update the productivity may be better for OEF than using a generic model and/or updating all parameters.

Evaluating trees as energy crops in Napa County

Treesearch

Dean R. Donaldson; Richard B. Standiford

1983-01-01

An evaluation of tree species for energy crops was initiated at two areas in Napa County, California. At one area, Eucalyptus viminalis at 39 months was significantly taller than E. camaldulensis at 50 months. Also evaluated were five clones of Pinus radiata, Juglans regia X hindsii...

Seismic Evidence of A Widely Distributed West Napa Fault Zone, Hendry Winery, Napa, California

NASA Astrophysics Data System (ADS)

Goldman, M.; Catchings, R.; Chan, J. H.; Criley, C.

2015-12-01

Following the 24 August 2014 Mw 6.0 South Napa earthquake, surface rupture was mapped along the West Napa Fault Zone (WNFZ) for a distance of ~ 14 km and locally within zones up to ~ 2 km wide. Near the northern end of the surface rupture, however, several strands coalesced to form a narrow, ~100-m-wide zone of surface rupture. To determine the location, width, and shallow (upper few hundred meters) geometry of the fault zone, we acquired an active-source seismic survey across the northern surface rupture in February 2015. We acquired both P- and S-wave data, from which we developed reflection images and tomographic images of Vp, Vs, Vp/Vs, and Poisson's ratio of the upper 100 m. We also used small explosive charges within surface ruptures located ~600 m north of our seismic array to record fault-zone guided waves. Our data indicate that at the latitude of the Hendry Winery, the WNFZ is characterized by at least five fault traces that are spaced 60 to 200 m apart. Zones of low-Vs, low-Vp/Vs, and disrupted reflectors highlight the fault traces on the tomography and reflection images. On peak-ground-velocity (PGV) plots, the most pronounced high-amplitude guided-wave seismic energy coincides precisely with the mapped surface ruptures, and the guided waves also show discrete high PGV zones associated with unmapped fault traces east of the surface ruptures. Although the surface ruptures of the WNFZ were observed only over a 100-m-wide zone at the Hendry Winery, our data indicate that the fault zone is at least 400 m wide, which is probably a minimum width given the 400-m length of our seismic profile. Slip on the WNFZ is generally considered to be low relative to most other Bay Area faults, but we suggest that the West Napa Fault is a zone of widely distributed shear, and to fully account for the total slip on the WNFZ, slip on all traces of this wide fault zone must be considered.

Ground-water resources in the lower Milliken--Sarco--Tulucay Creeks area, southeastern Napa County, California, 2000-2002

USGS Publications Warehouse

Farrar, Christopher D.; Metzger, Loren F.

2003-01-01

Ground water obtained from individual private wells is the sole source of water for about 4,800 residents living in the lower Milliken-Sarco-Tulucay Creeks area of southeastern Napa County. Increases in population and in irrigated vineyards during the past few decades have increased water demand. Estimated ground-water pumpage in 2000 was 5,350 acre-feet per year, an increase of about 80 percent since 1975. Water for agricultural irrigation is the dominant use, accounting for about 45 percent of the total. This increase in ground-water extraction has resulted in the general decline of ground-water levels. The purpose of this report is to present selected hydrologic data collected from 1975 to 2002 and to quantify changes in the ground-water system during the past 25 years. The study area lies in one of several prominent northwest-trending structural valleys in the North Coast Ranges. The area is underlain by alluvial deposits and volcanic rocks that exceed 1,000 feet in thickness in some places. Alluvial deposits and tuff beds in the volcanic sequence are the principal source of water to wells. The ground-water system is recharged by precipitation that infiltrates, in minor amounts, directly on the valley floor but mostly by infiltration in the Howell Mountains. Ground water moves laterally from the Howell Mountains into the study area. Although the area receives abundant winter precipitation in most years, nearly half of the precipitation is lost as surface runoff to the Napa River. Evapotranspiration also is high, accounting for nearly one-half of the total precipitation received. Because of the uncertainties in the estimates of precipitation, runoff, and evapotranspiration, a precise estimate of potential ground-water recharge cannot be made. Large changes in ground-water levels occurred between 1975 and 2001. In much of the western part of the area, water levels increased; but in the central and eastern parts, water levels declined by 25 to 125 feet. Ground

California's Central Valley Groundwater Study: A Powerful New Tool to Assess Water Resources in California's Central Valley

USGS Publications Warehouse

Faunt, Claudia C.; Hanson, Randall T.; Belitz, Kenneth; Rogers, Laurel

2009-01-01

Competition for water resources is growing throughout California, particularly in the Central Valley. Since 1980, the Central Valley's population has nearly doubled to 3.8 million people. It is expected to increase to 6 million by 2020. Statewide population growth, anticipated reductions in Colorado River water deliveries, drought, and the ecological crisis in the Sacramento-San Joaquin Delta have created an intense demand for water. Tools and information can be used to help manage the Central Valley aquifer system, an important State and national resource.

Groundwater quality in Coachella Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Coachella Valley is one of the study areas being evaluated. The Coachella study area is approximately 820 square miles (2,124 square kilometers) and includes the Coachella Valley groundwater basin (California Department of Water Resources, 2003). Coachella Valley has an arid climate, with average annual rainfall of about 6 inches (15 centimeters). The runoff from the surrounding mountains drains to rivers that flow east and south out of the study area to the Salton Sea. Land use in the study area is approximately 67 percent (%) natural, 21% agricultural, and 12% urban. The primary natural land cover is shrubland. The largest urban areas are the cities of Indio and Palm Springs (2010 populations of 76,000 and 44,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Coachella Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Coachella Valley are completed to depths between 490 and 900 feet (149 to 274 meters), consist of solid casing from the land surface to a depth of 260 to 510 feet (79 to 155 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to

27 CFR 9.37 - California Shenandoah Valley.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false California Shenandoah Valley. 9.37 Section 9.37 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU...) Boundaries. The Shenandoah Valley viticultural Area is located in portions of Amador and El Dorado Counties...

27 CFR 9.37 - California Shenandoah Valley.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false California Shenandoah Valley. 9.37 Section 9.37 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU...) Boundaries. The Shenandoah Valley viticultural Area is located in portions of Amador and El Dorado Counties...

California's restless giant: the Long Valley Caldera

USGS Publications Warehouse

Hill, David P.; Bailey, Roy A.; Hendley, James W.; Stauffer, Peter H.; Marcaida, Mae

2014-01-01

Scientists have monitored geologic unrest in the Long Valley, California, area since 1980. In that year, following a swarm of strong earthquakes, they discovered that the central part of the Long Valley Caldera had begun actively rising. Unrest in the area persists today. The U.S. Geological Survey (USGS) continues to provide the public and civil authorities with current information on the volcanic hazard at Long Valley and is prepared to give timely warnings of any impending eruption.

Death Valley California as seen from STS-59

NASA Technical Reports Server (NTRS)

1994-01-01

This oblique handheld Hasselblad 70mm photo shows Death Valley, near California's border with Nevada. The valley -- the central feature of Death Valley National Monument -- extends north to south for some 140 miles (225 kilometers). Hemmed in to the east by the Amargosa Range and to the west by the Panamints, its width varies from 5 to 15 miles (8 to 24 kilometers).

Three-dimensional fault framework of the 2014 South Napa Earthquake, San Francisco Bay region, California

NASA Astrophysics Data System (ADS)

Graymer, R. W.

2014-12-01

Assignment of the South Napa earthquake to a mapped fault is difficult, as it occurred where three large, northwest-trending faults converge and may interact in the subsurface. The surface rupture did not fall on the main trace of any of these faults, but instead between the Carneros and West Napa faults and northwest along strike from the northern mapped end of the Franklin Fault. The 2014 rupture plane appears to be nearly vertical, based on focal mechanisms of the mainshock and connection of the surface trace/rupture to the relocated hypocenter (J. Hardebeck, USGS). 3D surfaces constructed from published data show that the Carneros Fault is a steeply west-dipping fault that runs just west of the near-vertical 2014 rupture plane. The Carneros Fault does not appear to have been involved in the earthquake, although relocated aftershocks suggest possible minor triggered slip. The main West Napa Fault is also steeply west-dipping and that its projection intersects the 2014 rupture plane at around the depth of the mainshock hypocenter. UAVSAR data (A. Donnellan, JPL) and relocated aftershocks suggest that the main West Napa Fault experienced triggered slip/afterslip along a length of roughly 20 km. It is possible that the 2014 rupture took place along a largely unrecognized westerly strand of the West Napa Fault. The Franklin Fault is a steeply east-dipping fault (with a steeply west-dipping subordinate trace east of Mare Island) that has documented late Quaternary offset. Given the generally aligned orientation of the 3D fault surfaces, an alternative interpretation is that the South Napa earthquake occurred on the northernmost reach of the Franklin Fault within it's 3D junction with the West Napa Fault. This interpretation is supported, but not proven, by a short but prominent linear feature in the UAVSAR data at Slaughterhouse Point west of Vallejo, along trend south-southeast of the observed coseismic surface rupture.

Comparison of Iron-Binding Ability Between Thr70-NapA and Ser70-NapA of Helicobacter pylori.

PubMed

Shan, Weiran; Kung, Hsiang-Fu; Ge, Ruiguang

2016-06-01

The neutrophil-activating protein (NapA) of Helicobacter pylori (H. pylori), with DNA-binding and iron seizing properties, is a fundamental virulence factor involved in H. pylori-related diseases. Compared with Ser70-NapA strain, Thr70-NapA strain is more intimately correlated with iron-deficiency anemia. To investigate whether two types of proteins differ in iron-binding ability, mutated Thr70-NapA and Ser70-NapA strains were established. Isothermal titration calorimetry (ITC) method was conducted to measure the binding between the NapA protein and Fe(2+) . The structural changes of NapA protein were also tested during iron interaction by fast protein liquid chromatography (FPLC) and circular dichroism (CD) methods. DNA-binding assay was performed for evaluate the affinity of both mutated and wild types of NapA with DNA. Mutated Thr70-NapA had higher iron-binding ability than wild Ser70-NapA. The structural stability of Thr70-NapA was disrupted and became more active along with the rising concentration of Fe(2+) , whereas no similar association was observed between Ser70-NapA and Fe(2+) level. When the iron/protein molar ratio ranged from 10 to 20, both Ser70-NapA and Thr70-NapA displayed weaker DNA-binding ability. Thr70-NapA has much stronger ability to sequester ferrous ion compared with Ser70-NapA in H. pylori. In addition, the DNA-binding property of NapA is dependent upon the Fe(2+) concentration. © 2015 John Wiley & Sons Ltd.

Recent landscape change in California's Central Valley

NASA Astrophysics Data System (ADS)

Soulard, C. E.; Wilson, T. S.

2012-12-01

Long term monitoring of land use and land cover in California's intensively farmed Central Valley reveals several key physical and socioeconomic factors driving landscape change. As part of the USGS Land Cover Trends Project, we analyzed modern land-use/land-cover change for the California Central Valley ecoregion between 2000 and 2010, monitoring annual change between 2005 and 2010, while creating two new change intervals (2000-2005 and 2005-2010) to update the existing 27-year, interval-based analysis. Between 2000 and 2010, agricultural lands fluctuated due to changes in water allocations and emerging drought conditions, or were lost permanently to development (240 square km). Land-use pressure from agriculture and development also led to a decline in grasslands and shrublands across the region (280 square km). Overall, 400 square km of new developed lands were added in the first decade of the 21st century. From 2007 to 2010, development only expanded by 50 square km, coinciding with defaults in the banking system, the onset of historic foreclosure crisis in California and the global economic downturn. Our annual LULC change estimates capture landscape-level change in response to regional policy changes, climate, and fluctuations (e.g., growth or decline) in the national and global economy. The resulting change data provide insights into the drivers of landscape change in the California Central Valley and the combination of two consistent mapping efforts represents the first continuous, 37-year endeavor of its kind.

Groundwater availability of the Central Valley Aquifer, California

USGS Publications Warehouse

Faunt, Claudia C.

2009-01-01

California's Central Valley covers about 20,000 square miles and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the Central Valley with an estimated value of $17 billion per year. This irrigated agriculture relies heavily on surface-water diversions and groundwater pumpage. Approximately one-sixth of the Nation's irrigated land is in the Central Valley, and about one-fifth of the Nation's groundwater demand is supplied from its aquifers. The Central Valley also is rapidly becoming an important area for California's expanding urban population. Since 1980, the population of the Central Valley has nearly doubled from 2 million to 3.8 million people. The Census Bureau projects that the Central Valley's population will increase to 6 million people by 2020. This surge in population has increased the competition for water resources within the Central Valley and statewide, which likely will be exacerbated by anticipated reductions in deliveries of Colorado River water to southern California. In response to this competition for water, a number of water-related issues have gained prominence: conservation of agricultural land, conjunctive use, artificial recharge, hydrologic implications of land-use change, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS Groundwater Resources Program made a detailed assessment of groundwater availability of the Central Valley aquifer system, that includes: (1) the present status of groundwater resources; (2) how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change. This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at differing scales. The

Groundwater quality in the Antelope Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Antelope Valley is one of the study areas being evaluated. The Antelope study area is approximately 1,600 square miles (4,144 square kilometers) and includes the Antelope Valley groundwater basin (California Department of Water Resources, 2003). Antelope Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lakebeds in the lower parts of the valley. Land use in the study area is approximately 68 percent (%) natural (mostly shrubland and grassland), 24% agricultural, and 8% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Palmdale and Lancaster (2010 populations of 152,000 and 156,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Antelope Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Antelope Valley are completed to depths between 360 and 700 feet (110 to 213 meters), consist of solid casing from the land surface to a depth of 180 to 350 feet (55 to 107 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation and sewer and septic

2014 M=6.0 South Napa earthquake triggered widespread aftershocks and stressed several major faults and exotic fault clusters

USGS Publications Warehouse

Toda, Shinji; Stein, Ross

2015-01-01

The strongest San Francisco Bay area earthquake since the 1989 Mw 7.0 Loma Prieta shock struck near Napa on 24 August 2014. Field mapping (Dawson et al., 2014; Earthquake Engineering Research Institute [EERI], 2014; Brocher et al., 2015) and seismic and geodetic source inversions (Barnhart et al., 2015; Dreger et al., 2015; Wei et al., 2015) indicate that a 15-km-long northwest-trending section of the West Napa Valley fault ruptured in the earthquake. Remarkably, it was the first indisputable surface rupture in the Bay area since 1906. The Napa event, along with other smaller earthquakes such as the 1980 Mw 5.8 Livermore and 1984 Mw 6.2 Morgan Hill events on the Calaveras and Hayward faults over the past 3–4 decades, may indicate that the Bay area region is emerging from the stress shadow of the 1906 Mw 7.8 San Francisco earthquake (Harris and Simpson, 1998; Pollitz et al., 2004). Since 1979, there has been a 140% increase in the rate of Mw≥4.1 shocks (Fig. 1) in the broader Bay area, with most concentrated in a corridor extending north from the 1989 Loma Prieta aftershock zone through the Calaveras, Greenville, Green Valley, Napa, and Rodgers Creek faults east of the San Francisco Bay (Fig. 1a). This corridor roughly coincides with the 1906 stress shadow that is being eroded away by more than a century of stress reaccumulation. The Napa event, as well as the surrounding faults on which we calculate the resulting hazard increases, all lie within this zone.

Groundwater quality in the Santa Clara River Valley, California

USGS Publications Warehouse

Burton, Carmen A.; Landon, Matthew K.; Belitz, Kenneth

2011-01-01

The Santa Clara River Valley (SCRV) study unit is located in Los Angeles and Ventura Counties, California, and is bounded by the Santa Monica, San Gabriel, Topatopa, and Santa Ynez Mountains, and the Pacific Ocean. The 460-square-mile study unit includes eight groundwater basins: Ojai Valley, Upper Ojai Valley, Ventura River Valley, Santa Clara River Valley, Pleasant Valley, Arroyo Santa Rosa Valley, Las Posas Valley, and Simi Valley (California Department of Water Resources, 2003; Montrella and Belitz, 2009). The SCRV study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 12 to 28 inches. The study unit is drained by the Ventura and Santa Clara Rivers, and Calleguas Creek. The primary aquifer system in the Ventura River Valley, Ojai Valley, Upper Ojai Valley, and Simi Valley basins is largely unconfined alluvium. The primary aquifer system in the remaining groundwater basins mainly consists of unconfined sands and gravels in the upper portion and partially confined marine and nonmarine deposits in the lower portion. The primary aquifer system in the SCRV study unit is defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. Public-supply wells typically are completed in the primary aquifer system to depths of 200 to 1,100 feet below land surface (bls). The wells contain solid casing reaching from the land surface to a depth of about 60-700 feet, and are perforated below the solid casing to allow water into the well. Water quality in the primary aquifer system may differ from the water in the shallower and deeper parts of the aquifer. Land use in the study unit is approximately 40 percent (%) natural (primarily shrubs, grassland, and wetlands), 37% agricultural, and 23% urban. The primary crops are citrus, avocados, alfalfa, pasture, strawberries, and dry beans. The largest urban areas in the study unit are the cities of

Space Radar Image of Saline Valley, California

NASA Image and Video Library

1999-04-15

This is a three-dimensional perspective view of Saline Valley, about 30 km 19 miles east of the town of Independence, California created by combining two spaceborne radar images using a technique known as interferometry.

Ground water in the San Joaquin Valley, California

USGS Publications Warehouse

Kunkel, Fred; Hofman, Walter

1966-01-01

Ladies and gentlemen, it is a pleasure to be invited to attend this Irrigation Institute conference and to describe the Geological Survey's program of ground-water studies in the San Joaquin Valley. The U.S. Geological Survey has been making water-resources studies in cooperation with the State of California and other agencies in California for more than 70 years. Three of the earliest Geological Survey Water-Supply Papers--numbers 17, 18, and 19--published in 1898 and 1899, describe "Irrigation near Bakersfield," "Irrigation near Fresno," and "Irrigation near Merced." However, the first Survey report on ground-water occurrence in the San Joaquin Valley was "Ground Water in the San Joaquin Valley," by Mendenhall and others. The fieldwork was done from 1905 to 1910, and the report was published in 1916 as U.S. Geological Survey Water-Supply Paper 398.The current series of ground-water studies in the San Joaquin Valley was begun in 1952 as part of the California Department of Water Resources-U.S. Geological Survey cooperative water-resources program. The first report of this series is Geological Survey Water-Supply Paper 1469, "Ground-Water Conditions and Storage Capacity in the San Joaquin Valley." Other reports are Water-Supply Paper 1618, "Use of Ground-Water Reservoirs for Storage of Surface Water in the San Joaquin Valley;" Water-Supply Paper 1656, "Geology and Ground-Water Features of the Edison-Maricopa Area;" Water-Supply Paper 1360-G, "Ground- Water Conditions in the Mendota-Huron Area;" Water-Supply Paper 1457, "Ground-Water Conditions in the Avenal-McKittrick Area;" and an open-file report, "Geology, Hydrology, and Quality of Water in the Terra Bella-Lost Hills Area."In addition to the preceding published reports, ground-water studies currently are being made of the Kern Fan area, the Hanford- Visalia area, the Fresno area, the Merced area, and of the clays of Tulare Lake. Also, detailed studies of both shallow and deep subsidence in the southern part of

Groundwater quality in the Owens Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Owens Valley is one of the study areas being evaluated. The Owens study area is approximately 1,030 square miles (2,668 square kilometers) and includes the Owens Valley groundwater basin (California Department of Water Resources, 2003). Owens Valley has a semiarid to arid climate, with average annual rainfall of about 6 inches (15 centimeters). The study area has internal drainage, with runoff primarily from the Sierra Nevada draining east to the Owens River, which flows south to Owens Lake dry lakebed at the southern end of the valley. Beginning in the early 1900s, the City of Los Angeles began diverting the flow of the Owens River to the Los Angeles Aqueduct, resulting in the evaporation of Owens Lake and the formation of the current Owens Lake dry lakebed. Land use in the study area is approximately 94 percent (%) natural, 5% agricultural, and 1% urban. The primary natural land cover is shrubland. The largest urban area is the city of Bishop (2010 population of 4,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Owens Lake dry lakebed. The primary aquifers in Owens Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database

78 FR 45114 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-26

... the California State Implementation Plan, Antelope Valley Air Quality Management District AGENCY... the Antelope Valley Air Quality Management District (AVAQMD) portion of the California State... for the South Coast Air Quality Management District (SCAQMD). The Antelope Valley Air Pollution...

Death Valley, California

NASA Technical Reports Server (NTRS)

1994-01-01

This is an image of Death Valley, California, centered at 36.629 degrees north latitude, 117.069 degrees west longitude. The image shows Furnace Creek alluvial fan and Furnace Creek Ranch at the far right, and the sand dunes near Stove Pipe Wells at the center. The dark fork-shaped feature between Furnace Creek fan and the dunes is a smooth flood-plain which encloses Cottonball Basin. The bright dots near the center of the image are corner refectors that have been set-up to calibrate the radar as the Shuttle passes overhead with the SIR-C/X-SAR system. The Jet Propulsion Laboratory alternative photo number is P-43883.

Groundwater quality in the Northern Sacramento Valley, California

USGS Publications Warehouse

Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth

2011-01-01

Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The Northern Sacramento Valley is one of the study units being evaluated.

Groundwater quality in the Southern Sacramento Valley, California

USGS Publications Warehouse

Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth

2011-01-01

Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The Southern Sacramento Valley is one of the study units being evaluated.

Riparian valley oak (Quercus lobata) forest restoration on the middle Sacramento River, California

Treesearch

F. Thomas Griggs; Gregory H. Golet

2002-01-01

In 1989 The Nature Conservancy initiated a riparian horticultural restoration program on the floodplain of the middle Sacramento River, California. At nearly all restoration sites Valley oak (Quercus lobata Nee) comprised a major component of the planting design. Valley oaks are a keystone tree species of lowland floodplain habitats in California...

The 2014 Napa valley earthquake constrained by InSAR and GNSS observations

NASA Astrophysics Data System (ADS)

Polcari, Marco; Fernández, José; Palano, Mimmo; Albano, Matteo; Samsonov, Sergey; Stramondo, Salvatore; Zerbini, Susanna

2015-04-01

In this work InSAR and GNSS data have been exploited to evaluate the 3D displacement field produced by the Mw 6.0 earthquake occurred on August 24th, 2014, southwest of Napa Valley, California. The earthquake epicenter is located within the San Andreas Fault system, which forms the boundary between the North American and Pacific plates. As the Pacific plate moves to the northwest, relative to North America, deformation occurs between the major faults in the System. The InSAR data are those of the Sentinel-1 satellite recently launched on April 3rd, 2014. This satellite is capable of acquiring data in several modes such as Interferometric Wide (IW), Extra Wide (EW) swath mode or the Stripmap mode, thus varying area coverage and pixel resolution. Here a pair of SAR images, acquired in Stripmap mode with an incidence angle of about 23° and a pixel resolution of about 4 meters in both directions, covering an area of 70x180 Km have been used. The pre- and post-earthquake images have been acquired on August 7th and August 31st, 2014 respectively. They are characterized by a perpendicular baseline of 2 meters and have been cut around the epicenter and multi-looked by a factor of 15x15 in range and azimuth to obtain a pixel size of about 60x60 m. The Digital Elevation Model (DEM) provided by the SRTM mission has been used to remove the topographic phase. Moreover, the Goldstein filtering and the Minimum Cost Flow (MCF) phase unwrapping algorithm were also applied. The analyzed GNSS dataset, spanning the 1st August 2014 - 2nd September 2014 period, includes 32 stations belonging to the Bay Area Regional Deformation Network and 301 additional continuous stations available from the UNAVCO and the CDDIS archives. The whole network of stations has been organized into seven sub-networks of about 50 sites each. The sub-networks were processed sharing a number of common sites to provide the necessary ties between them. The results of this processing step are daily estimates of

Geophysical framework of the northern San Francisco Bay region, California

USGS Publications Warehouse

Langenheim, Victoria; Graymer, Russell W.; Jachens, Robert C.; McLaughlin, Robert J.; Wagner, D.L.; Sweetkind, Donald

2010-01-01

We use geophysical data to examine the structural framework of the northern San Francisco Bay region, an area that hosts the northward continuation of the East Bay fault system. Although this fault system has accommodated ∼175 km of right-lateral offset since 12 Ma, how this offset is partitioned north of the bay is controversial and important for understanding where and how strain is accommodated along this stretch of the broader San Andreas transform margin. Using gravity and magnetic data, we map these faults, many of which influenced basin formation and volcanism. Continuity of magnetic anomalies in certain areas, such as Napa and Sonoma Valleys, the region north of Napa Valley, and the region south of the Santa Rosa Plain, preclude significant (>10 km) offset. Much of the slip is partitioned around Sonoma and Napa Valleys and onto the Carneros, Rodgers Creek, and Green Valley faults. The absence of correlative magnetic anomalies across the Hayward–Rodgers Creek–Maacama fault system suggests that this system reactivated older basement structures, which appear to influence seismicity patterns in the region.

Unusual downhole and surface free-field records near the Carquinez Strait bridges during the 24 August 2014 Mw6.0 South Napa, California earthquake

USGS Publications Warehouse

Çelebi, Mehmet; Ghahari, S. Farid; Taciroglu, Ertugrul

2015-01-01

This paper reports the results of Part A of a study of the recorded strong-motion accelerations at the well-instrumented network of the two side-by-side parallel bridges over the Carquinez Strait during the 24 August 2014 (Mw6.0 ) South Napa, Calif. earthquake that occurred at 03:20:44 PDT with epicentral coordinates 38.22N, 122.31W. (http://earthquake.usgs.gov/earthquakes/eqarchives/poster/2014/20140824.php, last accessed on October 17, 2014). Both bridges and two boreholes were instrumented by the California Strong motion Instrumentation Program (CSMIP) of California Geological Survey (CGS) (Shakal et al., 2014). A comprehensive comparison of several ground motion prediction equations as they relate to recorded ground motions of the earthquake is provided by Baltay and Boatright (2015).

Microscopic Identification of Prokaryotes in Modern and Ancient Halite, Saline Valley and Death Valley, California

NASA Astrophysics Data System (ADS)

Schubert, Brian A.; Lowenstein, Tim K.; Timofeeff, Michael N.

2009-06-01

Primary fluid inclusions in halite crystallized in Saline Valley, California, in 1980, 2004-2005, and 2007, contain rod- and coccoid-shaped microparticles the same size and morphology as archaea and bacteria living in modern brines. Primary fluid inclusions from a well-dated (0-100,000 years), 90 m long salt core from Badwater Basin, Death Valley, California, also contain microparticles, here interpreted as halophilic and halotolerant prokaryotes. Prokaryotes are distinguished from crystals on the basis of morphology, optical properties (birefringence), and uniformity of size. Electron micrographs of microparticles from filtered modern brine (Saline Valley), dissolved modern halite crystals (Saline Valley), and dissolved ancient halite crystals (Death Valley) support in situ microscopic observations that prokaryotes are present in fluid inclusions in ancient halite. In the Death Valley salt core, prokaryotes in fluid inclusions occur almost exclusively in halite precipitated in perennial saline lakes 10,000 to 35,000 years ago. This suggests that trapping and preservation of prokaryotes in fluid inclusions is influenced by the surface environment in which the halite originally precipitated. In all cases, prokaryotes in fluid inclusions in halite from the Death Valley salt core are miniaturized (<1 μm diameter cocci, <2.5 μm long, very rare rod shapes), which supports interpretations that the prokaryotes are indigenous to the halite and starvation survival may be the normal response of some prokaryotes to entrapment in fluid inclusions for millennia. These results reinforce the view that fluid inclusions in halite and possibly other evaporites are important repositories of microbial life and should be carefully examined in the search for ancient microorganisms on Earth, Mars, and elsewhere in the Solar System.

GPS measurements of strain accumulation across the Imperial Valley, California: 1986-1989

NASA Technical Reports Server (NTRS)

Larsen, Shawn; Reilinger, Robert

1989-01-01

The Global Positioning System (GPS) data collected in southern California from 1986 to 1989 indicate considerable strain accumulation across the Imperial Valley. Displacements are computed at 29 stations in and near the valley from 1986 to 1988, and at 11 sites from 1988 to 1989. The earlier measurements indicate 5.9 +/- 1.0 cm/yr right-lateral differential velocity across the valley, although the data are heavily influenced by the 1987 Superstition Hills earthquake sequence. Some measurements, especially the east-trending displacements, are suspects for large errors. The 1988 to 1989 GPS displacements are best modeled by 5.2 +/- 0.9 cm/yr of valley crossing deformation, but rates calculated from conventional geodetic measurements (3.4 to 4.3 cm/yr) fit the data nearly as well. There is evidence from GPS and Very Long Base Interferometry (VLBI) observations that the present slip rate along the southern San Andreas fault is smaller than the long-term geologic estimate, suggesting a lower earthquake potential than is currently assumed. Correspondingly, a higher earthquake potential is indicated for the San Jacinto fault. The Imperial Valley GPS sites form part of a 183 station network in southern California and northern Baja California, which spans a cross-section of the North American-Pacific plate boundary.

76 FR 38589 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-01

... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2011-0383; FRL-9428-1] Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District AGENCY... the Antelope Valley Air Quality Management District (AVAQMD) portion of the California State...

Death Valley California as seen from STS-59

NASA Image and Video Library

1994-04-13

STS059-86-059 (9-20 April 1994) --- This oblique handheld Hasselblad 70mm photo shows Death Valley, near California's border with Nevada. The valley -- the central feature of Death Valley National Monument -- extends north to south for some 140 miles (225 kilometers). Hemmed in to the east by the Amargosa Range and to the west by the Panamints, its width varies from 5 to 15 miles (8 to 24 kilometers). Using Spaceborne Imaging Radar (SIR-C) and X-band Synthetic Aperture Radar (X-SAR) onboard the Space Shuttle Endeavour, the crew was able to record a great deal of data on this and other sites, as part of NASA's Mission to Planet Earth.

77 FR 7536 - Revisions to the California State Implementation Plan, Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-13

... the California State Implementation Plan, Joaquin Valley Unified Air Pollution Control District AGENCY... the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portions of the California... U.S.C. 804(2). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

Project Waiver of American Iron and Steel Requirements to the Napa Sanitation District for 24-Inch Diameter Butterfly Valves

EPA Pesticide Factsheets

Waiver approval by EPA pursuant to the American Iron and Steel Requirements of the Clean Water Act Section 608 to the Napa Sanitation District in California for the purchase of 24-inch butterfly valves.

Groundwater quality in the Indian Wells Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Indian Wells Valley is one of the study areas being evaluated. The Indian Wells study area is approximately 600 square miles (1,554 square kilometers) and includes the Indian Wells Valley groundwater basin (California Department of Water Resources, 2003). Indian Wells Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lake beds in the lower parts of the valley. Land use in the study area is approximately 97.0 percent (%) natural, 0.4% agricultural, and 2.6% urban. The primary natural land cover is shrubland. The largest urban area is the city of Ridgecrest (2010 population of 28,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from the Sierra Nevada to the west and from the other surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada and to the west and from the other surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada and direct infiltration from irrigation and septic systems. The primary sources of discharge are pumping wells and evapotranspiration near the dry lakebeds. The primary aquifers in the Indian Wells study area are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in

The Imperial Valley of California is critical to wintering Mountain Plovers

USGS Publications Warehouse

Wunder, Michael B.; Knopf, F.L.

2003-01-01

We surveyed Mountain Plovers (Charadrius montanus) wintering in the Imperial Valley of California in January 2001, and also recorded the types of crop fields used by plovers in this agricultural landscape. We tallied 4037 plovers in 36 flocks ranging in size from 4 to 596 birds. Plovers were more common on alfalfa and Bermudagrass fields than other field types. Further, most birds were on alfalfa fields that were currently being (or had recently been) grazed, primarily by domestic sheep. Plovers used Bermudagrass fields only after harvest and subsequent burning. Examination of Christmas Bird Count data from 1950–2000 indicated that the Mountain Plover has abandoned its historical wintering areas on the coastal plains of California. Numbers in the Central Valley seem to have undergone recent declines also. We believe that the cultivated landscape of the Imperial Valley provides wintering habitats for about half of the global population of Mountain Plovers. We attribute the current importance of the Imperial Valley for Mountain Plovers to loss of native coastal and Central Valley habitats rather than to a behavioral switching of wintering areas through time. Future changes in specific cropping or management practices in the Imperial Valley will have a major impact on the conservation status of this species.

75 FR 10690 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-09

... the California State Implementation Plan, San Joaquin Valley Air Pollution Control District AGENCY... the San Joaquin Valley Air Pollution Control District (SJVAPCD) portion of the California State...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

Color Image of Death Valley, California from SIR-C

NASA Image and Video Library

1999-09-27

This radar image shows the area of Death Valley, California and the different surface types in the area. Radar is sensitive to surface roughness with rough areas showing up brighter than smooth areas, which appear dark.

Revisiting the 1872 Owens Valley, California, Earthquake

USGS Publications Warehouse

Hough, S.E.; Hutton, K.

2008-01-01

The 26 March 1872 Owens Valley earthquake is among the largest historical earthquakes in California. The felt area and maximum fault displacements have long been regarded as comparable to, if not greater than, those of the great San Andreas fault earthquakes of 1857 and 1906, but mapped surface ruptures of the latter two events were 2-3 times longer than that inferred for the 1872 rupture. The preferred magnitude estimate of the Owens Valley earthquake has thus been 7.4, based largely on the geological evidence. Reinterpreting macroseismic accounts of the Owens Valley earthquake, we infer generally lower intensity values than those estimated in earlier studies. Nonetheless, as recognized in the early twentieth century, the effects of this earthquake were still generally more dramatic at regional distances than the macroseismic effects from the 1906 earthquake, with light damage to masonry buildings at (nearest-fault) distances as large as 400 km. Macroseismic observations thus suggest a magnitude greater than that of the 1906 San Francisco earthquake, which appears to be at odds with geological observations. However, while the mapped rupture length of the Owens Valley earthquake is relatively low, the average slip was high. The surface rupture was also complex and extended over multiple fault segments. It was first mapped in detail over a century after the earthquake occurred, and recent evidence suggests it might have been longer than earlier studies indicated. Our preferred magnitude estimate is Mw 7.8-7.9, values that we show are consistent with the geological observations. The results of our study suggest that either the Owens Valley earthquake was larger than the 1906 San Francisco earthquake or that, by virtue of source properties and/or propagation effects, it produced systematically higher ground motions at regional distances. The latter possibility implies that some large earthquakes in California will generate significantly larger ground motions than San

ANALYSIS OF LOTIC MACROINVERTEBRATE ASSEMBLAGES IN CALIFORNIA'S CENTRAL VALLEY

EPA Science Inventory

Using multivariate and cluster analyses, we examined the relaitonships between chemical and physical characteristics and macroinvertebrate assemblages at sites sampled by R-EMAP in California's Central Valley. By contrasting results where community structure was summarized as met...

Food and Environment. A Teachers' Resource Guide to California Valley Agriculture.

ERIC Educational Resources Information Center

Railton, Esther, Comp.

Presented is a compilation of teaching resources prepared by teachers enrolled in a graduate-level environmental education course at California State University, Hayward. The emphasis of these materials is upon agriculture and related environmental practices in California's San Joaquin Valley. Following a description of course logistics are six…

Feature Detection in SAR Interferograms With Missing Data Displays Fault Slip Near El Mayor-Cucapah and South Napa Earthquakes

NASA Astrophysics Data System (ADS)

Parker, J. W.; Donnellan, A.; Glasscoe, M. T.; Stough, T.

2015-12-01

Edge detection identifies seismic or aseismic fault motion, as demonstrated in repeat-pass inteferograms obtained by the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) program. But this identification, demonstrated in 2010, was not robust: for best results, it requires a flattened background image, interpolation into missing data (holes) and outliers, and background noise that is either sufficiently small or roughly white Gaussian. Proper treatment of missing data, bursting noise patches, and tiny noise differences at short distances apart from bursts are essential to creating an acceptably reliable method sensitive to small near-surface fractures. Clearly a robust method is needed for machine scanning of the thousands of UAVSAR repeat-pass interferograms for evidence of fault slip, landslides, and other local features: hand-crafted intervention will not do. Effective methods of identifying, removing and filling in bad pixels reveal significant features of surface fractures. A rich network of edges (probably fractures and subsidence) in difference images spanning the South Napa earthquake give way to a simple set of postseismically slipping faults. Coseismic El Mayor-Cucapah interferograms compared to post-seismic difference images show nearly disjoint patterns of surface fractures in California's Sonoran Desert; the combined pattern reveals a network of near-perpendicular, probably conjugate faults not mapped before the earthquake. The current algorithms for UAVSAR interferogram edge detections are shown to be effective in difficult environments, including agricultural (Napa, Imperial Valley) and difficult urban areas (Orange County.).

Near-Field Deformation Associated with the South Napa Earthquake (M 6.0) Using Differential Airborne LiDAR

NASA Astrophysics Data System (ADS)

Hudnut, K. W.; Glennie, C. L.; Brooks, B. A.; Hauser, D. L.; Ericksen, T.; Boatwright, J.; Rosinski, A.; Dawson, T. E.; Mccrink, T. P.; Mardock, D. K.; Hoirup, D. F., Jr.; Bray, J.

2014-12-01

Pre-earthquake airborne LiDAR coverage exists for the area impacted by the M 6.0 South Napa earthquake. The Napa watershed data set was acquired in 2003, and data sets were acquired in other portions of the impacted area in 2007, 2010 and 2014. The pre-earthquake data are being assessed and are of variable quality and point density. Following the earthquake, a coalition was formed to enable rapid acquisition of post-earthquake LiDAR. Coordination of this coalition took place through the California Earthquake Clearinghouse; consequently, a commercial contract was organized by Department of Water Resources that allowed for the main fault rupture and damaged Browns Valley area to be covered 16 days after the earthquake at a density of 20 points per square meter over a 20 square kilometer area. Along with the airborne LiDAR, aerial imagery was acquired and will be processed to form an orthomosaic using the LiDAR-derived DEM. The 'Phase I' airborne data were acquired using an Optech Orion M300 scanner, an Applanix 200 GPS-IMU, and a DiMac ultralight medium format camera by Towill. These new data, once delivered, will be differenced against the pre-earthquake data sets using a newly developed algorithm for point cloud matching, which is improved over prior methods by accounting for scan geometry error sources. Proposed additional 'Phase II' coverage would allow repeat-pass, post-earthquake coverage of the same area of interest as in Phase I, as well as an addition of up to 4,150 square kilometers that would potentially allow for differential LiDAR assessment of levee and bridge impacts at a greater distance from the earthquake source. Levee damage was reported up to 30 km away from the epicenter, and proposed LiDAR coverage would extend up to 50 km away and cover important critical lifeline infrastructure in the western Sacramento River delta, as well as providing full post-earthquake repeat-pass coverage of the Napa watershed to study transient deformation.

Victor Valley College Agreement between the Victor Valley Community College District and the Victor Valley College California Teachers Association Chapter 1170. July 1989 - June 1992.

ERIC Educational Resources Information Center

Victor Valley Community Coll. District, Victorville, CA.

The collective bargaining agreement between the Victor Valley College Board of Trustees and the Victor Valley College California Teachers Association/National Education Association is presented. This contract, covering the period from July 1989 through June 1992, deals with the following topics: bargaining agent recognition; district and…

77 FR 214 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-04

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approval of revisions to the San Joaquin Valley Air Pollution Control District (SJVUAPCD) portion of the... used by the California Air Resources Board and air districts for evaluating air pollution control...

77 FR 58312 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-20

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control... section 307(b)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

Fog and Haze in California's San Joaquin Valley

NASA Technical Reports Server (NTRS)

2001-01-01

This illustration features images of southern California and southwestern Nevada acquired on January 3, 2001 (Terra orbit 5569), and includes data from three of MISR's nine cameras. The San Joaquin Valley, which comprises the southern extent of California's Central Valley, covers much of the viewed area. Also visible are several of the Channel Islands near the bottom, and Mono and Walker Lakes, which stand out as darker patches near the top center, especially in the vertical and backward oblique images. Near the lower right of each image is the Los Angeles Basin, with the distinctive chevron shape of the Mojave Desert to its north.

The Central Valley is a well-irrigated and richly productive agricultural area situated between the Coast Range and the snow-capped Sierra Nevadas. During the winter, the region is noted for its hazy overcasts and a low, thick ground fog known as the Tule. Owing to the effects of the atmosphere on reflected sunlight, dramatic differences in the MISR images are apparent as the angle of view changes. An area of thick, white fog in the San Joaquin Valley is visible in all three of the images. However, the pervasive haze that fills most of the valley is only slightly visible in the vertical view. At the oblique angles, the haze is highly distinguishable against the land surface background, particularly in the forward-viewing direction. Just above image center, the forward view also reveals bluish-tinged plumes near Lava Butte in Sequoia National Forest, where the National Interagency Coordination Center reported an active forest fire.

The changing surface visibility in the multi-angle data allows us to derive the amount of atmospheric haze. In the lower right quadrant is a map of haze amount determined from automated processing of the MISR imagery. Low amounts of haze are shown in blue, and a variation in hue through shades of green, yellow, and red indicates progressively larger amounts of airborne particulates. Due to the

Gravity survey and depth to bedrock in Carson Valley, Nevada-California

USGS Publications Warehouse

Maurer, D.K.

1985-01-01

Gravity data were obtained from 460 stations in Carson Valley, Nevada and California. The data have been interpreted to obtain a map of approximate depth to bedrock for use in a ground-water model of the valley. This map delineates the shape of the alluvium-filled basin and shows that the maximum depth to bedrock exceeds 5,000 feet, on the west side of the valley. A north-south trending offset in the bedrock surface shows that the Carson-Valley/Pine-Nut-Mountain block has not been tilted to the west as a simple unit, but is comprised of several smaller blocks. (USGS)

Building a Rich Community-Contributed Phenology Dataset: Lessons Learned from Winegrapes in California’s Napa Valley

NASA Astrophysics Data System (ADS)

Cahill, K. N.; Cayan, D. R.; Dettinger, M.

2009-12-01

In the wine industry of California’s Napa Valley, there is great community interest in using legacy and modern observations of grapevine phenological stages to track trends in both phenology and climate. Although management such as changing pruning and winemaking preferences can affect phenological records, grapevines can serve as sensitive climate indicators. In collaboration with a local vintners’ organization, we conducted an outreach campaign to solicit contributions of climate and phenological data from winegrowers and winemakers. We received nearly 10,000 phenological records dating from 1940 to the present, including data on budbreak, bloom, véraison (color change), and harvest dates for 68 minor grape varieties (15% of the data) and 10 major varieties (85% of the data). Compiling a unified database from records collected by different individuals in different ways presented a challenge, and we developed several new approaches to using data from our newly compiled records to develop empirical corrections to standardize observations across the dataset. The time series of phenological observations, along with a companion set of regional climate observations, reveal, expectedly, a strong linkage to seasonal temperature and, unexpectedly, a significant association with winter precipitation. The series of harvest timing reports contains influences of both management and climate. We will also present lessons learned on data management, confidentiality, and science-stakeholder partnerships relevant for others interested in conducting community phenological partnerships.

78 FR 59840 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-30

...] Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District... of plan. * * * * * (c) * * * (428) * * * (i) * * * (B) Antelope Valley Air Quality Management...) * * * (i) * * * (B) Antelope Valley Air Quality Management District. (1) Rule 431.1, ``Sulfur Content of...

Comparison of inversion models using AIRSAR data for Death Valley, California

NASA Technical Reports Server (NTRS)

Kierein-Young, Kathryn S.

1993-01-01

Polarimetric Airborne Synthetic Aperture Radar (AIRSAR) data were collected for the Geologic Remote Sensing Field Experiment (GRSFE) over Death Valley, California, USA, in September 1989. AIRSAR is a four-look, quid-polarizaiton, three frequency instrument. It collects measurements at C-band (5.66 cm), L-band (23.98 cm), and P-band (68.13 cm), and has a GIFOV of 10 meters and a swath width of 12 kilometers. Because the radar measures at three wavelengths, different scales of surface roughness are measured. Also, dielectric constants can be calculated from the data. The scene used in this study is in Death Valley, California and is located over Trail Canyon alluvial fan, the valley floor, and Artists Drive alluvial fan. The fans are very different in mineralogic makeup, size, and surface roughness. Trail Canyon fan is located on the west side of the valley at the base of the Panamint Range and is a large fan with older areas of desert pavement and younger active channels. The source for the material on southern part of the fan is mostly quartzites and there is an area of carbonate source on the northern part of the fan. Artists Drive fan is located at the base of the Black Mountains on the east side of the valley and is a smaller, young fan with its source mostly from volcanic rocks. The valley floor contains playa and salt deposits that range from smooth to Devil's Golf course type salt pinnacles.

76 FR 38572 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-01

... the California State Implementation Plan, Antelope Valley Air Quality Management District AGENCY... approve revisions to the Antelope Valley Air Quality Management District (AVAQMD) portion of the... approving with the dates that they were adopted by the Antelope Valley Air Quality Management District...

Recent land-use/land-cover change in the Central California Valley

USGS Publications Warehouse

Soulard, Christopher E.; Wilson, Tamara S.

2013-01-01

Open access to Landsat satellite data has enabled annual analyses of modern land-use and land-cover change (LULCC) for the Central California Valley ecoregion between 2005 and 2010. Our annual LULCC estimates capture landscape-level responses to water policy changes, climate, and economic instability. From 2005 to 2010, agriculture in the region fluctuated along with regulatory-driven changes in water allocation as well as persistent drought conditions. Grasslands and shrublands declined, while developed lands increased in former agricultural and grassland/shrublands. Development rates stagnated in 2007, coinciding with the onset of the historic foreclosure crisis in California and the global economic downturn. We utilized annual LULCC estimates to generate interval-based LULCC estimates (2000–2005 and 2005–2010) and extend existing 27 year interval-based land change monitoring through 2010. Resulting change data provides insights into the drivers of landscape change in the Central California Valley ecoregion and represents the first, continuous, 37 year mapping effort of its kind.

Effects of Groundwater Development on Uranium: Central Valley, California, USA

USGS Publications Warehouse

Jurgens, Bryant C.; Fram, Miranda S.; Belitz, Kenneth; Burow, Karen R.; Landon, Matthew K.

2009-01-01

Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urban development during the last 100 years have changed the chemistry and magnitude of groundwater recharge, and increased the rate of downward groundwater movement. Strong correlations between U and bicarbonate suggest that U is leached from shallow sediments by high bicarbonate water, consistent with findings of previous work in Modesto, California. Summer irrigation of crops in agricultural areas and, to lesser extent, of landscape plants and grasses in urban areas, has increased Pco2 concentrations in the soil zone and caused higher temperature and salinity of groundwater recharge. Coupled with groundwater pumping, this process, as evidenced by increasing bicarbonate concentrations in groundwater over the last 100 years, has caused shallow, young groundwater with high U concentrations to migrate to deeper parts of the groundwater system that are tapped by public-supply wells. Continued downward migration of U-affected groundwater and expansion of urban centers into agricultural areas will likely be associated with increased U concentrations in public-supply wells. The results from this study illustrate the potential longterm effects of groundwater development and irrigation-supported agriculture on water quality in arid and semiarid regions around the world.

Afterslip behavior following the M6.0, 2014 South Napa earthquake with implications for afterslip forecasting on other seismogenic faults

USGS Publications Warehouse

Lienkaemper, James J.; DeLong, Stephen B.; Domrose, Carolyn J; Rosa, Carla M.

2016-01-01

The M6.0, 24 Aug. 2014 South Napa, California, earthquake exhibited unusually large slip for a California strike-slip event of its size with a maximum coseismic surface slip of 40-50 cm in the north section of the 15 km-long rupture. Although only minor (<10 cm) surface slip occurred coseismically in the southern 9-km section of the rupture, there was considerable postseismic slip, so that the maximum total slip one year after the event approached 40-50 cm, about equal to the coseismic maximum in the north. We measured the accumulation of postseismic surface slip on four, ~100-m-long alignment arrays for one year following the event. Because prolonged afterslip can delay reconstruction of fault-damaged buildings and infrastructure, we analyzed its gradual decay to estimate when significant afterslip would likely end. This forecasting of Napa afterslip suggests how we might approach the scientific and engineering challenges of afterslip from a much larger M~7 earthquake anticipated on the nearby, urban Hayward Fault. However, we expect its afterslip to last much longer than one year.The M6.0, 24 Aug. 2014 South Napa, California, earthquake exhibited unusually large slip for a California strike-slip event of its size with a maximum coseismic surface slip of 40-50 cm in the north section of the 15 km-long rupture. Although only minor (<10 cm) surface slip occurred coseismically in the southern 9-km section of the rupture, there was considerable postseismic slip, so that the maximum total slip one year after the event approached 40-50 cm, about equal to the coseismic maximum in the north. We measured the accumulation of postseismic surface slip on four, ~100-m-long alignment arrays for one year following the event. Because prolonged afterslip can delay reconstruction of fault-damaged buildings and infrastructure, we analyzed its gradual decay to estimate when significant afterslip would likely end. This forecasting of Napa afterslip suggests how we might approach the

Increased body mass of ducks wintering in California's Central Valley

USGS Publications Warehouse

Fleskes, Joseph P.; Yee, Julie L.; Yarris, Gregory S.; Loughman, Daniel L.

2016-01-01

Waterfowl managers lack the information needed to fully evaluate the biological effects of their habitat conservation programs. We studied body condition of dabbling ducks shot by hunters at public hunting areas throughout the Central Valley of California during 2006–2008 compared with condition of ducks from 1979 to 1993. These time periods coincide with habitat increases due to Central Valley Joint Venture conservation programs and changing agricultural practices; we modeled to ascertain whether body condition differed among waterfowl during these periods. Three dataset comparisons indicate that dabbling duck body mass was greater in 2006–2008 than earlier years and the increase was greater in the Sacramento Valley and Suisun Marsh than in the San Joaquin Valley, differed among species (mallard [Anas platyrhynchos], northern pintail [Anas acuta], America wigeon [Anas americana], green-winged teal [Anas crecca], and northern shoveler [Anas clypeata]), and was greater in ducks harvested late in the season. Change in body mass also varied by age–sex cohort and month for all 5 species and by September–January rainfall for all except green-winged teal. The random effect of year nested in period, and sometimes interacting with other factors, improved models in many cases. Results indicate that improved habitat conditions in the Central Valley have resulted in increased winter body mass of dabbling ducks, especially those that feed primarily on seeds, and this increase was greater in regions where area of post-harvest flooding of rice and other crops, and wetland area, has increased. Conservation programs that continue to promote post-harvest flooding and other agricultural practices that benefit wintering waterfowl and continue to restore and conserve wetlands would likely help maintain body condition of wintering dabbling ducks in the Central Valley of California.

76 FR 41745 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-15

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approval and limited disapproval of revisions to the San Joaquin Valley Unified Air Pollution Control... Valley Unified Air Pollution Control District (SJVUAPCD) Rule 4682, Polystyrene, Polyethylene, and...

76 FR 68103 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-03

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District Rule 4692...

Rare earth element content of thermal fluids from Surprise Valley, California

DOE Data Explorer

Andrew Fowler

2015-09-23

Rare earth element measurements for thermal fluids from Surprise Valley, California. Samples were collected in acid washed HDPE bottles and acidified with concentrated trace element clean (Fisher Scientific) nitric acid. Samples were pre-concentratated by a factor of approximately 10 using chelating resin with and IDA functional group and measured on magnetic sector ICP-MS. Samples include Seyferth Hot Springs, Surprise Valley Resort Mineral Well, Leonard's Hot Spring, and Lake City Mud Volcano Boiling Spring.

Effects of Groundwater Development on Uranium: Central Valley, California, USA

USGS Publications Warehouse

Jurgens, B.C.; Fram, M.S.; Belitz, K.; Burow, K.R.; Landon, M.K.

2010-01-01

Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urban development during the last 100 years have changed the chemistry and magnitude of groundwater recharge, and increased the rate of downward groundwater movement. Strong correlations between U and bicarbonate suggest that U is leached from shallow sediments by high bicarbonate water, consistent with findings of previous work in Modesto, California. Summer irrigation of crops in agricultural areas and, to lesser extent, of landscape plants and grasses in urban areas, has increased Pco2 concentrations in the soil zone and caused higher temperature and salinity of groundwater recharge. Coupled with groundwater pumping, this process, as evidenced by increasing bicarbonate concentrations in groundwater over the last 100 years, has caused shallow, young groundwater with high U concentrations to migrate to deeper parts of the groundwater system that are tapped by public-supply wells. Continued downward migration of U-affected groundwater and expansion of urban centers into agricultural areas will likely be associated with increased U concentrations in public-supply wells. The results from this study illustrate the potential long-term effects of groundwater development and irrigation-supported agriculture on water quality in arid and semiarid regions around the world. Journal compilation ?? 2009 National Ground Water Association. No claim to original US government works.

Preliminary hydrogeologic assessment near the boundary of the Antelope Valley and El Mirage Valley groundwater basins, California

USGS Publications Warehouse

Stamos, Christina L.; Christensen, Allen H.; Langenheim, Victoria

2017-07-19

The increasing demands on groundwater for water supply in desert areas in California and the western United States have resulted in the need to better understand groundwater sources, availability, and sustainability. This is true for a 650-square-mile area that encompasses the Antelope Valley, El Mirage Valley, and Upper Mojave River Valley groundwater basins, about 50 miles northeast of Los Angeles, California, in the western part of the Mojave Desert. These basins have been adjudicated to ensure that groundwater rights are allocated according to legal judgments. In an effort to assess if the boundary between the Antelope Valley and El Mirage Valley groundwater basins could be better defined, the U.S. Geological Survey began a cooperative study in 2014 with the Mojave Water Agency to better understand the hydrogeology in the area and investigate potential controls on groundwater flow and availability, including basement topography.Recharge is sporadic and primarily from small ephemeral washes and streams that originate in the San Gabriel Mountains to the south; estimates range from about 400 to 1,940 acre-feet per year. Lateral underflow from adjacent basins has been considered minor in previous studies; underflow from the Antelope Valley to the El Mirage Valley groundwater basin has been estimated to be between 100 and 1,900 acre-feet per year. Groundwater discharge is primarily from pumping, mostly by municipal supply wells. Between October 2013 and September 2014, the municipal pumpage in the Antelope Valley and El Mirage Valley groundwater basins was reported to be about 800 and 2,080 acre-feet, respectively.This study was motivated by the results from a previously completed regional gravity study, which suggested a northeast-trending subsurface basement ridge and saddle approximately 3.5 miles west of the boundary between the Antelope Valley and El Mirage Valley groundwater basins that might influence groundwater flow. To better define potential basement

75 FR 4759 - Withdrawal of Proposed Rule Revising the California State Implementation Plan, San Joaquin Valley...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-29

... Proposed Rule Revising the California State Implementation Plan, San Joaquin Valley Unified Air Pollution... approval of revisions to the San Joaquin Valley Unified Air Pollution Control District portion of the... revisions to the San Joaquin Valley Unified Air Pollution Control District (``District'') portion of the...

75 FR 3996 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-26

... the California State Implementation Plan, San Joaquin Valley Air Pollution Control District AGENCY... limited disapproval of revisions to the San Joaquin Valley Air Pollution Control District (SJVAPCD or... Valley Air Pollution Control District; letter dated and received August 17, 2009. After the close of the...

75 FR 28509 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-21

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... Joaquin Valley Unified Air Pollution Control District, No. 08-17309 (9th Circuit)). In that case, NAHB...

New streams and springs after the 2014 Mw6.0 South Napa earthquake.

PubMed

Wang, Chi-Yuen; Manga, Michael

2015-07-09

Many streams and springs, which were dry or nearly dry before the 2014 Mw6.0 South Napa earthquake, started to flow after the earthquake. A United States Geological Survey stream gauge also registered a coseismic increase in discharge. Public interest was heightened by a state of extreme drought in California. Since the new flows were not contaminated by pre-existing surface water, their composition allowed unambiguous identification of their origin. Following the earthquake we repeatedly surveyed the new flows, collecting data to test hypotheses about their origin. We show that the new flows originated from groundwater in nearby mountains released by the earthquake. The estimated total amount of new water is ∼ 10(6) m(3), about 1/40 of the annual water use in the Napa-Sonoma area. Our model also makes a testable prediction of a post-seismic decrease of seismic velocity in the shallow crust of the affected region.

78 FR 49925 - Revisions to California State Implementation Plan, Antelope Valley Air Quality Management...

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2013-08-16

... California State Implementation Plan, Antelope Valley Air Quality Management District and Ventura County Air...: EPA is taking direct final action to approve revisions to the Antelope Valley Air Quality Air Management District (AVAQMD) and Ventura County Air Pollution Control District (VCAPCD) portions of the...

Blue and Valley Oak Seedling Establishment on California's Hardwood Rangelands

Treesearch

Theodore E. Adams Jr.; Peter B. Sands; William H. Weitkamp; Neil K. McDougald

1991-01-01

Factors contributing to poor establishment of blue oak (Quercus douglasii) and valley oak (Q. lobata) in California oak-grassland savannas were studied in a series of acorn seeding experiments initiated in 1985. Exclusion of large herbivores permitted examination of herbaceous interference and small mammal and insect depredation....

Groundwater quality in the Bear Valley and Lake Arrowhead Watershed, California

USGS Publications Warehouse

Mathany, Timothy; Burton, Carmen; Fram, Miranda S.

2017-06-20

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Bear Valley and Lake Arrowhead Watershed study areas in southern California compose one of the study units being evaluated.

77 FR 2469 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

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2012-01-18

... the California State Implementation Plan, Antelope Valley Air Quality Management District and Imperial... Quality Management District (AVAQMD) and Imperial County Air Pollution Control District (ICAPCD) portions... Technology (RACT),'' adopted on February 23, 2010. * * * * * (G) Antelope Valley Air Quality Management...

77 FR 12526 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

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2012-03-01

... the California State Implementation Plan, Antelope Valley Air Quality Management District and Mojave Desert Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the Antelope Valley Air Quality Management District...

78 FR 25011 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

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2013-04-29

... the California State Implementation Plan, Antelope Valley Air Quality Management District, Santa Barbara County Air Pollution Control District, South Coast Air Quality Management District and Ventura... rule. SUMMARY: EPA is proposing to approve revisions to the Antelope Valley Air Quality Management...

78 FR 58459 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

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2013-09-24

... the California State Implementation Plan, Antelope Valley Air Quality Management District, Santa Barbara County Air Pollution Control District, South Coast Air Quality Management District and Ventura.... SUMMARY: EPA is finalizing approval of revisions to the Antelope Valley Air Quality Management District...

Research Spotlight: Groundwater is being depleted rapidly in California's Central Valley

NASA Astrophysics Data System (ADS)

Tretkoff, Ernie

2011-03-01

Groundwater is being depleted in California's Central Valley at a rapid rate, according to data from the Gravity Recovery and Climate Experiment (GRACE) satellite. Famiglietti et al. analyzed 78 months of GRACE data covering October 2003 to March 2010 to estimate water storage changes in California's Sacramento and San Joaquin river basins. They found that the basins are losing water at a rate of about 30 millimeters per year equivalent water height, or a total of about 30 cubic kilometers over the 78-month period. Furthermore, they found that two thirds of this loss, or a total of 20 cubic kilometers for the study period, came from groundwater depletion in the Central Valley. Quantifying groundwater depletion can be challenging in many areas because of a lack of monitoring infrastructure and reporting requirements; the study shows that satellite-based monitoring can be a useful way to track groundwater volumes. The authors warn that the current rate of groundwater depletion in the Central Valley may be unsustainable and could have “potentially dire consequences for the economic and food security of the United States.” (Geophysical Research Letters, doi:10.1029/2010GL046442, 2011)

Rock-fall potential in the Yosemite Valley, California

USGS Publications Warehouse

Wieczorek, G.F.; Morrissey, M.M.; Iovine, Giulio; Godt, Jonathan

1999-01-01

We used two methods of estimating rock-fall potential in the Yosemite Valley, California based on (1) physical evidence of previous rock-fall travel, in which the potential extends to the base of the talus, and (2) theoretical potential energy considerations, in which the potential can extend beyond the base of the talus, herein referred to as the rock-fall shadow. Rock falls in the valley commonly range in size from individual boulders of less than 1 m3 to moderate-sized falls with volumes of about 100,000 m3. Larger rock falls exceeding 100,000 m3, referred to as rock avalanches, are considered to be much less likely to occur based on the relatively few prehistoric rock-fall avalanche deposits in the Yosemite Valley. Because the valley has steep walls and is relatively narrow, there are no areas that are absolutely safe from large rock avalanches. The map shows areas of rock-fall potential, but does not predict when or how frequently a rock fall will occur. Consequently, neither the hazard in terms of probability of a rock fall at any specific location, nor the risk to people or facilities to such events can be assessed from this map.

76 FR 67369 - Revisions to the California State Implementation Plan, Joaquin Valley Unified Air Pollution...

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2011-11-01

... the California State Implementation Plan, Joaquin Valley Unified Air Pollution Control District and Imperial County Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution...

Digital Tabulation of Geologic and Hydrologic Data from Water Wells in the Northern San Francisco Bay Region, Northern California

USGS Publications Warehouse

Sweetkind, D.S.; Taylor, E.M.

2010-01-01

Downhole lithologic information and aquifer pumping test data are reported from 464 wells from a broad area of the northern part of the Coast Ranges in California. These data were originally published in paper form as numerous tables within three USGS Water-Supply Papers describing geology and groundwater conditions in Napa and Sonoma Valleys, the Santa Rosa and Petaluma Valley areas, and in the Russian River Valley and areas in Sonoma and Mendocino Counties, Calif. The well data are compiled in this report in digital form suitable for use in a digital mapping environment. These data, although mostly from relatively shallow water wells, provide important subsurface information that displays the disposition and facies transition of lithologic units throughout this broad area. Well lithologic data themselves and simple three-dimensional interpolation of those data show distinct spatial patterns that are linked to subsurface stratigraphy and structure and can be used to aid in the assessment of the groundwater resources.

Tearing the terroir: Details and implications of surface rupture and deformation from the 24 August 2014 M6.0 South Napa earthquake, California

USGS Publications Warehouse

DeLong, Stephen B.; Donnellan, Andrea; Ponti, Daniel J.; Rubin, Ron S.; Lienkaemper, James J.; Prentice, Carol S.; Dawson, Timothy E.; Seitz, Gordon G.; Schwartz, David P.; Hudnut, Kenneth W.; Rosa, Carla M.; Pickering, Alexandra J; Parker, Jay W.

2016-01-01

The Mw 6.0 South Napa earthquake of 24 August 2014 caused slip on several active fault strands within the West Napa Fault Zone (WNFZ). Field mapping identified 12.5 km of surface rupture. These field observations, near-field geodesy and space geodesy, together provide evidence for more than ~30 km of surface deformation with a relatively complex distribution across a number of subparallel lineaments. Along a ~7 km section north of the epicenter, the surface rupture is confined to a single trace that cuts alluvial deposits, reoccupying a low-slope scarp. The rupture continued northward onto at least four other traces through subparallel ridges and valleys. Postseismic slip exceeded coseismic slip along much of the southern part of the main rupture trace with total slip 1 year postevent approaching 0.5 m at locations where only a few centimeters were measured the day of the earthquake. Analysis of airborne interferometric synthetic aperture radar data provides slip distributions along fault traces, indicates connectivity and extent of secondary traces, and confirms that postseismic slip only occurred on the main trace of the fault, perhaps indicating secondary structures ruptured as coseismic triggered slip. Previous mapping identified the WNFZ as a zone of distributed faulting, and this was generally borne out by the complex 2014 rupture pattern. Implications for hazard analysis in similar settings include the need to consider the possibility of complex surface rupture in areas of complex topography, especially where multiple potentially Quaternary-active fault strands can be mapped.

SRTM Perspective View with Landsat Overlay: San Joaquin Valley, California

NASA Technical Reports Server (NTRS)

2000-01-01

San Joaquin, the name given to the southern portion of California's vast Central Valley, has been called the world's richest agricultural valley. In this perspective view generated using data from the Shuttle Radar Topography Mission and an enhanced Landsat image, we are looking toward the southwest over a checkerboard pattern of agricultural fields. Mt. Pinos, a popular location for stargazing at 2,692 meters (8,831 feet) looms above the valley floor and is visible on the left side of the image. The productive southern San Joaquin is in reality a desert, averaging less than 12.7 cm (5 inches) of rain per year. Through canals and irrigation, the region nurtures some two hundred crops including grapes, figs, apricots, oranges, and more than 4,047 square-km (1,000,000 acres) of cotton. The California Aqueduct, transporting water from the Sacramento River Delta through the San Joaquin, runs along the base of the low-lying Wheeler Ridge on the left side of the image. The valley is not all agriculture though. Kern County, near the valley's southern end, is the United States' number one oil producing county, and actually produces more crude oil than Oklahoma. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors, from Landsat data, approximate natural color.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U

Africanized bees extend their distribution in California.

PubMed

Lin, Wei; McBroome, Jakob; Rehman, Mahwish; Johnson, Brian R

2018-01-01

Africanized honey bees (Apis mellifera) arrived in the western hemisphere in the 1950s and quickly spread north reaching California in the 1990s. These bees are highly defensive and somewhat more difficult to manage for commercial purposes than the European honey bees traditionally kept. The arrival of these bees and their potentially replacing European bees over much of the state is thus of great concern. After a 25 year period of little systematic sampling, a recent small scale study found Africanized honey bees in the Bay Area of California, far north of their last recorded distribution. The purpose of the present study was to expand this study by conducting more intensive sampling of bees from across northern California. We found Africanized honey bees as far north as Napa and Sacramento. We also found Africanized bees in all counties south of these counties. Africanized honey bees were particularly abundant in parts of the central valley and Monterey. This work suggests the northern spread of Africanized honey bees may not have stopped. They may still be moving north at a slow rate, although due to the long gaps in sampling it is currently impossible to tell for certain. Future work should routinely monitor the distribution of these bees to distinguish between these two possibilities.

77 FR 5709 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2012-02-06

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77 FR 2496 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

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2012-01-18

... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2011-0987; FRL-9617-5] Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District and Imperial... rule. SUMMARY: EPA is proposing to approve revisions to the Antelope Valley Air Quality Management...

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2013-08-16

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Sources of Increased Spring and Streamflow Caused by the 2014 South Napa Earthquake

NASA Astrophysics Data System (ADS)

Rytuba, J. J.; Holzer, T. L.

2014-12-01

Seasonally dry springs and creeks began flowing over a broad region in the hills around Napa following the M6.0 South Napa earthquake on August 24, 2014. Flows in hillside creek beds, which were dry before the earthquake, were reported from 19 km west, to 6 km east, and 18 km north of Napa and the epicenter, an area that shook at MMI≥VI. The exact timing of the increased flow is unknown because the earthquake occurred at 3:20 AM PDT. A gaging station on the Napa River, which is downstream from several tributaries that began flowing after the earthquake, showed a sudden increase of flow rate within 45 minutes following the earthquake. The sudden increase at the gaging station suggests flows initiated either contemporaneously with or very soon after the strong shaking. This timing is consistent with eyewitness accounts of other streams and springs at daylight, a few hours after the earthquake. One of the largest increases of streamflow was in Green Valley, where a streamflow rate of about 100 cubic hectometers per day was measured in Wild Horse Creek. Two types of waters are being discharged in the Wild Horse Creek drainage: 1) water with low iron concentration that has exchanged with rhyolitic flows and tuffs in the upper part of the drainage; and 2) high iron concentration water that has exchanged with basaltic andesite in the middle part of drainage (vertical interval of about 75 meters). The high iron waters are depositing FeOOH other iron phases. Mixing of the two water types results in water with pH 6.9 and conductivity of 0.197 mS. This water is used by the Vallejo Water District for domestic purposes after it is mixed with recent surface water runoff stored in Lake Frey reservoir in order to improve its quality. Other drainages that have increased flow since the earthquake have water chemistry consistent with exchange with rhyolitic flows and tuffs that are the dominant rock type in these drainages.

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2011-11-16

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76 FR 33181 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2011-06-08

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76 FR 5276 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2011-01-31

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... protection, Air pollution control, Incorporation by reference, Intergovernmental relations, Nitrogen dioxide...

Death Valley, California

NASA Image and Video Library

1994-04-11

STS059-S-026 (11 April 1994) --- This is an image of Death Valley, California, centered at 36.629 degrees north latitude, 117.069 degrees west longitude. The image shows Furnace Creek alluvial fan and Furnace Creek Ranch at the far right, and the sand dunes near Stove Pipe Wells at the center. The dark fork-shaped feature between Furnace Creek fan and the dunes is a smooth flood-plain which encloses Cottonball Basin. The SIR-C/X-SAR supersite is an area of extensive field investigations and has been visited by both Space Radar Lab astronaut crews. Elevations in the Valley range from 70 meters below sea level, the lowest in the United States, to more than 3300 meters above sea level. Scientists are using SIR-C/X-SAR data from Death Valley to help answer a number of different questions about the Earth's geology. One question concerns how alluvial fans are formed and change through time under the influence of climatic changes and earthquakes. Alluvial fans are gravel deposits that wash down from the mountains over time. They are visible in the image as circular, fan-shaped bright areas extending into the darker valley floor from the mountains. Information about the alluvial fans help scientists study Earth's ancient climate. Scientists know the fans are bulit up through climatic and tectonic processes and they will use the SIR-C/X-SAR data to understand the nature and rates of weathering processes on the fans, soil formation, and the transport of sand and dust by the wind. SIR-C/X-SAR's sensitivity to centimeter-scale (or inch-scale) roughness provides detailed maps of surface texture. Such information can be used to study the occurrence and movement of dust storms and sand dunes. the goal of these studies is to gain a better understanding of the record of past climatic changes and the effects of those changes on a sensitive environment. This may lead to a better ability to predict future response of the land to different potential global cimate-change scenarios

Aquifer-test compilation for the San Joaquin Valley, California

USGS Publications Warehouse

McClelland, E.J.

1962-01-01

This report is the first of a series the purpose of which is to make available in standard tabular form the results of aquifer tests that have been made by various private and public agencies in California. The scope of the compilation is to describe systematically, in a form agreed upon by the California Department of Water Resources and the Geological Survey, the (1) test location, (2) pumping data, (3) well data, and (4) summary of results. The results of these tests sometimes have been published but most frequently have been used only as a step in obtaining other information, consequently the results and even the location of aquifer tests have not been readily available.This report has been prepared by the Geological Survey under the immediate supervision of Fred Kunkel, district geologist for California, in cooperation with the California Department of Water Resources, and tabulates through October 1962 all tests analyzed by the Geological Survey for the San Joaquin Valley. The report is designed to be expanded when additional tests are analyzed or new tests are made.

76 FR 37044 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2011-06-24

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... Glass Manufacturing'', US EPA, June 1994. 7. ``Integrated Pollution Prevention and Control (IPPC...

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2012-11-05

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76 FR 40660 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

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2011-07-11

... the California State Implementation Plan, San Joaquin Valley Air Pollution Control District (SJVUAPCD... approve revisions to the San Joaquin Valley Air Pollution Control District (SJVUAPCD) portion of the....0 for the following terms: Air Pollution Control Officer, Board, Environmental Protection Agency...

77 FR 24883 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2012-04-26

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76 FR 52623 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2011-08-23

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76 FR 56706 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2011-09-14

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77 FR 35329 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2012-06-13

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Imperial Valley and Salton Sea, California

NASA Technical Reports Server (NTRS)

2002-01-01

Southern California's Salton Sea is a prominent visual for astronauts. This large lake supports the rich agricultural fields of the Imperial, Coachella and Mexicali Valleys in the California and Mexico desert. The Salton Sea formed by accident in 1905 when an irrigation canal ruptured, allowing the Colorado River to flood the Salton Basin. Today the Sea performs an important function as the sink for agricultural runoff; water levels are maintained by the runoff from the surrounding agricultural valleys. The Salton Sea salinity is high-nearly 1/4 saltier than ocean water-but it remains an important stopover point for migratory water birds, including several endangered species. The region also experiences several environmental problems. The recent increased demands for the limited Colorado River water threatens the amount of water allowed to flow into the Salton Sea. Increased salinity and decreased water levels could trigger several regional environmental crises. The agricultural flow into the Sea includes nutrients and agricultural by-products, increasing the productivity and likelihood of algae blooms. This image shows either a bloom, or suspended sediment (usually highly organic) in the water that has been stirred up by winds. Additional information: The Salton Sea A Brief Description of Its Current Conditions, and Potential Remediation Projects and Land Use Across the U.S.-Mexico Border Astronaut photograph STS111-E-5224 was taken by the STS-111 Space Shuttle crew that recently returned from the International Space Station. The image was taken June 12, 2002 using a digital camera. The image was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

Satellites measure recent rates of groundwater depletion in California's Central Valley

NASA Astrophysics Data System (ADS)

Famiglietti, J. S.; Lo, M.; Ho, S. L.; Bethune, J.; Anderson, K. J.; Syed, T. H.; Swenson, S. C.; de Linage, C. R.; Rodell, M.

2011-02-01

In highly-productive agricultural areas such as California's Central Valley, where groundwater often supplies the bulk of the water required for irrigation, quantifying rates of groundwater depletion remains a challenge owing to a lack of monitoring infrastructure and the absence of water use reporting requirements. Here we use 78 months (October, 2003-March, 2010) of data from the Gravity Recovery and Climate Experiment satellite mission to estimate water storage changes in California's Sacramento and San Joaquin River Basins. We find that the basins are losing water at a rate of 31.0 ± 2.7 mm yr-1 equivalent water height, equal to a volume of 30.9 km3 for the study period, or nearly the capacity of Lake Mead, the largest reservoir in the United States. We use additional observations and hydrological model information to determine that the majority of these losses are due to groundwater depletion in the Central Valley. Our results show that the Central Valley lost 20.4 ± 3.9 mm yr-1 of groundwater during the 78-month period, or 20.3 km3 in volume. Continued groundwater depletion at this rate may well be unsustainable, with potentially dire consequences for the economic and food security of the United States.

An improved data integration algorithm to constrain the 3D displacement field induced by fast deformation phenomena tested on the Napa Valley earthquake

NASA Astrophysics Data System (ADS)

Polcari, Marco; Fernández, José; Albano, Matteo; Bignami, Christian; Palano, Mimmo; Stramondo, Salvatore

2017-12-01

In this work, we propose an improved algorithm to constrain the 3D ground displacement field induced by fast surface deformations due to earthquakes or landslides. Based on the integration of different data, we estimate the three displacement components by solving a function minimization problem from the Bayes theory. We exploit the outcomes from SAR Interferometry (InSAR), Global Positioning System (GNSS) and Multiple Aperture Interferometry (MAI) to retrieve the 3D surface displacement field. Any other source of information can be added to the processing chain in a simple way, being the algorithm computationally efficient. Furthermore, we use the intensity Pixel Offset Tracking (POT) to locate the discontinuity produced on the surface by a sudden deformation phenomenon and then improve the GNSS data interpolation. This approach allows to be independent from other information such as in-situ investigations, tectonic studies or knowledge of the data covariance matrix. We applied such a method to investigate the ground deformation field related to the 2014 Mw 6.0 Napa Valley earthquake, occurred few kilometers from the San Andreas fault system.

Groundwater quality in the western San Joaquin Valley, California

USGS Publications Warehouse

Fram, Miranda S.

2017-06-09

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Western San Joaquin Valley is one of the study units being evaluated. 

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2011-11-08

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2012-10-22

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2011-03-25

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2010-05-05

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2010-01-13

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2011-11-03

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76 FR 45212 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

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2011-07-28

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... proposing to approve San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) Rule 3170... (CAA or Act). EPA is also proposing to approve SJVUAPCD's fee-equivalent program, which includes Rule...

Rapid Response Products of The ARIA Project for the M6.0 August 24, 2014 South Napa Earthquake

NASA Astrophysics Data System (ADS)

Yun, S. H.; Owen, S. E.; Hua, H.; Milillo, P.; Fielding, E. J.; Hudnut, K. W.; Dawson, T. E.; Mccrink, T. P.; Jo, M. J.; Barnhart, W. D.; Manipon, G. J. M.; Agram, P. S.; Moore, A. W.; Jung, H. S.; Webb, F.; Milillo, G.; Rosinski, A.

2014-12-01

A magnitude 6.0 earthquake struck southern Napa county northeast of San Francisco, California, on Aug. 24, 2014, causing significant damage in the city of Napa and nearby areas. One day after the earthquake, the Advanced Rapid Imaging and Analysis (ARIA) team produced and released observations of coseismic ground displacement measured with continuous GPS stations of the Plate Boundary Observatory (operated by UNAVCO for the National Science Foundation) and the Bay Area Rapid Deformation network (operated by Berkeley Seismological Laboratory). Three days after the earthquake (Aug. 27), the Italian Space Agency's (ASI) COSMO-SkyMed (CSK) satellite acquired their first post-event data. On the same day, the ARIA team, in collaboration with ASI and University of Basilicata, produced and released a coseismic interferogram that revealed ground deformation and surface rupture. The depiction of the surface rupture - discontinuities of color fringes in the CSK interferogram - helped guide field geologists from the US Geological Survey and the California Geological Survey (CGS) to features that may have otherwise gone undetected. Small-scale cracks were found on a runway of the Napa County Airport, as well as bridge damage and damaged roads. ARIA's response to this event highlighted the importance of timeliness for mapping surface deformation features. ARIA's rapid response products were shared through Southern California Earthquake Center's response website and the California Earthquake Clearinghouse. A damage proxy map derived from InSAR coherence of CSK data was produced and distributed on Aug. 27. Field crews from the CGS identified true and false positives, including mobile home damage, newly planted grape vines, and a cripple wall failure of a house. Finite fault slip models constrained from CSK interferograms and continuous GPS observations reveal a north-propagating rupture with well-resolved slip from 0-10.5 km depth. We also measured along-track coseismic

Structural and lithologic study of Northern Coast Range and Sacramento Valley, California

NASA Technical Reports Server (NTRS)

Rich, E. I. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Preliminary analysis of the data received has disclosed two potentially important northwest-trending systems of linear features within the Northern California Coast Ranges. A third system, which trends northeast, can be traced with great uncertainty across the alluviated part of the Sacramento Valley and into the foothills of the Sierra Nevada. These linear features may represent fault systems or zones of shearing. Of interest, although not yet verified, is the observation that some of the mercury concentrations and some of the geothermally active areas of California may be located at the intersection of the Central and the Valley Systems. One, perhaps two, stratigraphic unconformities within the Late Mesozoic sedimentary rocks were detected during preliminary examination of the imagery; however, more analysis is necessary in order to verify this preliminary interpretation. A heretofore unrecognized, large circular depression, about 15 km in diameter, was detected within the alluviated part of the Sacramento Valley. The depression is adjacent to a large laccolithic intrusion and may be geologically related to it. Changes in the photogeologic characteristics of this feature will continue to be monitored.

76 FR 56134 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-12

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... preempt Tribal law. List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

76 FR 53640 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-29

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... section 307(b)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

76 FR 56132 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-12

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of... preempt Tribal law. List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

75 FR 57862 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-23

... the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the... section 307(b)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control...

Detection and characterization of pXFSL21, a novel single-copy plasmid from Xylella fastidiosa Strain Stag’s Leap

USDA-ARS?s Scientific Manuscript database

Xylella fastidiosa Strain Stag’s Leap, originally isolated from Napa Valley, California, is highly virulent in causing Pierce’s Disease (PD) of grapevine. Plasmids are extrachromosomal genetic elements associated with bacterial environmental adaptation such as virulence development. In this study, t...

Kirschenmann Road multi-well monitoring site, Cuyama Valley, Santa Barbara County, California

USGS Publications Warehouse

Everett, R.R.; Hanson, R.T.; Sweetkind, D.S.

2011-01-01

The U.S. Geological Survey (USGS), in cooperation with the Water Agency Division of the Santa Barbara County Department of Public Works, is evaluating the geohydrology and water availability of the Cuyama Valley, California (fig. 1). As part of this evaluation, the USGS installed the Cuyama Valley Kirschenmann Road multiple-well monitoring site (CVKR) in the South-Main subregion of the Cuyama Valley (fig. 1). The CVKR well site is designed to allow for the collection of depth-specific water-level and water-quality data. Data collected at this site provides information about the geology, hydrology, geophysics, and geochemistry of the local aquifer system, thus, enhancing the understanding of the geohydrologic framework of the Cuyama Valley. This report presents the construction information and initial geohydrologic data collected from the CVKR monitoring site, along with a brief comparison to selected supply and irrigation wells from the major subregions of the Cuyama Valley (fig. 1).

Northern California Fires

NASA Image and Video Library

2017-10-31

The October fires in Northern California were some of the most destructive in the state's history. The burned area on the right side of the image is the ATLAS fire, that burned east of Napa; the fire consumed 51,000 acres and destroyed almost 500 structures. The burned area on the left is part of the Nuns fire that burned between Sonoma and Napa; it consumed 110,000 acres, and destroyed almost 7,000 structures. The images were acquired September 7, 2016 and October 28, 2017, cover an area of 34.5 by 39 kilometers, and are located near 38.3 degrees north, 122.3 degrees east. https://photojournal.jpl.nasa.gov/catalog/PIA22019

3-D View of Death Valley, California

NASA Image and Video Library

2001-07-21

This 3-D perspective view looking north over Death Valley, California, was produced by draping ASTER nighttime thermal infrared data over topographic data from the US Geological Survey. The ASTER data were acquired April 7, 2000 with the multi-spectral thermal infrared channels, and cover an area of 60 by 80 km (37 by 50 miles). Bands 13, 12, and 10 are displayed in red, green and blue respectively. The data have been computer enhanced to exaggerate the color variations that highlight differences in types of surface materials. Salt deposits on the floor of Death Valley appear in shades of yellow, green, purple, and pink, indicating presence of carbonate, sulfate, and chloride minerals. The Panamint Mtns. to the west, and the Black Mtns. to the east, are made up of sedimentary limestones, sandstones, shales, and metamorphic rocks. The bright red areas are dominated by the mineral quartz, such as is found in sandstones; green areas are limestones. In the lower center part of the image is Badwater, the lowest point in North America. http://photojournal.jpl.nasa.gov/catalog/PIA02663

The 2014 Mw6.1 South Napa Earthquake: A unilateral rupture with shallow asperity and rapid afterslip

USGS Publications Warehouse

Wei, Shengji; Barbot, Sylvain; Graves, Robert; Lienkaemper, James J.; Wang, Teng; Hudnut, Kenneth W.; Fu, Yuning; Helmberger, Don

2015-01-01

The Mw6.1 South Napa earthquake occurred near Napa, California on August 24, 2014 (UTC), and was the largest inland earthquake in Northern California since the 1989 Mw6.9 Loma Prieta earthquake. The first report of the earthquake from the Northern California Earthquake Data Center (NCEDC) indicates a hypocentral depth of 11.0km with longitude and latitude of (122.3105°W, 38.217°N). Surface rupture was documented by field observations and Lidar imaging (Brooks et al. 2014; Hudnut et al. 2014; Brocher et al., 2015), with about 12 km of continuous rupture starting near the epicenter and extending to the northwest. The southern part of the rupture is relatively straight, but the strike changes by about 15° at the northern end over a 6-km segment. The peak dextral offset was observed near the Buhman residence with right-.‐lateral motion of 46 cm, near the location where the strike of fault begins to rotate clock-.‐wise (Hudnut et al., 2014). The earthquake was well recorded by the strong motion network operated by the NCEDC, the California Geological Survey and the U.S. Geological Survey (USGS). There are about 12 sites within an epicentral distance of 15km, with relatively good azimuthal coverage (Fig.1). The largest peak-ground-velocity (PGV) of nearly 100 cm/s was observed on station 1765, which is the closest station to the rupture and lies about 3 km east of the northern segment (Fig. 1). The ground deformation associated with the earthquake was also well recorded by the high-resolution COSMO-SkyMed satellite and Sentinel-1A satellite, providing independent static observations.

A Comparison of Groundwater Storage Using GRACE Data, Groundwater Levels, and a Hydrological Model in Californias Central Valley

NASA Technical Reports Server (NTRS)

Kuss, Amber; Brandt, William; Randall, Joshua; Floyd, Bridget; Bourai, Abdelwahab; Newcomer, Michelle; Skiles, Joseph; Schmidt, Cindy

2011-01-01

The Gravity Recovery and Climate Experiment (GRACE) measures changes in total water storage (TWS) remotely, and may provide additional insight to the use of well-based data in California's agriculturally productive Central Valley region. Under current California law, well owners are not required to report groundwater extraction rates, making estimation of total groundwater extraction difficult. As a result, other groundwater change detection techniques may prove useful. From October 2002 to September 2009, GRACE was used to map changes in TWS for the three hydrological regions (the Sacramento River Basin, the San Joaquin River Basin, and the Tulare Lake Basin) encompassing the Central Valley aquifer. Net groundwater storage changes were calculated from the changes in TWS for each of the three hydrological regions and by incorporating estimates for additional components of the hydrological budget including precipitation, evapotranspiration, soil moisture, snow pack, and surface water storage. The calculated changes in groundwater storage were then compared to simulated values from the California Department of Water Resource's Central Valley Groundwater- Surface Water Simulation Model (C2VSIM) and their Water Data Library (WDL) Geographic Information System (GIS) change in storage tool. The results from the three methods were compared. Downscaling GRACE data into the 21 smaller Central Valley sub-regions included in C2VSIM was also evaluated. This work has the potential to improve California's groundwater resource management and use of existing hydrological models for the Central Valley.

Geological literature on the San Joaquin Valley of California

USGS Publications Warehouse

Maher, J.C.; Trollman, W.M.; Denman, J.M.

1973-01-01

The following list of references includes most of the geological literature on the San Joaquin Valley and vicinity in central California (see figure 1) published prior to January 1, 1973. The San Joaquin Valley comprises all or parts of 11 counties -- Alameda, Calaveras, Contra Costa, Fresno, Kern, Kings, Madera, Merced, San Joaquin, Stanislaus, and Tulare (figure 2). As a matter of convenient geographical classification the boundaries of the report area have been drawn along county lines, and to include San Benito and Santa Clara Counties on the west and Mariposa and Tuolumne Counties on the east. Therefore, this list of geological literature includes some publications on the Diablo and Temblor Ranges on the west, the Tehachapi Mountains and Mojave Desert on the south, and the Sierra Nevada Foothills and Mountains on the east.

Isla Guadalupe, Mexico (GUAX, SCIGN/PBO) a Relative Constraint for California Borderland and Northern Gulf of California Motions.

NASA Astrophysics Data System (ADS)

Gonzalez-Garcia, J. J.

2004-12-01

Using ITRF2000 as a common reference frame link, I analyzed survey mode and permanent GPS published results, together with SOPAC public data and results (http://sopac.ucsd.edu), in order to evaluate relative present day crustal deformation in California and northern Mexico. The crustal velocity field of Mexico (Marquez-Azua and DeMets, 2003) obtained from continuous GPS measurements conducted by Instituto Nacional de Geografia e Informatica (INEGI) for 1993-2001, was partially used. The preferred model for an instantaneous rigid motion between North-America and Pacific plates (NAPA), is obtained using results of Isla Guadalupe GPS surveys (1991-2002) giving a new constraint for Pacific plate (PA) motion (Gonzalez-Garcia et al., 2003). It produces an apparent reduction of 1 mm/yr in the absolute motion in the border zone between PA and North-America (NA) plates in this region, as compared with other GPS models (v.g. Prawirodirdjo and Bock, 2004); and it is 3 mm/yr higher than NNRNUVEL-1A. In the PA reference frame, westernmost islands from San Francisco (FARB), Los Angeles (MIG1), and Ensenada (GUAX); give current residuals of 1.8, 1.7 and 0.9 mm/yr and azimuths that are consistent with local tectonic setting, respectively. In the NA reference frame, besides the confirmation of 2 mm/yr E-W extension for the southern Basin and Range province in northern Mexico; a present day deformation rate of 40.5 mm/yr between San Felipe, Baja California (SFBC) and Hermosillo, Sonora, is obtained. This rate agrees with a 6.3 to 6.7 Ma for the "initiation of a full sea-floor spreading" in the northern Gulf of California. SFBC has a 7 mm/yr motion in the PA reference frame, giving then, a full NAPA theoretical absolute motion of 47.5 mm/yr. For Puerto Penasco, Sonora (PENA) there is a NAPA motion of 46.2 mm/yr and a residual of 1.2 mm/yr in the NA reference frame, this site is located only 75 km to the northeast from the Wagner basin center. For southern Isla Guadalupe (GUAX) there

Stress-based aftershock forecasts made within 24h post mainshock: Expected north San Francisco Bay area seismicity changes after the 2014M=6.0 West Napa earthquake

USGS Publications Warehouse

Parsons, Thomas E.; Segou, Margaret; Sevilgen, Volkan; Milner, Kevin; Field, Edward; Toda, Shinji; Stein, Ross S.

2014-01-01

We calculate stress changes resulting from the M= 6.0 West Napa earthquake on north San Francisco Bay area faults. The earthquake ruptured within a series of long faults that pose significant hazard to the Bay area, and we are thus concerned with potential increases in the probability of a large earthquake through stress transfer. We conduct this exercise as a prospective test because the skill of stress-based aftershock forecasting methodology is inconclusive. We apply three methods: (1) generalized mapping of regional Coulomb stress change, (2) stress changes resolved on Uniform California Earthquake Rupture Forecast faults, and (3) a mapped rate/state aftershock forecast. All calculations were completed within 24 h after the main shock and were made without benefit of known aftershocks, which will be used to evaluative the prospective forecast. All methods suggest that we should expect heightened seismicity on parts of the southern Rodgers Creek, northern Hayward, and Green Valley faults.

Stress-based aftershock forecasts made within 24 h postmain shock: Expected north San Francisco Bay area seismicity changes after the 2014 M = 6.0 West Napa earthquake

NASA Astrophysics Data System (ADS)

Parsons, Tom; Segou, Margaret; Sevilgen, Volkan; Milner, Kevin; Field, Edward; Toda, Shinji; Stein, Ross S.

2014-12-01

We calculate stress changes resulting from the M = 6.0 West Napa earthquake on north San Francisco Bay area faults. The earthquake ruptured within a series of long faults that pose significant hazard to the Bay area, and we are thus concerned with potential increases in the probability of a large earthquake through stress transfer. We conduct this exercise as a prospective test because the skill of stress-based aftershock forecasting methodology is inconclusive. We apply three methods: (1) generalized mapping of regional Coulomb stress change, (2) stress changes resolved on Uniform California Earthquake Rupture Forecast faults, and (3) a mapped rate/state aftershock forecast. All calculations were completed within 24 h after the main shock and were made without benefit of known aftershocks, which will be used to evaluative the prospective forecast. All methods suggest that we should expect heightened seismicity on parts of the southern Rodgers Creek, northern Hayward, and Green Valley faults.

Geologic Map and Map Database of Eastern Sonoma and Western Napa Counties, California

USGS Publications Warehouse

Graymer, R.W.; Brabb, E.E.; Jones, D.L.; Barnes, J.; Nicholson, R.S.; Stamski, R.E.

2007-01-01

Introduction This report contains a new 1:100,000-scale geologic map, derived from a set of geologic map databases (Arc-Info coverages) containing information at 1:62,500-scale resolution, and a new description of the geologic map units and structural relations in the map area. Prepared as part of the San Francisco Bay Region Mapping Project, the study area includes the north-central part of the San Francisco Bay region, and forms the final piece of the effort to generate new, digital geologic maps and map databases for an area which includes Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Santa Cruz, Solano, and Sonoma Counties. Geologic mapping in Lake County in the north-central part of the map extent was not within the scope of the Project. The map and map database integrates both previously published reports and new geologic mapping and field checking by the authors (see Sources of Data index map on the map sheet or the Arc-Info coverage eswn-so and the textfile eswn-so.txt). This report contains new ideas about the geologic structures in the map area, including the active San Andreas Fault system, as well as the geologic units and their relations. Together, the map (or map database) and the unit descriptions in this report describe the composition, distribution, and orientation of geologic materials and structures within the study area at regional scale. Regional geologic information is important for analysis of earthquake shaking, liquifaction susceptibility, landslide susceptibility, engineering materials properties, mineral resources and hazards, as well as groundwater resources and hazards. These data also assist in answering questions about the geologic history and development of the California Coast Ranges.

A Crustal Velocity Model for South Mexicali Valley, Baja California, México.

NASA Astrophysics Data System (ADS)

Ramirez, E.; Vidal-Villegas, A.; Stock, J. M.; Gonzalez-Fernandez, A.

2016-12-01

The northern Baja California region consists of two subregions of different geological features: the Peninsular Ranges of Baja California, of granitic composition, and the Mexicali Valley region, characterized by a series of sedimentary basins: the Laguna Salada and the Mexicali Valley. Due to the lack of an appropriate crust model for South Mexicali Valley, a refraction study was conducted. We installed 16 three-component short period stations (2 Hz) and one broadband station (100 s - 50 Hz). The stations, spaced 6 km along a refraction profile, recorded a blast performed in the southwest Arizona near the border with Sonora, Mexico. Records gathered were used to estimate a crust velocity structure model for South Mexicali Valley. The beginning of the profile is at San Luis Rio Colorado (SLRC), Sonora and its ending is at the middle of Sierra Juarez, Baja California. As a "reverse shot", for a 47 km section between SLRC and El Mayor Mountain, we used an aftershock M 3.4 of the 2010 M 7.2 El Mayor - Cucapah earthquake. Record sections show seismograms with impulsive P arrivals for nearby stations. The arrival Pn wave is observed at three stations located in Laguna Salada and Sierra Juarez. From the first arrivals of refractions and reflections of the P wave we performed direct modeling of travel times and relative amplitudes (normalized synthetic seismograms). Method based on asymptotic ray theory programed in the RAYINVR software (Zelt and Smith, 1992). We propose an average-three-layer velocity structure model: 2.9, 5.6 and 6.9 km/s, with thicknesses of 1.2, 4.4 and 9.6 km, respectively. Velocities of our model for the region under study are about 1 km/s higher than the model proposed by McMechan and Mooney (1984) for the Imperial Valley. The preliminary interpretation using the "reverse shot" indicates a crust of 15 km depth beneath the Mexicali Valley and 19 km under the El Mayor Mountain and Laguna Salada basin. On the eastern side of the El Mayor Mountain we

Central California Valley Ecoregion: Chapter 17 in Status and trends of land change in the Western United States--1973 to 2000

USGS Publications Warehouse

Sleeter, Benjamin M.

2012-01-01

The Central California Valley Ecoregion, which covers approximately 45,983 km2 (17,754 mi2), is an elongated basin extending approximately 650 km north to south through central California (fig. 1) (Omernik, 1987; U.S. Environmental Protection Agency, 1997). The ecoregion is surrounded entirely by the Southern and Central California Chaparral and Oak Woodlands Ecoregion, which includes parts of the Coast Ranges to the west and which is bounded by the Sierra Nevada to the east. The Central California Valley Ecoregion accounts for more than half of California’s agricultural production value and is one of the most important agricultural regions in the country, with flat terrain, fertile soils, a favorable climate, and nearly 70 percent of its land in cultivation (Kuminoff and others, 2000; Sumner and others, 2003). Commodities produced in the region include milk and dairy, cattle and calves, cotton, almonds, citrus, and grapes, among others (U.S. Department of Agriculture, 2004; Johnston and McCalla, 2004; Kuminoff and others, 2000) (figs. 2A,B,C). Six of the top eight agricultural-producing counties in California are located at least partly within the Central California Valley Ecoregion (Kuminoff and others, 2000) (table 1). The Central California Valley Ecoregion is also home to nearly 5 million people spread throughout the region, including the major cities of Sacramento (state capital), Fresno, Bakersfield, and Stockton, California (U.S. Census Bureau, 2000) (fig. 1).

Mapping Drought Impacts on Agricultural Production in California's Central Valley

NASA Astrophysics Data System (ADS)

Melton, F. S.; Guzman, A.; Johnson, L.; Rosevelt, C.; Verdin, J. P.; Dwyer, J. L.; Mueller, R.; Zakzeski, A.; Thenkabail, P. S.; Wallace, C.; Jones, J.; Windell, S.; Urness, J.; Teaby, A.; Hamblin, D.; Post, K. M.; Nemani, R. R.

2014-12-01

The ongoing drought in California has substantially reduced surface water supplies for millions of acres of irrigated farmland in California's Central Valley. Rapid assessment of drought impacts on agricultural production can aid water managers in assessing mitigation options, and guide decision making with respect to requests for local water transfers, county drought disaster designations, and allocation of emergency funds to mitigate drought impacts. Satellite remote sensing offers an efficient way to provide quantitative assessments of drought impacts on agricultural production and increases in idle acreage associated with reductions in water supply. A key advantage of satellite-based assessments is that they can provide a measure of land fallowing that is consistent across both space and time. We describe an approach for monthly and seasonal mapping of uncultivated agricultural acreage developed as part of a joint effort by USGS, USDA, NASA, and the California Department of Water Resources to provide timely assessments of land fallowing during drought events. This effort has used the Central Valley of California as a pilot region for development and testing of an operational approach. To provide quantitative measures of uncultivated agricultural acreage from satellite data early in the season, we developed a decision tree algorithm and applied it to timeseries of data from Landsat TM, ETM+, OLI, and MODIS. Our effort has been focused on development of indicators of drought impacts in the March - August timeframe based on measures of crop development patterns relative to a reference period with average or above average rainfall. To assess the accuracy of the algorithms, monthly ground validation surveys were conducted across 640 fields from March - September, 2014. We present the algorithm along with updated results from the accuracy assessment, and discuss potential applications to other regions.

Seismic Intensity, PGA and PGV for the South Napa Earthquake, August 24, 2014

NASA Astrophysics Data System (ADS)

Chen, S.; Pickering, A.; Mooney, W. D.; Crewdson, E.

2014-12-01

Numerous studies have investigated the statistical relationship between Modified Mercalli Intensity (MMI) and peak ground acceleration (PGA) and peak ground velocity (PGV). The Mw 6.0 South Napa (California) earthquake of August 24, 2014 provides valuable data to examine these relationships for both urban and rural environments within northern California. The finite fault model (D. Dreger, 2014) indicates that the fault rupture propagated predominantly NNW and up-dip from a 11-km-deep hypocenter. The epicentral location was 8 km SSW of downtown Napa. Recorded PGA north of the epicenter is as high as 600 cm/s2 and PGV locally reaches 80 cm/s. Field studies by two teams of investigators were conducted on August 24-26 and September 8-11, 2014 to assign MMI values at 108 sites. The highest MMI values are strongly localized along the NNW-SSE rupture trend north of the epicenter. Parts of the city of Napa and some communities several km farther north on Dry Creek Road were found to have experienced shaking intensities of MMI VII to VIII. The observed effects include houses moved off their foundations, chimney collapse or damage, cracked foundations and/or interior walls, broken windows, and the lateral displacement of heavy furniture. Communities to the east and west of this zone of high seismic intensity reported significantly lower values of MMI, typically IV and V even at distances as close as 10 km from the mapped surface rupture. In comparison with previous estimates by Wald et al. (1999) and Dangkua and Cramer (2011), we find that MMI III-VIII uniformly correspond to significantly larger (>150%) PGA and PGV values, as reported by the Center for Engineering Strong Motion Data (2014). We attribute this observation to two primary factors: (1) improved earthquake engineering in the post-Loma Prieta earthquake era that has led to building construction, both new and retrofitted, that is more resistant to earthquake strong ground motions; and (2) a frequency band relevant

Overview of Reclamation's geothermal program in Imperial Valley, California

NASA Technical Reports Server (NTRS)

Fulcher, M. K.

1974-01-01

The Bureau of Reclamation is presently involved in a unique Geothermal Resource Development Program in Imperial Valley, California. The main purpose of the investigations is to determine the feasibility of providing a source of fresh water through desalting geothermal fluids stored in the aquifers underlying the valley. Significant progress in this research and development stage to date includes extensive geophysical investigations and the drilling of five geothermal wells on the Mesa anomaly. Four of the wells are for production and monitoring the anomaly, and one will be used for reinjection of waste brines from the desalting units. Two desalting units, a multistage flash unit and a vertical tube evaporator unit, have been erected at the East Mesa test site. The units have been operated on shakedown and continuous runs and have produced substantial quantities of high-quality water.

Quantitative rock-fall hazard and risk assessment for Yosemite Valley, Yosemite National Park, California

USGS Publications Warehouse

Stock, Greg M.; Luco, Nicolas; Collins, Brian D.; Harp, Edwin L.; Reichenbach, Paola; Frankel, Kurt L.

2014-01-01

Rock falls are common in Yosemite Valley, California, posing substantial hazard and risk to the approximately four million annual visitors to Yosemite National Park. Rock falls in Yosemite Valley over the past few decades have damaged structures and caused injuries within developed regions located on or adjacent to talus slopes highlighting the need for additional investigations into rock-fall hazard and risk. This assessment builds upon previous investigations of rock-fall hazard and risk in Yosemite Valley and focuses on hazard and risk to structures posed by relatively frequent fragmental-type rock falls as large as approximately 100,000 (cubic meters) in volume.

California; Antelope Valley Air Quality Management District; VOCs from Motor Vehicle Assembly Coating Operations

EPA Pesticide Factsheets

EPA is proposing to approve a revision to the Antelope Valley Air Quality Management District portion of the California SIP concerning emissions of volatile organic compounds (VOCs) from motor vehicle assembly coating operations.

Study of responses of 64-story Rincon Building to Napa, Fremont, Piedmont, San Ramon earthquakes and ambient motions

USGS Publications Warehouse

Çelebi, Mehmet; Hooper, John; Klemencic, Ron

2017-01-01

We analyze the recorded responses of a 64-story, instrumented, concrete core shear wall building in San Francisco, California, equipped with tuned sloshing liquid dampers (TSDs) and buckling restraining braces (BRBs). Previously, only ambient data from the 72-channel array in the building were studied (Çelebi et al. 2013). Recently, the 24 August 2014 Mw 6.0 Napa and three other earthquakes were recorded. The peak accelerations of ambient and the larger Napa earthquake responses at the basement are 0.12 cm/s/s and 5.2 cm/s/s respectively—a factor of ~42. At the 61st level, they are 0.30 cm/s/s (ambient) and 16.8 cm/s/s (Napa), respectively—a factor of ~56. Fundamental frequencies (NS ~ 0.3, EW ~ 0.27 Hz) from earthquake responses vary within an insignificant frequency band of ~0.02–0.03 Hz when compared to those from ambient data. In the absence of soil-structure interaction (SSI), these small and insignificant differences may be attributed to (1) identification errors, (2) any nonlinear behavior, and (3) shaking levels that are not large enough to activate the BRBs and TSDs to make significant shifts in frequencies and increase damping.

Life cycle greenhouse gas and energy assessment of winegrape production in California

USDA-ARS?s Scientific Manuscript database

Purpose: This study applies life cycle assessment (LCA) to assess greenhouse gas (GHG) emissions, energy use, and direct water use in winegrape production across common vineyard management scenarios in two representative growing regions of California, USA (Napa and Lodi). California hosts 90 percent...

Groundwater quality in the shallow aquifers of the Monterey Bay, Salinas Valley, and adjacent highland areas, Southern Coast Ranges, California

USGS Publications Warehouse

Burton, Carmen

2018-05-30

The Monterey-Salinas Shallow Aquifer study unit covers approximately 7,820 square kilometers (km2) in Santa Cruz, Monterey, and San Luis Obispo Counties in the Central Coast Hydrologic Region of California. The study unit was divided into four study areas—Santa Cruz, Pajaro Valley, Salinas Valley, and Highlands. More than 75 percent of the water used for drinking-water supply in the Central Coast Hydrologic Region of California is groundwater, and there are more than 8,000 well driller’s logs for domestic wells (California Department of Water Resources, 2013).

Groundwater Quality in the Shallow Aquifers of the Monterey Bay, Salinas Valley, and Adjacent Highland Areas, Southern Coast Ranges, California

USGS Publications Warehouse

Burton, Carmen

2018-05-30

The Monterey-Salinas Shallow Aquifer study unit covers approximately 7,820 square kilometers (km2) in Santa Cruz, Monterey, and San Luis Obispo Counties in the Central Coast Hydrologic Region of California. The study unit was divided into four study areas—Santa Cruz, Pajaro Valley, Salinas Valley, and Highlands. More than 75 percent of the water used for drinking-water supply in the Central Coast Hydrologic Region of California is groundwater, and there are more than 8,000 well driller’s logs for domestic wells (California Department of Water Resources, 2013).

Hydro-economic analysis of groundwater pumping for irrigated agriculture in California's Central Valley, USA

NASA Astrophysics Data System (ADS)

Medellín-Azuara, Josué; MacEwan, Duncan; Howitt, Richard E.; Koruakos, George; Dogrul, Emin C.; Brush, Charles F.; Kadir, Tariq N.; Harter, Thomas; Melton, Forrest; Lund, Jay R.

2015-09-01

As in many places, groundwater in California (USA) is the major alternative water source for agriculture during drought, so groundwater's availability will drive some inevitable changes in the state's water management. Currently, agricultural, environmental, and urban uses compete for groundwater, resulting in substantial overdraft in dry years with lowering of water tables, which in turn increases pumping costs and reduces groundwater pumping capacity. In this study, SWAP (an economic model of agricultural production and water use in California) and C2VISim (the California Department of Water Resources groundwater model for California's Central Valley) are connected. This paper examines the economic costs of pumping replacement groundwater during drought and the potential loss of pumping capacity as groundwater levels drop. A scenario of three additional drought years continuing from 2014 show lower water tables in California's Central Valley and loss of pumping capacity. Places without access to groundwater and with uncertain surface-water deliveries during drought are the most economically vulnerable in terms of crop revenues, employment and household income. This is particularly true for Tulare Lake Basin, which relies heavily on water imported from the Sacramento-San Joaquin Delta. Remote-sensing estimates of idle agricultural land between 2012 and 2014 confirm this finding. Results also point to the potential of a portfolio approach for agriculture, in which crop mixing and conservation practices have substantial roles.

Subsidence in the Central Valley, California 2007 - present measured by InSAR

NASA Astrophysics Data System (ADS)

Farr, T. G.; Liu, Z.; Jones, C. E.

2015-12-01

Subsidence caused by groundwater pumping in the rich agricultural area of California's Central Valley has been a problem for decades. Over the last few years, interferometric synthetic aperture radar (InSAR) observations from satellite and aircraft platforms have been used to produce maps of subsidence with ~cm accuracy. For this study, we have obtained and analyzed Japanese PALSAR data for 2006 - 2011, Canadian Radarsat-1 data for 2011 - 2013, Radarsat-2 data for 2012 - 2015, and ESA's Sentinel-1A for 2015 and produced maps of subsidence for those periods. High resolution InSAR data were also acquired along the California Aqueduct by the NASA UAVSAR from 2013 - 2015. Using multiple scenes acquired by these systems, we were able to produce the time histories of subsidence at selected locations and transects showing how subsidence varies both spatially and temporally. The maps show that subsidence is continuing in areas with a history of subsidence and that the rates and areas affected have increased due to increased groundwater extraction during the extended western US drought. The high resolution maps from UAVSAR were used to identify and quantify new, highly localized areas of accelerated subsidence along the California Aqueduct that occurred in 2014. The California Department of Water Resources (DWR) funded this work to provide the background and an update on subsidence in the Central Valley to support future policy. Geographic Information System (GIS) files are being furnished to DWR for further analysis of the 4 dimensional subsidence time-series maps. Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.

Contaminated fish consumption in California's Central Valley Delta.

PubMed

Shilling, Fraser; White, Aubrey; Lippert, Lucas; Lubell, Mark

2010-05-01

Extensive mercury contamination and angler selection of the most contaminated fish species coincide in California's Central Valley. This has led to a policy conundrum: how to balance the economic and cultural impact of advising subsistence anglers to eat less fish with the economic cost of reducing the mercury concentrations in fish? State agencies with regulatory and other jurisdictional authority lack sufficient data and have no consistent approach to this problem. The present study focused on a critical and contentious region in California's Central Valley (the Sacramento-San Joaquin Rivers Delta) where mercury concentrations in fish and subsistence fishing rates are both high. Anglers and community members were surveyed for their fish preferences, rates of consumption, the ways that they receive health information, and basic demographic information. The rates of fish consumption for certain ethnicities were higher than the rates used by state agencies for planning pollution remediation. A broad range of ethnic groups were involved in catching and eating fish. The majority of anglers reported catching fish in order to feed to their families, including children and women of child-bearing age. There were varied preferences for receiving health information and no correlation between knowledge of fish contamination and rates of consumption. Calculated rates of mercury intake by subsistence anglers were well above the EPA reference dose. The findings here support a comprehensive policy strategy of involvement of the diverse communities in decision-making about education and clean-up and an official recognition of subsistence fishers in the region. Copyright 2010 Elsevier Inc. All rights reserved.

Geology and water resources of Owens Valley, California

USGS Publications Warehouse

Hollett, Kenneth J.; Danskin, Wesley R.; McCaffrey, William F.; Walti, Caryl L.

1991-01-01

Owens Valley, a long, narrow valley located along the east flank of the Sierra Nevada in east-central California, is the main source of water for the city of Los Angeles. The city diverts most of the surface water in the valley into the Owens River-Los Angeles Aqueduct system, which transports the water more than 200 miles south to areas of distribution and use. Additionally, ground water is pumped or flows from wells to supplement the surface-water diversions to the river-aqueduct system. Pumpage from wells needed to supplement water export has increased since 1970, when a second aqueduct was put into service, and local concerns have been expressed that the increased pumpage may have had a detrimental effect on the environment and the indigenous alkaline scrub and meadow plant communities in the valley. The scrub and meadow communities depend on soil moisture derived from precipitation and the unconfined part of a multilayered aquifer system. This report, which describes the hydrogeology of the aquifer system and the water resources of the valley, is one in a series designed to (1) evaluate the effects that groundwater pumping has on scrub and meadow communities and (2) appraise alternative strategies to mitigate any adverse effects caused by, pumping. Two principal topographic features are the surface expression of the geologic framework--the high, prominent mountains on the east and west sides of the valley and the long, narrow intermountain valley floor. The mountains are composed of sedimentary, granitic, and metamorphic rocks, mantled in part by volcanic rocks as well as by glacial, talus, and fluvial deposits. The valley floor is underlain by valley fill that consists of unconsolidated to moderately consolidated alluvial fan, transition-zone, glacial and talus, and fluvial and lacustrine deposits. The valley fill also includes interlayered recent volcanic flows and pyroclastic rocks. The bedrock surface beneath the valley fill is a narrow, steep-sided graben

Climate controls on valley fever incidence in Kern County, California

NASA Astrophysics Data System (ADS)

Zender, Charles S.; Talamantes, Jorge

2006-01-01

Coccidiodomycosis (valley fever) is a systemic infection caused by inhalation of airborne spores from Coccidioides immitis, a soil-dwelling fungus found in the southwestern United States, parts of Mexico, and Central and South America. Dust storms help disperse C. immitis so risk factors for valley fever include conditions favorable for fungal growth (moist, warm soil) and for aeolian soil erosion (dry soil and strong winds). Here, we analyze and inter-compare the seasonal and inter-annual behavior of valley fever incidence and climate risk factors for the period 1980-2002 in Kern County, California, the US county with highest reported incidence. We find weak but statistically significant links between disease incidence and antecedent climate conditions. Precipitation anomalies 8 and 20 months antecedent explain only up to 4% of monthly variability in subsequent valley fever incidence during the 23 year period tested. This is consistent with previous studies suggesting that C. immitis tolerates hot, dry periods better than competing soil organisms and, as a result, thrives during wet periods following droughts. Furthermore, the relatively small correlation with climate suggests that the causes of valley fever in Kern County could be largely anthropogenic. Seasonal climate predictors of valley fever in Kern County are similar to, but much weaker than, those in Arizona, where previous studies find precipitation explains up to 75% of incidence. Causes for this discrepancy are not yet understood. Higher resolution temporal and spatial monitoring of soil conditions could improve our understanding of climatic antecedents of severe epidemics.

Subsidence and Rebound in California's Central Valley: Effects of Pumping, Geology, and Precipitation

NASA Astrophysics Data System (ADS)

Farr, T. G.; Fairbanks, A.

2017-12-01

Recent rains in California caused a pause, and even a reversal in some areas, of the subsidence that has plagued the Central Valley for decades. The 3 main drivers of surface deformation in the Central Valley are: Subsurface hydro-geology, precipitation and surface water deliveries, and groundwater pumping. While the geology is relatively fixed in time, water inputs and outputs vary greatly both in time and space. And while subsurface geology and water inputs are reasonably well-known, information about groundwater pumping amounts and rates is virtually non-existent in California. We have derived regional maps of surface deformation in the region for the period 2006 - present which allow reconstruction of seasonal and long-term changes. In order to understand the spatial and temporal patterns of subsidence and rebound in the Central Valley, we have been compiling information on the geology and water inputs and have attempted to infer pumping rates using maps of fallowed fields and published pumping information derived from hydrological models. In addition, the spatial and temporal patterns of hydraulic head as measured in wells across the region allow us to infer the spatial and temporal patterns of groundwater pumping and recharge more directly. A better understanding of how different areas (overlying different stratigraphy) of the Central Valley respond to water inputs and outputs will allow a predictive capability, potentially defining sustainable pumping rates related to water inputs. * work performed under contract to NASA and the CA Dept. of Water Resources

Ground-water modeling of the Death Valley Region, Nevada and California

USGS Publications Warehouse

Belcher, W.R.; Faunt, C.C.; Sweetkind, D.S.; Blainey, J.B.; San Juan, C. A.; Laczniak, R.J.; Hill, M.C.

2006-01-01

The Death Valley regional ground-water flow system (DVRFS) of southern Nevada and eastern California covers an area of about 100,000 square kilometers and contains very complex geology and hydrology. Using a computer model to represent the complex system, the U.S. Geological Survey simulated ground-water flow in the Death Valley region for use with U.S. Department of Energy projects in southern Nevada. The model was created to help address contaminant cleanup activities associated with the underground nuclear testing conducted from 1951 to 1992 at the Nevada Test Site and to support the licensing process for the proposed geologic repository for high-level nuclear waste at Yucca Mountain, Nevada.

Statistical modeling of valley fever data in Kern County, California

NASA Astrophysics Data System (ADS)

Talamantes, Jorge; Behseta, Sam; Zender, Charles S.

2007-03-01

Coccidioidomycosis (valley fever) is a fungal infection found in the southwestern US, northern Mexico, and some places in Central and South America. The fungus that causes it ( Coccidioides immitis) is normally soil-dwelling but, if disturbed, becomes air-borne and infects the host when its spores are inhaled. It is thus natural to surmise that weather conditions that foster the growth and dispersal of the fungus must have an effect on the number of cases in the endemic areas. We present here an attempt at the modeling of valley fever incidence in Kern County, California, by the implementation of a generalized auto regressive moving average (GARMA) model. We show that the number of valley fever cases can be predicted mainly by considering only the previous history of incidence rates in the county. The inclusion of weather-related time sequences improves the model only to a relatively minor extent. This suggests that fluctuations of incidence rates (about a seasonally varying background value) are related to biological and/or anthropogenic reasons, and not so much to weather anomalies.

space Radar Image of Long Valley, California

NASA Image and Video Library

1999-05-01

An area near Long Valley, California, was mapped by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar aboard the space shuttle Endeavor on April 13, 1994, during the first flight of the radar instrument, and on October 4, 1994, during the second flight of the radar instrument. The orbital configurations of the two data sets were ideal for interferometric combination -- that is overlaying the data from one image onto a second image of the same area to create an elevation map and obtain estimates of topography. Once the topography is known, any radar-induced distortions can be removed and the radar data can be geometrically projected directly onto a standard map grid for use in a geographical information system. The 50 kilometer by 50 kilometer (31 miles by 31 miles) map shown here is entirely derived from SIR-C L-band radar (horizontally transmitted and received) results. The color shown in this image is produced from the interferometrically determined elevations, while the brightness is determined by the radar backscatter. The map is in Universal Transverse Mercator (UTM) coordinates. Elevation contour lines are shown every 50 meters (164 feet). Crowley Lake is the dark feature near the south edge of the map. The Adobe Valley in the north and the Long Valley in the south are separated by the Glass Mountain Ridge, which runs through the center of the image. The height accuracy of the interferometrically derived digital elevation model is estimated to be 20 meters (66 feet) in this image. http://photojournal.jpl.nasa.gov/catalog/PIA01749

Structural and lithologic study of northern coast ranges and Sacramento Valley, California

NASA Technical Reports Server (NTRS)

Rich, E. I. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Analysis of ERTS-1 imagery of the Northern California Coast Ranges has disclosed a potential relation between a heretofore unrecognized fracture system and known deposits of mercury and geothermally active areas in the Coast Range and between oil and gas fields in the Sacramento Valley. Three potentially important systems of linear elements within the Coast Ranges, detected on ERTS-1 imagery, may represent fault systems or zones of shearing because topographic offset and stratigraph disruption can be seen along one or two of the lineations. One of the systems in subparallel to the San Andreas fault and is confined to the Pacific Coastal Belt. Another set is confined to the central core of the Coast Ranges. The third set of linear features (Valley System) has not heretofore been recognized. Some of the known mercury deposits and geothermally active areas near Clear Lake, in the Coast Ranges, are along the Valley System or at the intersection of the Central and Valley Systems. The plotted locations of some of the oil and gas fields in the Sacramento Valley are associated with the Valley and/or Central Systems. If these relations prove reliable, the ERTS-1 imagery may prove to be an extremely useful exploration tool.

Space Radar Image of Saline Valley, California

NASA Technical Reports Server (NTRS)

1999-01-01

This is a three-dimensional perspective view of Saline Valley, about 30 km (19 miles) east of the town of Independence, California created by combining two spaceborne radar images using a technique known as interferometry. Visualizations like this one are helpful to scientists because they clarify the relationships of the different types of surfaces detected by the radar and the shapes of the topographic features such as mountains and valleys. The view is looking southwest across Saline Valley. The high peaks in the background are the Inyo Mountains, which rise more than 3,000 meters (10,000 feet) above the valley floor. The dark blue patch near the center of the image is an area of sand dunes. The brighter patches to the left of the dunes are the dry, salty lake beds of Saline Valley. The brown and orange areas are deposits of boulders, gravel and sand known as alluvial fans. The image was constructed by overlaying a color composite radar image on top of a digital elevation map. The radar image was taken by the Spaceborne Imaging Radar-C/X-bandSynthetic Aperture Radar (SIR-C/X-SAR) on board the space shuttleEndeavour in October 1994. The digital elevation map was producedusing radar interferometry, a process in which radar data are acquired on different passes of the space shuttle. The two data passes are compared to obtain elevation information. The elevation data were derived from a 1,500-km-long (930-mile) digital topographic map processed at JPL. Radar image data are draped over the topography to provide the color with the following assignments: red is L-band vertically transmitted, vertically received; green is C-band vertically transmitted, vetically received; and blue is the ratio of C-band vertically transmitted, vertically received to L-band vertically transmitted, vertically received. This image is centered near 36.8 degrees north latitude and 117.7 degrees west longitude. No vertical exaggeration factor has been applied to the data. SIR-C/X-SAR, a joint

SRTM Perspective View with Landsat Overlay: Santa Paula, and Santa Clara River Valley, California

NASA Technical Reports Server (NTRS)

2000-01-01

Rectangular fields of the agriculturally rich Santa Clara River Valley are visible in this perspective view generated using data from the Shuttle Radar Topography Mission and an enhanced Landsat image. The Santa Clara River, which lends its name to this valley, flows from headwaters near Acton, California, 160 km (100 miles) to the Pacific Ocean, and is one of only two natural river systems remaining in southern California. In the foreground of this image, the largely dry riverbed can be seen as a bright feature as it winds its way along the base of South Mountain. The bright region at the right end of this portion of the valley is the city of Santa Paula, California. Founded in 1902, this small, picturesque town at the geographic center of Ventura County is referred to as the 'Citrus Capital of the World.' The city is surrounded by orange, lemon, and avocado groves and is a major distribution point for citrus fruits in the United States. The bright, linear feature in the center of the valley is State Highway 126, the valley's 'main drag.' For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors, from Landsat data, approximate natural color.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory

77 FR 12527 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-01

...EPA is proposing to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD) and San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portions of the California State Implementation Plan (SIP). These revisions concern negative declarations for volatile organic compound (VOC) and oxides of sulfur source categories. We are proposing to approve these negative declarations under the Clean Air Act as amended in 1990 (CAA or the Act).

Transboundary Contributions To Surface Ozone In California's Central Valley

NASA Astrophysics Data System (ADS)

Post, A.; Faloona, I. C.; Conley, S. A.; Lighthall, D.

2014-12-01

Rising concern over the impacts of exogenous air pollution in California's Central Valley has prompted the establishment of a coastal, high altitude monitoring site at the Chews Ridge Observatory (1550 m) approximately 30 km east of Point Sur in Monterey County, under the auspices of the Monterey Institute for Research in Astronomy. Two and a half years of continuous ozone data are presented in the context of long-range transport and its potential impact on surface air quality in the San Joaquin Valley (SJV). Past attempts to quantify the impact of transboundary ozone on surface levels have relied on uncertain model estimates, or have been limited to weekly ozonesonde data. Here, we present an observationally derived quantification of the contribution of free tropospheric ozone to surface sites in the San Joaquin Valley throughout three ozone seasons (June through September, 2012-2014). The diurnal ozone patterns at Chews Ridge, and their correlations with ozone aloft over the Valley, have been presented previously. Furthermore, reanalysis data of geopotential heights indicate consistent flow from Chews Ridge to the East, directly over the SJV. In a related airborne project we quantify the vertical exchange, or entrainment, rate over the Southern SJV from a series of focused flights measuring ozone concentrations during peak photochemical hours in conjunction with local meteorological data to quantify an ozone budget for the area. By applying the entrainment rates observed in that study here we are able to quantify the seasonal contributions of free tropospheric ozone measured at Chews Ridge to surface sites in the San Joaquin Valley, and compare prior model estimates to our observationally derived values.

RELATIONSHIPS BETWEEN ENVIRONMENTAL VARIABLES AND BENTHIC DIATOM ASSEMBLAGES IN CALIFORNIA CENTRAL VALLEY STREAMS (USA)

EPA Science Inventory

Streams and rivers in the California Central Valley Ecoregion have been substantially modified by human activities. This study examines distributional patterns of benthic diatom assemblages in relation to environmental characteristics in streams and rivers of this region. Benthic...

MANAGEMENT OF SMALL MAMMALS IN A RELICT GRASSLAND IN CALIFORNIA'S CENTRAL VALLEY

Treesearch

ANNE POOPATANAPONG; DOUGLAS A. KELT

1999-01-01

land-use patterns over the past century. In California's Central Valley these changes have resulted in replacement of native grassland vegetation by non-native annual grasses. Jepson Prairie is a natural reserve that has been set aside to preserve native vernal pool and bunchgrass habitats. Jepson Prairie also provides habitat for several state and federally...

Global positioning system surveying to monitor land subsidence in Sacramento Valley, California, USA

USGS Publications Warehouse

Ikehara, M.E.

1994-01-01

A subsidence research program began in 1985 to document the extent and magnitude of land subsidence in Sacramento Valley, California, an area of about 15 600 km2m, using Global Positioning System (GPS) surveying. In addition to periodic conventional spirit levelling, an examination was made of the changes in GPS-derived ellipsoidal height differences (summary differences) between pairs of adjacent bench marks in central Sacramento Valley from 1986 to 1989. The average rates of land subsidence in the southern Sacramento Valley for the past several decades were determined by comparing GPS-derived orthometric heights with historic published elevations. A maximum average rate of 0.053 m year-1 (0.90 m in 17 years) of subsidence has been measured. -Author

Geomorphology and Tectonics at the Intersection of Silurian and Death Valleys, Southern California - 2005 Guidebook Pacific Cell Friends of the Pleistocene

USGS Publications Warehouse

Miller, David M.; Valin, Zenon C.

2007-01-01

This publication describes results from new regional and detailed surficial geologic mapping, combined with geomorphologic, geochronologic, and tectonic studies, in Silurian Valley and Death Valley, California. The studies address a long-standing problem, the tectonic and geomorphic evolution of the intersection between three regional tectonic provinces: the eastern California shear zone, the Basin and Range region of southern Nevada and adjacent California, and the eastern Mojave Desert region. The chapters represent work presented on the 2005 Friends of the Pleistocene field trip and meeting as well as the field trip road log.

Groundwater quality in the Monterey Bay and Salinas Valley groundwater basins, California

USGS Publications Warehouse

Kulongoski, Justin T.; Belitz, Kenneth

2011-01-01

The Monterey-Salinas study unit is nearly 1,000 square miles and consists of the Santa Cruz Purisima Formation Highlands, Felton Area, Scotts Valley, Soquel Valley, West Santa Cruz Terrace, Salinas Valley, Pajaro Valley, and Carmel Valley groundwater basins (California Department of Water Resources, 2003; Kulongski and Belitz, 2011). These basins were grouped into four study areas based primarily on geography. Groundwater basins in the north were grouped into the Santa Cruz study area, and those to the south were grouped into the Monterey Bay, the Salinas Valley, and the Paso Robles study areas (Kulongoski and others, 2007). The study unit has warm, dry summers and cool, moist winters. Average annual rainfall ranges from 31 inches in Santa Cruz in the north to 13 inches in Paso Robles in the south. The study areas are drained by several rivers and their principal tributaries: the Salinas, Pajaro, and Carmel Rivers, and San Lorenzo Creek. The Salinas Valley is a large intermontane valley that extends southeastward from Monterey Bay to Paso Robles. It has been filled, up to a thickness of 2,000 feet, with Tertiary and Quaternary marine and terrestrial sediments that overlie granitic basement. The Miocene-age Monterey Formation and Pliocene- to Pleistocene-age Paso Robles Formation, and Pleistocene to Holocene-age alluvium contain freshwater used for supply. The primary aquifers in the study unit are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells are typically drilled to depths of 200 to 650 feet, consist of solid casing from the land surface to depths of about 175 to 500 feet, and are perforated below the solid casing. Water quality in the primary aquifers may differ from that in the shallower and deeper parts of the aquifer system. Groundwater movement is generally from the southern part of the Salinas Valley north towards the Monterey Bay

Drought Impacts on Agricultural Production and Land Fallowing in California's Central Valley in 2015

NASA Technical Reports Server (NTRS)

Rosevelt, Carolyn; Melton, Forrest S.; Johnson, Lee; Guzman, Alberto; Verdin, James P.; Thenkabail, Prasad S.; Mueller, Rick; Jones, Jeanine; Willis, Patrick

2016-01-01

The ongoing drought in California substantially reduced surface water supplies for millions of acres of irrigated farmland in California's Central Valley. Rapid assessment of drought impacts on agricultural production can aid water managers in assessing mitigation options, and guide decision making with respect to mitigation of drought impacts. Satellite remote sensing offers an efficient way to provide quantitative assessments of drought impacts on agricultural production and increases in fallow acreage associated with reductions in water supply. A key advantage of satellite-based assessments is that they can provide a measure of land fallowing that is consistent across both space and time. We describe an approach for monthly and seasonal mapping of uncultivated agricultural acreage developed as part of a joint effort by USGS, USDA, NASA, and the California Department of Water Resources to provide timely assessments of land fallowing during drought events. This effort has used the Central Valley of California as a pilot region for development and testing of an operational approach. To provide quantitative measures of uncultivated agricultural acreage from satellite data early in the season, we developed a decision tree algorithm and applied it to time-series data from Landsat TM (Thematic Mapper), ETM+ (Enhanced Thematic Mapper Plus), OLI (Operational Land Imager), and MODIS (Moderate Resolution Imaging Spectroradiometer). Our effort has been focused on development of indicators of drought impacts in the March-August timeframe based on measures of crop development patterns relative to a reference period with average or above average rainfall. To assess the accuracy of the algorithms, monthly ground validation surveys were conducted across 650 fields from March-September in 2014 and 2015. We present the algorithm along with updated results from the accuracy assessment, and data and maps of land fallowing in the Central Valley in 2015.

Drought Impacts on Agricultural Production and Land Fallowing in California's Central Valley in 2015

NASA Astrophysics Data System (ADS)

Rosevelt, C.; Melton, F. S.; Johnson, L.; Guzman, A.; Verdin, J. P.; Thenkabail, P. S.; Mueller, R.; Jones, J.; Willis, P.

2015-12-01

The ongoing drought in California substantially reduced surface water supplies for millions of acres of irrigated farmland in California's Central Valley. Rapid assessment of drought impacts on agricultural production can aid water managers in assessing mitigation options, and guide decision making with respect to mitigation of drought impacts. Satellite remote sensing offers an efficient way to provide quantitative assessments of drought impacts on agricultural production and increases in fallow acreage associated with reductions in water supply. A key advantage of satellite-based assessments is that they can provide a measure of land fallowing that is consistent across both space and time. We describe an approach for monthly and seasonal mapping of uncultivated agricultural acreage developed as part of a joint effort by USGS, USDA, NASA, and the California Department of Water Resources to provide timely assessments of land fallowing during drought events. This effort has used the Central Valley of California as a pilot region for development and testing of an operational approach. To provide quantitative measures of uncultivated agricultural acreage from satellite data early in the season, we developed a decision tree algorithm and applied it to timeseries of data from Landsat TM, ETM+, OLI, and MODIS. Our effort has been focused on development of indicators of drought impacts in the March - August timeframe based on measures of crop development patterns relative to a reference period with average or above average rainfall. To assess the accuracy of the algorithms, monthly ground validation surveys were conducted across 650 fields from March - September in 2014 and 2015. We present the algorithm along with updated results from the accuracy assessment, and data and maps of land fallowing in the Central Valley in 2015.

Land use and water use in the Antelope Valley, California

USGS Publications Warehouse

Templin, William E.; Phillips, Steven P.; Cherry, Daniel E.; DeBortoli, Myrna L.; Haltom, T.C.; McPherson, Kelly R.; Mrozek, C.A.

1995-01-01

Urban land use and water use in the Antelope Valley, California, have increased significantly since development of the valley began in the late 1800's.. Ground water has been a major source of water in this area because of limited local surface-water resources. Ground-water pumpage is reported to have increased from about 29,000 acre-feet in 1919 to about 400,000 acre-feet in the 1950's. Completion of the California Aqueduct to this area in the early 1970's conveyed water from the Sacramento-San Joaquin Delta, about 400 miles to the north. Declines in groundwater levels and increased costs of electrical power in the 1970's resulted in a reduction in the quantity of ground water that was pumped annually for irrigation uses. Total annual reported ground-water pumpage decreased to a low of about 53,200 acre-feet in 1983 and increased to about 91,700 acre-feet in 1991 as a result of rapid urban development and the 1987-92 drought. This increased urban development, in combination with several years of drought, renewed concern about a possible return to extensive depletion of ground-water storage and increased land subsidence.Increased water demands are expected to continue as a result of increased urban development. Water-demand forecasts in 1980 for the Antelope Valley indicated that total annual water demand by 2020 was expected to be about 250,000 acre-feet, with agricultural demand being about 65 percent of this total. In 1990, total water demand was projected to be about 175,000 acre-feet by 2010; however, agricultural water demand was expected to account for only 37 percent of the total demand. New and existing land- and water-use data were collected and compiled during 1992-93 to identify present and historical land and water uses. In 1993, preliminary forecasts for total water demand by 2010 ranged from about 127,500 to 329,000 acre-feet. These wide-ranging estimates indicate that forecasts can change with time as factors that affect water demand change and

Drought impacts to water footprints and virtual water transfers of the Central Valley of California

NASA Astrophysics Data System (ADS)

Marston, Landon; Konar, Megan

2017-07-01

The Central Valley of California is one of the most productive agricultural locations in the world, which is made possible by a complex and vast irrigation system. Beginning in 2012, California endured one of the worst droughts in its history. Local impacts of the drought have been evaluated, but it is not yet well understood how the drought reverberated through the global food system. Here we quantify drought impacts to the water footprint (WF) of agricultural production and virtual water transfers (VWT) from the Central Valley of California. To do this, we utilize high-resolution spatial and temporal data sets and a crop model from predrought conditions (2011) through 3 years of exceptional drought (2012-2014). Despite a 12% reduction in harvested area, the WF of agricultural production in the Central Valley increased by 3%. This was due to greater crop water requirements from higher temperatures and a shift to more water-intensive orchard and vine crops. The groundwater WF increased from 7.00 km3 in 2011 to 13.63 km3 in 2014, predominantly in the Tulare Basin. Transfers of food commodities declined by 1% during the drought, yet total VWT increased by 3% (0.51 km3). From 2011 to 2014, groundwater VWT increased by 3.42 km3, offsetting the 0.94 km3 reduction in green VWT and the 1.96 km3 decrease in surface VWT. During the drought, local and global consumers nearly doubled their reliance on the Central Valley Aquifer. These results indicate that drought may strengthen the telecoupling between groundwater withdrawals and distant consumers of agricultural commodities.

Age constraints for the present fault configuration in the Imperial Valley, California: Evidence for northwestward propagation of the Gulf of California rift system

NASA Technical Reports Server (NTRS)

Larsen, Shawn; Reilinger, Robert

1990-01-01

Releveling and other geophysical data for the Imperial Valley of southern California suggest the northern section of the Imperial-Brawley fault system, which includes the Mesquite Basin and Brawley Seismic Zone, is much younger than the 4 to 5 million year age of the valley itself. A minimum age of 3000 years is calculated for the northern segment of the Imperial fault from correlations between surface topography and geodetically observed seismic/interseismic vertical movements. Calculations of a maximum age of 80,000 years is based upon displacements in the crystalline basement along the Imperial fault, inferred from seismic refraction surveys. This young age supports recent interpretations of heat flow measurements, which also suggest that the current patterns of seismicity and faults in the Imperial Valley are not long lived. The current fault geometry and basement morphology suggest northwestward growth of the Imperial fault and migration of the Brawley Seismic Zone. It is suggested that this migration is a manifestation of the propagation of the Gulf of California rift system into the North American continent.

The 2014 Mw 6.0 Napa Earthquake, California: Observations from Real-time GPS-enhanced Earthquake Early Warning

NASA Astrophysics Data System (ADS)

Johanson, I. A.; Grapenthin, R.; Allen, R. M.

2014-12-01

Recently, progress has been made to demonstrate feasibility and benefits of including real-time GPS (rtGPS) in earthquake early warning and rapid response systems. While most concepts have yet to be integrated into operational environments, the Berkeley Seismological Laboratory is currently running an rtGPS based finite fault inversion scheme in true real-time, which is triggered by the seismic-based ShakeAlert system and then sends updated earthquake alerts to a test receiver. The Geodetic Alarm System (G-larmS) was online and responded to the 2014 Mw6.0 South Napa earthquake in California. We review G-larmS' performance during this event and for 13 aftershocks, and we present rtGPS observations and real-time modeling results for the main shock. The first distributed slip model and a magnitude estimate of Mw5.5 were available 24 s after the event origin time, which could be reduced to 14 s after a bug fix (~8 s S-wave travel time, ~6 s data latency). The system continued to re-estimate the magnitude once every second: it increased to Mw5.9 3 s after the first alert and stabilized at Mw5.8 after 15 s. G-larmS' solutions for the subsequent small magnitude aftershocks demonstrate that Mw~6.0 is the current limit for alert updates to contribute back to the seismic-based early warning system.

View of the Salinas River Valley area south of Monterey Bay, California

NASA Image and Video Library

1973-08-15

SL3-88-004 (July-September 1973) --- A vertical view of the Salinas River Valley area south of Monterey Bay, California area is seen in this Skylab 3 Earth Resources Experiments Package S190-B (five-inch Earth terrain camera) photograph taken from the Skylab space station in Earth orbit. The valley is an irrigated agricultural area, and is indicated by the dark-green and light-gray rectangular patterns in the centre of the picture. The city of Salinas is barely visible under the cloud cover at the top (north) end of the valley. The dark mass on the left (west) side of the valley is the Santa Lucia mountain range. The Big Sur area is on the left and partly covered by clouds. The Diablo Range forms the dark mass in the lower right (southeast) corner of the photograph. The town of Hollister is the gray area in the dark-green rectangular farm tracts which occupy the floor of the San Benito Valley in the upper right (northeast) corner of the photograph. The Salinas River flows northwestward toward Monterey Bay. The towns of Soledad, Greenfield and King City appear as gray areas along U.S. 101 in the Salinas Valley. The geology of the area is complex, and has been racked by several earthquakes resulting from movement along the San Andreas and subsidiary faults. Here, the surface expression of the San Andreas Fault can be traced from a point just west of Hollister at the contrast of dark brown and tan to a point about one inch left of the lower right (southeast) corner of the picture. Subsidiary faults are indicated by the curving trend of the rocks along the right side. The photograph will provide detailed information on land use patterns (Dr. R. Colwell, University of California, Berkeley) and fault tectonics (Dr. P. Merifield, Earth Science Res., Inc. and Dr. M. Abdel-Gawad, Rockwell International). Federal agencies participating with NASA on the EREP project are the Departments of Agriculture, Commerce, Interior, the Environmental Protection Agency and the Corps of

Wildlife Diversity in Valley-Foothill Riparian Habitat: North Central vs. Central Coast California

Treesearch

William D. Tietje; Reginald H. Barrett; Eric B. Kleinfelter; Brett T. Carré

1991-01-01

Habitat characteristics and diversity of terrestrial vertebrates were studied September 1989 to August 1990 in valley-foothill riparian habitat on two study areas: Dye Creek, Tehama County, and Avenales Ranch, San Luis Obispo County, California. The assumption considered was that differences between study areas in physical and vegetation characteristics would be...

Measuring ground movement in geothermal areas of Imperial Valley, California

NASA Technical Reports Server (NTRS)

Lofgren, B. E.

1974-01-01

Significant ground movement may accompany the extraction of large quantities of fluids from the subsurface. In Imperial Valley, California, one of the potential hazards of geothermal development is the threat of both subsidence and horizontal movement of the land surface. Regional and local survey nets are being monitored to detect and measure possible ground movement caused by future geothermal developments. Precise measurement of surface and subsurface changes will be required to differentiate man-induced changes from natural processes in this tectonically active region.

Map showing locations of damaging landslides in Napa County, California, resulting from 1997-98 El Nino rainstorms

USGS Publications Warehouse

Godt, Jonathan W.; Savage, William Z.; Wilson, Raymond C.

1999-01-01

Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. Napa County was relatively unaffected in comparison to other counties in the region with approximately $1.1 million in damages assessed.

Coho Salmon Habitat in a Changing Environment-Green Valley Creek, Graton, California

NASA Astrophysics Data System (ADS)

O'Connor, M. D.; Kobor, J. S.; Sherwood, M. N.

2013-12-01

Green Valley Creek (GVC) is a small (101 sq km) aquatic habitat refugium in the Russian River watershed (3,840 sq km) in coastal northern California. Coho salmon (Onchorhynchus kisutch) is endangered per the Federal Endangered Species Act, and GVC is one stream where coho have persisted. Fish surveys in GVC have found high species diversity, growth rates, and over-summer survival. The upper portion of GVC comprises a principal tributary (20 sq km) that provides spawning and rearing habitat for coho. The second principal tributary, Atascadero Creek, is comparable in size, but has few fish. Atascadero Creek and lower GVC have broad, densely vegetated floodplains. A Recovery Plan for the Central Coastal California coho Evolutionarily Significant Unit has been developed by the National Marine Fisheries Service (NMFS), which applies to the Russian River and its tributaries. Cooperative research regarding fish populations and habitat, a captive breeding and release program for native coho salmon, and efforts to plan for and restore habitat are ongoing. These regional efforts are particularly active in GVC, and participants include NMFS, the California Department of Fish and Wildlife, the Gold Ridge Resource Conservation District, the California Coastal Conservancy, the University of California Cooperative Extension, and the National Fish and Wildlife Foundation, among others. Our research focuses on hydrologic, geomorphic and hydrogeologic characteristics of the watershed in relation to aquatic habitat. Natural watershed factors contributing to habitat for coho include proximity to the coastal summer fog belt with cool temperatures, the Wilson Grove Formation aquifer that maintains dry season stream flow, and structural geology favorable for active floodplain morphology. Human impacts include water use and agriculture and rural residential development. Historic human impacts include stream clearing and draining of wetlands and floodplain for agriculture, which likely

Water availability and land subsidence in the Central Valley, California, USA

NASA Astrophysics Data System (ADS)

Faunt, Claudia C.; Sneed, Michelle; Traum, Jon; Brandt, Justin T.

2016-05-01

The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007-2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

Communication/Culture Study for Victor Valley College, Victorville, California, November 1991-April 1992.

ERIC Educational Resources Information Center

Caldwell, Patricia F.

In November 1991, a study was conducted to assess the corporate culture and state of communication at Victor Valley College (VVC), in Victorville, California. The study was designed to determine the extent to which "trust" or "distrust" existed at VVC, and whether the lack of communication on campus was real or perceived. Study…

Space Radar Image of Owens Valley, California

NASA Technical Reports Server (NTRS)

1999-01-01

This is a three-dimensional perspective view of Owens Valley, near the town of Bishop, California that was created by combining two spaceborne radar images using a technique known as interferometry. Visualizations like this one are helpful to scientists because they clarify the relationships of the different types of surfaces detected by the radar and the shapes of the topographic features such as mountains and valleys. The view is looking southeast along the eastern edge of Owens Valley. The White Mountains are in the center of the image, and the Inyo Mountains loom in the background. The high peaks of the White Mountains rise more than 3,000 meters (10,000 feet) above the valley floor. The runways of the Bishop airport are visible at the right edge of the image. The meandering course of the Owens River and its tributaries appear light blue on the valley floor. Blue areas in the image are smooth, yellow areas are rock outcrops, and brown areas near the mountains are deposits of boulders, gravel and sand known as alluvial fans. The image was constructed by overlaying a color composite radar image on top of a digital elevation map. The radar data were taken by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on board the space shuttle Endeavour in October 1994. The digital elevation map was produced using radar interferometry, a process in which radar data are acquired on different passes of the space shuttle. The two data passes are compared to obtain elevation information. The elevation data were derived from a 1,500-km-long (930-mile) digital topographic map processed at JPL. Radar image data are draped over the topography to provide the color with the following assignments: red is L-band vertically transmitted, vertically received; green is C-band vertically transmitted, vertically received; and blue is the ratio of C-band vertically transmitted, vertically received to L-band vertically transmitted, vertically received. This image is

A Test of the California Wildlife-Habitat Relationship System for Breeding Birds in Valley-Foothill Riparian Habitat

Treesearch

Stephen A. Laymon

1989-01-01

The California Wildlife-Habitat Relationship (WHR) system was tested for birds breeding in the Valley-Foothill Riparian habitat along California's Sacramento and South Fork Kern rivers. The model performed poorly with 33 pct and 21 pct correct predictions respectively at the two locations. Changes to the model for 60 species on the Sacramento River and 66 species...

Miocene rapakivi granites in the southern Death Valley region, California, USA

USGS Publications Warehouse

Calzia, J.P.; Ramo, O.T.

2005-01-01

Rapakivi granites in the southern Death Valley region, California, include the 12.4-Ma granite of Kingston Peak, the ca. 10.6-Ma Little Chief stock, and the 9.8-Ma Shoshone pluton. All of these granitic rocks are texturally zoned from a porphyritic rim facies, characterized by rapakivi textures and miarolitic cavities, to an equigranular aplite core. These granites crystallized from anhydrous and peraluminous to metaluminous magmas that were more oxidized and less alkalic than type rapakivi granites from southern Finland. Chemical and isotope (Nd-Sr-Pb) data suggest that rapakivi granites of the southern Death Valley region were derived by partial melting of lower crustal rocks (possibly including Mesozoic plutonic component) with some mantle input as well; they were emplaced at shallow crustal levels (4 km) in an actively extending orogen.

Miocene rapakivi granites in the southern Death Valley region, California, USA

USGS Publications Warehouse

Calzia, James P.; Ramo, O.T.

2005-01-01

Rapakivi granites in the southern Death Valley region, California, include the 12.4-Ma granite of Kingston Peak, the ca. 10.6-Ma Little Chief stock, and the 9.8-Ma Shoshone pluton. All of these granitic rocks are texturally zoned from a porphyritic rim facies, characterized by rapakivi textures and miarolitic cavities, to an equigranular aplite core. These granites crystallized from anhydrous and peraluminous to metaluminous magmas that were more oxidized and less alkalic than type rapakivi granites from southern Finland. Chemical and isotope (Nd–Sr–Pb) data suggest that rapakivi granites of the southern Death Valley region were derived by partial melting of lower crustal rocks (possibly including Mesozoic plutonic component) with some mantle input as well; they were emplaced at shallow crustal levels (4 km) in an actively extending orogen.

77 FR 12495 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-01

... the California State Implementation Plan, Antelope Valley Air Quality Management District and Mojave Desert Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION: Direct final... Quality Management District (AVAQMD) and Mojave Desert Air Quality Management District (MDAQMD) portion of...

A consortium of three brings real geothermal power for California's Imperial valley -- at last

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wehlage, E.F.

1983-04-01

Imperial Valley's geothermal history gets a whole new chapter with dedication ceremony for southern California's unusual 10,000 kilowatt power station-SCE in joint corporate venture with Southern Pacific and Union Oil. America's newest and unique electric power generation facility, The Salton Sea Geothermal-Electric Project, was the the site of a formal dedication ceremony while the sleek and stainless jacketed piping and machinery were displayed against a flawlessly brilliant January sky - blue and flecked with a few whisps of high white clouds, while plumes of geothermal steam rose across the desert. The occasion was the January 19, 1983, ceremonial dedication ofmore » the unique U.S.A. power generation facility constructed by an energy consortium under private enterprise, to make and deliver electricity, using geothermal steam released (with special cleaning and treatment) from magma-heated fluids produced at depths of 3,000 to 6,000 feet beneath the floor of the Imperial Valley near Niland and Brawley, California.« less

Proposed Approval of California Air Plan Revision; San Joaquin Valley Unified Air Pollution Control District; Reasonably Available Control Technology Demonstration

EPA Pesticide Factsheets

EPA isproposing to approve revisions to the SJVUAPCD portion of the California SIP applying to the San Joaquin Valley of California concerning demonstration regarding RACT requirements for the 2008 8-hour ozone National Ambient Air Quality Standard (NAAQS)

Provenance, Offset Equivalent and Palinspastic Reconstruction of the Miocene Cajon Valley Formation, Southern California

NASA Astrophysics Data System (ADS)

Stang, Dallon Michael

Petrographic, conglomerate and detrital-zircon analyses of formations in southern California can determine consanguineous petrofacies and lithofacies that help constrain paleotectonic and paleogeographic reconstructions of the southwestern United States. Arkosic sandstone of the lower Middle Miocene Cajon Valley formation is exposed on the southwest edge of the Mojave block and juxtaposed against Mesozoic and Paleozoic rocks by the San Andreas fault (SAf). Early work in Cajon Valley referred to the formation as Punchbowl, due to its similar appearance to the Punchbowl Formation at Devil's Punchbowl (northwest along the SAf). However, paleontological work placed Cajon Valley strata in the Hemingfordian-Barstovian (18-14 Ma), as opposed to the Clarendonian-Hemphillian (13-9 Ma) Punchbowl Formation. Since the Cajon Valley formation was deposited prior to being truncated by the San Andreas fault, the 2400m-thick, laterally extensive subaerial deposits likely were deposited across what is now the fault trace. Restoring 310 km of dextral slip on the SAf system should indicate the location of offset equivalent sandstone. Restoration of slip on the SAf system places Cajon Valley adjacent to the Caliente and La Panza Ranges, east of San Luis Obispo. Although analysis of detrital zircon from Cenozoic sandstone throughout southern California has been crucial in establishing paleodrainage areas, detrital zircon from the Cajon Valley and equivalent formations had not been analyzed prior to this study. Paleocurrents measured throughout the Cajon Valley formation indicate a source to the NE, in the Mojave Desert. Sandstone samples analyzed in thin section using the Gazzi-Dickinson method of point-counting are homogeneously arkosic, with slight compositional variability, making differentiation of the Cajon Valley formation and potential offset equivalents problematic. However, Branch Canyon Sandstone and Santa Margarita Formation samples are compositionally the best match for the

Thirty Years of Cloud Cover Patterns from Satellite Data: Fog in California's Central Valley and Coast

NASA Astrophysics Data System (ADS)

Waller, E.; Baldocchi, D. D.

2012-12-01

In an effort to assess long term trends in winter fog in the Central Valley of California, custom maps of daily cloud cover from an approximately 30 year record of AVHRR (1981-1999) and MODIS (2000-2012) satellite data were generated. Spatial rules were then used to differentiate between fog and general cloud cover. Differences among the sensors (e.g., spectral content, spatial resolution, overpass time) presented problems of consistency, but concurrent climate station data were used to resolve systematic differences in products, and to confirm long term trends. The frequency and extent of Central Valley ("Tule") fog appear to have some periodic oscillation, but also appear to be on the decline, especially in the Sacramento Valley and in the "shoulder" months of November and February. These results may have strong implications for growers of fruit and nut trees in the Central Valley dependent on winter chill hours that are augmented by the foggy daytime conditions. Conclusions about long term trends in fog are limited to daytime patterns, as results are primarily derived from reflectance-based products. Similar analyses of daytime cloud cover are performed on other areas of concern, such as the coastal fog belt of California. Large area and long term patterns here appear to have periodic oscillation similar to that for the Central Valley. However, the relatively coarse spatial resolution of the AVHRR LTDR (Long Term Data Record) data (~5-km) may be limiting for fine-scale analysis of trends.

Constrained Inclusion: Access and Persistence Among Undocumented Community College Students in California's Central Valley

ERIC Educational Resources Information Center

Negrón-Gonzales, Genevieve

2017-01-01

This article examines the ways in which citizenship status uniquely shapes both the access and persistence of undocumented community college students in the Central Valley of California. Drawing on more than 2 years of qualitative fieldwork, it is argued that undocumented community college students navigate an institutional landscape of…

Water availability and land subsidence in the Central Valley, California, USA

USGS Publications Warehouse

Faunt, Claudia; Sneed, Michelle; Traum, Jonathan A.; Brandt, Justin

2016-01-01

The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007–2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

Biology and Molecular Characterization of Cucurbit leaf crumple virus, an Emergent Cucurbit-Infecting Begomovirus in the Imperial Valley of California

USDA-ARS?s Scientific Manuscript database

Cucurbit leaf crumple virus (CuLCrV) is an emergent and potentially economically important bipartite begomovirus first identified in volunteer watermelon plants in the Imperial Valley of southern California in 1998. Field surveys indicated that CuLCrV has become established in the Imperial Valley; a...

Water budgets for major streams in the Central Valley, California, 1961-77

USGS Publications Warehouse

Mullen, J.R.; Nady, Paul

1985-01-01

A compilation of annual streamflow data for 20 major stream systems in the central Valley of California, for water years 1961-77, is presented. The water-budget tables list gaged and ungaged inflow from tributaries and canals, diversions, and gaged outflow. Theoretical outflow and gain or loss in a reach are computed. A schematic diagram and explanation of the data are provided for each water-budget table. (USGS)

Isostatic gravity map of the Death Valley ground-water model area, Nevada and California

USGS Publications Warehouse

Ponce, D.A.; Blakely, R.J.; Morin, R.L.; Mankinen, E.A.

2001-01-01

An isostatic gravity map of the Death Valley groundwater model area was prepared from over 40,0000 gravity stations as part of an interagency effort by the U.S. Geological Survey and the U.S. Department of Energy to help characterize the geology and hydrology of southwest Nevada and parts of California.

Land subsidence in the San Joaquin Valley, California, as of 1980

USGS Publications Warehouse

Ireland, R.L.; Poland, J.F.; Riley, F.S.

1982-01-01

Land subsidence due to ground-water overdraft in the San Joaquin Valley began in the mid-1920 's and continued at alarming rates until surface was imported through major canals and aqueducts in the 1950 's and late 1960's. In areas where surface water replaced withdrawal of ground-water, water levels in the confined system rose sharply and subsidence slowed. In the late 1960 's and early 1970 's water levels in wells recovered to levels of the 1940 's and 1950 's throughout most of the western and southern parts of the Valley, in response to the importation of surface water through the California aqueduct. During the 1976-77 drought data collected at water-level and extensometer sites showed the effect of heavy demand on the ground-water resevoir. With the ' water of compaction ' gone, artesian head declined 10 to 20 times as fast as during the first cycle of long-term drawdown that ended in the late 1960's. In the 1978-79 water levels recovered to or above the 1976 pre-drought levels. The report suggests continued monitoring of land subsidence in the San Joaquin Valley. (USGS)

Structural evolution of the east Sierra Valley system (Owens Valley and vicinity), California: a geologic and geophysical synthesis

USGS Publications Warehouse

Stevens, Calvin H.; Stone, Paul; Blakely, Richard J.

2013-01-01

The tectonically active East Sierra Valley System (ESVS), which comprises the westernmost part of the Walker Lane-Eastern California Shear Zone, marks the boundary between the highly extended Basin and Range Province and the largely coherent Sierra Nevada-Great Valley microplate (SN-GVm), which is moving relatively NW. The recent history of the ESVS is characterized by oblique extension partitioned between NNW-striking normal and strike-slip faults oriented at an angle to the more northwesterly relative motion of the SN-GVm. Spatially variable extension and right-lateral shear have resulted in a longitudinally segmented valley system composed of diverse geomorphic and structural elements, including a discontinuous series of deep basins detected through analysis of isostatic gravity anomalies. Extension in the ESVS probably began in the middle Miocene in response to initial westward movement of the SN-GVm relative to the Colorado Plateau. At ca. 3-3.5 Ma, the SN-GVm became structurally separated from blocks directly to the east, resulting in significant basin-forming deformation in the ESVS. We propose a structural model that links high-angle normal faulting in the ESVS with coeval low-angle detachment faulting in adjacent areas to the east.

Pesticide Risk Communication, Risk Perception, and Self-Protective Behaviors among Farmworkers in California's Salinas Valley

ERIC Educational Resources Information Center

Cabrera, Nolan L.; Leckie, James O.

2009-01-01

Agricultural pesticide use is the highest of any industry, yet there is little research evaluating farmworkers' understandings of the health risks chemical exposure poses. This study examines pesticide education, risk perception, and self-protective behaviors among farmworkers in California's Salinas Valley. Fifty current and former farmworkers…

Mapping Aquifer Systems with Airborne Electromagnetics in the Central Valley of California.

PubMed

Knight, Rosemary; Smith, Ryan; Asch, Ted; Abraham, Jared; Cannia, Jim; Viezzoli, Andrea; Fogg, Graham

2018-03-09

The passage of the Sustainable Groundwater Management Act in California has highlighted a need for cost-effective ways to acquire the data used in building conceptual models of the aquifer systems in the Central Valley of California. One approach would be the regional implementation of the airborne electromagnetic (AEM) method. We acquired 104 line-kilometers of data in the Tulare Irrigation District, in the Central Valley, to determine the depth of investigation (DOI) of the AEM method, given the abundance of electrically conductive clays, and to assess the usefulness of the method for mapping the hydrostratigraphy. The data were high quality providing, through inversion of the data, models displaying the variation in electrical resistivity to a depth of approximately 500 m. In order to transform the resistivity models to interpreted sections displaying lithology, we established the relationship between resistivity and lithology using collocated lithology logs (from drillers' logs) and AEM data. We modeled the AEM response and employed a bootstrapping approach to solve for the range of values in the resistivity model corresponding to sand and gravel, mixed coarse and fine, and clay in the unsaturated and saturated regions. The comparison between the resulting interpretation and an existing cross section demonstrates that AEM can be an effective method for mapping the large-scale hydrostratigraphy of aquifer systems in the Central Valley. The methods employed and developed in this study have widespread application in the use of the AEM method for groundwater management in similar geologic settings. © 2018 The Authors. Groundwater published by Wiley Periodicals, Inc. on behalf of National Ground Water Association.

Optimal pumping strategies for managing shallow, poorquality groundwater, western San Joaquin Valley, California

USGS Publications Warehouse

Barlow, P.; Wagner, B.; Belitz, K.

1995-01-01

Continued agricultural productivity in the western San Joaquin Valley, California, is threatened by the presence of shallow, poor-quality groundwater that can cause soil salinization. We evaluate the management alternative of using groundwater pumping to control the altitude of the water table and provide irrigation water requirements. A transient, three-dimensional, groundwater flow model was linked with nonlinear optimization to simulate management alternatives for the groundwater flow system. Optimal pumping strategies have been determined that substantially reduce the area subject to a shallow water table and bare-soil evaporation (that is, areas with a water table within 2.1 m of land surface) and the rate of drainflow to on-farm drainage systems. Optimal pumping strategies are constrained by the existing distribution of wells between the semiconfined and confined zones of the aquifer, by the distribution of sediment types (and associated hydraulic conductivities) in the western valley, and by the historical distribution of pumping throughout the western valley.

Prevalence of hepatitis B infection among young and unsuspecting Hmong blood donors in the Central California Valley.

PubMed

Sheikh, Muhammad Y; Atla, Pradeep R; Raoufi, Rahim; Sadiq, Humaira; Sadler, Patrick C

2012-02-01

Chronic hepatitis B virus (HBV) infection may result in cirrhosis and/or hepatocellular carcinoma and is one of the leading causes of mortality in Asian Americans including Hmong Americans. The Central California Valley is home to a huge Hmong population. To date, the true prevalence of HBV among Hmong is largely unknown. The aim of this study was to contribute to the limited data on HBV prevalence and its trends in Hmong population in the Central California Valley. Between fiscal years 2006 and 2010, a total of 219, 450 voluntary donors were identified at Central California Blood Center in Fresno. Of these, 821 (399 males and 422 females) were Hmong donors. A cross-sectional review of the HBV (hepatitis B surface antigen) positivity among all donors was carried out. Prevalence estimates with 95% confidence intervals (CI) were calculated. Ninety-two percent of Hmong donors were between age groups 16 and 35 years, and only 8% were ≥36 years. The overall prevalence in Hmong was noted at 3.41% (95%CI 2.3-4.9) compared to 0.06% (95%CI 0.05-0.07) in donors of all ethnicities. The calculated prevalence could be an underestimate of the true HBV prevalence in Hmong as the study enrolled only healthy blood donors with predominant younger age (≤35 years) population. These results underscore the persistent burden of HBV infection and potentially increased risk of premature death even in the second generation Hmong community of the Central California Valley. This study reemphasizes the unequivocal need to develop robust preventive and treatment strategies for HBV in Hmong community.

Water resources development in Santa Clara Valley, California: insights into the human-hydrologic relationship

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reynolds, Jesse L.

2000-06-01

Groundwater irrigation is critical to food production and, in turn, to humankind's relationship with its environment. The development of groundwater in Santa Clara Valley, California during the early twentieth century is instructive because (1) responses to unsustainable resource use were largely successful; (2) the proposals for the physical management of the water, although not entirely novel, incorporated new approaches which reveal an evolving relationship between humans and the hydrologic cycle; and (3) the valley serves as a natural laboratory where natural (groundwater basin, surface watershed) and human (county, water district) boundaries generally coincide. Here, I investigate how water resources developmentmore » and management in Santa Clara Valley was influenced by, and reflective of, a broad understanding of water as a natural resource, including scientific and technological innovations, new management approaches, and changing perceptions of the hydrologic cycle. Market demands and technological advances engendered reliance on groundwater. This, coupled with a series of dry years and laissez faire government policies, led to overdraft. Faith in centralized management and objective engineering offered a solution to concerns over resource depletion, and a group dominated by orchardists soon organized, fought for a water conservation district, and funded an investigation to halt the decline of well levels. Engineer Fred Tibbetts authored an elaborate water salvage and recharge plan that optimized the local water resources by integrating multiple components of the hydrologic cycle. Informed by government investigations, groundwater development in Southern California, and local water law cases, it recognized the limited surface storage possibilities, the spatial and temporal variability, the relatively closed local hydrology, the interconnection of surface and subsurface waters, and the value of the groundwater basin for its storage, transportation, and

SRTM Perspective View with Landsat Overlay: Caliente Range and Cuyama Valley, California

NASA Technical Reports Server (NTRS)

2001-01-01

Before the arrival of Europeans, California's Cuyama Valley was inhabited by Native Americans who were culturally and politically tied to the Chumash tribes of coastal Santa Barbara County. Centuries later, the area remains the site of noted Native American rock art paintings. In the 1800s, when Europeans established large cattle and horse-breeding ranches in the valley, the early settlers reported the presence of small villages along the Cuyama River. This perspective view looks upstream toward the southeast through the Cuyama Valley. The Caliente Range, with maximum elevations of 1,550 meters (5,085 feet), borders the valley on the left. The Cuyama River, seen as a bright meandering line on the valley floor, enters the valley from headwaters more than 2,438 meters (8,000 feet) above sea level near Mount Abel and flows 154 kilometers (96 miles) before emptying into the Pacific Ocean. The river's course has been determined in large part by displacement along numerous faults.

Today, the Cuyama Valley is the home of large ranches and small farms. The area has a population of 1,120 and is more than an hour and a half drive from the nearest city in the county.

This image was generated by draping an enhanced Landsat satellite image over elevation data from the Shuttle Radar Topography Mission (SRTM). Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors approximate natural colors.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM

The Mw6.0 24 August 2014 South Napa earthquake

USGS Publications Warehouse

Brocher, Thomas M.; Baltay, Annemarie S.; Hardebeck, Jeanne L.; Pollitz, Fred F.; Murray, Jessica R.; Llenos, Andrea L.; Schwartz, David P.; Blair, James Luke; Ponti, Daniel J.; Lienkaemper, James J.; Langenheim, V.E.; Dawson, Timothy E.; Hudnut, Kenneth W.; Shelly, David R.; Dreger, Douglas S.; Boatwright, John; Aagaard, Brad T.; Wald, David J.; Allen, Richard M.; Barnhart, William D.; Knudsen, Keith L.; Brooks, Benjamin A.; Scharer, Katherine M.

2015-01-01

The Mw 6.0 South Napa earthquake, which occurred at 10:20 UTC 24 August 2014 was the largest earthquake to strike the greater San Francisco Bay area since the Mw 6.9 1989 Loma Prieta earthquake. The rupture from this right‐lateral earthquake propagated mostly unilaterally to the north and up‐dip, directing the strongest shaking toward the city of Napa, where peak ground accelerations (PGAs) between 45%g and 61%g were recorded and modified Mercalli intensities (MMIs) of VII–VIII were reported. Tectonic surface rupture with dextral slip of up to 46 cm was observed on a 12.5 km long segment, some of which was along a previously mapped strand of the West Napa fault system, although the rupture extended to the north of the mapped Quaternary strand. Modeling of seismic and geodetic data suggests an average coseismic slip of 50 cm, with a maximum slip of about 1 m at depths of 10–11 km. We observed up to 35 cm of afterslip along the surface trace in the week following the mainshock, primarily along the southern half of the surface rupture that experienced relatively little coseismic offset. Relocation of the sparse aftershock sequence suggests en echelon southwest‐ and northeast‐dipping fault planes, reflective of the complex fault geometry in this region. The Napa basin and historic and late Holocene alluvial flood deposits in downtown Napa amplified the ground motions there. Few ground failures were mapped, reflecting the dry season (as well as a persistent drought that had lowered the groundwater table) and the short duration of strong shaking in the epicentral area.

27 CFR 9.194 - San Antonio Valley.

Code of Federal Regulations, 2011 CFR

2011-04-01

... significance. (b) Approved Maps. The appropriate maps for determining the boundary of the San Antonio Valley...) Hames Valley, California, 1949, photorevised 1978; (2) Tierra Redonda Mountain, California, 1949... southeast corner of section 14, T23S, R9E, on the Hames Valley map; (2) From the beginning point, proceed...

A public health issue related to collateral seismic hazards: The valley fever outbreak triggered by the 1994 Northridge, California earthquake

USGS Publications Warehouse

Jibson, R.W.

2002-01-01

Following the 17 January 1994 Northridge. California earthquake (M = 6.7), Ventura County, California, experienced a major outbreak of coccidioidomycosis (CM), commonly known as valley fever, a respiratory disease contracted by inhaling airborne fungal spores. In the 8 weeks following the earthquake (24 January through 15 March), 203 outbreak-associated cases were reported, which is about an order of magnitude more than the expected number of cases, and three of these cases were fatal. Simi Valley, in easternmost Ventura County, had the highest attack rate in the county, and the attack rate decreased westward across the county. The temporal and spatial distribution of CM cases indicates that the outbreak resulted from inhalation of spore-contaminated dust generated by earthquake-triggered landslides. Canyons North East of Simi Valley produced many highly disrupted, dust-generating landslides during the earthquake and its aftershocks. Winds after the earthquake were from the North East, which transported dust into Simi Valley and beyond to communities to the West. The three fatalities from the CM epidemic accounted for 4 percent of the total earthquake-related fatalities.

Potential effects of drought on carrying capacity for wintering waterfowl in the Central Valley of California

USGS Publications Warehouse

Petrie, Mark J.; Fleskes, Joseph P.; Wolder, Mike A.; Isola, Craig R.; Yarris, Gregory S.; Skalos, Daniel A.

2016-01-01

We used the bioenergetics model TRUEMET to evaluate potential effects of California's recent drought on food supplies for waterfowl wintering in the Central Valley under a range of habitat and waterfowl population scenarios. In nondrought years in the current Central Valley landscape, food supplies are projected to be adequate for waterfowl from fall through early spring (except late March) even if waterfowl populations reach North American Waterfowl Management Plan goals. However, in all drought scenarios that we evaluated, food supplies were projected to be exhausted for ducks by mid- to late winter and by late winter or early spring for geese. For ducks, these results were strongly related to projected declines in winter-flooded rice fields that provide 45% of all the food energy available to ducks in the Central Valley in nondrought water years. Delayed flooding of some managed wetlands may help alleviate food shortages by providing wetland food resources better timed with waterfowl migration and abundance patterns in the Central Valley, as well as reducing the amount of water needed to manage these habitats. However, future research is needed to evaluate the impacts of delayed flooding on waterfowl hunting, and whether California's existing water delivery system would make delayed flooding feasible. Securing adequate water supplies for waterfowl and other wetland-dependent birds is among the greatest challenges facing resource managers in coming years, especially in the increasingly arid western United States.

76 FR 35167 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-16

... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2011-0312; FRL-9319-8] Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District... Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Intergovernmental relations...

Preliminary evaluation of the hydrogeologic system in Owens Valley, California

USGS Publications Warehouse

Danskin, W.R.

1988-01-01

A preliminary, two-layer, steady-state, groundwater flow model was used to evaluate present data and hydrologic concepts of Owens Valley, California. Simulations of the groundwater system indicate that areas where water levels are most affected by changes in recharge and discharge are near toes of alluvial fans and along the edge of permeable volcanic deposits. Sensitivity analysis for each model parameter shows that steady state simulations are most sensitive to uncertainties in evapotranspiration rates. Tungsten Hills, Poverty Hills, and Alabama Hills were found to act as virtually impermeable barriers to groundwater flow. Accurate simulation of the groundwater system between Bishop and Lone Pine appears to be possible without simulating the groundwater system in Round Valley, near Owens Lake, or in aquifer materials more than 1,000 ft below land surface. Although vast amounts of geologic and hydrologic data have been collected for Owens Valley, many parts of the hydrogeologic system have not been defined with sufficient detail to answer present water management questions. Location and extent of geologic materials that impede the vertical movement of water are poorly documented. The likely range of aquifer characteristics, except vertical hydraulic conductivity, is well known, but spatial distribution of these characteristics is not well documented. A set of consistent water budgets is needed, including one for surface water, groundwater, and the entire valley. The largest component of previous water budgets (evapotranspiration) is largely unverified. More definitive estimates of local gains and losses for Owens River are needed. Although groundwater pumpage from each well is measured, the quantity of withdrawal from different zones of permeable material has not been defined. (USGS)

Abundance and sexual size dimorphism of the giant gartersnake (Thamnophis gigas) in the Sacramento valley of California

USGS Publications Warehouse

Wylie, G.D.; Casazza, Michael L.; Gregory, C.J.; Halstead, B.J.

2010-01-01

The Giant Gartersnake (Thamnophis gigas) is restricted to wetlands of the Central Valley of California. Because of wetland loss in this region, the Giant Gartersnake is both federally and state listed as threatened. We conducted markrecapture studies of four populations of the Giant Gartersnake in the Sacramento Valley (northern Central Valley), California, to obtain baseline data on abundance and density to assist in recovery planning for this species. We sampled habitats that ranged from natural, unmanaged marsh to constructed managed marshes and habitats associated with rice agriculture. Giant Gartersnake density in a natural wetland (1.90 individuals/ha) was an order of magnitude greater than in a managed wetland subject to active season drying (0.17 individuals/ha). Sex ratios at all sites were not different from 1 1, and females were longer and heavier than males. Females had greater body condition than males, and individuals at the least disturbed sites had significantly greater body condition than individuals at the managed wetland. The few remaining natural wetlands in the Central Valley are important, productive habitat for the Giant Gartersnake, and should be conserved and protected. Wetlands constructed and restored for the Giant Gartersnake should be modeled after the permanent, shallow wetlands representative of historic Giant Gartersnake habitat. ?? 2010 Society for the Study of Amphibians and Reptiles.

Unrest in Long Valley Caldera, California, 1978-2004

USGS Publications Warehouse

Hill, David P.; ,

2006-01-01

Long Valley Caldera and the Mono-Inyo Domes volcanic field in eastern California lie in a left-stepping offset along the eastern escarpment of the Sierra Nevada, at the northern end of the Owens Valley and the western margin of the Basin and Range Province. Over the last 4 Ma, this volcanic field has produced multiple volcanic eruptions, including the caldera-forming eruption at 760 000 a BP and the recent Mono-Inyo Domes eruptions 500–660 a BP and 250 a BP. Beginning in the late 1970s, the caldera entered a sustained period of unrest that persisted through the end of the century without culminating in an eruption. The unrest has included recurring earthquake swarms; tumescence of the resurgent dome by nearly 80 cm; the onset of diffuse magmatic carbon dioxide emissions around the flanks of Mammoth Mountain on the southwest margin of the caldera; and other indicators of magma transport at mid- to upper-crustal depths. Although we have made substantial progress in understanding the processes driving this unrest, many key questions remain, including the distribution, size, and relation between magma bodies within the mid-to-upper crust beneath the caldera, Mammoth Mountain, and the Inyo Mono volcanic chain, and how these magma bodies are connected to the roots of the magmatic system in the lower crust or upper mantle.

Groundwater quality in the shallow aquifers of the Monterey Bay, Salinas Valley, and adjacent highland areas, California

USGS Publications Warehouse

Burton, Carmen

2018-05-30

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The shallow aquifers of the groundwater basins around Monterey Bay, the Salinas Valley, and the highlands adjacent to the Salinas Valley constitute one of the study units.

Predicted pH at the domestic and public supply drinking water depths, Central Valley, California

USGS Publications Warehouse

Rosecrans, Celia Z.; Nolan, Bernard T.; Gronberg, Jo Ann M.

2017-03-08

This scientific investigations map is a product of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project modeling and mapping team. The prediction grids depicted in this map are of continuous pH and are intended to provide an understanding of groundwater-quality conditions at the domestic and public supply drinking water zones in the groundwater of the Central Valley of California. The chemical quality of groundwater and the fate of many contaminants is often influenced by pH in all aquifers. These grids are of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to pH. In this work, the median well depth categorized as domestic supply was 30 meters below land surface, and the median well depth categorized as public supply is 100 meters below land surface. Prediction grids were created using prediction modeling methods, specifically boosted regression trees (BRT) with a Gaussian error distribution within a statistical learning framework within the computing framework of R (http://www.r-project.org/). The statistical learning framework seeks to maximize the predictive performance of machine learning methods through model tuning by cross validation. The response variable was measured pH from 1,337 wells and was compiled from two sources: USGS National Water Information System (NWIS) database (all data are publicly available from the USGS: http://waterdata.usgs.gov/ca/nwis/nwis) and the California State Water Resources Control Board Division of Drinking Water (SWRCB-DDW) database (water quality data are publicly available from the SWRCB: http://www.waterboards.ca.gov/gama/geotracker_gama.shtml). Only wells with measured pH and well depth data were selected, and for wells with multiple records, only the most recent sample in the period 1993–2014 was used. A total of 1,003 wells (training dataset) were used to train the BRT

New observations of VOC emissions and concentrations in, above, and around the Central Valley of California

NASA Astrophysics Data System (ADS)

Goldstein, A. H.; Fares, S.; Gentner, D. R.; Park, J.; Weber, R.; Ormeno, E.; Holzinger, R.; Misztal, P. K.; Karl, T. R.; Guenther, A. B.; Fischer, M. L.; Harley, R. A.; Karlik, J. F.

2011-12-01

Large portions of the Central Valley of California are out of compliance with current state and federal air quality standards for ozone and particulate matter, and the relative importance of biogenic and anthropogenic VOC emissions to their photochemical production in this region remains uncertain. In 2009-2011 multiple measurement campaigns were completed investigating the VOC emission inventory and concentration distributions. In 2009 BVOC emissions from more than 20 species of major agricultural crops in California were measured in a greenhouse using branch enclosures by both PTRMS and in-situ GC. Overall, crops were found to emit low amounts of BVOC compared to the natural forests surrounding the valley. Crops mainly emitted methanol and terpenes, with a broad array of other species emitted at lower levels, and all the measured crops showed negligible emissions of isoprene. Navel oranges were the largest crop BVOC emitters measured so a full year of flux measurements were made in an orange grove near Visalia in 2010 by eddy covariance(EC)-PTRMS with two multi-week periods of concentration measurements by hourly in-situ GC, and one month of high mass resolution flux measurements by EC-PTR-TOF-MS. The dominant BVOC emissions from the orange grove were methanol and terpenes, followed by acetone, acetaldehyde, and a low level of emissions for many other species. In 2011 aircraft eddy covariance measurements of BVOC fluxes were made by EC-PTRMS covering a large area of California as part of the California Airborne Bvoc Emission Research in Natural Ecosystem Transects (CABERNET) campaign aimed at improving BVOC emission models on regional scales, mainly profiling BVOC emissions from oak woodlands surrounding the Central Valley. In 2010, hourly in-situ VOC measurements were made via in-situ GC in Bakersfield, CA as part of the CalNex experiment. Additionally, in-situ measurements of fresh motor vehicle exhaust were made in Oakland's Caldecott tunnel. Measurements by

Understanding Public Views about Air Quality and Air Pollution Sources in the San Joaquin Valley, California.

PubMed

Cisneros, Ricardo; Brown, Paul; Cameron, Linda; Gaab, Erin; Gonzalez, Mariaelena; Ramondt, Steven; Veloz, David; Song, Anna; Schweizer, Don

2017-01-01

The San Joaquin Valley of California has poor air quality and high rates of asthma. Surveys were collected from 744 residents of the San Joaquin Valley from November 2014 to January 2015 to examine the public's views about air quality. The results of this study suggest that participants exposed to high PM 2.5 (particulate matter less than 2.5 microns in size) concentrations perceived air pollution to be of the worst quality. Air quality in the San Joaquin Valley was primarily perceived as either moderate or unhealthy for sensitive groups. Females perceived air pollution to be of worse quality compared to males. Participants perceived unemployment, crime, and obesity to be the top three most serious community problems in the San Joaquin Valley. Participants viewed cars and trucks, windblown dust, and factories as the principle contributors to air pollution in the area. There is a need to continue studying public perceptions of air quality in the San Joaquin Valley with a more robust survey with more participants over several years and seasons.

Understanding Public Views about Air Quality and Air Pollution Sources in the San Joaquin Valley, California

PubMed Central

Brown, Paul; Cameron, Linda; Gaab, Erin; Gonzalez, Mariaelena; Ramondt, Steven; Veloz, David; Song, Anna; Schweizer, Don

2017-01-01

The San Joaquin Valley of California has poor air quality and high rates of asthma. Surveys were collected from 744 residents of the San Joaquin Valley from November 2014 to January 2015 to examine the public's views about air quality. The results of this study suggest that participants exposed to high PM2.5 (particulate matter less than 2.5 microns in size) concentrations perceived air pollution to be of the worst quality. Air quality in the San Joaquin Valley was primarily perceived as either moderate or unhealthy for sensitive groups. Females perceived air pollution to be of worse quality compared to males. Participants perceived unemployment, crime, and obesity to be the top three most serious community problems in the San Joaquin Valley. Participants viewed cars and trucks, windblown dust, and factories as the principle contributors to air pollution in the area. There is a need to continue studying public perceptions of air quality in the San Joaquin Valley with a more robust survey with more participants over several years and seasons. PMID:28469673

Santa Clara Valley water district multi-aquifer monitoring-well site, Coyote Creek Outdoor Classroom, San Jose, California

USGS Publications Warehouse

Hanson, R.T.; Newhouse, M.W.; Wentworth, C.M.; Williams, C.F.; Noce, T.E.; Bennett, M.J.

2002-01-01

The U.S. Geological Survey (USGS), in cooperation with the Santa Clara Valley Water District (SCVWD), has completed the first of several multiple-aquifer monitoring-well sites in the Santa Clara Valley. This site monitors ground-water levels and chemistry in the one of the major historic subsidence regions south of San Jose, California, at the Coyote Creek Outdoor Classroom (CCOC) (fig. 1) and provides additional basic information about the geology, hydrology, geochemistry, and subsidence potential of the upper- and lower-aquifer systems that is a major source of public water supply in the Santa Clara Valley. The site also serves as a science education exhibit at the outdoor classroom operated by SCVWD.

Asian Americans and Latinos in San Gabriel Valley, California: Ethnic Political Cooperation and Redistricting 1990-92.

ERIC Educational Resources Information Center

Saito, Leland T.

1993-01-01

Examines political relationships between Asian Americans and Latinos in the San Gabriel Valley, Los Angeles (California), focusing on an Asian-American organization dealing with redistricting and reapportioning, and reviews how this group allied with its Latino counterpart. The importance of federal law and legal precedent is demonstrated. (SLD)

77 FR 745 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-06

... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2011-0547; FRL-9480-1] Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) Correction In rule document 2011-33660 appearing on pages 214-217 in the issue of Wednesday...

Winter habitat associations of diurnal raptors in Californias Central Valley

USGS Publications Warehouse

Pandolrno, E.R.; Herzog, M.P.; Hooper, S.L.; Smith, Z.

2011-01-01

The wintering raptors of California's Central Valley are abundant and diverse. Despite this, little information exists on the habitats used by these birds in winter. We recorded diurnal raptors along 19 roadside survey routes throughout the Central Valley for three consecutive winters between 2007 and 2010. We obtained data sufficient to determine significant positive and negative habitat associations for the White-tailed Kite (Elanus leucurus), Bald Eagle {Haliaeetus leucocephalus), Northern Harrier (Circus cyaneus), Red-tailed Hawk (Buteo jamaicensis), Ferruginous Hawk (Buteo regalis), Rough-legged Hawk (Buteo lagopus), American Kestrel (Falco sparverius), and Prairie Falcon (Falco mexicanus). The Prairie Falcon and Ferruginous and Rough-legged hawks showed expected strong positive associations with grasslands. The Bald Eagle and Northern Harrier were positively associated not only with wetlands but also with rice. The strongest positive association for the White-tailed Kite was with wetlands. The Red-tailed Hawk was positively associated with a variety of habitat types but most strongly with wetlands and rice. The American Kestrel, Northern Harrier, and White-tailed Kite were positively associated with alfalfa. Nearly all species were negatively associated with urbanized landscapes, orchards, and other intensive forms of agriculture. The White-tailed Kite, Northern Harrier, Redtailed Hawk, Ferruginous Hawk, and American Kestrel showed significant negative associations with oak savanna. Given the rapid conversion of the Central Valley to urban and intensive agricultural uses over the past few decades, these results have important implications for conservation of these wintering raptors in this region.

27 CFR 9.191 - Ramona Valley.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Ramona Valley. 9.191 Section 9.191 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...) Borrego Valley, California, 1982 edition; and (2) El Cajon, California, 1979 edition. (c) Boundary. The...

27 CFR 9.191 - Ramona Valley.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ramona Valley. 9.191 Section 9.191 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...) Borrego Valley, California, 1982 edition; and (2) El Cajon, California, 1979 edition. (c) Boundary. The...

Phenotypic variation in California populations of valley oak (Quercus lobata Née) sampled along elevational gradients

Treesearch

Ana L. Albarrán-Lara; Jessica W. Wright; Paul F. Gugger; Annette Delfino-Mix; Juan Manuel Peñaloza-Ramírez; Victoria L. Sork

2015-01-01

California oaks exhibit tremendous phenotypic variation throughout their range. This variation reflects phenotypic plasticity in tree response to local environmental conditions as well as genetic differences underlying those phenotypes. In this study, we analyze phenotypic variation in leaf traits for valley oak adults sampled along three elevational transects and in...

Twenty-first century learning in schools: A case study of New Technology High School in Napa, California.

PubMed

Pearlman, Bob

2006-01-01

The most pertinent question concerning teaching and learning in the twenty-first century is not what knowledge and skills students need--that laundry list was identified over a decade ago--but rather how to foster twenty-first century learning. What curricula, experiences, assessments, environments, and technology best support twenty-first century learning? New Technology High School (NTHS) in Napa, California, is one example of a successful twenty-first century school. In this chapter, the author describes the components of this exemplary high school, illustrating an environment that will cultivate twenty-first century student learning. New Technology High School began by defining eight learning outcomes, aligned with the standards of the Partnership for 21st Century Skills; to graduate, students demonstrate mastery of these outcomes through an online portfolio. To help students achieve the outcomes, NTHS employs project- and problem-based learning. Whereas in traditional classrooms students work alone on short-term assignments that do not lend themselves to deep understanding, the project-based learning approach has students working in teams on long-term, in-depth, rigorous projects. Students' work is supported by the school's workplace-like environment and effectiv use of technology. Meaningful assessment is essential to project-based learning; students receive continuous feedback, helping them become self-directed learners. In fact, NTHS uses outcome-based grading through which students constantly know how they are performing on the twenty-first century outcomes. Research has shown that NTHS graduates are better prepared for postsecondary education, careers, and citizenship than their peers from other schools. To facilitate twenty-first century learning, all schools need to rethink their approach to teaching and learning. New Technology High School is one way to do so.

Airborne observations of methane emissions from rice cultivation in the Sacramento Valley of California

NASA Astrophysics Data System (ADS)

Peischl, J.; Ryerson, T. B.; Holloway, J. S.; Trainer, M.; Andrews, A. E.; Atlas, E. L.; Blake, D. R.; Daube, B. C.; Dlugokencky, E. J.; Fischer, M. L.; Goldstein, A. H.; Guha, A.; Karl, T.; Kofler, J.; Kosciuch, E.; Misztal, P. K.; Perring, A. E.; Pollack, I. B.; Santoni, G. W.; Schwarz, J. P.; Spackman, J. R.; Wofsy, S. C.; Parrish, D. D.

2012-12-01

Airborne measurements of methane (CH4) and carbon dioxide (CO2) were taken over the rice growing region of California's Sacramento Valley in the late spring of 2010 and 2011. From these and ancillary measurements, we show that CH4 mixing ratios were higher in the planetary boundary layer above the Sacramento Valley during the rice growing season than they were before it, which we attribute to emissions from rice paddies. We derive daytime emission fluxes of CH4 between 0.6 and 2.0% of the CO2 taken up by photosynthesis on a per carbon, or mole to mole, basis. We also use a mixing model to determine an average CH4/CO2 flux ratio of -0.6% for one day early in the growing season of 2010. We conclude the CH4/CO2 flux ratio estimates from a single rice field in a previous study are representative of rice fields in the Sacramento Valley. If generally true, the California Air Resources Board (CARB) greenhouse gas inventory emission rate of 2.7 × 1010 g CH4/yr is approximately three times lower than the range of probable CH4 emissions (7.8-9.3 × 1010 g CH4/yr) from rice cultivation derived in this study. We attribute this difference to decreased burning of the residual rice crop since 1991, which leads to an increase in CH4 emissions from rice paddies in succeeding years, but which is not accounted for in the CARB inventory.

The Salton Seismic Imaging Project: Tomographic characterization of a sediment-filled rift valley and adjacent ranges, southern California

NASA Astrophysics Data System (ADS)

Davenport, K.; Hole, J. A.; Stock, J. M.; Fuis, G. S.; Carrick, E.; Tikoff, B.

2011-12-01

The Salton Trough in Southern California represents the northernmost rift of the Gulf of California extensional system. Relative motion between the Pacific and North American plates is accommodated by continental rifting in step-over zones between the San Andreas, Imperial, and Cerro Prieto transform faults. Rapid sedimentation from the Colorado River has isolated the trough from the southern portion of the Gulf of California, progressively filling the subsiding rift basin. Based on data from previous seismic surveys, the pre-existing continent has ruptured completely, and a new ~22 km thick crust has been created entirely by sedimentation overlying rift-related magmatism. The MARGINS, EarthScope, and USGS-funded Salton Seismic Imaging Project (SSIP) was designed to investigate the nature of this new crust, the ongoing process of continental rifting, and associated earthquake hazards. SSIP, acquired in March 2011, comprises 7 lines of onshore seismic refraction / wide-angle reflection data, 2 lines of refraction / reflection data in the Salton Sea, and a line of broadband stations. This presentation focuses on the refraction / wide-angle reflection line across the Imperial Valley, extending ~220 km across California from Otay Mesa, near Tijuana, to the Colorado River. The data from this line includes seventeen 100-160 kg explosive shots and receivers at 100 m spacing across the Imperial Valley to constrain the structure of the Salton Trough rift basin, including the Imperial Fault. Eight larger shots (600-920 kg) at 20-35 km spacing and receivers at 200-500 m spacing extend the line across the Peninsular Ranges and the Chocolate Mountains. These data will contrast the structure of the rift to that of the surrounding crust and provide constraints on whole-crust and uppermost mantle structure. Preliminary work has included tomographic inversion of first-arrival travel times across the Valley, emphasizing a minimum-structure approach to create a velocity model of the

Death Valley, California

NASA Image and Video Library

2009-06-29

Death Valley, Calif., has the lowest point in North America, Badwater at 85.5 meters 282 feet below sea level. It is also the driest and hottest location in North America. This image is from NASA Terra spacecraft.

Comparison of Oxygenate Mixing Ratios Observed in the San Joaquin Valley, California, as a Consequence of Dairy Farming

NASA Astrophysics Data System (ADS)

Yang, M. M.; Blake, D. R.

2009-12-01

The San Joaquin Valley Air Basin in Central California is plagued with air quality problems, and is classified by the U.S. Environmental Protection Agency (EPA) as a serious non-attainment area for health-based eight-hour federal ozone (smog) standard (1). One of the main sources of Volatile Organic Compounds (VOCs), and indirect sources of ozone in the Valley, has been identified as dairy farming (2). Among these compounds, we have found that several OVOCs such as ethanol, methanol, acetone and acetaldehyde are produced in major quantities throughout the San Joaquin valley as by-products of yeast fermentation of silage and photochemical oxidation. These oxygenates, especially ethanol, play an important role in ozone (O3) formation within the valley. Since 2008, several different types of sampling protocols have been employed by our group in order to determine the degree of enhancement of the four oxygenates in the valley air shed, as well as to determine their sources, emission profiles and emission rates (2). In 2008 and 2009, samples were in early summer, allowing us to compare the difference in concentration levels between both years.The photochemical production of ozone was calculated for each of the four oxygenates and approximately one hundred other quantified VOCs. Based on the Maximum Incremental Reactivity (MIR) scale and concentrations of each oxygenate in the atmosphere, for both 2008 and 2009, as much as 15% of O3 production in the valley is from ethanol and its photochemical by-product acetaldehyde. Our findings suggest that the data observed in 2008 is consistent with that observed in 2009, with a slight decrease in concentrations overall for 2009. 1. Lindberg, J. Analysis of the San Joaquin Valley 2007 Ozone Plan. State of California Air Resources Board. Final Draft Staff Report. 5/30/2007. 2. M. Yang, S. Meinardi, C. Krauter, D.R. Blake. Characterization of VOC Emissions from Various Components of Dairy Farming and their effect on San Joaquin

Borehole strainmeter measurements spanning the 2014, Mw6.0 South Napa Earthquake, California: The effect from instrument calibration

USGS Publications Warehouse

Langbein, John O.

2015-01-01

The 24 August 2014 Mw6.0 South Napa, California earthquake produced significant offsets on 12 borehole strainmeters in the San Francisco Bay area. These strainmeters are located between 24 and 80 km from the source and the observed offsets ranged up to 400 parts-per-billion (ppb), which exceeds their nominal precision by a factor of 100. However, the observed offsets of tidally calibrated strains differ by up to 130 ppb from predictions based on a moment tensor derived from seismic data. The large misfit can be attributed to a combination of poor instrument calibration and better modeling of the strain fit from the earthquake. Borehole strainmeters require in-situ calibration, which historically has been accomplished by comparing their measurements of Earth tides with the strain-tides predicted by a model. Although the borehole strainmeter accurately measure the deformation within the borehole, the long-wavelength strain signals from tides or other tectonic processes recorded in the borehole are modified by the presence of the borehole and the elastic properties of the grout and the instrument. Previous analyses of surface-mounted, strainmeter data and their relationship with the predicted tides suggest that tidal models could be in error by 30%. The poor fit of the borehole strainmeter data from this earthquake can be improved by simultaneously varying the components of the model tides up to 30% and making small adjustments to the point-source model of the earthquake, which reduces the RMS misfit from 130 ppb to 18 ppb. This suggests that relying on tidal models to calibrate borehole strainmeters significantly reduces their accuracy.

Reservoir properties of submarine- fan facies: Great Valley sequence, California.

USGS Publications Warehouse

McLean, H.

1981-01-01

Submarine-fan sandstones of the Great Valley sequence west of the Sacramento Valley, California, have low porosities and permeabilities. However, petrography and scanning electron microscope studies indicate that most sands in almost all submarine-fan environments are originally porous and permeable. Thin turbidite sandstones deposited in areas dominated by shale in the outer-fan and basin-plain are cemented mainly by calcite; shale dewatering is inferred to contribute to rapid cementation early in the burial process. Sands deposited in inner- and middle-fan channels with only thin shale beds have small percentrages of intergranular cement. The original porosity is reduced mechanically at shallow depths and by pressure solution at deeperlevels. Permeability decreases with increasing age of the rocks, as a result of increasing burial depths. Computer-run stepwise regression analyses show that the porosity is inversely related to the percentage of calcite cement. The results reported here indicate original porosity and permeability can be high in deep-water submarine fans and that fan environments dominated by sand (with high sand/shale ratios) are more likely to retain higher porosity and permeability to greater depths than sand interbedded with thick shale sequences.-from Author

Space Radar Image of Death Valley, California

NASA Technical Reports Server (NTRS)

1999-01-01

This image shows Death Valley, California, centered at 36.629 degrees north latitude, 117.069 degrees west longitude. The image shows Furnace Creek alluvial fan and Furnace Creek Ranch at the far right, and the sand dunes near Stove Pipe Wells at the center. The dark fork-shaped feature between Furnace Creek fan and the dunes is a smooth flood-plain which encloses Cottonball Basin. This SIR-C/X-SAR supersite is an area of extensive field investigations and has been visited by both Space Radar Lab astronaut crews. Elevations in the valley range from 70 meters (230 feet) below sea level, the lowest in the United States, to more than 3,300 meters (10,800 feet) above sea level. Scientists are using SIR-C/X-SAR data from Death Valley to help answer a number of different questions about Earth's geology. One question concerns how alluvial fans are formed and change through time under the influence of climatic changes and earthquakes. Alluvial fans are gravel deposits that wash down from the mountains over time. They are visible in the image as circular, fan-shaped bright areas extending into the darker valley floor from the mountains. Information about the alluvial fans helps scientists study Earth's ancient climate. Scientists know the fans are built up through climatic and tectonic processes and they will use the SIR-C/X-SAR data to understand the nature and rates of weathering processes on the fans, soil formation and the transport of sand and dust by the wind. SIR-C/X-SAR's sensitivity to centimeter-scale (inch-scale) roughness provides detailed maps of surface texture. Such information can be used to study the occurrence and movement of dust storms and sand dunes. The goal of these studies is to gain a better understanding of the record of past climatic changes and the effects of those changes on a sensitive environment. This may lead to a better ability to predict future response of the land to different potential global climate-change scenarios. Death Valley is

Winter fog is decreasing in the fruit growing region of the Central Valley of California

NASA Astrophysics Data System (ADS)

Baldocchi, Dennis; Waller, Eric

2014-05-01

The Central Valley of California is home to a variety of fruit and nut trees. These trees account for 95% of the U.S. production, but they need a sufficient amount of winter chill to achieve rest and quiescence for the next season's buds and flowers. In prior work, we reported that the accumulation of winter chill is declining in the Central Valley. We hypothesize that a reduction in winter fog is cooccurring and is contributing to the reduction in winter chill. We examined a 33 year record of satellite remote sensing to develop a fog climatology for the Central Valley. We find that the number of winter fog events, integrated spatially, decreased 46%, on average, over 32 winters, with much year to year variability. Less fog means warmer air and an increase in the energy balance on buds, which amplifies their warming, reducing their chill accumulation more.

Introducing Teachers to Geospatial Technology While Helping Them to Discover Vegetation Patterns in Owens Valley, California

ERIC Educational Resources Information Center

Sherman-Morris, Kathleen; Morris, John; Thompson, Keith

2009-01-01

A field course attended by science teachers in California's Owens Valley incorporated geospatial technology to reinforce the relationship between elevation, aspect, or the direction a mountain slope faces, and vegetation. Teachers were provided GPS units to record locations and plant communities throughout the 9-day field course. At the end of the…

Late Quaternary faulting along the Death Valley-Furnace Creek fault system, California and Nevada

USGS Publications Warehouse

Brogan, George E.; Kellogg, Karl; Slemmons, D. Burton; Terhune, Christina L.

1991-01-01

The Death Valley-Furnace Creek fault system, in California and Nevada, has a variety of impressive late Quaternary neotectonic features that record a long history of recurrent earthquake-induced faulting. Although no neotectonic features of unequivocal historical age are known, paleoseismic features from multiple late Quaternary events of surface faulting are well developed throughout the length of the system. Comparison of scarp heights to amount of horizontal offset of stream channels and the relationships of both scarps and channels to the ages of different geomorphic surfaces demonstrate that Quaternary faulting along the northwest-trending Furnace Creek fault zone is predominantly right lateral, whereas that along the north-trending Death Valley fault zone is predominantly normal. These observations are compatible with tectonic models of Death Valley as a northwest-trending pull-apart basin. The largest late Quaternary scarps along the Furnace Creek fault zone, with vertical separation of late Pleistocene surfaces of as much as 64 m (meters), are in Fish Lake Valley. Despite the predominance of normal faulting along the Death Valley fault zone, vertical offset of late Pleistocene surfaces along the Death Valley fault zone apparently does not exceed about 15 m. Evidence for four to six separate late Holocene faulting events along the Furnace Creek fault zone and three or more late Holocene events along the Death Valley fault zone are indicated by rupturing of Q1B (about 200-2,000 years old) geomorphic surfaces. Probably the youngest neotectonic feature observed along the Death Valley-Furnace Creek fault system, possibly historic in age, is vegetation lineaments in southernmost Fish Lake Valley. Near-historic faulting in Death Valley, within several kilometers south of Furnace Creek Ranch, is represented by (1) a 2,000-year-old lake shoreline that is cut by sinuous scarps, and (2) a system of young scarps with free-faceted faces (representing several faulting

Construction of 3-D geologic framework and textural models for Cuyama Valley groundwater basin, California

USGS Publications Warehouse

Sweetkind, Donald S.; Faunt, Claudia C.; Hanson, Randall T.

2013-01-01

Groundwater is the sole source of water supply in Cuyama Valley, a rural agricultural area in Santa Barbara County, California, in the southeasternmost part of the Coast Ranges of California. Continued groundwater withdrawals and associated water-resource management concerns have prompted an evaluation of the hydrogeology and water availability for the Cuyama Valley groundwater basin by the U.S. Geological Survey, in cooperation with the Water Agency Division of the Santa Barbara County Department of Public Works. As a part of the overall groundwater evaluation, this report documents the construction of a digital three-dimensional geologic framework model of the groundwater basin suitable for use within a numerical hydrologic-flow model. The report also includes an analysis of the spatial variability of lithology and grain size, which forms the geologic basis for estimating aquifer hydraulic properties. The geologic framework was constructed as a digital representation of the interpreted geometry and thickness of the principal stratigraphic units within the Cuyama Valley groundwater basin, which include younger alluvium, older alluvium, and the Morales Formation, and underlying consolidated bedrock. The framework model was constructed by creating gridded surfaces representing the altitude of the top of each stratigraphic unit from various input data, including lithologic and electric logs from oil and gas wells and water wells, cross sections, and geologic maps. Sediment grain-size data were analyzed in both two and three dimensions to help define textural variations in the Cuyama Valley groundwater basin and identify areas with similar geologic materials that potentially have fairly uniform hydraulic properties. Sediment grain size was used to construct three-dimensional textural models that employed simple interpolation between drill holes and two-dimensional textural models for each stratigraphic unit that incorporated spatial structure of the textural data.

Dissolved Pesticide and Organic Carbon Concentrations Detected in Surface Waters, Northern Central Valley, California, 2001-2002

USGS Publications Warehouse

Orlando, James L.; Jacobson, Lisa A.; Kuivila, Kathryn

2004-01-01

Field and laboratory studies were conducted to determine the effects of pesticide mixtures on Chinook salmon under various environmental conditions in surface waters of the northern Central Valley of California. This project was a collaborative effort between the U.S. Geological Survey (USGS) and the University of California. The project focused on understanding the environmental factors that influence the toxicity of pesticides to juvenile salmon and their prey. During the periods January through March 2001 and January through May 2002, water samples were collected at eight surface water sites in the northern Central Valley of California and analyzed by the USGS for dissolved pesticide and dissolved organic carbon concentrations. Water samples were also collected by the USGS at the same sites for aquatic toxicity testing by the Aquatic Toxicity Laboratory at the University of California Davis; however, presentation of the results of these toxicity tests is beyond the scope of this report. Samples were collected to characterize dissolved pesticide and dissolved organic carbon concentrations, and aquatic toxicity, associated with winter storm runoff concurrent with winter run Chinook salmon out-migration. Sites were selected that represented the primary habitat of juvenile Chinook salmon and included major tributaries within the Sacramento and San Joaquin River Basins and the Sacramento?San Joaquin Delta. Water samples were collected daily for a period of seven days during two winter storm events in each year. Additional samples were collected weekly during January through April or May in both years. Concentrations of 31 currently used pesticides were measured in filtered water samples using solid-phase extraction and gas chromatography-mass spectrometry at the U.S. Geological Survey's organic chemistry laboratory in Sacramento, California. Dissolved organic carbon concentrations were analyzed in filtered water samples using a Shimadzu TOC-5000A total organic carbon

Nitrate Contamination of Deep Aquifers in the Salinas Valley, California

NASA Astrophysics Data System (ADS)

Moran, J. E.; Esser, B. K.; Hillegonds, D. J.; Holtz, M.; Roberts, S. K.; Singleton, M. J.; Visser, A.; Kulongoski, J. T.; Belitz, K.

2011-12-01

The Salinas Valley, known as 'the salad bowl of the world', has been an agricultural center for more than 100 years. Irrigated row crops such as lettuce and strawberries dominate both land use and water use. Groundwater is the exclusive supply for both irrigation and drinking water. Some irrigation wells and most public water supply wells in the Salinas Valley are constructed to draw water from deep portions of the aquifer system, where contamination by nitrate is less likely than in the shallow portions of the aquifer system. However, a number of wells with top perforations greater than 75 m deep, screened below confining or semi-confining units, have nitrate concentrations greater than the Maximum Contaminant Limit (MCL) of 45 mg/L as NO3-. This study uses nitrate concentrations from several hundred irrigation, drinking water, and monitoring wells (Monterey County Water Resources Agency, 1997), along with tritium-helium groundwater ages acquired at Lawrence Livermore National Laboratory through the State of California Groundwater Monitoring and Assessment (GAMA) program (reported in Kulongoski et al., 2007 and in Moran et al., in press), to identify nitrate 'hot spots' in the deep aquifer and to examine possible modes of nitrate transport to the deep aquifer. In addition, observed apparent groundwater ages are compared with the results of transport simulations that use particle tracking and a stochastic-geostatistical framework to incorporate aquifer heterogeneity to determine the distribution of travel times from the water table to each well (Fogg et al., 1999). The combined evidence from nitrate, tritium, tritiogenic 3He, and radiogenic 4He concentrations, reveals complex recharge and flow to the capture zone of the deep drinking water wells. Widespread groundwater pumping for irrigation accelerates vertical groundwater flow such that high nitrate groundwater reaches some deep drinking water wells. Deeper portions of the wells often draw in water that recharged

Principal facts for gravity stations in the Dry Valley area, west-central Nevada and east-central California

USGS Publications Warehouse

Sanger, Elizabeth A.; Ponce, David A.

2003-01-01

In June, 2002, the U.S. Geological Survey (USGS) established 143 new gravity stations and 12 new rock samples in the Dry Valley area, 30 miles north of Reno, Nevada, on the California - Nevada border (see fig. 1). This study reports on gravity, magnetic, and physical property data intended for use in modeling the geometry and depth of Dry Valley for groundwater analysis. It is part of a larger study that aims to characterize the hydrologic framework of several basins in Washoe County. Dry Valley is located south of the Fort Sage Mountains and south-east of Long Valley, on USGS 7.5’ quadrangles Constantia and Seven Lakes (fig. 2). The Cretaceous granitic rocks and Tertiary volcanic rocks that bound the sediment filled basin (fig. 3) may be especially important to future modeling because of their impact on groundwater flow. The granitic and volcanic rocks of Dry Valley exhibit densities and magnetic susceptibilities higher than the overlaying sediments, and create a distinguishable pattern of gravity and magnetic anomalies that reflect these properties.

75 FR 74517 - Approval and Promulgation of Implementation Plans; State of California; 2008 San Joaquin Valley...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-30

...EPA is proposing to approve in part and disapprove in part state implementation plan (SIP) revisions submitted by California to provide for attainment of the 1997 annual and 24-hour fine particulate matter (PM2.5) national ambient air quality standards (NAAQS) in the San Joaquin Valley (SJV) nonattainment area. The SIP revisions are the SJV 2008 PM2.5 Plan (revised 2010) and portions of the 2007 State Strategy (revised 2009). Specifically, EPA is proposing to approve the emissions inventories as meeting the requirements of the Clean Air Act and EPA's fine particle implementing rule and to approve commitments to implement specific measures and meet specific aggregate emissions reductions by the San Joaquin Valley Air Pollution Control District and the California Air Resource Board. In addition, we are proposing to find that volatile organic compounds are a PM2.5 attainment plan precursor in the SJV for which controls should be evaluated. EPA is proposing to disapprove the attainment demonstration. EPA is also proposing to disapprove the reasonably available control measures/reasonably available control technology demonstration, the air quality modeling, the reasonable further progress (RFP) demonstration, the contingency measures, and the attainment and RFP conformity motor vehicle emissions budgets. EPA is also proposing to not grant California's request to extend to April 5, 2015 the deadline for the SJV nonattainment area to attain the 1997 PM2.5 NAAQS.

Transtensional deformation and structural control of contiguous but independent magmatic systems: Mono-Inyo Craters, Mammoth Mountain, and Long Valley Caldera, California

USGS Publications Warehouse

Riley, P.; Tikoff, B.; Hildreth, Wes

2012-01-01

The Long Valley region of eastern California (United States) is the site of abundant late Tertiary–present magmatism, including three geochemically distinct stages of magmatism since ca. 3 Ma: Mammoth Mountain, the Mono-Inyo volcanic chain, and Long Valley Caldera. We propose two tectonic models, one explaining the Mammoth Mountain–Mono-Inyo magmatism and the other explaining the presence of Long Valley Caldera. First, the ongoing Mammoth Mountain–Mono-Inyo volcanic chain magmatism is explained by a ridge-transform-ridge system, with the Mono-Inyo volcanic chain acting as one ridge segment and the South Moat fault acting as a transform fault. Implicit in this first model is that this region of eastern California is beginning to act as an incipient plate boundary. Second, the older Long Valley Caldera system is hypothesized to occur in a region of enhanced extension resulting from regional fault block rotation, specifically involving activation of the sinistral faults of the Mina deflection. The tectonic models are consistent with observed spatial and temporal differences in the geochemistry of the regional magmas, and the westward progression of magmatism since ca. 12 Ma.

Chemical and isotopic prediction of aquifer temperatures in the geothermal system at Long Valley, California

USGS Publications Warehouse

Fournier, R.O.; Sorey, M.L.; Mariner, R.H.; Truesdell, A.H.

1979-01-01

Temperatures of aquifers feeding thermal springs and wells in Long Valley, California, estimated using silica and Na-K-Ca geothermometers and warm spring mixing models, range from 160/dg to about 220??C. This information was used to construct a diagram showing enthalpy-chloride relations for the various thermal waters in the Long Valley region. The enthalpy-chloride information suggests that a 282 ?? 10??C aquifer with water containing about 375 mg chloride per kilogram of water is present somewhere deep in the system. That deep water would be related to ??? 220??C Casa Diablo water by mixing with cold water, and to Hot Creek water by first boiling with steam loss and then mixing with cold water. Oxygen and deuterium isotopic data are consistent with that interpretation. An aquifer at 282??C with 375 mg/kg chloride implies a convective heat flow in Long Valley of 6.6 ?? 107 cal/s. ?? 1979.

Precipitation depth-duration and frequency characteristics for Antelope Valley, Mojave Desert, California

USGS Publications Warehouse

Blodgett, J.C.

1995-01-01

Methods to evaluate changes in the volume of storm runoff from drainage basins that are likely to be urbanized are needed by land-use planning agencies to establish criteria for the design of flood-control systems. To document the changes in runoff volume of basins that may be urbanized, nine small basins that are considered representative of varying hydrologic conditions in Antelope Valley, California, were selected for detailed study. Precipitation and stream-gaging stations were established and data were collected for the period 1990-93. The data collected at these U.S. Geological Survey stations were supplemented by data collected at 35 Long-term precipitation stations operated by the National Oceanic and Atmospheric Administration and the Los Angeles County Department of Public Works. These data will be used to calibrate and verify rainfall-runoff models for the nine basins. Results of the model runs will then be used as a guide for estimating basin runoff characteristics throughout Antelope Valley. Annual precipitation in Antelope Valley ranges from more than 20 inches in the mountains to less than 4 inches on the valley floor. Most precipitation in the valley falls during the months of December through March, but cyclonic storms in the fall and convectional storms in the summer sometimes occur. The duration of most storms ranges from 1 to 8 days, but most of the precipitation usually occurs within the first 2 days. Many parts of the valley have been affected by storms with precipitation depths that equal or exceed 0.60 inch per hour. The storms of January 1943 and March 1983 were the most intense storms of record, with recurrence intervals greater than 100 years in some parts of the valley. Depth-duration ratios were calculated by disaggregating daily total precipitation data for intervals of 1, 2, 3, 4, 6, 12, and 18 hours for storms that occurred during 1990-93. The hourly total precipitation data were then disaggregated at 5-minute intervals. A comparison

Fish communities of the Sacramento River Basin: Implications for conservation of native fishes in the Central Valley, California

USGS Publications Warehouse

May, J.T.; Brown, L.R.

2002-01-01

The associations of resident fish communities with environmental variables and stream condition were evaluated at representative sites within the Sacramento River Basin, California between 1996 and 1998 using multivariate ordination techniques and by calculating six fish community metrics. In addition, the results of the current study were compared with recent studies in the San Joaquin River drainage to provide a wider perspective of the condition of resident fish communities in the Central Valley of California as a whole. Within the Sacramento drainage, species distributions were correlated with elevational and substrate size gradients; however, the elevation of a sampling site was correlated with a suite of water-quality and habitat variables that are indicative of land use effects on physiochemical stream parameters. Four fish community metrics - percentage of native fish, percentage of intolerant fish, number of tolerant species, and percentage of fish with external anomalies - were responsive to environmental quality. Comparisons between the current study and recent studies in the San Joaquin River drainage suggested that differences in water-management practices may have significant effects on native species fish community structure. Additionally, the results of the current study suggest that index of biotic integrity-type indices can be developed for the Sacramento River Basin and possibly the entire Central Valley, California. The protection of native fish communities in the Central Valley and other arid environments continues to be a conflict between human needs for water resources and the requirements of aquatic ecosystems; preservation of these ecosystems will require innovative management strategies.

Timber resource statistics for the Sacramento resource area of California.

Treesearch

Karen L. Waddell; Patricia M. Bassett

1997-01-01

This report is a summary of timber resource statistics for the Sacramento Resource Area of California, which includes Butte, Colusa, El Dorado, Glenn, Lake, Napa, Nevada, Placer, Plumas, Sacramento, Sierra, Sutter, Tehama, Yolo, and Yuba Counties. Data were collected as part of a statewide multiresource inventory. The inventory sampled private and public lands except...

Hematology and plasma biochemistry values for the giant garter snake (Thamnophis gigas) and valley garter snake (Thamnophis sirtalis fitchi) in the Central Valley of California.

PubMed

Wack, Raymund F; Hansen, Eric; Small, Marilyn; Poppenga, Robert; Bunn, David; Johnson, Christine K

2012-04-01

Hematology and plasma biochemistry parameters are useful in the assessment and management of threatened and endangered species. Although reference ranges are readily available for many mammalian species, reference ranges for snakes are lacking for most species. We determined hematology and plasma biochemistry reference ranges for giant garter snakes (Thamnophis gigas) and valley garter snakes (Thamnophis sirtalis fitchi) living in four management areas in the Central Valley of California. White blood cell, heterophil, lymphocyte, and azurophil counts in giant garter snakes were approximately twice the values of valley garter snakes. Statistically significant differences in aspartate aminotransferase, globulin, and potassium between the two species did not appear clinically significant. No significant differences were found in the measured parameters between male and female giant garter snakes. Some differences were found among collection sites. These reference ranges provide baseline data for comparisons over time and between collection sites.

Sacramento Valley, CA, USA

NASA Technical Reports Server (NTRS)

1973-01-01

The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects.

Subsidence due to Excessive Groundwater Withdrawal in the San Joaquin Valley, California

NASA Astrophysics Data System (ADS)

Corbett, F.; Harter, T.; Sneed, M.

2011-12-01

Francis Corbett1, Thomas Harter1 and Michelle Sneed2 1Department of Land Air and Water Resources, University of California, Davis. 2U.S. Geological Survey Western Remote Sensing and Visualization Center, Sacramento. Abstract: Groundwater development within the Central Valley of California began approximately a century ago. Water was needed to supplement limited surface water supplies for the burgeoning population and agricultural industries, especially within the arid but fertile San Joaquin Valley. Groundwater levels have recovered only partially during wet years from drought-induced lows creating long-term groundwater storage overdraft. Surface water deliveries from Federal and State sources led to a partial alleviation of these pressure head declines from the late 1960s. However, in recent decades, surface water deliveries have declined owing to increasing environmental pressures, whilst water demands have remained steady. Today, a large portion of the San Joaquin Valley population, and especially agriculture, rely upon groundwater. Groundwater levels are again rapidly declining except in wet years. There is significant concern that subsidence due to groundwater withdrawal, first observed at a large scale in the middle 20th century, will resume as groundwater resources continue to be depleted. Previous subsidence has led to problems such as infrastructure damage and flooding. To provide a support tool for groundwater management on a naval air station in the southern San Joaquin Valley (Tulare Lake Basin), a one-dimensional MODFLOW subsidence model covering the period 1925 to 2010 was developed incorporating extensive reconstruction of historical subsidence and water level data from various sources. The stratigraphy used for model input was interpreted from geophysical logs and well completion reports. Gaining good quality data proved problematic, and often values needed to be estimated. In part, this was due to the historical lack of awareness/understanding of

A Public Health Issue Related To Collateral Seismic Hazards: The Valley Fever Outbreak Triggered By The 1994 Northridge, California Earthquake

NASA Astrophysics Data System (ADS)

Jibson, Randall W.

Following the 17 January 1994 Northridge, California earthquake (M = 6.7), Ventura County, California, experienced a major outbreak ofcoccidioidomycosis (CM), commonly known as valley fever, a respiratory disease contracted byinhaling airborne fungal spores. In the 8 weeks following the earthquake (24 Januarythrough 15 March), 203 outbreak-associated cases were reported, which is about an order of magnitude more than the expected number of cases, and three of these cases were fatal.Simi Valley, in easternmost Ventura County, had the highest attack rate in the county,and the attack rate decreased westward across the county. The temporal and spatial distribution of CM cases indicates that the outbreak resulted from inhalation of spore-contaminated dust generated by earthquake-triggered landslides. Canyons North East of Simi Valleyproduced many highly disrupted, dust-generating landslides during the earthquake andits aftershocks. Winds after the earthquake were from the North East, which transporteddust into Simi Valley and beyond to communities to the West. The three fatalities from the CM epidemic accounted for 4 percent of the total earthquake-related fatalities.

CRUSTAL REFRACTION PROFILE OF THE LONG VALLEY CALDERA, CALIFORNIA, FROM THE JANUARY 1983 MAMMOTH LAKES EARTHQUAKE SWARM.

USGS Publications Warehouse

Luetgert, James H.; Mooney, Walter D.

1985-01-01

Seismic-refraction profiles recorded north of Mammoth Lakes, California, using earthquake sources from the January 1983 swarm complement earlier explosion refraction profiles and provide velocity information from deeper in the crust in the area of the Long Valley caldera. Eight earthquakes from a depth range of 4. 9 to 8. 0 km confirm the observation of basement rocks with seismic velocities ranging from 5. 8 to 6. 4 km/sec extending at least to depths of 20 km. The data provide further evidence for the existence of a partial melt zone beneath Long Valley caldera and constrain its geometry. Refs.

Hydrogeologic framework of the Santa Clara Valley, California

USGS Publications Warehouse

Hanson, Randall T.

2015-01-01

The hydrologic framework of the Santa Clara Valley in northern California was redefined on the basis of new data and a new hydrologic model. The regional groundwater flow systems can be subdivided into upper-aquifer and lower-aquifer systems that form a convergent flow system within a basin bounded by mountains and hills on three sides and discharge to pumping wells and the southern San Francisco Bay. Faults also control the flow of groundwater within the Santa Clara Valley and subdivide the aquifer system into three subregions.After decades of development and groundwater depletion that resulted in substantial land subsidence, Santa Clara Valley Water District (SCVWD) and the local water purveyors have refilled the basin through conservation and importation of water for direct use and artificial recharge. The natural flow system has been altered by extensive development with flow paths toward major well fields. Climate has not only affected the cycles of sedimentation during the glacial periods over the past million years, but interannual to interdecadal climate cycles also have affected the supply and demand components of the natural and anthropogenic inflows and outflows of water in the valley. Streamflow has been affected by development of the aquifer system and regulated flow from reservoirs, as well as conjunctive use of groundwater and surface water. Interaquifer flow through water-supply wells screened across multiple aquifers is an important component to the flow of groundwater and recapture of artificial recharge in the Santa Clara Valley. Wellbore flow and depth-dependent chemical and isotopic data indicate that flow into wells from multiple aquifers, as well as capture of artificial recharge by pumping of water-supply wells, predominantly is occurring in the upper 500 ft (152 m) of the aquifer system. Artificial recharge represents about one-half of the inflow of water into the valley for the period 1970–1999. Most subsidence is occurring below 250 ft

Space Radar Image of Long Valley, California - 3-D view

NASA Image and Video Library

1999-05-01

This is a three-dimensional perspective view of Long Valley, California by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar on board the space shuttle Endeavour. This view was constructed by overlaying a color composite SIR-C image on a digital elevation map. The digital elevation map was produced using radar interferometry, a process by which radar data are acquired on different passes of the space shuttle and, which then, are compared to obtain elevation information. The data were acquired on April 13, 1994 and on October 3, 1994, during the first and second flights of the SIR-C/X-SAR radar instrument. The color composite radar image was produced by assigning red to the C-band (horizontally transmitted and vertically received) polarization; green to the C-band (vertically transmitted and received) polarization; and blue to the ratio of the two data sets. Blue areas in the image are smooth and yellow areas are rock outcrops with varying amounts of snow and vegetation. The view is looking north along the northeastern edge of the Long Valley caldera, a volcanic collapse feature created 750,000 years ago and the site of continued subsurface activity. Crowley Lake is off the image to the left. http://photojournal.jpl.nasa.gov/catalog/PIA01757

Timber resource statistics of the Sacramento resource area of California.

Treesearch

J.D. Lloyd; Joel Moen; Charles L. Bolsinger

1986-01-01

This report is one of five that provide timber resource statistics for 57 of the 58 counties in California (San Francisco is excluded). This report presents statistics from a 1981-84 inventory of the timber resources of Butte, Colusa, El Dorado, Glenn, Lake, Napa, Nevada, Placer, Plumas, Sacramento, Sierra, Sutter, Tehama, Yolo, and Yuba Counties. Tables presented are...

Seroprevalence of Hepatitis B and C Infections among Healthy Volunteer Blood Donors in the Central California Valley.

PubMed

Sheikh, Muhammad Y; Atla, Pradeep R; Ameer, Adnan; Sadiq, Humaira; Sadler, Patrick C

2013-01-01

The Central California Valley has a diverse population with significant proportions of Hispanics and Asians. This cross-sectional study was conducted to evaluate the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) in healthy blood donors in the Valley. A total of 217,738 voluntary blood donors were identified between 2006 and 2010 (36,795 first-time donors; 180,943 repeat donors). Among the first-time donors, the HBV and HCV prevalence was 0.28% and 0.52%, respectively. Higher HBV prevalence seen in Asians (3%) followed by Caucasians (0.05%), African Americans (0.15%), and Hispanics (0.05%). Hmong had a HBV prevalence of 7.63% with a peak prevalence of 8.76% among the 16- to 35-year-old age group. Highest HCV prevalence in Native Americans (2.8) followed by Caucasians (0.59%), Hispanics (0.45%), African Americans (0.38%), and Asians (0.2%). Ethnic disparities persist with regard to the prevalence of HBV and HCV in the Central California Valley. The reported prevalence may be an underestimate because our study enrolled healthy volunteer blood donors only. The development of aggressive public health measures to evaluate the true prevalence of HBV and HCV and to identify those in need of HBV and HCV prevention measures and therapy is critically important.

Seroprevalence of Hepatitis B and C Infections among Healthy Volunteer Blood Donors in the Central California Valley

PubMed Central

Atla, Pradeep R.; Ameer, Adnan; Sadiq, Humaira; Sadler, Patrick C.

2013-01-01

Background/Aims The Central California Valley has a diverse population with significant proportions of Hispanics and Asians. This cross-sectional study was conducted to evaluate the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) in healthy blood donors in the Valley. Methods A total of 217,738 voluntary blood donors were identified between 2006 and 2010 (36,795 first-time donors; 180,943 repeat donors). Results Among the first-time donors, the HBV and HCV prevalence was 0.28% and 0.52%, respectively. Higher HBV prevalence seen in Asians (3%) followed by Caucasians (0.05%), African Americans (0.15%), and Hispanics (0.05%). Hmong had a HBV prevalence of 7.63% with a peak prevalence of 8.76% among the 16- to 35-year-old age group. Highest HCV prevalence in Native Americans (2.8) followed by Caucasians (0.59%), Hispanics (0.45%), African Americans (0.38%), and Asians (0.2%). Conclusions Ethnic disparities persist with regard to the prevalence of HBV and HCV in the Central California Valley. The reported prevalence may be an underestimate because our study enrolled healthy volunteer blood donors only. The development of aggressive public health measures to evaluate the true prevalence of HBV and HCV and to identify those in need of HBV and HCV prevention measures and therapy is critically important. PMID:23423771

Availability of high-magnitude streamflow for groundwater banking in the Central Valley, California

NASA Astrophysics Data System (ADS)

Kocis, Tiffany N.; Dahlke, Helen E.

2017-08-01

California’s climate is characterized by the largest precipitation and streamflow variability observed within the conterminous US This, combined with chronic groundwater overdraft of 0.6-3.5 km3 yr-1, creates the need to identify additional surface water sources available for groundwater recharge using methods such as agricultural groundwater banking, aquifer storage and recovery, and spreading basins. High-magnitude streamflow, i.e. flow above the 90th percentile, that exceeds environmental flow requirements and current surface water allocations under California water rights, could be a viable source of surface water for groundwater banking. Here, we present a comprehensive analysis of the magnitude, frequency, duration and timing of high-magnitude streamflow (HMF) for 93 stream gauges covering the Sacramento, San Joaquin and Tulare basins in California. The results show that in an average year with HMF approximately 3.2 km3 of high-magnitude flow is exported from the entire Central Valley to the Sacramento-San Joaquin Delta often at times when environmental flow requirements of the Delta and major rivers are exceeded. High-magnitude flow occurs, on average, during 7 and 4.7 out of 10 years in the Sacramento River and the San Joaquin-Tulare Basins, respectively, from just a few storm events (5-7 1-day peak events) lasting for 25-30 days between November and April. The results suggest that there is sufficient unmanaged surface water physically available to mitigate long-term groundwater overdraft in the Central Valley.

76 FR 14047 - Notice of Intent to Repatriate Cultural Items: California Department of Transportation (Caltrans...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-15

... of California; California Valley Miwok Tribe, California; Chicken Ranch Rancheria of Me-Wuk Indians...; California Valley Miwok Tribe, California; Chicken Ranch Rancheria of Me-Wuk Indians of California; Ione Band...; California Valley Miwok Tribe, California; Chicken Ranch Rancheria of Me-Wuk Indians of California; Ione Band...

Emissions of organic carbon and methane from petroleum and dairy operations in California's San Joaquin Valley

NASA Astrophysics Data System (ADS)

Gentner, D. R.; Ford, T. B.; Guha, A.; Boulanger, K.; Brioude, J.; Angevine, W. M.; de Gouw, J. A.; Warneke, C.; Gilman, J. B.; Ryerson, T. B.; Peischl, J.; Meinardi, S.; Blake, D. R.; Atlas, E.; Lonneman, W. A.; Kleindienst, T. E.; Beaver, M. R.; St. Clair, J. M.; Wennberg, P. O.; VandenBoer, T. C.; Markovic, M. Z.; Murphy, J. G.; Harley, R. A.; Goldstein, A. H.

2014-05-01

Petroleum and dairy operations are prominent sources of gas-phase organic compounds in California's San Joaquin Valley. It is essential to understand the emissions and air quality impacts of these relatively understudied sources, especially for oil/gas operations in light of increasing US production. Ground site measurements in Bakersfield and regional aircraft measurements of reactive gas-phase organic compounds and methane were part of the CalNex (California Research at the Nexus of Air Quality and Climate Change) project to determine the sources contributing to regional gas-phase organic carbon emissions. Using a combination of near-source and downwind data, we assess the composition and magnitude of emissions, and provide average source profiles. To examine the spatial distribution of emissions in the San Joaquin Valley, we developed a statistical modeling method using ground-based data and the FLEXPART-WRF transport and meteorological model. We present evidence for large sources of paraffinic hydrocarbons from petroleum operations and oxygenated compounds from dairy (and other cattle) operations. In addition to the small straight-chain alkanes typically associated with petroleum operations, we observed a wide range of branched and cyclic alkanes, most of which have limited previous in situ measurements or characterization in petroleum operation emissions. Observed dairy emissions were dominated by ethanol, methanol, acetic acid, and methane. Dairy operations were responsible for the vast majority of methane emissions in the San Joaquin Valley; observations of methane were well correlated with non-vehicular ethanol, and multiple assessments of the spatial distribution of emissions in the San Joaquin Valley highlight the dominance of dairy operations for methane emissions. The petroleum operations source profile was developed using the composition of non-methane hydrocarbons in unrefined natural gas associated with crude oil. The observed source profile is

Grapevine red blotch-associated virus is widespread in California and U.S. vineyards.

USDA-ARS?s Scientific Manuscript database

In fall 2011, Grapevine red blotch-associated virus (GRBaV), a circular ssDNA virus, was detected in grapevines exhibiting leaves with red blotch symptoms in Napa, CA. Extensive sampling of symptomatic grapevines in California vineyards and analysis of the nucleic acid fractions by SYBR®Green qPCR a...

Ozone Laminae and Their Entrainment Into a Valley Boundary Layer, as Observed From a Mountaintop Monitoring Station, Ozonesondes, and Aircraft Over California's San Joaquin Valley

NASA Astrophysics Data System (ADS)

Faloona, I. C.; Conley, S. A.; Caputi, D.; Trousdell, J.; Chiao, S.; Eiserloh, A. J., Jr.; Clark, J.; Iraci, L. T.; Yates, E. L.; Marrero, J. E.; Ryoo, J. M.; McNamara, M. E.

2016-12-01

The San Joaquin Valley of California is wide ( 75 km) and long ( 400 km), and is situated under strong atmospheric subsidence due, in part, to the proximity of the midlatitude anticyclone of the Pacific High. The capping effect of this subsidence is especially prominent during the warm season when ground level ozone is a serious air quality concern across the region. While relatively clean marine boundary layer air is primarily funneled into the valley below the strong subsidence inversion at significant gaps in the upwind Coast Range mountains, airflow aloft also spills over these barriers and mixes into the valley from above. Because this transmountain flow occurs under the influence of synoptic subsidence it tends to present discrete, laminar sheets of differing air composition above the valley boundary layer. Meanwhile, although the boundary layers tend to remain shallow due to the prevailing subsidence, orographic and anabatic venting of valley boundary layer air around the basin whips up a complex admixture of regional air masses into a "buffer layer" just above the boundary layer (zi) and below the lower free troposphere. We present scalar data of widely varying lifetimes including ozone, methane, NOx, and thermodynamic observations from upwind and within the San Joaquin Valley to better explain this layering and its subsequent erosion into the valley boundary layer via entrainment. Data collected at a mountaintop monitoring station on Chews Ridge in the Coast Range, by coastal ozonesondes, and aircraft are analyzed to document the dynamic layering processes around the complex terrain surrounding the valley. Particular emphasis will be made on observational methods whereby distal ozone can be distinguished from the regional ozone to better understand the influence of exogenous sources on air quality in the valley.

Structure and regional significance of the Late Permian(?) Sierra Nevada - Death Valley thrust system, east-central California

USGS Publications Warehouse

Stevens, C.H.; Stone, P.

2005-01-01

An imbricate system of north-trending, east-directed thrust faults of late Early Permian to middle Early Triassic (most likely Late Permian) age forms a belt in east-central California extending from the Mount Morrison roof pendant in the eastern Sierra Nevada to Death Valley. Six major thrust faults typically with a spacing of 15-20 km, original dips probably of 25-35??, and stratigraphic throws of 2-5 km compose this structural belt, which we call the Sierra Nevada-Death Valley thrust system. These thrusts presumably merge into a de??collement at depth, perhaps at the contact with crystalline basement, the position of which is unknown. We interpret the deformation that produced these thrusts to have been related to the initiation of convergent plate motion along a southeast-trending continental margin segment probably formed by Pennsylvanian transform truncation. This deformation apparently represents a period of tectonic transition to full-scale convergence and arc magmatism along the continental margin beginning in the Late Triassic in central California. ?? 2005 Elsevier B.V. All rights reserved.

PoroTomo Subtask 3.2 Data files from the Distributed Acoustic Sensing experiment at Garner Valley, California

DOE Data Explorer

Chelsea Lancelle

2013-09-11

In September 2013, an experiment using Distributed Acoustic Sensing (DAS) was conducted at Garner Valley, a test site of the University of California Santa Barbara (Lancelle et al., 2014). This submission includes all DAS data recorded during the experiment. The sampling rate for all files is 1000 samples per second. Any files with the same filename but ending in _01, _02, etc. represent sequential files from the same test. Locations of the sources are plotted on the basemap in GDR submission 481, titled: "PoroTomo Subtask 3.2 Sample data from a Distributed Acoustic Sensing experiment at Garner Valley, California (PoroTomo Subtask 3.2)." Lancelle, C., N. Lord, H. Wang, D. Fratta, R. Nigbor, A. Chalari, R. Karaulanov, J. Baldwin, and E. Castongia (2014), Directivity and Sensitivity of Fiber-Optic Cable Measuring Ground Motion using a Distributed Acoustic Sensing Array (abstract # NS31C-3935), AGU Fall Meeting. 
https://agu.confex.com/agu/fm1/meetingapp.cgi#Paper/19828 The e-poster is available at: https://agu.confex.com/data/handout/agu/fm14/Paper_19828_handout_696_0.pdf

Final Approval of California Air Plan Revision; Antelope Valley Air Quality Management District; VOCs From Motor Vehicle Assembly Coating Operations

EPA Pesticide Factsheets

EPA is taking final action to approve a revision to the Antelope Valley Air Quality Management District (AVAQMD) portion of the California SIP concerning the emissions of volatile organic compounds (VOCs) from motor vehicle assembly coating operations.

Influence of weather on the stable isotopic ratios of wines: Tools for weather/climate reconstruction?

NASA Astrophysics Data System (ADS)

Ingraham, Neil L.; Caldwell, Eric A.

1999-01-01

Precipitation, local ground water, soil water, atmospheric water vapor, grape leaf and grape berry water just prior to harvest, and grape must during the wine-making process, from the Napa Valley in northern California were collected for stable isotopic analysis. In addition, 27 red wines and 4 white wines produced in the Napa Valley, and 8 red wines produced in Livermore Valley located over 110 km to the southeast, were analyzed for both oxygen and hydrogen isotopic compositions. The isotopic compositions of the grape leaf water fall on a transpiration line with a slope of 2.1, while those of the grape berry water fall on a transpiration line with a slope of 2.8. The stable isotopic compositions of the 27 red wines from the Napa Valley range from -3 to +20‰ in δD and from +4.6 to + 10.2‰ in δ18O and plot along a line described by δD = 3.4 δ18O - 17.2. The maximum difference in the stable oxygen composition between two wineries 110 km apart is only 1.4‰, while the differences between the vintage years within each winery are 4.8 and 5.8‰ in δ18O. The stable isotopic composition of the grape water is controlled by transpiration in the weeks prior to harvest, overshadowing all other effects. As a result of the timing of harvest, the red wines are some 4 to 5‰ more enriched in δ18O than the white wines.

Logs and Scarp Data from a Paloseismic Investigation of the Surprise Valley Fault Zone, Modoc County, California

USGS Publications Warehouse

Personius, Stephen F.; Crone, Anthony J.; Machette, Michael N.; Lidke, David J.; Bradley, Lee-Ann; Mahan, Shannon

2007-01-01

This report contains field and laboratory data from a paleoseismic study of the Surprise Valley fault zone near Cedarville, California. The 85-km-long Surprise Valley fault zone forms the western active margin of the Basin and Range province in northeastern California. The down-to-the-east normal fault is marked by Holocene fault scarps along most of its length, from Fort Bidwell on the north to near the southern end of Surprise Valley. We studied the central section of the fault to determine ages of paleoearthquakes and to better constrain late Quaternary slip rates, which we hope to compare to deformation rates derived from a recently established geodetic network in the region (Hammond and Thatcher, 2005; 2007). We excavated a trench in June 2005 across a prominent fault scarp on pluvial Lake Surprise deltaic sediments near the mouth of Cooks Canyon, 4 km north of Cedarville. This site was chosen because of the presence of a well-preserved fault scarp and its development on lacustrine deposits thought to be suitable for luminescence dating. We also logged a natural exposure of the fault in similar deltaic sediments near the mouth of Steamboat Canyon, 11 km south of Cedarville, to better understand the along-strike extent of surface ruptures. The purpose of this report is to present photomosaics, trench, drill hole, and stream exposure logs; scarp profiles; and fault slip, tephrochronologic, radiocarbon, luminescence, and unit description data obtained during this investigation. We do not attempt to use the data presented herein to construct a paleoseismic history of this part of the Surprise Valley fault zone; that history will be the subject of a future report.

Characterization of PCC Cement by Addition of Napa Soil from Subdistrict Sarilamak 50 Kota District as Alternative Additional Material for Semen Padang

NASA Astrophysics Data System (ADS)

Mawardi, M.; Deyundha, D.; Zainul, R.; Zalmi P, R.

2018-04-01

The study has been conducted to determine characteristics of the portland composite cement by the addition of napa soil from Sarilamak subdistrict, 50 Kota District as an alternative additional material at PT. Semen Padang. Napa soil is a natural material highly containing silica and alumina minerals so that it can be one of material in producing cement. This study aims to determine the effect of napa soil on the quality of portland composite cement. Napa soil used in the variation compositions 0%, 4%, 8%, 12% and 16%, for control of cement used 8 % of pozzolan and 0 % of napa soil. Determination of cement quality by testing cement characteristics include blaine test, sieving, lost of ignition or LOI, insoluble residue, normal consistency, setting time and compressive strength. Cement was characterized using XRF. Fineness of cement decreases with the addition of napa soil. Lost of Ignition of cement decreased, while the insoluble residue increased with the addition of napa soil. Normal consistency of cement increasing, so does initial setting time and final setting time of cement. While the resultant compressive strength decreases with the addition of napa soil on 28 days, 342, 325, 307, 306, and 300 kg / cm2.

Partitioning Evapotranspiration over a Vineyard in California's Central Valley

NASA Astrophysics Data System (ADS)

Alfieri, J. G.; Kustas, W. P.; Prueger, J. H.; Agam, N.

2016-12-01

The increasing demand for limited water resources due to the ongoing California drought hampers crop production and damages the state's economy. In order to ameliorate the negative consequences of drought and ensure the sustainability of California agriculture, policymakers, resource managers, and agricultural producers must maximize the effective use of the available water. In turn, achieving this goal is predicated on accurate information regarding crop water productivity, the fraction of the total evapotranspiration (ET) that contributes to crop yield expressed in terms of transpiration. However, while a number of approaches, such as isotope analysis and microlysimeter systems, have been developed to partition ET between soil evaporation (E) and transpiration (T), these approaches can be both costly and labor-intensive. Collecting reliable continuous measurements at field scales remains problematic. This study presents the application of a recently developed correlation-based technique that overcomes these difficulties by leveraging high frequency data measured via eddy covariance. Specifically, this scheme combines wavelet decomposition and the theoretical relationship between stomatal and non-stomatal moisture and carbon fluxes to separate E and T. The technique was evaluated over a drip-irrigated vineyard located in California's Central Valley using data collected during the 2015 growing season as a part of the GRAPEX (Grape Remote sensing and Atmospheric Profile Experiment) field campaign. The results indicate a clear diurnal pattern in the fraction of ET due to T with a mid-day peak averaging 80% during the growing season. Similarly, there is a strong seasonal trend with the fraction of ET due T increasing in proportion to the increasing vine biomass during the growing season; at its maximum T accounts for approximately 90% of the total moisture flux. These results are in agreement with those from microlysimeter and sapflow measurements collected at the

Napa River Sediment TMDL Implementation and Habitat Enhancement Project

EPA Pesticide Factsheets

Information about the SFBWQP Napa River Sediment TMDL Implementation and Habitat Enhancement Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

The Cenozoic evolution of the San Joaquin Valley, California

USGS Publications Warehouse

Bartow, J. Alan

1991-01-01

The San Joaquin Valley, which is the southern part of the 700-km-long Great Valley of California, is an asymmetric structural trough that is filled with a prism of upper Mesozoic and Cenozoic sediments up to 9 km thick; these sediments rest on crystalline basement rocks of the southwestward-tilted Sierran block. The San Joaquin sedimentary basin is separated from the Sacramento basin to the north by the buried Stockton arch and associated Stockton fault. The buried Bakersfield arch near the south end of the valley separates the small Maricopa-Tejon subbasin at the south end of the San Joaquin basin from the remainder of the basin. Cenozoic strata in the San Joaquin basin thicken southeastward from about 800 m in the north to over 9,000 m in the south. The San Joaquin Valley can be subdivided into five regions on the basis of differing structural style. They are the northern Sierran block, the southern Sierran block, the northern Diablo homocline, the westside fold belt, and the combined Maricopa-Tejon subbasin and southmargin deformed belt. Considerable facies variation existed within the sedimentary basin, particularly in the Neogene when a thick section of marine sediment accumulated in the southern part of the basin, while a relatively thin and entirely nonmarine section was deposited in the northern part. The northern Sierran block, the stable east limb of the valley syncline between the Stockton fault and the San Joaquin River, is the least deformed region of the valley. Deformation consists mostly of a southwest tilt and only minor late Cenozoic normal faulting. The southern Sierran block, the stable east limb of the valley syncline between the San Joaquin River and the Bakersfield arch, is similar in style to the northern part of the block, but it has a higher degree of deformation. Miocene or older normal faults trend mostly north to northwest and have a net down-to-the-west displacement with individual offsets of as much as 600 m. The northern Diablo

A preliminary investigation of the variables affecting the distribution of giant gartersnakes (Thamnophis gigas) in the Sacramento Valley, California

USGS Publications Warehouse

Halstead, Brian J.; Skalos, Shannon M.; Casazza, Michael L.; Wylie, Glenn D.

2015-09-30

Giant gartersnakes (Thamnophis gigas) comprise a species of rare, semi-aquatic snake precinctive to the Central Valley of California. Because of the loss of more than 90% of their natural habitat, giant gartersnakes are listed as Threatened by the United States and California endangered species acts. Little is known, however, about the distribution of giant gartersnakes in the Sacramento Valley, which is where most extant populations occur. We conducted detection-nondetection surveys for giant gartersnakes throughout the rice-growing regions of the Sacramento Valley, and used occupancy models to examine evidence for the effects of landscape-scale GIS-derived variables, local habitat and vegetation composition, and prey communities on patterns of giant gartersnake occurrence. Although our results are based on a relatively small sample of sites, we found that distance to historic marsh, relative fish count, and an interaction of distance to historic marsh with proportion of habitat composed of submerged vegetation were important variables for explaining occupancy of giant gartersnakes. In particular, giant gartersnakes were more likely to occur closer to historic marsh and where relatively fewer fish were captured in traps. At locations in or near historic marsh, giant gartersnakes were more likely to occur in areas with less submerged vegetation, but this relationship was reversed (and more uncertain) at sites distant from historic marsh. Additional research with a larger sample of sites would further elucidate the distribution of giant gartersnakes in the Sacramento Valley.

Sacramento Valley, CA, USA

NASA Image and Video Library

1973-06-22

SL2-04-179 (22 June 1973) --- The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects. Photo credit: NASA

An Investigation into the Involvement of California Central Valley High School Students with Disabilities in the IEP Process

ERIC Educational Resources Information Center

Anderson, Cheryle Ann

2012-01-01

The purpose of this study was to investigate the involvement of California Central Valley high school students with disabilities in the Individual Education Plan (IEP) process. Specifically, this study investigated the involvement of students with disabilities in the development of the IEP and IEP meetings. In addition, this study explored the…

A brief history of oil and gas exploration in the southern San Joaquin Valley of California: Chapter 3 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

USGS Publications Warehouse

Takahashi, Kenneth I.; Gautier, Donald L.

2007-01-01

The Golden State got its nickname from the Sierra Nevada gold that lured so many miners and settlers to the West, but California has earned much more wealth from so-called “black gold” than from metallic gold. The San Joaquin Valley has been the principal source for most of the petroleum produced in the State during the past 145 years. In attempting to assess future additions to petroleum reserves in a mature province such as the San Joaquin Basin, it helps to be mindful of the history of resource development. In this chapter we present a brief overview of the long and colorful history of petroleum exploration and development in the San Joaquin Valley. This chapter relies heavily upon the work of William Rintoul, who wrote extensively on the history of oil and gas exploration in California and especially in the San Joaquin Valley. No report on the history of oil and gas exploration in the San Joaquin Valley would be possible without heavily referencing his publications. We also made use of publications by Susan Hodgson and a U.S. Geological Survey Web site, Natural Oil and Gas Seeps in California (http://seeps.wr.usgs.gov/seeps/index.html), for much of the material describing the use of petroleum by Native Americans in the San Joaquin Valley. Finally, we wish to acknowledge the contribution of Don Arnot, who manages the photograph collection at the West Kern Oil Museum in Taft, California. The collection consists of more than 10,000 photographs that have been scanned and preserved in digital form on CD-ROM. Many of the historical photographs used in this paper are from that collection. Finally, to clarify our terminology, we use the term “San Joaquin Valley” when we refer to the geographical or topographical feature and the term “San Joaquin Basin” when we refer to geological province and the rocks therein.

A comprehensive analysis of high-magnitude streamflow and trends in the Central Valley, California

NASA Astrophysics Data System (ADS)

Kocis, T. N.; Dahlke, H. E.

2017-12-01

California's climate is characterized by the largest precipitation and streamflow variability observed within the conterminous US. This, combined with chronic groundwater overdraft of 0.6-3.5 km3 yr-1, creates the need to identify additional surface water sources available for groundwater recharge using methods such as agricultural groundwater banking, aquifer storage and recovery, and spreading basins. High-magnitude streamflow, i.e. flow above the 90th percentile, that exceeds environmental flow requirements and current surface water allocations under California water rights, could be a viable source of surface water for groundwater banking. Here, we present a comprehensive analysis of the magnitude, frequency, duration and timing of high-magnitude streamflow (HMF "metrics") over multiple time periods for 93 stream gauges covering the Sacramento, San Joaquin and Tulare basins in California. In addition, we present trend analyses conducted on the same dataset and all HMF metrics using generalized additive models, the Mann-Kendall trend test, and the Signal to Noise Ratio test. The results of the comprehensive analysis show, in short, that in an average year with HMF approximately 3.2 km3 of high-magnitude flow is exported from the entire Central Valley to the Sacramento-San Joaquin Delta, often at times when environmental flow requirements of the Delta and major rivers are exceeded. High-magnitude flow occurs, on average, during 7 and 4.7 out of 10 years in the Sacramento River and the San Joaquin-Tulare Basins, respectively, from just a few storm events (5-7 1-day peak events) lasting for a total of 25-30 days between November and April. Preliminary trend tests suggest that all HMF metrics show limited change over the last 50 years. As a whole, the results suggest that there is sufficient unmanaged surface water physically available to mitigate long-term groundwater overdraft in the Central Valley.

Investigating Groundwater Depletion and Aquifer Degradation in Central Valley California from Space

NASA Astrophysics Data System (ADS)

Ojha, C.; Shirzaei, M.; Werth, S.; Argus, D. F.

2017-12-01

The Central Valley in California includes one of the world's largest and yet most stressed aquifer systems. The large demand for groundwater, accelerated by population growth and extreme droughts, has been depleting the region's groundwater resources for decades. However, the lack of dense monitoring networks and inaccurate information on geophysical aquifer response pose serious challenges to water management efforts in the area and put the groundwater at high risk. Here, we performed a joint analysis of large SAR interferometric data sets acquired by ALOS L-band satellite in conjunction with the groundwater level observations across the Central Valley. We used 420 L-band SAR images acquired on the ascending orbit track during period Dec 24, 2006 - Jan 1, 2010, and generated more than 1600 interferograms with a pixel size of 100 m × 100 m. We also use data from 1600 observational wells providing continuous measurements of groundwater level within the study period for our analysis. We find that in the south and near Tulare Lake, north of Tule and south of Kaweah basin in San Joaquin valley, the subsidence rate is greatest at up to 20-25 cm/yr, while in Sacramento Valley the subsidence rate is lower at 1-3 cm/yr. From the characterization of the elastic and inelastic storage coefficients, we find that Kern, Tule, Tulare, Kaweah and Merced basins in the San Joaquin Valley are more susceptible to permanent compaction and aquifer storage loss. Kern County shows 0.23%-1.8% of aquifer storage loss during the study period, and has higher percentage loss than adjacent basins such as Tule and Tulare Lake with 0.15%-1.2% and 0.2 %-1.5% loss, respectively. Overall, we estimate that the aquifers across the valley lost a total of 28 km3 of groundwater and 2% of their storage capacity during the study period. Our unique observational evidence including valley-wide estimate of mechanical properties of aquifers and model results will not only facilitate monitoring water deficits

Population and reproductive health in National Adaptation Programmes of Action (NAPAs) for climate change in Africa.

PubMed

Mutunga, Clive; Hardee, Karen

2010-12-01

This paper reviews 44 National Adaptation Programmes of Action (NAPAs) to assess the NAPA process and identify the range of interventions included in countries' priority adaptation actions and highlight how population issues and reproductive health/family planning (RH/FP) are addressed as part of the adaptation agenda. A majority of the 44 NAPAs identify rapid population growth as a key component of vulnerability to climate change impacts. However, few chose to prioritise NAPA funds for family planning/reproductive health programmes. The paper emphasizes the need to translate the recognition of population pressure as a factor related to countries' ability to adapt to climate change into relevant project activities. Such projects should include access to RH/FP, in addition to other strategies such as girls' education and women's empowerment that lead to lower fertility. Attention to population and integrated strategies should be central and aligned to longer-term national adaptation plans and strategies.

Map showing depth to pre-Cenozoic basement in the Death Valley ground-water model area, Nevada and California

USGS Publications Warehouse

Blakely, R.J.; Ponce, D.A.

2001-01-01

A depth to basement map of the Death Valley groundwater model area was prepared using over 40,0000 gravity stations as part of an interagency effort by the U.S. Geological Survey and the U.S. Department of Energy to help characterize the geology and hydrology of southwest Nevada and parts of California.

Site Characterization at Napa Strong Motion Sites Using Tomography, MASW, and MALW

NASA Astrophysics Data System (ADS)

Chan, J. H.; Catchings, R.; Goldman, M.; Criley, C.

2015-12-01

The 24 August 2014 Mw 6.0 South Napa earthquake caused $300 million in damage to private and commercial properties. Previous studies indicate areas underlain by deposits with low average shear-wave velocity to 30 m depth (Vs30) can experience extensive structural damage during earthquakes. Thus, Vs30 is considered a predictor of the influence of local geology on strong shaking from earthquakes. The goal of our study was to evaluate Vs30 at six accelerograph stations in the City and County of Napa and in the City of Vallejo. We used active seismic sources and 4.5-Hz sensors recorded on 120 channels to investigate the shallow velocity structure. Geophones and shots were spaced at 3 m along each profile, which ranged in length from 85 to 260 m. We used a 226-kg accelerated weight-drop and a seisgun to generate P and Rayleigh waves for P-wave tomography and MASW, and we used a 3.5-kg sledgehammer and block to generate S and Love waves for S-wave tomography and MALW. One of the six accelerographs was housed inside Napa Fire Station #3, where the local surface geology consists of late Pleistocene to Holocene alluvium and alluvial fan deposits. The average Vs30 determined from MASW (Rayleigh waves) is 312 m/s, and the average Vs30 from MALW (Love waves) is 340 m/s, with an average velocity difference of about 8% between the two methods. These average values are both slightly less than the average Vs30 of 375 m/s determined from S-wave tomography, which suggests the three methods are complimentary and can be useful in evaluating site response. The 0.42g median horizontal peak ground acceleration (PGA) recorded at Napa Fire Station #3 indicates the area experienced strong shaking during the Mw 6.0 South Napa earthquake, consistent with expectations for a site with relatively low average Vs30.

Color Image of Death Valley, California from SIR-C

NASA Technical Reports Server (NTRS)

1999-01-01

This radar image shows the area of Death Valley, California and the different surface types in the area. Radar is sensitive to surface roughness with rough areas showing up brighter than smooth areas, which appear dark. This is seen in the contrast between the bright mountains that surround the dark, smooth basins and valleys of Death Valley. The image shows Furnace Creek alluvial fan (green crescent feature) at the far right, and the sand dunes near Stove Pipe Wells at the center. Alluvial fans are gravel deposits that wash down from the mountains over time. Several other alluvial fans (semicircular features) can be seen along the mountain fronts in this image. The dark wrench-shaped feature between Furnace Creek fan and the dunes is a smooth flood-plain which encloses Cottonball Basin. Elevations in the valley range from 70 meters (230 feet) below sea level, the lowest in the United States, to more than 3,300 meters (10,800 feet) above sea level. Scientists are using these radar data to help answer a number of different questions about Earth's geology including how alluvial fans form and change through time in response to climatic changes and earthquakes. The image is centered at 36.629 degrees north latitude, 117.069 degrees west longitude. Colors in the image represent different radar channels as follows: red =L-band horizontally polarized transmitted, horizontally polarized received (LHH); green =L-band horizontally transmitted, vertically received (LHV) and blue = CHV.

SIR-C/X-SAR is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground

Space Radar Image of Long Valley, California in 3-D

NASA Image and Video Library

1999-05-01

This three-dimensional perspective view of Long Valley, California was created from data taken by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar on board the space shuttle Endeavour. This image was constructed by overlaying a color composite SIR-C radar image on a digital elevation map. The digital elevation map was produced using radar interferometry, a process by which radar data are acquired on different passes of the space shuttle. The two data passes are compared to obtain elevation information. The interferometry data were acquired on April 13,1994 and on October 3, 1994, during the first and second flights of the SIR-C/X-SAR instrument. The color composite radar image was taken in October and was produced by assigning red to the C-band (horizontally transmitted and vertically received) polarization; green to the C-band (vertically transmitted and received) polarization; and blue to the ratio of the two data sets. Blue areas in the image are smooth and yellow areas are rock outcrops with varying amounts of snow and vegetation. The view is looking north along the northeastern edge of the Long Valley caldera, a volcanic collapse feature created 750,000 years ago and the site of continued subsurface activity. Crowley Lake is the large dark feature in the foreground. http://photojournal.jpl.nasa.gov/catalog/PIA01769

New streams and springs after the 2014 Mw6.0 South Napa earthquake

PubMed Central

Wang, Chi-Yuen; Manga, Michael

2015-01-01

Many streams and springs, which were dry or nearly dry before the 2014 Mw6.0 South Napa earthquake, started to flow after the earthquake. A United States Geological Survey stream gauge also registered a coseismic increase in discharge. Public interest was heightened by a state of extreme drought in California. Since the new flows were not contaminated by pre-existing surface water, their composition allowed unambiguous identification of their origin. Following the earthquake we repeatedly surveyed the new flows, collecting data to test hypotheses about their origin. We show that the new flows originated from groundwater in nearby mountains released by the earthquake. The estimated total amount of new water is ∼106 m3, about 1/40 of the annual water use in the Napa–Sonoma area. Our model also makes a testable prediction of a post-seismic decrease of seismic velocity in the shallow crust of the affected region. PMID:26158898

Down in the Valley.

ERIC Educational Resources Information Center

Salter, Linda Graef

1999-01-01

Describes the partnerships formed by West Valley Mission Community College District (California) with its surrounding Silicon Valley business community in an effort to benefit workforce development. Asserts that community colleges are uniquely positioned to provide a lifelong education that will yield a skilled workforce to meet the needs of…

Structure and Velocities of the Northeastern Santa Cruz Mountains and the Western Santa Clara Valley, California, from the SCSI-LR Seismic Survey

USGS Publications Warehouse

Catchings, R.D.; Goldman, M.R.; Gandhok, G.

2006-01-01

Introduction: The Santa Clara Valley is located in the southern San Francisco Bay area of California and generally includes the area south of the San Francisco Bay between the Santa Cruz Mountains on the southwest and the Diablo Ranges on the northeast. The area has a population of approximately 1.7 million including the city of San Jose, numerous smaller cities, and much of the high-technology manufacturing and research area commonly referred to as the Silicon Valley. Major active strands of the San Andreas Fault system bound the Santa Clara Valley, including the San Andreas fault to the southwest and the Hayward and Calaveras faults to the northeast; related faults likely underlie the alluvium of the valley. This report focuses on subsurface structures of the western Santa Clara Valley and the northeastern Santa Cruz Mountains and their potential effects on earthquake hazards and ground-water resource management in the area. Earthquake hazards and ground-water resources in the Santa Clara Valley are important considerations to California and the Nation because of the valley's preeminence as a major technical and industrial center, proximity to major earthquakes faults, and large population. To assess the earthquake hazards of the Santa Clara Valley better, the U.S. Geological Survey (USGS) has undertaken a program to evaluate potential earthquake sources and potential effects of strong ground shaking within the valley. As part of that program, and to better assess water resources of the valley, the USGS and the Santa Clara Valley Water District (SCVWD) began conducting collaborative studies to characterize the faults, stratigraphy, and structures beneath the alluvial cover of the Santa Clara Valley in the year 2000. Such geologic features are important to both agencies because they directly influence the availability and management of groundwater resources in the valley, and they affect the severity and distribution of strong shaking from local or regional

78 FR 53113 - Approval and Promulgation of Implementation Plans; California; San Joaquin Valley; Contingency...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-28

...EPA is proposing to approve a state implementation plan (SIP) revision submitted by the State of California to address Clean Air Act nonattainment area contingency measure requirements for the 1997 annual and 24-hour fine particulate matter (PM2.5) national ambient air quality standards in the San Joaquin Valley. Final approval of this SIP revision would terminate the sanctions clocks and a federal implementation plan clock that were triggered by EPA's partial disapproval of a related SIP submission on November 9, 2011 (76 FR 69896).

September-March survival of female northern pintails radiotagged in San Joaquin Valley, California

USGS Publications Warehouse

Fleskes, J.P.; Jarvis, R.L.; Gilmer, D.S.

2002-01-01

To improve understanding of pintail ecology, we radiotagged 191 hatch-year (HY) and 228 after-hatch-year (AHY) female northern pintails (Anas acuta) in the San Joaquin Valley (SJV), and studied their survival throughout central California, USA, during September-March, 1991-1994. We used adjusted Akaike Information Criterion (AICc) values to contrast known-fate models and examine variation in survival rates relative to year, interval, wintering region (AJV, other central California), pintail age, body mass at capture, capture date, capture area, and radio type. The best-fitting model included only interval x year and age x body mass; the next 2 best-fitting models also included wintering region and capture date. Hunting caused 83% of the mortalities we observed, and survival was consistently lower during hunting than nonhunting intervals. Nonhunting and hunting mortality during early winter was highest during the 1991-1992 drought year. Early-winter survival improved during the study along with habitat conditions in the Grassland Ecological Area (EA), where most radiotagged pintails spent early winter. Survival was more closely related to body mass at capture for HY than AHY pintails, even after accounting for the later arrival (based on capture date) of HY pintails, suggesting HY pintails are less adept at improving their condition. Thus, productivity estimates based on harvest age ratios may be biased if relative vulnerability of HY and AHY pintails is assumed to be constant because fall body condition of pintails may vary greatly among years. Cumulative winter survival was 75.6% (95% CI = 68.3% to 81.7%) for AHY and 65.4% (56.7% to 73.1%) for HY female pintails. Daily odds of survival in the cotton-agriculture landscape of the SJV were -21.3% (-40.3% to +3.7%) lower than in the rice-agriculture landscape of the Sacramento Valley (SACV) and other central California areas. Higher hunting mortality may be 1 reason pintails have declined more in SJV than in SACV.

Predicting arsenic in drinking water wells of the Central Valley, California

USGS Publications Warehouse

Ayotte, Joseph; Nolan, Bernard T.; Gronberg, JoAnn M.

2016-01-01

Probabilities of arsenic in groundwater at depths used for domestic and public supply in the Central Valley of California are predicted using weak-learner ensemble models (boosted regression trees, BRT) and more traditional linear models (logistic regression, LR). Both methods captured major processes that affect arsenic concentrations, such as the chemical evolution of groundwater, redox differences, and the influence of aquifer geochemistry. Inferred flow-path length was the most important variable but near-surface-aquifer geochemical data also were significant. A unique feature of this study was that previously predicted nitrate concentrations in three dimensions were themselves predictive of arsenic and indicated an important redox effect at >10 μg/L, indicating low arsenic where nitrate was high. Additionally, a variable representing three-dimensional aquifer texture from the Central Valley Hydrologic Model was an important predictor, indicating high arsenic associated with fine-grained aquifer sediment. BRT outperformed LR at the 5 μg/L threshold in all five predictive performance measures and at 10 μg/L in four out of five measures. BRT yielded higher prediction sensitivity (39%) than LR (18%) at the 10 μg/L threshold–a useful outcome because a major objective of the modeling was to improve our ability to predict high arsenic areas.

Estimating soil matric potential in Owens Valley, California

USGS Publications Warehouse

Sorenson, Stephen K.; Miller, R.F.; Welch, M.R.; Groeneveld, D.P.; Branson, F.A.

1988-01-01

Much of the floor of the Owens Valley, California, is covered with alkaline scrub and alkaline meadow plant communities, whose existence is dependent partly on precipitation and partly on water infiltrated into the rooting zone from the shallow water table. The extent to which these plant communities are capable of adapting to and surviving fluctuations in the water table depends on physiological adaptations of the plants and on the water content, matric potential characteristics of the soils. Two methods were used to estimate soil matric potential in test sites in Owens Valley. The first was the filter-paper method, which uses water content of filter papers equilibrated to water content of soil samples taken with a hand auger. The other method of estimating soil matric potential was a modeling approach based on data from this and previous investigations. These data indicate that the base 10 logarithm of soil matric potential is a linear function of gravimetric soil water content for a particular soil. Estimates of soil water characteristic curves were made at two sites by averaging the gravimetric soil water content and soil matric potential values from multiple samples at 0.1 m depths derived by using the hand auger and filter paper method and entering these values in the soil water model. The characteristic curves then were used to estimate soil matric potential from estimates of volumetric soil water content derived from neutron-probe readings. Evaluation of the modeling technique at two study sites indicated that estimates of soil matric potential within 0.5 pF units of the soil matric potential value derived by using the filter paper method could be obtained 90 to 95% of the time in soils where water content was less than field capacity. The greatest errors occurred at depths where there was a distinct transition between soils of different textures. (Lantz-PTT)

Water-Quality Data for Selected Stream Sites in Bridgeport Valley, Mono County, California, April 2000 to June 2003

USGS Publications Warehouse

Rockwell, Gerald L.; Honeywell, Paul D.

2004-01-01

The U.S. Geological Survey, in cooperation with the California Regional Water Quality Control Board, Lahonton Region, carried out a water-quality data collection program of selected streams in and near Bridgeport Valley, California, during April 2000 to June 2003. These data were collected to provide information used by the California Regional Water Quality Control Board to develop total maximum daily load standards. Field measurements of streamflow, barometric pressure, dissolved oxygen, pH, specific conductance, and water temperature were made at 15 sites located on 6 streams. Water samples were analyzed for nutrients, major ions, turbidity, fecal coliform, fecal streptococci, and suspended sediment. Field data, turbidity, nutrient, major ion, and sediment concentrations and fecal coliform and fecal streptococci densities are given in tables for each site. Field blank data are also presented in a table.

Rockfall hazard and risk assessment in the Yosemite Valley, California, USA

USGS Publications Warehouse

Guzzetti, F.; Reichenbach, P.; Wieczorek, G.F.

2003-01-01

Rock slides and rock falls are the most frequent types of slope movements in Yosemite National Park, California. In historical time (1857-2002) 392 rock falls and rock slides have been documented in the valley, and some of them have been mapped in detail. We present the results of an attempt to assess rock fall hazards in the Yosemite Valley. Spatial and temporal aspects of rock falls hazard are considered. A detailed inventory of slope movements covering the 145-year period from 1857 to 2002 is used to determine the frequency-volume statistics of rock falls and to estimate the annual frequency of rock falls, providing the temporal component of rock fall hazard. The extent of the areas potentially subject to rock fall hazards in the Yosemite Valley were obtained using STONE, a physically-based rock fall simulation computer program. The software computes 3-dimensional rock fall trajectories starting from a digital elevation model (DEM), the location of rock fall release points, and maps of the dynamic rolling friction coefficient and of the coefficients of normal and tangential energy restitution. For each DEM cell the software calculates the number of rock falls passing through the cell, the maximum rock fall velocity and the maximum flying height. For the Yosemite Valley, a DEM with a ground resolution of 10 ?? 10 m was prepared using topographic contour lines from the U.S. Geological Survey 1:24 000-scale maps. Rock fall release points were identified as DEM cells having a slope steeper than 60??, an assumption based on the location of historical rock falls. Maps of the normal and tangential energy restitution coefficients and of the rolling friction coefficient were produced from a surficial geologic map. The availability of historical rock falls mapped in detail allowed us to check the computer program performance and to calibrate the model parameters. Visual and statistical comparison of the model results with the mapped rock falls confirmed the accuracy of

Bioindicators from Mosquitofish (Gambusia affinis) Sampled from the Imperial Valley in Southern California

USGS Publications Warehouse

Jenkins, Jill A.; Draugelis-Dale, Rassa O.

2006-01-01

The Sonny Bono Salton Sea National Wildlife Refuge (SSNWR) is located 64 km north of the Mexican border at the southern end of the Salton Sea in California's Imperial Valley. Freshwater ponds and managed habitats at the SSNWR, Calipatria, Calif. are supplied with Colorado River water that carries compounds from upstream sources. Components include municipal and industrial discharges, agricultural drainage, and sewage plant inputs. Aquatic animals in these ecosystems are continuously exposed to multiple constituents, several of which have been demonstrated to be associated with hormonal disturbances. We investigated possible endocrine impacts to fish in the Imperial Valley, Calif., by addressing the null hypothesis that aquatic species in impacted sites did not exhibit evidence of endocrine disruption as compared with those from nonimpacted sites. The results presented are intended to provide managers with science-based information and interpretations about the condition of the animals in their ecosystems for the minimization of potential adverse effects to trust fish and wildlife resources and for the maximization of available water resources.

78 FR 21545 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-11

...EPA is taking direct final action to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD) and Monterey Bay Unified Air Pollution Control District (MBUAPCD) and Santa Barbara County Air Pollution Control District (SBCAPCD) portions of the California State Implementation Plan (SIP). Under authority of the Clean Air Act as amended in 1990 (CAA or the Act), we are approving local rules that address emission statements for AVAQMD, rule rescissions that addresses public records for MBUAPCD, and define terms for SBCAPCD.

78 FR 21581 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-11

...EPA is proposing to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD), Monterey Bay Unified Air Pollution Control District (MBUAPCD) and Santa Barbara County Air Pollution Control District (SCAPCD) portions of the California State Implementation Plan (SIP). We are proposing to approve revisions local rules that address emission statements for AVAQMD, rule rescissions that address public records for MBUAPCD, and define terms for SBCAPCD, under the Clean Air Act as amended in 1990 (CAA or the Act).

Rare alluvial sands of El Monte Valley, California (San Diego County), support high herpetofaunal species richness and diversity, despite severe habitat disturbance

USGS Publications Warehouse

Richmond, Jonathan Q.; Rochester, Carlton J.; Smith, Nathan W.; Nordland, Jeffrey A.; Fisher, Robert N.

2016-01-01

We characterized the species richness, diversity, and distribution of amphibians and reptiles inhabiting El Monte Valley, a heavily disturbed, alluvium-filled basin within the lower San Diego River in Lakeside, California. This rare habitat type in coastal southern California is designated as a critical sand resource by the state of California and is currently under consideration for a large-scale sand mining operation with subsequent habitat restoration. We conducted field surveys from June 2015 to May 2016 using drift fence lines with funnel traps, coverboard arrays, walking transects, and road driving. We recorded 1,208 total captures, revealing high species richness and diversity, but with marked unevenness in species' abundances. Snakes were the most species-rich taxonomic group (13 species representing 11 genera), followed by lizards (11 species representing 9 genera). After the southern Pacific rattlesnake (Crotalus oreganus helleri), the California glossy snake (Arizona elegans occidentalis) was the second most frequently detected snake species (n = 23 captures). Amphibian species richness was limited to only three species in three genera. Despite the relatively limited 12-month sampling period, a longstanding drought, and severe habitat disturbance, our study demonstrates that El Monte Valley harbors a rich herpetofauna that includes many sensitive species.

Inflation of Long Valley caldera, California, Basin and Range strain, and possible Mono Craters dike opening from 1990-94 GPS surveys

USGS Publications Warehouse

Marshall, G.A.; Langbein, J.; Stein, R.S.; Lisowski, M.; Svarc, J.

1997-01-01

Five years of annual Global Positioning System (GPS) surveys of a network centered on Long Valley, California, constrain displacement rates for these stations relative to a central station in the network. These observations are consistent with recent models of resurgent dome inflation in Long Valley (Langbein et al., 1995) and have sufficient signal to detect the presence of Basin and Range strain in the Long Valley region. The data also allow for the possibility of dike inflation beneath the Mono Craters; dike intrusion is consistent with the Mono Craters' recent geologic history of ash eruptions, with seismic tomography, leveling data, and geologic studies of these volcanic domes and flows. Copyright 1997 by the American Geophysical Union.

Reclaiming agricultural drainage water with nanofiltration membranes: Imperial Valley, California, USA

USGS Publications Warehouse

Kharaka, Y.K.; Schroeder, R.A.; Setmire, J.G.; ,

2003-01-01

We conducted pilot-scale field experiments using nanofiltration membranes to lower the salinity and remove Se, As and other toxic contaminants from saline agricultural wastewater in the Imperial Valley, California, USA. Farmlands in the desert climate (rainfall - 7.4 cm/a) of Imperial Valley cover -200,000 ha that are irrigated with water (-1.7 km3 annually) imported from the Colorado River. The salinity (-850 mg/L) and concentration of Se (-2.5 ??g/L) in the Colorado River water are high and evapotranpiration further concentrates salts in irrigation drainage water, reaching salinities of 3,000-15,000 mg/L TDS and a median Se value of -30 ??g/L. Experiments were conducted with two commercially available nanofiltration membranes, using drainage water of varying composition, and with or without the addition of organic precipitation inhibitors. Results show that these membranes selectively remove more than 95% of Se, SO4, Mo, U and DOC, and -30% of As from this wastewater. Low percentages of Cl, NO3 and HCO3, with enough cations to maintain electrical neutrality also were removed. The product water treated by these membranes comprised more than 90% of the wastewater tested. Results indicate that the treated product water from the Alamo River likely will have less than 0.2 ??g/L Se, salinity of 300-500 mg/L TDS and other chemical concentrations that meet the water quality criteria for irrigation and potable use. Because acceptability is a major issue for providing treated wastewater to urban centers, it may be prudent to use the reclaimed water for irrigation and creation of lower salinity wetlands near the Salton Sea; an equivalent volume of Colorado River water can then be diverted for the use of increasing populations of San Diego and other urban centers in southern California. Nanofiltration membranes yield greater reclaimed-water output and require lower pressure and less pretreatment, and therefore are generally more cost effective than traditional reverse

Atmospheric transport of organophosphate pesticides from California's Central Valley to the Sierra Nevada Mountains

USGS Publications Warehouse

Zabik, John M.; Seiber, James N.

1993-01-01

Atmospheric transport of organophosphate pesticides from California's Central Valley to the Sierra Nevada mountains was assessed by collecting air- and wet-deposition samples during December, January, February, and March, 1990 to 1991. Large-scale spraying of these pesticides occurs during December and January to control insect infestations in valley orchards. Sampling sites were placed at 114- (base of the foothills), 533-, and 1920-m elevations. Samples acquired at these sites contained chlorpyrifos [phosphorothioic acid; 0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl) ester], parathion [phosphorothioic acid, 0-0-diethylo-(4-nitrophenyl) ester], diazinon {phosphorothioic acid, 0,0-diethyl 0-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] ester} diazinonoxon {phosphoric acid, 0,0-diethyl 0-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] ester}, and paraoxon [phosphoric acid, 0,0-diethyl 0-(4-nitrophenyl) ester] in both air and wet deposition samples. Air concentrations of chloropyrifos, diazinon and parathion ranged from 13 to 13 000 pg/m3 at the base of the foothills. At 533-m air concentrations were below the limit of quantification (1.4 pg/m3) to 83 pg/m3 and at 1920 m concentrations were below the limit of quantification. Concentrations in wet deposition varied with distance and elevation from the Central Valley. Rainwater concentrations at the base of the foot hills ranged from 16 to 7600 pg/mL. At 533-m rain and snow water concentrations ranged from below the limit of quantification (1.3 pg/mL) to 140 pg/mL and at 1920 m concentrations ranged from below the limit of quantification to 48 pg/mL. These findings indicate that atmospheric transport of pesticides applied in the valley to the Sierra Nevada mountains is occurring, but the levels decrease as distance and elevation increase from the valley floor.

Cone penetration tests and soil borings at the Mason Road site in Green Valley, Solano County, California

USGS Publications Warehouse

Bennett, Michael J.; Noce, Thomas E.; Lienkaemper, James J.

2011-01-01

In support of a study to investigate the history of the Green Valley Fault, 13 cone penetration test soundings and 3 auger borings were made at the Mason Road site in Green Valley, Solano County, California. Three borings were made at or near two of the cone penetration test soundings. The soils are mostly clayey with a few sandy layers or lenses. Fine-grained soils range from low plasticity sandy lean clay to very plastic fat clay. Lack of stratigraphic correlation in the subsurface prevented us from determining whether any channels had been offset at this site. Because the soils are generally very clayey and few sand layers or lenses are loose, the liquefaction potential at the site is very low.

Chuckwalla Valley multiple-well monitoring site, Chuckwalla Valley, Riverside County

USGS Publications Warehouse

Everett, Rhett

2013-01-01

The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management, is evaluating the geohydrology and water availability of the Chuckwalla Valley, California. As part of this evaluation, the USGS installed the Chuckwalla Valley multiple-well monitoring site (CWV1) in the southeastern portion of the Chuckwalla Basin. Data collected at this site provide information about the geology, hydrology, geophysics, and geochemistry of the local aquifer system, thus enhancing the understanding of the geohydrologic framework of the Chuckwalla Valley. This report presents construction information for the CWV1 multiple-well monitoring site and initial geohydrologic data collected from the site.

HCMM: Soil moisture in relation to geologic structure and lithology, northern California. [Sacramento Valley, California

NASA Technical Reports Server (NTRS)

Rich, E. I. (Principal Investigator)

1980-01-01

The author has identified the following significant results. Empirical observations on the ground and examination of aerial color IR photographs indicate that in grassland terrain, the vegetation overlying sandstone tends to become less vigorous sooner in the late spring season than does the area overlain by an adjacent shale unit. The reverse relationship obtains in the fall. These relationships are thought to be a reflection of the relative porosity of each of the units and hence of their ability to retain or lose soil moisture. A comparison of the optically enlarged day and nite IR imagery of the Late Mesozoic interbedded sandstone and shale units along the western margin of the Sacramento Valley, California, taken at seasonally critical times of the year (late spring/early summer and late fall/early winter) reveals subtle seasonal variations of graytone which tend to support the empirical observations after consideration of Sun angle and azimuth, and the internal consistency of the data on each set of satellite imagery.

Groundwater quality in the Madera and Chowchilla subbasins of the San Joaquin Valley, California

USGS Publications Warehouse

Shelton, Jennifer L.; Fram, Miranda S.; Belitz, Kenneth

2013-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality information. The Madera and Chowchilla subbasins of the San Joaquin Valley constitute one of the study units being evaluated. The Madera-Chowchilla study unit is about 860 square miles and consists of the Madera and Chowchilla groundwater subbasins of the San Joaquin Valley Basin (California Department of Water Resources, 2003; Shelton and others, 2009). The study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 11 to 15 inches, most of which occurs between November and February. The main surface-water features in the study unit are the San Joaquin, Fresno, and Chowchilla Rivers, and the Madera and Chowchilla canals. Land use in the study unit is about 69 percent (%) agricultural, 28% natural (mainly grasslands), and 3% urban. The primary crops are orchards and vineyards. The largest urban area is the city of Madera. The primary aquifer system is defined as those parts of the aquifer corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. In the Madera-Chowchilla study unit, these wells typically are drilled to depths between 200 and 800 feet, consist of a solid casing from land surface to a depth of about 140 to 400 feet, and are perforated below the solid casing. Water quality in the primary aquifer system may differ from that in the shallower and deeper parts of the aquifer system. The primary aquifer system in the study unit consists of Quaternary-age alluvial-fan and fluvial deposits that were formed by the rivers draining the Sierra Nevada. Sediments consist of gravels, sands

The hydrothermal system of Long Valley Caldera, California

USGS Publications Warehouse

Sorey, M.L.; Lewis, Robert Edward; Olmsted, F.H.

1978-01-01

Long Valley caldera, an elliptical depression covering 450 km 2 on the eastern front of the Sierra Nevada in east-central California, contains a hot-water convection system with numerous hot springs and measured and estimated aquifer temperatures at depths of 180?C to 280?C. In this study we have synthesized the results of previous geologic, geophysical, geochemical, and hydrologic investigations of the Long Valley area to develop a generalized conceptual and mathematical model which describes the gross features of heat and fluid flow in the hydrothermal system. Cenozoic volcanism in the Long Valley region began about 3.2 m.y. (million years) ago and has continued intermittently until the present time. The major event that resulted in the formation of the Long Valley caldera took place about 0.7 m.y. ago with the eruption of 600 km 3 or more of Bishop Tuff of Pleistocene age, a rhyolitic ash flow, and subsequent collapse of the roof of the magma chamber along one or more steeply inclined ring fractures. Subsequent intracaldera volcanism and uplift of the west-central part of the caldera floor formed a subcircular resurgent dome about 10 km in diameter surrounded by a moat containing rhyolitic, rhyodacitic, and basaltic rocks ranging in age from 0.5 to 0.05 m.y. On the basis of gravity and seismic studies, we estimate an aver- age thickness of fill of 2.4 km above the precaldera granitic and metamorphic basement rocks. A continuous layer of densely welded Bishop Tuff overlies the basement rocks, with an average thickness of 1.4 km; the fill above the welded Bishop Tuff consists of intercalated volcanic flows and tuffs and fluvial and lacustrine deposits. Assuming the average grain density of the fill is between 2.45 and 2.65 g/cm 3 , we calculate the average bulk porosity of the total fill as from 0.11 to 0.21. Comparison of published values of porosity of the welded Bishop Tuff exposed southeast of the caldera with calculated values indicates average bulk porosity

Social Disparities in Drinking Water Quality in California's San Joaquin Valley

NASA Astrophysics Data System (ADS)

Ray, I.; Balazs, C.; Hubbard, A.; Morello-Frosch, R.

2011-12-01

Social Disparities in Drinking Water Quality in California's San Joaquin Valley Carolina Balazs, Rachel Morello-Frosch, Alan Hubbard and Isha Ray Little attention has been given to research on social disparities and environmental justice in access to safe drinking water in the USA. We examine the relationship between nitrate and arsenic concentrations in community water systems (CWS) and the ethnic and socioeconomic characteristics of their customers. We hypothesized that systems in the San Joaquin Valley that serve a higher proportion of minority (especially Latino) residents, and/or lower socioeconomic status (proxied by rates of home ownership) residents, have higher nitrate levels and higher arsenic levels. We used water quality monitoring datasets (1999-2001) to estimate nitrate as well as arsenic levels in CWS, and source location and Census block group data to estimate customer demographics. We found that percent Latino was associated with a .04 mg NO3/L increase in a CWS' estimated nitrate ion concentration (95% CI, -.08, .16) and rate of home ownership was associated with a .16 mg NO3/L decrease (95% CI, -.32, .002). We also found that each percent increase in home ownership rate was associated with a .30 ug As/L decrease in arsenic concentrations (p<.05), but our data showed no significant correlation between arsenic concentration and percent Latino. These results show that exposure disparities and compliance burdens in accordance with EPA standards fell most heavily on socio-economically disadvantaged communities. Selected References Cory DC, Rahman T. 2009. Environmental justice and enforcement of the safe drinking water act: The arizona arsenic experience. Ecological Economics 68: 1825-1837. Krieger N, Williams DR, Moss NE. 1997. Measuring social class in us public health research: Concepts, methodologies, and guidelines. Annual Review of Public Health 18(341-378). Moore E, Matalon E, Balazs C, Clary J, Firestone L, De Anda S, Guzman, M. 2011. The

77 FR 26475 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-04

...EPA is proposing to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD), Eastern Kern Air Pollution Control District (EKAPCD), and Santa Barbara County Air Pollution Control District (SBCAPCD) portions of the California State Implementation Plan (SIP). We are proposing to approve revisions to local rules that define terms used in other air pollution regulations in these areas and a rule rescission that address Petroleum Coke Calcining Operations--Oxides of Sulfur, under the Clean Air Act as amended in 1990 (CAA or the Act).

Mapping Aquifer Systems with Airborne Electromagnetics in the Central Valley of California

NASA Astrophysics Data System (ADS)

Knight, R. J.; Smith, R.; Asch, T. H.; Abraham, J.; Cannia, J.; Fogg, G. E.; Viezzoli, A.

2016-12-01

The Central Valley of California is an important agricultural region struggling to meet the need for irrigation water. Recent periods of drought have significantly reduced the delivery of surface water, resulting in extensive pumping of groundwater. This has exacerbated an already serious problem in the Central Valley, where a number of areas have experienced declining water levels for several decades leading to ongoing concerns about depletion of aquifers and impacts on ecosystems, as well as subsidence of the ground surface. The overdraft has been so significant, that there are now approximately140 million acre-feet (MAF) of unused groundwater storage in the Central Valley, storage that could be used to complement the 42 MAF of surface storage. The alluvial sedimentary geology of the Central Valley is typically composed of more than 50 to 70 percent fine-grained deposits dominated by silt and clay beds. These fine grained deposits can block potential recharge, and are associated with the large amount of observed subsidence. Fortunately, the geologic processes that formed the region created networks of sand and gravel which provide both a supply of water and pathways for recharge from the surface to the aquifers. The challenge is to find these sand and gravel deposits and thus identify optimal locations for surface spreading techniques so that recharge could be dramatically increased, and re-pressurization of the confined aquifer networks could be accomplished. We have acquired 100 line kilometers of airborne electromagnetic data over an area in the San Joaquin Valley, imaging the subsurface hydrostratigraphy to a depth of 500 m with spatial resolution on the order of meters to tens of meters. Following inversion of the data to obtain resistivity models along the flight lines, we used lithology logs in the area to transform the models to images displaying the distribution of sand and gravel, clay, and mixed fine and coarse materials. The quality of the data and

77 FR 35327 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-13

...EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation Plan (SIP). These revisions concern volatile organic compound (VOC) emissions from the manufacture of polystyrene, polyethylene, and polypropylene products. We are approving a local rule that regulates these emission sources under the Clean Air Act (CAA or the Act). We are taking comments on this proposal and plan to follow with a final action.

Map of the Rinconada and Reliz Fault Zones, Salinas River Valley, California

USGS Publications Warehouse

Rosenberg, Lewis I.; Clark, Joseph C.

2009-01-01

The Rinconada Fault and its related faults constitute a major structural element of the Salinas River valley, which is known regionally, and referred to herein, as the 'Salinas Valley'. The Rinconada Fault extends 230 km from King City in the north to the Big Pine Fault in the south. At the south end of the map area near Santa Margarita, the Rinconada Fault separates granitic and metamorphic crystalline rocks of the Salinian Block to the northeast from the subduction-zone assemblage of the Franciscan Complex to the southwest. Northwestward, the Rinconada Fault lies entirely within the Salinian Block and generally divides this region into two physiographically and structurally distinct areas, the Santa Lucia Range to the west and the Salinas Valley to the east. The Reliz Fault, which continues as a right stepover from the Rinconada Fault, trends northwestward along the northeastern base of the Sierra de Salinas of the Santa Lucia Range and beyond for 60 km to the vicinity of Spreckels, where it is largely concealed. Aeromagnetic data suggest that the Reliz Fault continues northwestward another 25 km into Monterey Bay, where it aligns with a high-definition magnetic boundary. Geomorphic evidence of late Quaternary movement along the Rinconada and Reliz Fault Zones has been documented by Tinsley (1975), Dibblee (1976, 1979), Hart (1976, 1985), and Klaus (1999). Although definitive geologic evidence of Holocene surface rupture has not been found on these faults, they were regarded as an earthquake source for the California Geological Survey [formerly, California Division of Mines and Geology]/U.S. Geological Survey (CGS/USGS) Probabilistic Seismic Hazards Assessment because of their postulated slip rate of 1+-1 mm/yr and their calculated maximum magnitude of 7.3. Except for published reports by Durham (1965, 1974), Dibblee (1976), and Hart (1976), most information on these faults is unpublished or is contained in theses, field trip guides, and other types of reports

Groundwater Pumping and Streamflow in the Yuba Basin, Sacramento Valley, California

NASA Astrophysics Data System (ADS)

Moss, D. R.; Fogg, G. E.; Wallender, W. W.

2011-12-01

Water transfers during drought in California's Sacramento Valley can lead to increased groundwater pumping, and as yet unknown effects on stream baseflow. Two existing groundwater models of the greater Sacramento Valley together with localized, monitoring of groundwater level fluctuations adjacent to the Bear, Feather, and Yuba Rivers, indicate cause and effect relations between the pumping and streamflow. The models are the Central Valley Hydrologic Model (CVHM) developed by the U.S. Geological Survey and C2VSIM developed by Department of Water Resources. Using two models which have similar complexity and data but differing approaches to the agricultural water boundary condition illuminates both the water budget and its uncertainty. Water budget and flux data for localized areas can be obtained from the models allowing for parameters such as precipitation, irrigation recharge, and streamflow to be compared to pumping on different temporal scales. Continuous groundwater level measurements at nested, near-stream piezometers show seasonal variations in streamflow and groundwater levels as well as the timing and magnitude of recharge and pumping. Preliminary results indicate that during years with relatively wet conditions 65 - 70% of the surface recharge for the groundwater system comes from irrigation and precipitation and 30 - 35% comes from streamflow losses. The models further indicate that during years with relatively dry conditions, 55 - 60% of the surface recharge for the groundwater system comes from irrigation and precipitation while 40 - 45% comes from streamflow losses. The models irrigation water demand, surface-water and groundwater supply, and deep percolation are integrated producing values for irrigation pumping. Groundwater extractions during the growing season, approximately between April and October, increase by almost 200%. The effects of increased pumping seasonally are not readily evident in stream stage measurements. However, during dry time

Tracing ground-water movement by using the stable isotopes of oxygen and hydrogen, upper Penitencia Creek alluvial fan, Santa Clara Valley, California

USGS Publications Warehouse

Muir, K.S.; Coplen, Tyler B.

1981-01-01

Starting in 1965 the Santa Clara Valley Water District began importing about i00,000 acre-feet per year of northern California water. About one-half of this water was used to artificially recharge the Upper Penitencia Creek alluvial fan in Santa Clara Valley. In order to determine the relative amounts of local ground water and recharged imported water being pumped from the wells, stable isotopes of oxygen and hydrogen were used to trace the movement of the imported water in the alluvial fan. To trace the movement of imported water in the Upper Penitencia Creek alluvial fan, well samples were selected to give areal and depth coverage for the whole fan. The stable isotopes of oxygen-16, oxygen-18, and deuterium were measured in the water samples of imported water and from the wells and streams in the Santa Clara Valley. The d18oand dD compositions of the local runoff were about -6.00 o/oo (parts per thousand) and -40 o/oo, respectively; the average compositions for the local native ground-water samples were about -6.1 o/oo and -41 o/oo, respectively; and the average compositions of the imported water samples were -10.2 o/oo and -74 o/oo, respectively. (The oxygen isotopic composition of water samples is reported relative to Standard Mean Ocean Water, in parts per thousand.) The difference between local ground water and recharged imported water was about 4.1 o/oo in d18o and 33 o/oo in dL. The isotopic data indicate dilution of northern California water with local ground water in a downgradient direction. Two wells contain approximately 74 percent northern California water, six wells more than 50 percent. Data indicate that there may be a correlation between the percentage of northern California water and the depth or length of perforated intervals in wells.

An Integrated Hydrologic Model and Remote Sensing Synthesis Approach to Study Groundwater Extraction During a Historic Drought in the California Central Valley

NASA Astrophysics Data System (ADS)

Thatch, L. M.; Maxwell, R. M.; Gilbert, J. M.

2017-12-01

Over the past century, groundwater levels in California's San Joaquin Valley have dropped more than 30 meters in some areas due to excessive groundwater extraction to irrigate agricultural lands and feed a growing population. Between 2012 and 2016 California experienced the worst drought in its recorded history, further exacerbating this groundwater depletion. Due to lack of groundwater regulation, exact quantities of extracted groundwater in California are unknown and hard to quantify. We use a synthesis of integrated hydrologic model simulations and remote sensing products to quantify the impact of drought and groundwater pumping on the Central Valley water tables. The Parflow-CLM model was used to evaluate groundwater depletion in the San Joaquin River basin under multiple groundwater extraction scenarios simulated from pre-drought through recent drought years. Extraction scenarios included pre-development conditions, with no groundwater pumping; historical conditions based on decreasing groundwater level measurements; and estimated groundwater extraction rates calculated from the deficit between the predicted crop water demand, based on county land use surveys, and available surface water supplies. Results were compared to NASA's Gravity Recover and Climate Experiment (GRACE) data products to constrain water table decline from groundwater extraction during severe drought. This approach untangles various factors leading to groundwater depletion within the San Joaquin Valley both during drought and years of normal recharge to help evaluate which areas are most susceptible to groundwater overdraft, as well as further evaluating the spatially and temporally variable sustainable yield. Recent efforts to improve water management and ensure reliable water supplies are highlighted by California's Sustainable Groundwater Management Act (SGMA) which mandates Groundwater Sustainability Agencies to determine the maximum quantity of groundwater that can be withdrawn through

High-resolution seismic reflection/refraction imaging from Interstate 10 to Cherry Valley Boulevard, Cherry Valley, Riverside County, California: implications for water resources and earthquake hazards

USGS Publications Warehouse

Gandhok, G.; Catchings, R.D.; Goldman, M.R.; Horta, E.; Rymer, M.J.; Martin, P.; Christensen, A.

1999-01-01

This report is the second of two reports on seismic imaging investigations conducted by the U.S. Geological Survey (USGS) during the summers of 1997 and 1998 in the Cherry Valley area in California (Figure 1a). In the first report (Catchings et al., 1999), data and interpretations were presented for four seismic imaging profiles (CV-1, CV-2, CV-3, and CV-4) acquired during the summer of 1997 . In this report, we present data and interpretations for three additional profiles (CV-5, CV-6, and CV-7) acquired during the summer of 1998 and the combined seismic images for all seven profiles. This report addresses both groundwater resources and earthquake hazards in the San Gorgonio Pass area because the shallow (upper few hundred meters) subsurface stratigraphy and structure affect both issues. The cities of Cherry Valley and Beaumont are located approximately 130 km (~80 miles) east of Los Angeles, California along the southern alluvial fan of the San Bernardino Mountains (see Figure 1b). These cities are two of several small cities that are located within San Gorgonio Pass, a lower-lying area between the San Bernardino and the San Jacinto Mountains. Cherry Valley and Beaumont are desert cities with summer daytime temperatures often well above 100 o F. High water usage in the arid climate taxes the available groundwater supply in the region, increasing the need for efficient management of the groundwater resources. The USGS and the San Gorgonio Water District (SGWD) work cooperatively to evaluate the quantity and quality of groundwater supply in the San Gorgonio Pass region. To better manage the water supplies within the District during wet and dry periods, the SGWD sought to develop a groundwater recharge program, whereby, excess water would be stored in underground aquifers during wet periods (principally winter months) and retrieved during dry periods (principally summer months). The SGWD preferred a surface recharge approach because it could be less expensive than a

Paleogeomorphology of the early Colorado River inferred from relationships in Mohave and Cottonwood Valleys, Arizona, California and Nevada

USGS Publications Warehouse

Pearthree, Philip; House, P. Kyle

2014-01-01

Geologic investigations of late Miocene–early Pliocene deposits in Mohave and Cottonwood valleys provide important insights into the early evolution of the lower Colorado River system. In the latest Miocene these valleys were separate depocenters; the floor of Cottonwood Valley was ∼200 m higher than the floor of Mohave Valley. When Colorado River water arrived from the north after 5.6 Ma, a shallow lake in Cottonwood Valley spilled into Mohave Valley, and the river then filled both valleys to ∼560 m above sea level (asl) and overtopped the bedrock divide at the southern end of Mohave Valley. Sediment-starved water spilling to the south gradually eroded the outlet as siliciclastic Bouse deposits filled the lake upstream. When sediment accumulation reached the elevation of the lowering outlet, continued erosion of the outlet resulted in recycling of stored lacustrine sediment into downstream basins; depth of erosion of the outlet and upstream basins was limited by the water levels in downstream basins. The water level in the southern Bouse basin was ∼300 m asl (modern elevation) at 4.8 Ma. It must have drained and been eroded to a level <150 m asl soon after that to allow for deep erosion of bedrock divides and basins upstream, leading to removal of large volumes of Bouse sediment prior to massive early Pliocene Colorado River aggradation. Abrupt lowering of regional base level due to spilling of a southern Bouse lake to the Gulf of California could have driven observed upstream river incision without uplift. Rapid uplift of the entire region immediately after 4.8 Ma would have been required to drive upstream incision if the southern Bouse was an estuary.

Status of groundwater quality in the Southern, Middle, and Northern Sacramento Valley study units, 2005-08: California GAMA Priority Basin Project

USGS Publications Warehouse

Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth

2011-01-01

Groundwater quality in the Southern, Middle, and Northern Sacramento Valley study units was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study units are located in California's Central Valley and include parts of Butte, Colusa, Glenn, Placer, Sacramento, Shasta, Solano, Sutter, Tehama, Yolo, and Yuba Counties. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The three study units were designated to provide spatially-unbiased assessments of the quality of untreated groundwater in three parts of the Central Valley hydrogeologic province, as well as to provide a statistically consistent basis for comparing water quality regionally and statewide. Samples were collected in 2005 (Southern Sacramento Valley), 2006 (Middle Sacramento Valley), and 2007-08 (Northern Sacramento Valley). The GAMA studies in the Southern, Middle, and Northern Sacramento Valley were designed to provide statistically robust assessments of the quality of untreated groundwater in the primary aquifer systems that are used for drinking-water supply. The assessments are based on water-quality data collected by the USGS from 235 wells in the three study units in 2005-08, and water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer systems (hereinafter, referred to as primary aquifers) assessed in this study are defined by the depth intervals of the wells in the CDPH database for each study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from quality of groundwater in the primary aquifers; shallow groundwater may be more vulnerable to contamination from the surface. The status of the current quality of the groundwater resource was assessed by using data from samples analyzed for volatile organic

A conceptual ground-water-quality monitoring network for San Fernando Valley, California

USGS Publications Warehouse

Setmire, J.G.

1985-01-01

A conceptual groundwater-quality monitoring network was developed for San Fernando Valley to provide the California State Water Resources Control Board with an integrated, basinwide control system to monitor the quality of groundwater. The geology, occurrence and movement of groundwater, land use, background water quality, and potential sources of pollution were described and then considered in designing the conceptual monitoring network. The network was designed to monitor major known and potential point and nonpoint sources of groundwater contamination over time. The network is composed of 291 sites where wells are needed to define the groundwater quality. The ideal network includes four specific-purpose networks to monitor (1) ambient water quality, (2) nonpoint sources of pollution, (3) point sources of pollution, and (4) line sources of pollution. (USGS)

Integration of AIRSAR and AVIRIS data for Trail Canyon alluvial fan, Death Valley, California

NASA Technical Reports Server (NTRS)

Kierein-Young, Kathryn S.

1995-01-01

Combining quantitative geophysical information extracted from the optical and microwave wavelengths provides complementary information about both the surface mineralogy and morphology. This study combines inversion results from two remote sensing instruments, a polarimetric synthetic aperture radar, AIRSAR, and an imaging spectrometer, AVIRIS, for Trail Canyon alluvial fan in Death Valley, California. The NASA/JPL Airborne Synthetic Aperture Radar (AIRSAR) is a quad-polarization, three frequency instrument. AIRSAR collects data at C-band = 5.66 cm, L-band = 23.98 cm, and P-band = 68.13 cm. The data are processed to four-looks and have a spatial resolution of 10 m and a swath width of 12 km. The AIRSAR data used in this study were collected as part of the Geologic Remote Sensing Field Experiment (GRSFE) over Death Valley on 9/14/89. The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) is a NASA/JPL instrument that flies in an ER-2 aircraft at an altitude of 20 km. AVIRIS uses four spectrometers to collect data in 224 spectral channels from 0.4 micrometer to 2.45 micrometer. The width of each spectral band is approximately 10 nm. AVIRIS collects data with a swath width of 11 km and a pixel size of 20 m. The AVIRIS data used in this study were collected over Death Valley on 5/31/92.

Terrestrial Cosmogenic-Nuclide Dating of Alluvial Fans in Death Valley, California

USGS Publications Warehouse

Machette, Michael N.; Slate, Janet L.; Phillips, Fred M.

2008-01-01

We have used terrestrial cosmogenic nuclides (TCN) to establish the age of some of the most extensive Quaternary alluvial fans in Death Valley, California. These intermediate-age alluvial fans are most extensive on the western side of the valley, where tectonic deformation is considerably less pronounced than on the eastern side of the valley. These fans are characterized by a relatively smooth, densely packed desert pavement formed by well-varnished (blackened) clasts. These surfaces have been mapped as the Q2 gravel by previous workers and as unit Qai (intermediate age) by us. However, the intermediate-age gravels probably contain multiple subunits, as evidenced by slight differences in morphologic expression, soil formation, and inset geomorphic relations. The TCN technique used herein sums the cosmogenic 36Cl in approximately 2.5-meter-deep profiles through soil and host alluvium, thus avoiding some of the problems associated with the more typical surface-exposure dating of boulders or smaller clasts. Our TCN 36Cl dating of 12 depth profiles indicates that these intermediate-age (Qai) alluvial fans range from about 100 to 40 kilo-annum (ka), with a mean age of about 70 ka. An alternative interpretation is that alluvial unit Qai was deposited in two discrete episodes from 90 to 80 ka and from 60 to 50 ka, before and after MIS (marine oxygen-isotope stage) 4 (respectively). Without an intermediate-age unit, such as MIS 4 lake deposits, we can neither disprove nor prove that Qai was deposited in two discrete intervals or over a longer range of time. Thus, in Death Valley, alluvial unit Qai largely brackets MIS 4, which is not associated with a deep phase of Lake Manly. These Qai fans extend to elevations of about -46 meters (150 feet below sea level) and have not been transgressed by Lake Manly, suggesting that MIS 4 or MIS 2 lakes were rather shallow in Death Valley, perhaps because they lacked inflow from surface runoff of the Sierra Nevada drainages through

Structural and lithologic study of northern coast ranges and Sacramento Valley, California

NASA Technical Reports Server (NTRS)

Rich, E. I. (Principal Investigator)

1973-01-01

The author has identified the following significant results. The pattern of linear systems within the project area has been extended into the western foothill belt of the Sierra Nevada. The chief pattern of linear features in the western Sierran foothill belt trends about N. 10 - 15 deg W., but in the vicinity of the Feather River the trend of the features abruptly changes to about N. 50-60 deg W and appears to be contiguous across the Sacramento Valley with a similar system of linear features in the Coast Ranges. The linear features in the Modoc Plateau and Klamath Mt. areas appear unrelated to the systems detected in the Coast Ranges of Sierran foothill belt. Although the change in trend of the Sierran structural features has been previously suggested and the interrelationship of the Klamath Mt. region with the northern Sierra Nevadas has been postulated, the data obtained from the ERTS-1 imagery strengthens these notions and provides for the first time evidence of a direct connection of the structural trends within the alluviated part of the Sacramento Valley. In addition rocks of Pleistocene and Holocene age are offset by some of the linear features seen on ERTS-1 imagery and hence may record the latest episode of geologic deformation in north-central California.

Interbasin flow in the Great Basin with special reference to the southern Funeral Mountains and the source of Furnace Creek springs, Death Valley, California, U.S.

USGS Publications Warehouse

Belcher, W.R.; Bedinger, M.S.; Back, J.T.; Sweetkind, D.S.

2009-01-01

Interbasin flow in the Great Basin has been established by scientific studies during the past century. While not occurring uniformly between all basins, its occurrence is common and is a function of the hydraulic gradient between basins and hydraulic conductivity of the intervening rocks. The Furnace Creek springs in Death Valley, California are an example of large volume springs that are widely accepted as being the discharge points of regional interbasin flow. The flow path has been interpreted historically to be through consolidated Paleozoic carbonate rocks in the southern Funeral Mountains. This work reviews the preponderance of evidence supporting the concept of interbasin flow in the Death Valley region and the Great Basin and addresses the conceptual model of pluvial and recent recharge [Nelson, S.T., Anderson, K., Mayo, A.L., 2004. Testing the interbasin flow hypothesis at Death Valley, California. EOS 85, 349; Anderson, K., Nelson, S., Mayo, A., Tingey, D., 2006. Interbasin flow revisited: the contribution of local recharge to high-discharge springs, Death Valley, California. Journal of Hydrology 323, 276-302] as the source of the Furnace Creek springs. We find that there is insufficient modern recharge and insufficient storage potential and permeability within the basin-fill units in the Furnace Creek basin for these to serve as a local aquifer. Further, the lack of high sulfate content in the spring waters argues against significant flow through basin-fill sediments and instead suggests flow through underlying consolidated carbonate rocks. The maximum temperature of the spring discharge appears to require deep circulation through consolidated rocks; the Tertiary basin fill is of insufficient thickness to generate such temperatures as a result of local fluid circulation. Finally, the stable isotope data and chemical mass balance modeling actually support the interbasin flow conceptual model rather than the alternative presented in Nelson et al. [Nelson

Hydraulic and mechanical properties affecting ground-water flow and aquifer-system compaction, San Joaquin Valley, California

USGS Publications Warehouse

Sneed, Michelle

2001-01-01

This report summarizes hydraulic and mechanical properties affecting ground-water flow and aquifer-system compaction in the San Joaquin Valley, a broad alluviated intermontane structural trough that constitutes the southern two-thirds of the Central Valley of California. These values will be used to constrain a coupled ground-water flow and aquifer-system compaction model of the western San Joaquin Valley called WESTSIM. A main objective of the WESTSIM model is to evaluate potential future land subsidence that might occur under conditions in which deliveries of imported surface water for agricultural use are reduced and ground-water pumping is increased. Storage values generally are components of the total aquifer-system storage and include inelastic and elastic skeletal storage values of the aquifers and the aquitards that primarily govern the potential amount of land subsidence. Vertical hydraulic conductivity values generally are for discrete thicknesses of sediments, usually aquitards, that primarily govern the rate of land subsidence. The data were compiled from published sources and include results of aquifer tests, stress-strain analyses of borehole extensometer observations, laboratory consolidation tests, and calibrated models of aquifer-system compaction.

Geohydrology of the Antelope Valley Area, California and design for a ground-water-quality monitoring network

USGS Publications Warehouse

Duell, L.F.

1987-01-01

A basinwide ideal network and an actual network were designed to identify ambient groundwater quality, trends in groundwater quality, and degree of threat from potential pollution sources in Antelope Valley, California. In general, throughout the valley groundwater quality has remained unchanged, and no specific trends are apparent. The main source of groundwater for the valley is generally suitable for domestic, irrigation, and most industrial uses. Water quality data for selected constituents of some network wells and surface-water sites are presented. The ideal network of 77 sites was selected on the basis of site-specific criteria, geohydrology, and current land use (agricultural, residential, and industrial). These sites were used as a guide in the design of the actual network consisting of 44 existing wells. Wells are currently being monitored and were selected whenever possible because of budgetary constraints. Of the remaining ideal sites, 20 have existing wells not part of a current water quality network, and 13 are locations where no wells exist. The methodology used for the selection of sites, constituents monitored, and frequency of analysis will enable network users to make appropriate future changes to the monitoring network. (USGS)

A summary of ground-water pumpage in the Central Valley, California, 1961-77

USGS Publications Warehouse

Diamond, Jonathan; Williamson, A.K.

1983-01-01

In the Central Valley of California, a great agricultural economy has been developed in a semiarid environment. This economy is supported by imported surface water and 9 to 15 million acre-feet per year of ground water. Estimates of ground-water pumpage computed from power consumption have been compiled and summarized. Under ideal conditions, the accuracy of the methods used is about 3 percent. This level of accuracy is not sustained over the entire study area. When pumpage for the entire area is mapped, the estimates seem to be consistent areally and through time. A multiple linear-regression model was used to synthesize data for the years 1961 through 1977, when power data were not available. The model used a relation between ground-water pumpage and climatic indexes to develop a full suite of pumpage data to be used as input to a digital ground-water model, one of the products of the Central Valley Aquifer Project. Statistical analysis of well-perforation data from drillers ' logs and water-temperature data was used to determine the percentage of pumpage that was withdrawn from each of two horizontal layers. (USGS)

Geologic map of the Lockwood Valley Quadrangle, Ventura County, California

USGS Publications Warehouse

Kellogg, Karl S.

2001-01-01

The Lockwood Valley quadrangle is located in the western Transverse Ranges of California, about 10 km southwest of Frazier Park. It includes the western flank of Frazier Mountain, southern Lockwood Valley, and a region of the Los Padres National Forest near northern Piru Creek. The oldest rocks are mostly biotite augen gneiss, in the hanging wall of the Frazier Mountain thrust and in a large body south of the thrust. A U-Pb zircon age for the gneiss is 1690+5 Ma (W. Premo, unpublished data). Two Cretaceous intrusive rocks are named the quartz monzonite of Sheep Creek and the coarse-grained granodiorite of Lockwood Peak. A U-Pb zircon age on the latter is 76.05+0.22 Ma (W. Premo, unpublished data). The northeastern edge of a large Eocene marine basin, comprising the sandstones, shales, and conglomerates of the Juncal Formation, occupies the southwestern 25 percent of the quadrangle. Miocene fluvial rocks, including coarse boulder conglomerates, sandstones, and shale, of the Caliente Formation crop out mostly in the northwestern part of the quadrangle. Commercially exploitable Lockwood Clay unconformably overlies the Caliente, which, in turn, is overlain by the mostly fluvial Pliocene Quatal Formation. Two major south-directed thrusts, the Frazier Mountain thrust and the South Frazier Mountain thrust, place crystalline rocks over Miocene and Pliocene sedimentary rocks. The South Frazier Mountain thrust is transected by the newly recognized, north-directed Lockwood Peak reverse fault. In addition, the newly recognized south-directed Yellowjacket thrust displaces rocks of the Pliocene Quatal Formation.

Late Cenozoic geology and lacustrine history of Searles Valley, Inyo and San Bernardino Counties, California

NASA Astrophysics Data System (ADS)

Nathenson, M.; Smith, G. I.; Robinson, J. E.; Stauffer, P. H.; Zigler, J. L.

2010-12-01

George Smith’s career-long study of the surface geology of the Searles Valley was recently published by the USGS (Smith, 2009, online and printed). The co-authors of this abstract are the team responsible for completing the publication from the original materials. Searles Valley is an arid, closed basin lying 70 km east of the south end of the Sierra Nevada, California. During those parts of late Pliocene and Pleistocene time when precipitation and runoff from the east side of the Sierra Nevada into the Owens River were much greater than at present, a chain of as many as five large lakes was created, of which Searles Lake was third. The stratigraphic record left in Searles Valley when that lake expanded, contracted, or desiccated is fully revealed by cores taken from beneath the surface of Searles (dry) Lake and partly recorded by sediments cropping out around the edge of the valley. Although this outcrop record is discontinuous, it provides direct evidence of the lake’s water depths during each expansion, which the subsurface record does not. Maximum-depth lakes rose to the 2,280-ft (695 m) contour, the level of the spillway that led overflowing waters to Panamint Valley; that spillway is about 660 ft (200 m) above the present dry-lake surface. Most of this study concerns sediments of the newly described Searles Lake Formation, whose deposition spanned the period between about 150 ka and 2 ka. The outcrop record is documented in six geologic maps (scales: 1:50,000 and 1:10,000). The Searles Lake Formation is divided into seven main units. The depositional intervals of the units that make up the Searles Lake Formation are determined primarily by correlation with subsurface deposits that are dated by radiocarbon ages on organic carbon and U-series dates on salts. Shorelines, the most obvious geologic expressions of former lakes, are abundant around Searles Valley. Erosional shorelines have cut as much as 100 m into brecciated bedrock; depositional shorelines

Crustal Spreading in Southern California: The Imperial Valley and the Gulf of California formed by the rifting apart of a continental plate.

PubMed

Elders, W A; Rex, R W; Robinson, P T; Biehler, S; Meidav, T

1972-10-06

The current excitement among geologists and geophysicists stemming from the "new global tectonics" has led to a widespread, speculative reinterpretation of continental geology. The Gulf of California and its continuation into the Imperial Valley provide an excellent opportunity for studying the border zone between the North American and Pacific plates, and an interface of continental and oceanic tectonics. The Salton trough, the landward extension of the gulf, is a broad structural depression, comparable in size with the deeper marine basins of the southern part of the gulf, but here partially filled with sediments deposited by the Colorado River.

Space Radar Image of Long Valley, California -Interferometry/Topography

NASA Image and Video Library

1999-05-01

These four images of the Long Valley region of east-central California illustrate the steps required to produced three dimensional data and topographics maps from radar interferometry. All data displayed in these images were acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour during its two flights in April and October, 1994. The image in the upper left shows L-band (horizontally transmitted and received) SIR-C radar image data for an area 34 by 59 kilometers (21 by 37 miles). North is toward the upper right; the radar illumination is from the top of the image. The bright areas are hilly regions that contain exposed bedrock and pine forest. The darker gray areas are the relatively smooth, sparsely vegetated valley floors. The dark irregular patch near the lower left is Lake Crowley. The curving ridge that runs across the center of the image from top to bottom is the northeast rim of the Long Valley Caldera, a remnant crater from a massive volcanic eruption that occurred about 750,000 years ago. The image in the upper right is an interferogram of the same area, made by combining SIR-C L-band data from the April and October flights. The colors in this image represent the difference in the phase of the radar echoes obtained on the two flights. Variations in the phase difference are caused by elevation differences. Formation of continuous bands of phase differences, known as interferometric "fringes," is only possible if the two observations were acquired from nearly the same position in space. For these April and October data takes, the shuttle tracks were less than 100 meters (328 feet) apart. The image in the lower left shows a topographic map derived from the interferometric data. The colors represent increments of elevation, as do the thin black contour lines, which are spaced at 50-meter (164-foot) elevation intervals. Heavy contour lines show 250-meter intervals (820-foot). Total relief in

Geology, tephrochronology, radiometric ages, and cross sections of the Mark West Springs 7.5' quadrangle, Sonoma and Napa counties, California

USGS Publications Warehouse

McLaughlin, R.J.; Sarna-Wojicki, A. M.; Fleck, R.J.; Wright, W.H.; Levin, V.R.G.; Valin, Z.C.

2004-01-01

The purpose of this geologic map is to provide a context within which to interpret the Neogene evolution of the active strike-slip fault system traversing the Mark West Springs 7.5' quadrangle and adjacent areas. Based on this geologic framework, the timing and total amounts of displacement and the Neogene rates of slip for faults of the right-stepover area between the Healdsburg and Maacama Faults are addressed.The Mark West Springs quadrangle is located in the northern California Coast Ranges north of San Francisco Bay. It is underlain by Mesozoic rocks of the Franciscan Complex, the Coast Range ophiolite, and the Great Valley sequence, considered here to be the pre-Tertiary basement of the northern Coast Ranges. These rocks are overlain by a complexly interstratified and mildly to moderately deformed sequence of Pleistocene to late Miocene marine and nonmarine sedimentary and largely subaerial volcanic rocks. These rocks and unconformably overlying, less-deformed Holocene and Pleistocene strata are cut by the active right-lateral Healdsburg and Maacama Fault Zones.Mapping of the Mark West Springs quadrangle began in 1996 and was completed in October 2002. Most of the mapping presented here is original, although a few other sources of existing geologic mapping were also utilized. Funding for the project was provided by the National Cooperative Geologic Mapping and Earthquake Hazards Reduction programs of the U.S. Geological Survey, in cooperation with geologic hazards mapping investigations of the California Geological Survey.

Effects of the Structure of Water Rights on Agricultural Production During Drought: A Spatiotemporal Analysis of California's Central Valley

NASA Astrophysics Data System (ADS)

Nelson, K. S.; Burchfield, E. K.

2017-10-01

California's Central Valley region has been called the "bread-basket" of the United States. The region is home to one of the most productive agricultural systems on the planet. Such high levels of agricultural productivity require large amounts of fresh water for irrigation. However, the long-term availability of water required to sustain high levels of agricultural production is being called into question following the latest drought in California. In this paper, we use Bayesian multilevel spatiotemporal modeling techniques to examine the influence of the structure of surface water rights in the Central Valley on agricultural production during the recent drought. California is an important place to study these dynamics as it is the only state to recognize the two dominant approaches to surface water management in the United States: riparian and appropriative rights. In this study, Bayesian spatiotemporal modeling is employed to account for spatial processes that have the potential to influence the effects of water right structures on agricultural production. Results suggest that, after accounting for spatiotemporal dependencies in the data, seniority in surface water access significantly improves crop health and productivity on cultivated lands but does not independently affect the ability to maintain cultivated extent. In addition, agricultural productivity in watersheds with more junior surface water rights shows less sensitivity to cumulative drought exposure than other watersheds, however the extent of cultivation in these same watersheds is relatively more sensitive to cumulative drought exposure.

Pliocene transpressional modification of depositional basins by convergent thrusting adjacent to the "Big Bend" of the San Andreas fault: An example from Lockwood Valley, southern California

USGS Publications Warehouse

Kellogg, K.S.; Minor, S.A.

2005-01-01

The "Big Bend" of the San Andreas fault in the western Transverse Ranges of southern California is a left stepping flexure in the dextral fault system and has long been recognized as a zone of relatively high transpression compared to adjacent regions. The Lockwood Valley region, just south of the Big Bend, underwent a profound change in early Pliocene time (???5 Ma) from basin deposition to contraction, accompanied by widespread folding and thrusting. This change followed the recently determined initiation of opening of the northern Gulf of California and movement along the southern San Andreas fault at about 6.1 Ma, with the concomitant formation of the Big Bend. Lockwood Valley occupies a 6-km-wide, fault-bounded structural basin in which converging blocks of Paleoproterozoic and Cretaceous crystalline basement and upper Oligocene and lower Miocene sedimentary rocks (Plush Ranch Formation) were thrust over Miocene and Pliocene basin-fill sedimentary rocks (in ascending order, Caliente Formation, Lockwood Clay, and Quatal Formation). All the pre-Quatal sedimentary rocks and most of the Pliocene Quatal Formation were deposited during a mid-Tertiary period of regional transtension in a crustal block that underwent little clockwise vertical-axis rotation as compared to crustal blocks to the south. Ensuing Pliocene and Quaternary transpression in the Big Bend region began during deposition of the poorly dated Quatal Formation and was marked by four converging thrust systems, which decreased the areal extent of the sedimentary basin and formed the present Lockwood Valley structural basin. None of the thrusts appears presently active. Estimated shortening across the center of the basin was about 30 percent. The fortnerly defined eastern Big Pine fault, now interpreted to be two separate, oppositely directed, contractional reverse or thrust faults, marks the northwestern structural boundary of Lockwood Valley. The complex geometry of the Lockwood Valley basin is similar

Modeling applications for precision agriculture in the California Central Valley

NASA Astrophysics Data System (ADS)

Marklein, A. R.; Riley, W. J.; Grant, R. F.; Mezbahuddin, S.; Mekonnen, Z. A.; Liu, Y.; Ying, S.

2017-12-01

Drought in California has increased the motivation to develop precision agriculture, which uses observations to make site-specific management decisions throughout the growing season. In agricultural systems that are prone to drought, these efforts often focus on irrigation efficiency. Recent improvements in soil sensor technology allow the monitoring of plant and soil status in real-time, which can then inform models aimed at improving irrigation management. But even on farms with resources to deploy soil sensors across the landscape, leveraging that sensor data to design an efficient irrigation scheme remains a challenge. We conduct a modeling experiment aimed at simulating precision agriculture to address several questions: (1) how, when, and where does irrigation lead to optimal yield? and (2) What are the impacts of different precision irrigation schemes on yields, soil organic carbon (SOC), and total water use? We use the ecosys model to simulate precision agriculture in a conventional tomato-corn rotation in the California Central Valley with varying soil water content thresholds for irrigation and soil water sensor depths. This model is ideal for our question because it includes explicit process-based functions for the plant growth, plant water use, soil hydrology, and SOC, and has been tested extensively in agricultural ecosystems. Low irrigation thresholds allows the soil to become drier before irrigating compared to high irrigation thresholds; as such, we found that the high irrigation thresholds use more irrigation over the course of the season, have higher yields, and have lower water use efficiency. The irrigation threshold did not affect SOC. Yields and water use are highest at sensor depths of 0.5 to 0.15 m, but water use efficiency was also lowest at these depths. We found SOC to be significantly affected by sensor depth, with the highest SOC at the shallowest sensor depths. These results will help regulate irrigation water while maintaining yield

Continuity of the West Napa–Franklin fault zone inferred from guided waves generated by earthquakes following the 24 August 2014 Mw 6.0 South Napa earthquake

USGS Publications Warehouse

Catchings, Rufus D.; Goldman, Mark R.; Li, Yong-Gang; Chan, Joanne

2016-01-01

We measure peak ground velocities from fault‐zone guided waves (FZGWs), generated by on‐fault earthquakes associated with the 24 August 2014 Mw 6.0 South Napa earthquake. The data were recorded on three arrays deployed across north and south of the 2014 surface rupture. The observed FZGWs indicate that the West Napa fault zone (WNFZ) and the Franklin fault (FF) are continuous in the subsurface for at least 75 km. Previously published potential‐field data indicate that the WNFZ extends northward to the Maacama fault (MF), and previous geologic mapping indicates that the FF extends southward to the Calaveras fault (CF); this suggests a total length of at least 110 km for the WNFZ–FF. Because the WNFZ–FF appears contiguous with the MF and CF, these faults apparently form a continuous Calaveras–Franklin–WNFZ–Maacama (CFWM) fault that is second only in length (∼300  km) to the San Andreas fault in the San Francisco Bay area. The long distances over which we observe FZGWs, coupled with their high amplitudes (2–10 times the S waves) suggest that strong shaking from large earthquakes on any part of the CFWM fault may cause far‐field amplified fault‐zone shaking. We interpret guided waves and seismicity cross sections to indicate multiple upper crustal splays of the WNFZ–FF, including a northward extension of the Southhampton fault, which may cause strong shaking in the Napa Valley and the Vallejo area. Based on travel times from each earthquake to each recording array, we estimate average P‐, S‐, and guided‐wave velocities within the WNFZ–FF (4.8–5.7, 2.2–3.2, and 1.1–2.8  km/s, respectively), with FZGW velocities ranging from 58% to 93% of the average S‐wave velocities.

Assessment of Climate Change Impacts on Agricultural Water Demands and Crop Yields in California's Central Valley

NASA Astrophysics Data System (ADS)

Tansey, M. K.; Flores-Lopez, F.; Young, C. A.; Huntington, J. L.

2012-12-01

Long term planning for the management of California's water resources requires assessment of the effects of future climate changes on both water supply and demand. Considerable progress has been made on the evaluation of the effects of future climate changes on water supplies but less information is available with regard to water demands. Uncertainty in future climate projections increases the difficulty of assessing climate impacts and evaluating long range adaptation strategies. Compounding the uncertainty in the future climate projections is the fact that most readily available downscaled climate projections lack sufficient meteorological information to compute evapotranspiration (ET) by the widely accepted ASCE Penman-Monteith (PM) method. This study addresses potential changes in future Central Valley water demands and crop yields by examining the effects of climate change on soil evaporation, plant transpiration, growth and yield for major types of crops grown in the Central Valley of California. Five representative climate scenarios based on 112 bias corrected spatially downscaled CMIP 3 GCM climate simulations were developed using the hybrid delta ensemble method to span a wide range future climate uncertainty. Analysis of historical California Irrigation Management Information System meteorological data was combined with several meteorological estimation methods to compute future solar radiation, wind speed and dew point temperatures corresponding to the GCM projected temperatures and precipitation. Future atmospheric CO2 concentrations corresponding to the 5 representative climate projections were developed based on weighting IPCC SRES emissions scenarios. The Land, Atmosphere, and Water Simulator (LAWS) model was used to compute ET and yield changes in the early, middle and late 21st century for 24 representative agricultural crops grown in the Sacramento, San Joaquin and Tulare Lake basins. Study results indicate that changes in ET and yield vary

Regional variations in water quality and relationships to soil and bedrock weathering in the southern Sacramento Valley, California, USA

USGS Publications Warehouse

Wanty, R.B.; Goldhaber, M.B.; Morrison, J.M.; Lee, L.

2009-01-01

Regional patterns in ground- and surface-water chemistry of the southern Sacramento Valley in California were evaluated using publicly available geochemical data from the US Geological Survey's National Water Information System (NWIS). Within the boundaries of the study area, more than 2300 ground-water analyses and more than 20,000 surface-water analyses were available. Ground-waters from the west side of the Sacramento Valley contain greater concentrations of Na, Ca, Mg, B, Cl and SO4, while the east-side ground-waters contain greater concentrations of silica and K. These differences result from variations in surface-water chemistry as well as from chemical reactions between water and aquifer materials. Sediments that fill the Sacramento Valley were derived from highlands to the west (the Coast Ranges) and east (the Sierra Nevada Mountains), the former having an oceanic provenance and the latter continental. These geologic differences are at least in part responsible for the observed patterns in ground-water chemistry. Thermal springs that are common along the west side of the Sacramento Valley appear to have an effect on surface-water chemistry, which in turn may affect the ground-water chemistry.

Mediterranean California, Chapter 13

Treesearch

M.E. Fenn; E.B. Allen; L.H. Geiser

2011-01-01

The Mediterranean California ecoregion (CEC 1997; Fig 2.2) encompasses the greater Central Valley, Sierra foothills, and central coast ranges of California south to Mexico and is bounded by the Pacific Ocean, Sierra Nevada Mountains and Mojave Desert.

High-resolution three-dimensional imaging and analysis of rock falls in Yosemite valley, California

USGS Publications Warehouse

Stock, Gregory M.; Bawden, G.W.; Green, J.K.; Hanson, E.; Downing, G.; Collins, B.D.; Bond, S.; Leslar, M.

2011-01-01

We present quantitative analyses of recent large rock falls in Yosemite Valley, California, using integrated high-resolution imaging techniques. Rock falls commonly occur from the glacially sculpted granitic walls of Yosemite Valley, modifying this iconic landscape but also posing signifi cant potential hazards and risks. Two large rock falls occurred from the cliff beneath Glacier Point in eastern Yosemite Valley on 7 and 8 October 2008, causing minor injuries and damaging structures in a developed area. We used a combination of gigapixel photography, airborne laser scanning (ALS) data, and ground-based terrestrial laser scanning (TLS) data to characterize the rock-fall detachment surface and adjacent cliff area, quantify the rock-fall volume, evaluate the geologic structure that contributed to failure, and assess the likely failure mode. We merged the ALS and TLS data to resolve the complex, vertical to overhanging topography of the Glacier Point area in three dimensions, and integrated these data with gigapixel photographs to fully image the cliff face in high resolution. Three-dimensional analysis of repeat TLS data reveals that the cumulative failure consisted of a near-planar rock slab with a maximum length of 69.0 m, a mean thickness of 2.1 m, a detachment surface area of 2750 m2, and a volume of 5663 ?? 36 m3. Failure occurred along a surfaceparallel, vertically oriented sheeting joint in a clear example of granitic exfoliation. Stress concentration at crack tips likely propagated fractures through the partially attached slab, leading to failure. Our results demonstrate the utility of high-resolution imaging techniques for quantifying far-range (>1 km) rock falls occurring from the largely inaccessible, vertical rock faces of Yosemite Valley, and for providing highly accurate and precise data needed for rock-fall hazard assessment. ?? 2011 Geological Society of America.

76 FR 41337 - Approval and Promulgation of Implementation Plans; California; 2008 San Joaquin Valley PM2.5

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-13

...EPA is proposing to approve in part and disapprove in part state implementation plan (SIP) revisions submitted by California to provide for attainment of the 1997 fine particulate matter (PM2.5) national ambient air quality standards in the San Joaquin Valley (SJV). These SIP revisions are the SJV 2008 PM2.5 Plan (revised 2010 and 2011) and SJV-related provisions of the 2007 State Strategy (revised 2009 and 2011). EPA is proposing to approve the emissions inventories; air quality modeling; the reasonably available control measures/reasonably available control technology, reasonable further progress, and attainment demonstrations; and the transportation conformity motor vehicle emissions budgets. EPA is also proposing to grant California's request to extend the attainment deadline for the SJV to April 5, 2015 and to approve commitments to measures and reductions by the SJV Air Pollution Control District and the California Air Resources Board. Finally, it is proposing to disapprove the SIP's contingency measures. This proposed rule amends EPA's November 30, 2010 proposed rule (75 FR 74518) on the SJV 2008 PM2.5 Plan and 2007 State Strategy.

Groundwater quality in the shallow aquifers of the Madera–Chowchilla and Kings subbasins, San Joaquin Valley, California

USGS Publications Warehouse

Fram, Miranda S.; Shelton, Jennifer L.

2018-01-08

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Program’s Priority Basin Project assesses the quality of groundwater resources used for drinking-water supply and increases public access to groundwater-quality information. Many households and small communities in the Madera– Chowchilla and Kings subbasins of the San Joaquin Valley rely on private domestic wells for their drinking-water supplies.

Three-dimensional electrical resistivity model of the hydrothermal system in Long Valley Caldera, California, from magnetotellurics

USGS Publications Warehouse

Peacock, Jared R.; Mangan, Margaret T.; McPhee, Darcy K.; Wannamaker, Phil E.

2016-01-01

Though shallow flow of hydrothermal fluids in Long Valley Caldera, California, has been well studied, neither the hydrothermal source reservoir nor heat source has been well characterized. Here a grid of magnetotelluric data were collected around the Long Valley volcanic system and modeled in 3-D. The preferred electrical resistivity model suggests that the source reservoir is a narrow east-west elongated body 4 km below the west moat. The heat source could be a zone of 2–5% partial melt 8 km below Deer Mountain. Additionally, a collection of hypersaline fluids, not connected to the shallow hydrothermal system, is found 3 km below the medial graben, which could originate from a zone of 5–10% partial melt 8 km below the south moat. Below Mammoth Mountain is a 3 km thick isolated body containing fluids and gases originating from an 8 km deep zone of 5–10% basaltic partial melt.

Dissolved-selenium data for wells in the western San Joaquin Valley, California, February to July 1985

USGS Publications Warehouse

Neil, J.M.

1986-01-01

Water samples were collected for selenium analysis from 63 wells in western San Joaquin Valley, California, during February to July 1985. Results of the data collection indicate that dissolved selenium concentrations ranged from less than 1 to 120 micrograms per liter; more than 50 percent of the wells sampled had concentrations of less than 1 microgram per liter. Four additional samples collected from public supply wells in the western valley had concentrations ranging from less than 1 to 2 micrograms per liter. All samples from five public supply wells east of the study area had concentrations less than 1 microgram per liter. The U.S. Environmental Protection Agency 's drinking-water standard of 10 micrograms per liter for selenium was slightly exceeded in 2 of 39 domestic wells (11 and 13 micrograms per liter) and substantially exceeded in 2 of 11 irrigation and agricultural wells (55 and 120 micrograms per liter). (USGS)

Seismic calibration shots conducted in 2009 in the Imperial Valley, southern California, for the Salton Seismic Imaging Project (SSIP)

USGS Publications Warehouse

Murphy, Janice; Goldman, Mark; Fuis, Gary; Rymer, Michael; Sickler, Robert; Miller, Summer; Butcher, Lesley; Ricketts, Jason; Criley, Coyn; Stock, Joann; Hole, John; Chavez, Greg

2011-01-01

Rupture of the southern section of the San Andreas Fault, from the Coachella Valley to the Mojave Desert, is believed to be the greatest natural hazard facing California in the near future. With an estimated magnitude between 7.2 and 8.1, such an event would result in violent shaking, loss of life, and disruption of lifelines (freeways, aqueducts, power, petroleum, and communication lines) that would bring much of southern California to a standstill. As part of the Nation's efforts to prevent a catastrophe of this magnitude, a number of projects are underway to increase our knowledge of Earth processes in the area and to mitigate the effects of such an event. One such project is the Salton Seismic Imaging Project (SSIP), which is a collaborative venture between the United States Geological Survey (USGS), California Institute of Technology (Caltech), and Virginia Polytechnic Institute and State University (Virginia Tech). This project will generate and record seismic waves that travel through the crust and upper mantle of the Salton Trough. With these data, we will construct seismic images of the subsurface, both reflection and tomographic images. These images will contribute to the earthquake-hazard assessment in southern California by helping to constrain fault locations, sedimentary basin thickness and geometry, and sedimentary seismic velocity distributions. Data acquisition is currently scheduled for winter and spring of 2011. The design and goals of SSIP resemble those of the Los Angeles Region Seismic Experiment (LARSE) of the 1990's. LARSE focused on examining the San Andreas Fault system and associated thrust-fault systems of the Transverse Ranges. LARSE was successful in constraining the geometry of the San Andreas Fault at depth and in relating this geometry to mid-crustal, flower-structure-like decollements in the Transverse Ranges that splay upward into the network of hazardous thrust faults that caused the 1971 M 6.7 San Fernando and 1987 M 5

Land use investigations in the central valley and central coastal test sites, California

NASA Technical Reports Server (NTRS)

Estes, J. E.

1973-01-01

The Geography Remote Sensing Unit (GRSU) at the University of California, Santa Barbara is responsible for investigations with ERTS-1 data in the Central Coastal Zone and West Side of the San Joaquin Valley. The nature of investigative effort involves the inventory, monitoring, and assessment of the natural and cultural resources of the two areas. Land use, agriculture, vegetation, landforms, geology, and hydrology are the principal subjects for attention. These parameters are the key indicators of the dynamically changing character of the areas. Monitoring of these parameters with ERTS-1 data will provide the techniques and methodologies required to generate the information needed by federal, state, county, and local agencies to assess change-related phenomena and plan for management and development.

Keeping the History in Historical Seismology: The 1872 Owens Valley, California Earthquake

NASA Astrophysics Data System (ADS)

Hough, Susan E.

2008-07-01

The importance of historical earthquakes is being increasingly recognized. Careful investigations of key pre-instrumental earthquakes can provide critical information and insights for not only seismic hazard assessment but also for earthquake science. In recent years, with the explosive growth in computational sophistication in Earth sciences, researchers have developed increasingly sophisticated methods to analyze macroseismic data quantitatively. These methodological developments can be extremely useful to exploit fully the temporally and spatially rich information source that seismic intensities often represent. For example, the exhaustive and painstaking investigations done by Ambraseys and his colleagues of early Himalayan earthquakes provides information that can be used to map out site response in the Ganges basin. In any investigation of macroseismic data, however, one must stay mindful that intensity values are not data but rather interpretations. The results of any subsequent analysis, regardless of the degree of sophistication of the methodology, will be only as reliable as the interpretations of available accounts—and only as complete as the research done to ferret out, and in many cases translate, these accounts. When intensities are assigned without an appreciation of historical setting and context, seemingly careful subsequent analysis can yield grossly inaccurate results. As a case study, I report here on the results of a recent investigation of the 1872 Owen's Valley, California earthquake. Careful consideration of macroseismic observations reveals that this event was probably larger than the great San Francisco earthquake of 1906, and possibly the largest historical earthquake in California. The results suggest that some large earthquakes in California will generate significantly larger ground motions than San Andreas fault events of comparable magnitude.

Keeping the History in Historical Seismology: The 1872 Owens Valley, California Earthquake

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hough, Susan E.

2008-07-08

The importance of historical earthquakes is being increasingly recognized. Careful investigations of key pre-instrumental earthquakes can provide critical information and insights for not only seismic hazard assessment but also for earthquake science. In recent years, with the explosive growth in computational sophistication in Earth sciences, researchers have developed increasingly sophisticated methods to analyze macroseismic data quantitatively. These methodological developments can be extremely useful to exploit fully the temporally and spatially rich information source that seismic intensities often represent. For example, the exhaustive and painstaking investigations done by Ambraseys and his colleagues of early Himalayan earthquakes provides information that can bemore » used to map out site response in the Ganges basin. In any investigation of macroseismic data, however, one must stay mindful that intensity values are not data but rather interpretations. The results of any subsequent analysis, regardless of the degree of sophistication of the methodology, will be only as reliable as the interpretations of available accounts - and only as complete as the research done to ferret out, and in many cases translate, these accounts. When intensities are assigned without an appreciation of historical setting and context, seemingly careful subsequent analysis can yield grossly inaccurate results. As a case study, I report here on the results of a recent investigation of the 1872 Owen's Valley, California earthquake. Careful consideration of macroseismic observations reveals that this event was probably larger than the great San Francisco earthquake of 1906, and possibly the largest historical earthquake in California. The results suggest that some large earthquakes in California will generate significantly larger ground motions than San Andreas fault events of comparable magnitude.« less

Tailored nanopost arrays (NAPA) for laser desorption ionization in mass spectrometry

DOEpatents

Vertes, Akos; Walker, Bennett N.; Stolee, Jessica A.; Retterer, Scott T.

2016-11-08

The production and use of semiconducting nanopost arrays made by nanofabrication is described herein. These nanopost arrays (NAPA) provide improved laser ionization yields and controllable fragmentation with switching or modulation capabilities for mass spectrometric detection and identification of samples deposited on them.

Subsurface fault damage zone of the 2014 Mw 6.0 South Napa, California, earthquake viewed from fault‐zone trapped waves

USGS Publications Warehouse

Li, Yong-Gang; Catchings, Rufus D.; Goldman, Mark R.

2016-01-01

The aftershocks of the 24 August 2014 Mw 6.0 South Napa earthquake generated prominent fault‐zone trapped waves (FZTWs) that were recorded on two 1.9‐km‐long seismic arrays deployed across the northern projection (array 1, A1) and the southern part (A2) of the surface rupture of the West Napa fault zone (WNFZ). We also observed FZTWs on an array (A3) deployed across the intersection of the Franklin and Southampton faults, which appear to be the southward continuations of the WNFZ. A1, A2, and A3 consisted of 20, 20, and 10 L28 (4.5 Hz) three‐component seismographs. We analyzed waveforms of FZTWs from 55 aftershocks in both time and frequency to characterize the fault damage zone associated with this Mw 6.0 earthquake. Post‐S coda durations of FZTWs increase with epicentral distances and focal depths from the recording arrays, suggesting a low‐velocity waveguide along the WNFZ to depths in excess of 5–7 km. Locations of the aftershocks showing FZTWs, combined with 3D finite‐difference simulations, suggest the subsurface rupture zone having an S‐wave speed reduction of ∼40%–50% between A1 and A2, coincident with the ∼14‐km‐long mapped surface rupture zone and at least an ∼500‐m‐wide deformation zone. The low‐velocity waveguide along the WNFZ extends further southward to at least A3, but with a more moderate‐velocity reduction of 30%–35% at ray depth. This last FZTW observation suggests continuity between the WNFZ and Franklin fault. The waveguide effect may have localized and amplified ground shaking along the WNFZ and the faults farther to the south (see a companion paper by Catchings et al., 2016).

3D View of Death Valley, California

NASA Technical Reports Server (NTRS)

2000-01-01

This 3-D perspective view looking north over Death Valley, California, was produced by draping ASTER nighttime thermal infrared data over topographic data from the US Geological Survey. The ASTER data were acquired April 7, 2000 with the multi-spectral thermal infrared channels, and cover an area of 60 by 80 km (37 by 50 miles). Bands 13, 12, and 10 are displayed in red, green and blue respectively. The data have been computer enhanced to exaggerate the color variations that highlight differences in types of surface materials. Salt deposits on the floor of Death Valley appear in shades of yellow, green, purple, and pink, indicating presence of carbonate, sulfate, and chloride minerals. The Panamint Mtns. to the west, and the Black Mtns. to the east, are made up of sedimentary limestones, sandstones, shales, and metamorphic rocks. The bright red areas are dominated by the mineral quartz, such as is found in sandstones; green areas are limestones. In the lower center part of the image is Badwater, the lowest point in North America.

Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

The broad spectral coverage and high spectral resolution of ASTER

A plan to study the aquifer system of the Central Valley of California

USGS Publications Warehouse

Bertoldi, Gilbert L.

1979-01-01

Unconsolidated Quaternary alluvial deposits comprise a large complex aquifer system in the Central Valley of California. Millions of acre-feet of water is pumped from the system annually to support a large and expanding agribusiness industry. Since the 1950's, water levels have been steadily declining in many areas of the valley and concern has been expressed about the ability of the entire ground-water system to support agribusiness at current levels, not to mention its ability to function at projected expansion levels. At current levels of ground-water use, an estimated 1.5 to 2 million acre-feet is withdrawn from storage each year; that is, 1.5 to 2 million acre-feet of water is pumped annually in excess of annual replenishment. The U.S. Geological Survey has initiated a 4-year study to develop geologic, hydrologic, and hydraulic information and to establish a valleywide ground-water data base that will be used to build computer models of the ground-water flow system. Subsequently, these models may be used to evaluate the system response to various ground-water management alternatives. This report describes current problems, objectives of the study, and outlines the general work to be accomplished in the study area. A bibliography of about 600 references is included. (Kosco-USGS)

Outdoor air pollution and uncontrolled asthma in the San Joaquin Valley, California.

PubMed

Meng, Ying-Ying; Rull, Rudolph P; Wilhelm, Michelle; Lombardi, Christina; Balmes, John; Ritz, Beate

2010-02-01

The San Joaquin Valley (SJV) in California ranks among the worst in the USA in terms of air quality, and its residents report some of the highest rates of asthma symptoms and asthma-related emergency department (ED) visits and hospitalisations in California. Using California Health Interview Survey data, the authors examined associations between air pollution and asthma morbidity in this region. Eligible subjects were SJV residents (2001 California Health Interview Survey) who reported physician-diagnosed asthma (n=1502, 14.6%). The authors considered two outcomes indicative of uncontrolled asthma: (1) daily or weekly asthma symptoms and (2) asthma-related ED visits or hospitalisation in the past year. Based on residential zip code, subjects were assigned annual average concentrations of ozone, PM(10) and PM(2.5) for the 1-year period prior to the interview date from their closest government air monitoring station within an 8 km (5 miles) radius. Adjusting for age, gender, race/ethnicity, poverty level and insurance status, the authors observed increased odds of experiencing daily or weekly asthma symptoms for ozone, PM(10) and PM(2.5) (OR(ozone) 1.23, 95% CI 0.94 to 1.60 per 10 ppb; OR(PM10) 1.29, 95% CI 1.05 to 1.57 per 10 microg/m(3); and OR(PM2.5) 1.82; 95% CI 1.11 to 2.98 per 10 microg/m(3)). The authors also observed increased odds of asthma-related ED visits or hospitalisations for ozone (OR 1.49, 95% CI 1.05 to 2.11 per 10 ppb) and a 29% increase in odds for PM(10) (OR 1.29, 95% CI 0.99 to 1.69 per 10 microg/m(3)). Overall, these findings suggest that individuals with asthma living in areas of the SJV with high ozone and particulate pollution levels are more likely to have frequent asthma symptoms and asthma-related ED visits and hospitalisations.

A guide for using the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

USGS Publications Warehouse

Blainey, Joan B.; Faunt, Claudia C.; Hill, Mary C.

2006-01-01

This report is a guide for executing numerical simulations with the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California using the U.S. Geological Survey modular finite-difference ground-water flow model, MODFLOW-2000. Model inputs, including observations of hydraulic head, discharge, and boundary flows, are summarized. Modification of the DVRFS transient ground-water model is discussed for two common uses of the Death Valley regional ground-water flow system model: predictive pumping scenarios that extend beyond the end of the model simulation period (1998), and model simulations with only steady-state conditions.

Imperial Valley, California and Mexico as seen from STS-60 Discovery

NASA Image and Video Library

1994-02-09

STS060-93-081 (3-11 Feb 1994)--- The Imperial Valley was documented using three films - color visible (seen here), the American infrared film (Kodak Aerochrome 2443), and the Russian panchromatic infrared film (SN-10). Results of this test still await detailed science analysis. However it does appear that good data was acquired of the region, and this data will be complemented by photography acquired by the Mir cosmonauts. In this frame, the U.S.-Mexico border goes from the upper left to the middle right. It is discernible as a vegetation line between Calexico, California and Mexicali, Mexico. The darker vegetation north of that line is due to different agricultural practices, heavier uses of fertilizers and pesticides, and lined (tiled) agricultural fields allowing subterraneean runoff of saline irrigation runoff. South of the line, the more polluted water draining out of the U.S. agricultural areas into the Mexican area has resulted in higher soil salinities and a consequent reduction in agricultural productivity. At the center of the frame, a large settling and desalinization plant has been built to attempt to purify, to some degree, the polluted irrigation waters draining south out of California. The All-American Canal, which brings in water from the Colorado River (off the frame, to the right), is located in the middle right hand portion of the frame. To the upper left is the normally dry Laguna Salada.

Smart Valley Infrastructure.

ERIC Educational Resources Information Center

Maule, R. William

1994-01-01

Discusses prototype information infrastructure projects in northern California's Silicon Valley. The strategies of the public and private telecommunications carriers vying for backbone services and industries developing end-user infrastructure technologies via office networks, set-top box networks, Internet multimedia, and "smart homes"…

Emission rates of organics from vegetation in California's Central Valley

NASA Astrophysics Data System (ADS)

Winer, Arthur M.; Arey, Janet; Atkinson, Roger; Aschmann, Sara M.; Long, William D.; Morrison, C. Lynn; Olszyk, David M.

Rates of emission of speciated hydrocarbons have been determined for more than 30 of the most dominant (based on acreage) agricultural and natural plant types found in California's Central Valley. These measurements employed flow-through Teflon chambers, sample collection on solid adsorbent and thermal desorption gas chromatography (GC) and GC-mass spectrometry analysis to identify more than 40 individual organic compounds. In addition to isoprene and the monoterpenes, we observed sesquiterpenes, alcohols, acetates, aldehydes, ketones, ethers, esters, alkanes, alkenes and aromatics as emissions from these plant species. Mean emission rates for total monoterpenes ranged from none detected in the case of beans, grapes, rice and wheat, to as high as 12-30 μg h -1 g -1 for pistachio and tomato (normalized to dry leaf and total biomass, respectively). Other agricultural species exhibiting substantial rates of emission of monoterpenes included carrot, cotton, lemon, orange and walnut. All of the plant species studied showed total assigned compound emission rates in the range between 0.1 and 36 νg h -1 g -1.

Structural and lithographic study of northern coast ranges and Sacramento Valley, California

NASA Technical Reports Server (NTRS)

Rich, E. I. (Principal Investigator)

1973-01-01

The author has identified the following significant results. The analysis of the ERTS data has disclosed three potentially important linear systems within the northern coast ranges and Sacramento Valley, California. A preliminary geomorphic analysis of the northern coast ranges discloses that the geomorphic characteristics of the area underlain by the Coastal system are much different from those associated with the Central system in the core of the Coast Ranges. Within the Coastal system, or Coastal belt, the drainage networks are moderately fine-textured and have moderately high density. The area associated with the Central system seems to be underlain by an heterogeneous assemblage of rock types which vary in their resistance to erosion. The boundary between the Coastal and Central geomorphic regions is poorly defined and, in a few places, the two regions can be separated only approximately.

Potential for using the Upper Coachella Valley ground-water basin, California, for storage of artificially recharged water

USGS Publications Warehouse

Mallory, Michael J.; Swain, Lindsay A.; Tyley, Stephen J.

1980-01-01

This report presents a preliminary evaluation of the geohydrologic factors affecting storage of water by artificial recharge in the upper Coachella Valley, Calif. The ground-water basin of the upper Coachella Valley seems to be geologically suitable for large-scale artificial recharge. A minimum of 900 ,000 acre-feet of water could probably be stored in the basin without raising basinwide water levels above those that existed in 1945. Preliminary tests indicate that a long-term artificial recharge rate of 5 feet per day may be feasible for spreading grounds in the basin if such factors as sediment and bacterial clogging can be controlled. The California Department of Water Resources, through the Future Water Supply Program, is investigating the use of ground-water basins for storage of State Water Project water in order to help meet maximum annual entitlements to water project contractors. (USGS)

Nanosatellite and Plug-and-Play Architecture 2 (NAPA 2)

DTIC Science & Technology

2017-02-28

potentially other militarily relevant roles. The "i- Missions" focus area studies the kinetics of rapid mission development. The methodology involves...the US and Sweden in the Nanosatellite and Plug-and-play Architecture or "NAPA" program) is to pioneer a methodology for creating mission capable 6U...spacecraft. The methodology involves interchangeable blackbox (self-describing) components, software (middleware and applications), advanced

Aeromagnetic survey map of Sacramento Valley, California

USGS Publications Warehouse

Langenheim, Victoria E.

2015-01-01

Three aeromagnetic surveys were flown to improve understanding of the geology and structure in the Sacramento Valley. The resulting data serve as a basis for geophysical interpretations, and support geological mapping, water and mineral resource investigations, and other topical studies. Local spatial variations in the Earth's magnetic field (evident as anomalies on aeromagnetic maps) reflect the distribution of magnetic minerals, primarily magnetite, in the underlying rocks. In many cases the volume content of magnetic minerals can be related to rock type, and abrupt spatial changes in the amount of magnetic minerals commonly mark lithologic or structural boundaries. Bodies of serpentinite and other mafic and ultramafic rocks tend to produce the most intense positive magnetic anomalies (for example, in the northwest part of the map). These rock types are the inferred sources, concealed beneath weakly magnetic, valley-fill deposits, of the most prominent magnetic features in the map area, the magnetic highs that extend along the valley axis. Cenozoic volcanic rocks are also an important source of magnetic anomalies and coincide with short-wavelength anomalies that can be either positive (strong central positive anomaly flanked by lower-amplitude negative anomalies) or negative (strong central negative anomaly flanked by lower-amplitude positive anomalies), reflecting the contribution of remanent magnetization. Rocks with more felsic compositions or even some sedimentary units also can cause measurable magnetic anomalies. For example, the long, linear, narrow north-trending anomalies (with amplitudes of <50 nanoteslas [nT]) along the western margin of the valley coincide with exposures of the Mesozoic Great Valley sequence. Note that isolated, short-wavelength anomalies, such as those in the city of Sacramento and along some of the major roads, are caused by manmade features.

Sierra Nevada, California

NASA Image and Video Library

1994-09-30

STS068-267-097 (30 September-11 October 1994) --- An extensive view eastward from the irrigated San Joaquin Valley in the foreground, across the Sierra Nevada (living up to its name in early October), into the desert of eastern California and Nevada (which has no snow, despite the name). Mono Lake is just visible at the left edge of the frame; Owens Valley extends southward to Owens Lake, the next valley is Panamint Valley, and then Death Valley. Las Vegas and Lake Mead are visible at the upper right of the frame. The Space Radar Laboratory 2 (SRL-2) obtained extensive, multiple-pass data from many test sites within the region displayed, including Mammoth Mountain ski area south of Mono Lake, and in Death Valley.

Estimating soil matric potential in Owens Valley, California

USGS Publications Warehouse

Sorenson, Stephen K.; Miller, Reuben F.; Welch, Michael R.; Groeneveld, David P.; Branson, Farrel A.

1989-01-01

Much of the floor of Owens Valley, California, is covered with alkaline scrub and alkaline meadow plant communities, whose existence is dependent partly on precipitation and partly on water infiltrated into the rooting zone from the shallow water table. The extent to which these plant communities are capable of adapting to and surviving fluctuations in the water table depends on physiological adaptations of the plants and on the water content, matric potential characteristics of the soils. Two methods were used to estimate soil matric potential in test sites in Owens Valley. The first, the filter-paper method, uses water content of filter papers equilibrated to water content of soil samples taken with a hand auger. The previously published calibration relations used to estimate soil matric potential from the water content of the filter papers were modified on the basis of current laboratory data. The other method of estimating soil matric potential was a modeling approach based on data from this and previous investigations. These data indicate that the base-10 logarithm of soil matric potential is a linear function of gravimetric soil water content for a particular soil. The slope and intercepts of this function vary with the texture and saturation capacity of the soil. Estimates of soil water characteristic curves were made at two sites by averaging the gravimetric soil water content and soil matric potential values from multiple samples at 0.1-m depth intervals derived by using the hand auger and filter-paper method and entering these values in the soil water model. The characteristic curves then were used to estimate soil matric potential from estimates of volumetric soil water content derived from neutron-probe readings. Evaluation of the modeling technique at two study sites indicated that estimates of soil matric potential within 0.5 pF units of the soil matric potential value derived by using the filter-paper method could be obtained 90 to 95 percent of the

Population Structure of Xylella fastidiosa Associated with Almond Leaf Scorch Disease in the San Joaquin Valley of California.

PubMed

Lin, Hong; Islam, Md Sajedul; Cabrera-La Rosa, Juan C; Civerolo, Edwin L; Groves, Russell L

2015-06-01

Xylella fastidiosa causes disease in many commercial crops, including almond leaf scorch (ALS) disease in susceptible almond (Prunus dulcis). In this study, genetic diversity and population structure of X. fastidiosa associated with ALS disease were evaluated. Isolates obtained from two almond orchards in Fresno and Kern County in the San Joaquin Valley of California were analyzed for two successive years. Multilocus simple-sequence repeat (SSR) analysis revealed two major genetic clusters that were associated with two host cultivars, 'Sonora' and 'Nonpareil', respectively, regardless of the year of study or location of the orchard. These relationships suggest that host cultivar selection and adaptation are major driving forces shaping ALS X. fastidiosa population structure in the San Joaquin Valley. This finding will provide insight into understanding pathogen adaptation and host selection in the context of ALS disease dynamics.

Kinematics at the intersection of the Garlock and Death Valley fault zones, California: Integration of TM data and field studies

NASA Technical Reports Server (NTRS)

Abrams, Michael; Verosub, Ken; Finnerty, Tony; Brady, Roland

1987-01-01

The Garlock and Death Valley fault zones in SE California are two active strike-slip faults coming together on the east side of the Avawatz Mtns. The kinematics of this intersection, and the possible continuation of either fault zone, are being investigated using a combination of field mapping, and processing and interpretation of remotely sensed image data. Regional and local relationships are derivable from Thematic Mapper data (30 m resolution), including discrimination and relative age dating of alluvial fans, bedrock mapping, and fault mapping. Aircraft data provide higher spatial resolution over more limited areas. Hypotheses being considered are: (1) the Garlock fault extends east of the intersection; (2) the Garlock fault terminates at the intersection and the Death Valley fault continues southeastward; and (3) the Garlock fault has been offset right laterally by the Death Valley fault which continues to the southeast. Preliminary work indicates that the first hypothesis is invalid. From kinematic considerations, image analysis, and field work the third hypothesis is favored. The projected continuation of the Death Valley zone defines the boundary between the Mojave crustal block and the Basin and Range block.

Field Scale Groundwater Nitrate Loading Model for the Central Valley, California, 1945-Current

NASA Astrophysics Data System (ADS)

Harter, T.; Dzurella, K.; Bell, A.; Kourakos, G.

2015-12-01

Anthropogenic groundwater nitrate contamination in the Central Valley aquifer system, California, is widespread, with over 40% of domestic wells in some counties exceeding drinking water standards. Sources of groundwater nitrate include leaky municipal wastewater systems, municipal wastewater recharge, onsite wastewater treatment (septic) systems, atmospheric nitrogen deposition, animal farming, application of organic waste materials (sludge, biosolids, animal manure) to agricultural lands, and synthetic fertilizer. At the site or field scale, nitrogen inputs to the landscape are balanced by plant nitrogen uptake and harvest, atmospheric nitrogen losses, surface runoff of nitrogen, soil nitrogen storage changes, and leaching to groundwater. Irrigated agriculture is a dominant player in the Central Valley nitrogen cycle: The largest nitrogen fluxes are synthetic fertilizer and animal manure applications to cropland, crop nitrogen uptake, and groundwater nitrogen losses. We construct a historic field/parcel scale groundwater nitrogen loading model distinguishing urban and residential areas, individual animal farming areas, leaky wastewater lagoons, and approximately 50 different categories of agricultural crops. For non-agricultural landuses, groundwater nitrate loading is based on reported leaching values, animal population, and human population. For cropland, groundwater nitrate loading is computed from mass balance, taking into account diverse and historically changing management practices between different crops. Groundwater nitrate loading is estimated for 1945 to current. Significant increases in groundwater nitrate loading are associated with the expansion of synthetic fertilizer use in the 1950s to 1970s. Nitrate loading from synthetic fertilizer use has stagnated over the past 20 years due to improvements in nutrient use efficiency. However, an unbroken 60 year exponential increase in dairy production until the late 2000s has significantly impacted the

Stable sulfur isotope hydrogeochemical studies using desert shrubs and tree rings, Death Valley, California, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Wenbo; Spencer, R.J.; Krouse, H.R.

1996-08-01

The {delta}{sup 34}S values of two dominant xerophytes, Atriplex hymenehytra and Larrea tridentata, in Death Valley, California, vary similarly from +7 to +18{per_thousand}, corresponding isotopically to sulfate in the water supplies at a given location. Going radially outwards, tree ring data from a phreatophyte tree, Tamarix aphylla, show a distinct time dependence, with {delta}{sup 34}S values increasing from +13.5 to +18{per_thousand} for soluble sulfate and from +12 to +17% for total sulfur. These data are interpreted in terms of sulfur sources, water sources and flow paths, and tree root growth. 32 refs., 3 figs., 3 tabs.

Structure of the San Fernando Valley region, California: implications for seismic hazard and tectonic history

USGS Publications Warehouse

Langenheim, V.E.; Wright, T.L.; Okaya, D.A.; Yeats, R.S.; Fuis, G.S.; Thygesen, K.; Thybo, H.

2011-01-01

Industry seismic reflection data, oil test well data, interpretation of gravity and magnetic data, and seismic refraction deep-crustal profiles provide new perspectives on the subsurface geology of San Fernando Valley, home of two of the most recent damaging earthquakes in southern California. Seismic reflection data provide depths to Miocene–Quaternary horizons; beneath the base of the Late Miocene Modelo Formation are largely nonreflective rocks of the Middle Miocene Topanga and older formations. Gravity and seismic reflection data reveal the North Leadwell fault zone, a set of down-to-the-north faults that does not offset the top of the Modelo Formation; the zone strikes northwest across the valley, and may be part of the Oak Ridge fault system to the west. In the southeast part of the valley, the fault zone bounds a concealed basement high that influenced deposition of the Late Miocene Tarzana fan and may have localized damage from the 1994 Northridge earthquake. Gravity and seismic refraction data indicate that the basin underlying San Fernando Valley is asymmetric, the north part of the basin (Sylmar subbasin) reaching depths of 5–8 km. Magnetic data suggest a major boundary at or near the Verdugo fault, which likely started as a Miocene transtensional fault, and show a change in the dip sense of the fault along strike. The northwest projection of the Verdugo fault separates the Sylmar subbasin from the main San Fernando Valley and coincides with the abrupt change in structural style from the Santa Susana fault to the Sierra Madre fault. The Simi Hills bound the basin on the west and, as defined by gravity data, the boundary is linear and strikes ~N45°E. That northeast-trending gravity gradient follows both the part of the 1971 San Fernando aftershock distribution called the Chatsworth trend and the aftershock trends of the 1994 Northridge earthquake. These data suggest that the 1971 San Fernando and 1994 Northridge earthquakes reactivated portions of

The Long Valley Caldera GIS database

USGS Publications Warehouse

Battaglia, Maurizio; Williams, M.J.; Venezky, D.Y.; Hill, D.P.; Langbein, J.O.; Farrar, C.D.; Howle, J.F.; Sneed, M.; Segall, P.

2003-01-01

This database provides an overview of the studies being conducted by the Long Valley Observatory in eastern California from 1975 to 2001. The database includes geologic, monitoring, and topographic datasets related to Long Valley caldera. The CD-ROM contains a scan of the original geologic map of the Long Valley region by R. Bailey. Real-time data of the current activity of the caldera (including earthquakes, ground deformation and the release of volcanic gas), information about volcanic hazards and the USGS response plan are available online at the Long Valley observatory web page (http://lvo.wr.usgs.gov). If you have any comments or questions about this database, please contact the Scientist in Charge of the Long Valley observatory.

Water availability and subsidence in California's Central Valley

USGS Publications Warehouse

Faunt, Claudia C.; Sneed, Michelle

2015-01-01

California’s Central Valley covers about 52,000 square kilometers (km2) and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the broad alluvial filled structural trough, with an estimated value exceeding $20 billion per year (Faunt 2009) (Figure 1). Central Valley agriculture depends on state and federal water systems that divert surface water, predominantly originating from Sierra Nevada snowmelt, to agricultural fields. Because the valley is semi-arid and the availability of surface water varies substantially from year to year, season to season, and from north to south, agriculture, as it grew, developed a reliance on groundwater for irrigation.

Preliminary digital geologic maps of the Mariposa, Kingman, Trona, and Death Valley Sheets, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

D`Agnese, F.A.; Faunt, C.C.; Turner, A.K.

1995-10-01

Parts of four 1:250,000-scale geologic maps by the California Department of Natural Resources, Division of Mines and Geology have been digitized for use in hydrogeologic characterization. These maps include the area of California between lat. 35{degree}N; Long. 115{degree}W and lat. 38{degree}N, long. 118{degree}W of the Kingman Sheet (Jennings, 1961), Trona Sheet (Jennings and others, 1962), Mariposa Sheet (Strand, 1967), and Death Valley Sheet (Streitz and Stinson, 1974). These digital maps are being released by the US Geological Survey in the ARC/INFO Version 6.1 Export format. The digitized data include geologic unit boundaries, fault traces, and identity of geologic units. Themore » procedure outlined in US Geological Survey Circular 1054 (Soller and others, 1990) was sued during the map construction. The procedure involves transferring hard-copy data into digital format by scanning manuscript maps, manipulating the digital map data, and outputting the data. Most of the work was done using Environmental Systems Research Institute`s ARC/INFO software. The digital maps are available in ARC/INFO Rev. 6.1 Export format, from the USGS, Yucca Mountain Project, in Denver, Colorado.« less

Water savings from reduced alfalfa cropping in California's Upper San Joaquin Valley

NASA Astrophysics Data System (ADS)

Singh, K. K.; Gray, J.

2017-12-01

Water and food and forage security are inextricably linked. In fact, 90% of global freshwater is consumed for food production. Food demand increases as populations grow and diets change, making water increasingly scarce. This tension is particularly acute, contentious, and popularly appreciated in California's Central Valley, which is one of the most important non-grain cropping areas in the United States. While the water-intensive production of tree nuts like almonds and pistachios has received the most popular attention, it is California's nation-leading alfalfa production that consumes the most water. Alfalfa, the "Queen of Forages" is the preferred feedstock for California's prodigious dairy industry. It is grown year-round, and single fields can be harvested more than four times a year; a practice which can require in excess of 1.5 m of irrigation water. Given the water scarcity in the region, the production of alfalfa is under increasing scrutiny with respect to long-term sustainability. However, the potential water savings associated with alternative crops, and various levels of alfalfa replacement have not been quantified. Here, we address that knowledge gap by simulating the ecohydrology of the Upper San Joaquin's cropping system under various scenarios of alfalfa crop replacement with crops of comparable economic value. Specifically, we use the SWAT model to evaluate the water savings that would be realized at 33%, 66%, and 100% alfalfa replacement with economically comparable, but more water efficient crops such as tomatoes. Our results provide an important quantification of the potential water savings under alternative cropping systems that, importantly, also addresses the economic concerns of farmers. Results like these provide critical guidance to farmers and land/water decision makers as they plan for a more sustainable and productive agricultural future.

Groundwater Age in Multi-Level Water Quality Monitor Wells on California Central Valley Dairies

NASA Astrophysics Data System (ADS)

Esser, B. K.; Visser, A.; Hillegonds, D. J.; Singleton, M. J.; Moran, J. E.; Harter, T.

2011-12-01

Dairy farming in California's Central Valley is a significant source of nitrate to underlying aquifers. One approach to mitigation is to implement farm-scale management plans that reduce nutrient loading to groundwater while sustaining crop yield. While the effect of different management practices on crop yield is easily measured, their effect on groundwater quality has only infrequently been evaluated. Documenting and predicting the impact of management on water quality requires a quantitative assessment of transport (including timescale and mixing) through the vadose and saturated zones. In this study, we measured tritium, helium isotopic composition, and noble gas concentrations in groundwater drawn from monitor wells on several dairies in the Lower San Joaquin Valley and Tulare Lake Basin of California's Central Valley in order to predict the timescales on which changes in management may produce observable changes in groundwater quality. These dairies differ in age (from <10 to >100 years old), thickness of the vadose zone (from <10 to 60 m), hydrogeologic setting, and primary source of irrigation water (surface or groundwater). All of the dairies use manure wastewater for irrigation and fertilization. Three of the dairies have implemented management changes designed to reduce nutrient loading and/or water usage. Monitor wells in the southern Tulare Lake Basin dairies were installed by UC-Davis as multi-level nested wells allowing depth profiling of tritium and noble gases at these sites. Tritium/helium-3 groundwater ages, calculated using a simple piston-flow model, range from <2 to >50 years. Initial tritium (the sum of measured tritium and tritiogenic helium-3) is close to or slightly above precipitation in the calculated recharge year for young samples; and significantly above the precipitation curve for older samples. This pattern is consistent with the use of 20-30 year old groundwater recharged before 1980 for irrigation, and illustrates how irrigation

Thin-skinned tectonics of the Upper Ojai Valley and Sulphur Mountain area, Ventura basin, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huftile, G.J.

1991-08-01

By integrating surface mapping with subsurface well data and drawing cross sections and subsurface maps, the geometry of shallow structures and their geologic history of the Upper Ojai Valley of California can be reconstructed. The geometry of shallow structures, the geologic history, and the location of earthquake foci then offer constraints on the deep structure of this complex area. The Upper Ojai Valley is a tectonic depression between opposing reverse faults. Its northern border is formed by the active, north-dipping San Cayetano fault, which has 6.0 km of stratigraphic separation in the Silverthread area of the Ojai oil field andmore » 2.6 km of stratigraphic separation west of Sisar Creek. The fault dies out farther west in Ojai Valley, where the south-vergent shortening is transferred to a blind thrust. The southern border of the Upper Ojai Valley is formed by the Quaternary Lion fault set, which dips south and merges into the Sisar decollement within the south-dipping, ductile, lower Miocene Rincon formation. By the middle Pleistocene, the Sulphur Mountain anticlinorium and the Big Canyon syncline began forming as a fault-propagation fold; the fault-propagation fold is rooted in the Sisar decollement, a passive backthrust rising from a blind thrust at depth. The formation of the Sulphur Mountain anticlinorium was followed closely by the ramping of the south-dipping Lion fault set to the surface over the nonmarine upper Pleistocene Saugus Formation. To the east, the San Cayetano fault overrides and folds the Lion Fault set near the surface. Area-balancing of the deformation shows shortening of 15.5 km, and suggests a 17 km depth to the brittle-ductile transition.« less

Conservation Effects Assessment Project-Wetlands assessment in California's Central Valley and Upper Klamath River Basin

USGS Publications Warehouse

Duffy, Walter G.; Kahara, Sharon N.; Records, Rosemary M.

2011-01-01

Executive Summary-Ecosystem Services Derived from Wetlands Reserve Program Conservation Practices in California's Central Valley and Oregon's Upper Klamath River Basin. The Wetlands Reserve Program (WRP) is one of several programs implemented by the U.S. Department of Agriculture (USDA). Since the WRP's inception in 1990, it has resulted in the restoration of approximately 29,000 hectares in California's Central Valley (CCV) and roughly 12,300 hectares in Oregon's Upper Klamath River Basin (UKRB). Both the CCV and UKRB are agricultural dominated landscapes that have experienced extensive wetland losses and hydrological alteration. Restored habitats in the CCV and UKRB are thought to provide a variety of ecosystem services, but little is known about the actual benefits afforded. The U.S. Geological Survey (USGS) California Cooperative Fish and Wildlife Unit in collaboration with the USDA Natural Resources Conservation Service surveyed 70 WRP sites and 12 National Wildlife Refuge sites in the CCV, and 11 sites in the UKRB to estimate ecosystem services provided. In the CCV, sites were selected along three primary gradients; (1) restoration age, (2) management intensity, and (3) latitude (climate). Sites in the UKRB were assessed along restoration age and management intensity gradients where possible. The management intensity gradient included information about the type and frequency of conservation practices applied at each site, which was then ranked into three categories that differentiated sites primarily along a hydrological gradient. Information collected was used to estimate the following ecosystem services: Soil and vegetation nutrient content, soil loss reduction, floodwater storage as well as avian, amphibian, fish, and pollinator use and habitat availability. Prior to this study, very little was known about WRP habitat morphology in the CCV and UKRB. Therefore in this study, we described these habitats and related them to ecosystem services provided. Our

Valley aggradation in the San Gabriel Mountains, California: climate change versus catastrophic landslide

NASA Astrophysics Data System (ADS)

Scherler, D.; Lamb, M. P.; Rhodes, E. J.; Avouac, J. P.

2014-12-01

The San Gabriel Mountains (SGM) in Southern California, rate amongst the most rapidly uplifting and eroding mountains in the United States. Their steep slopes and sensitivity to wildfires, flash floods, landslides, and debris flows account for imminent hazards to nearby urban areas that might be accentuated by climatic and other environmental changes. Previous studies suggested that river terraces along the North Fork of the San Gabriel River, record temporal variations in sediment supply and river transport capacity that are representative for the SGM and related to climatic changes during the Quaternary. Based on field observations, digital topographic analysis, and dating of Quaternary deposits, we suggest that valley aggradation in the North Fork San Gabriel Canyon was spatially confined and a consequence of the sudden supply of unconsolidated material to upstream reaches by one of the largest known landslides in the SGM. New 10Be-derived surface exposure ages from the landslide deposits, previously assumed to be early to middle Pleistocene in age, indicate at least three Holocene events at ~8-9 ka, ~4-5 ka, and ~0.5-1 ka. The oldest landslide predates the valley aggradation period, which is constrained by existing 14C ages and new luminescence ages to ~7-8 ka. The spatial distribution, morphology, and sedimentology of the river terraces are consistent with deposition from far-travelling debris flows that originated within the landslide deposits. Valley aggradation in the North Fork San Gabriel Canyon therefore resulted from locally enhanced sediment supply that temporarily overwhelmed river capacity but the lack of similar deposits in other parts of the SGM argues against a regional climatic signal. So far, there exists no evidence that in the San Gabriel Mountains, climatic changes can cause sustained increases in hillslope sediment supply that lead to river aggradation and terrace formation.

Geology, geochronology, and paleogeography of the southern Sonoma volcanic field and adjacent areas, northern San Francisco Bay region, California

USGS Publications Warehouse

Wagner, David L.; Saucedo, George J.; Clahan, Kevin B.; Fleck, Robert J.; Langenheim, Victoria E.; McLaughlin, Robert J.; Sarna-Wojcicki, Andrei M.; Allen, James R.; Deino, Alan L.

2011-01-01

Recent geologic mapping in the northern San Francisco Bay region (California, USA) supported by radiometric dating and tephrochronologic correlations, provides insights into the framework geology, stratigraphy, tectonic evolution, and geologic history of this part of the San Andreas transform plate boundary. There are 25 new and existing radiometric dates that define three temporally distinct volcanic packages along the north margin of San Pablo Bay, i.e., the Burdell Mountain Volcanics (11.1 Ma), the Tolay Volcanics (ca. 10–8 Ma), and the Sonoma Volcanics (ca. 8–2.5 Ma). The Burdell Mountain and the Tolay Volcanics are allochthonous, having been displaced from the Quien Sabe Volcanics and the Berkeley Hills Volcanics, respectively. Two samples from a core of the Tolay Volcanics taken from the Murphy #1 well in the Petaluma oilfield yielded ages of 8.99 ± 0.06 and 9.13 ± 0.06 Ma, demonstrating that volcanic rocks exposed along Tolay Creek near Sears Point previously thought to be a separate unit, the Donnell Ranch volcanics, are part of the Tolay Volcanics. Other new dates reported herein show that volcanic rocks in the Meacham Hill area and extending southwest to the Burdell Mountain fault are also part of the Tolay Volcanics. In the Sonoma volcanic field, strongly bimodal volcanic sequences are intercalated with sediments. In the Mayacmas Mountains a belt of eruptive centers youngs to the north. The youngest of these volcanic centers at Sugarloaf Ridge, which lithologically, chemically, and temporally matches the Napa Valley eruptive center, was apparently displaced 30 km to the northwest by movement along the Carneros and West Napa faults. The older parts of the Sonoma Volcanics have been displaced at least 28 km along the Rodgers Creek fault since ca. 7 Ma. The Petaluma Formation also youngs to the north along the Rodgers Creek–Hayward fault and the Bennett Valley fault. The Petaluma basin formed as part of the Contra Costa basin in the Late Miocene and

Transportation impacts to wildlife on state route 37 in northern San Pablo Bay, California

USGS Publications Warehouse

Winton, Bryan R.; Takekawa, John Y.

2002-01-01

State Route 37 bisects conservation lands managed by San Pablo Bay National Wildlife Refuge (U.S. Fish & Wildlife Service) and Napa-Sonoma Marshes Wildlife Area (California Department of Fish and Game) in Solano and Sonoma Counties. The 2-lane highway connects Interstates 101 and 80 in northern San Francisco Bay and experiences ~26,000 vehicles per day. Road-killed wildlife between Napa River and Tolay Creek bridges (14.7 km) were counted in 2000 to ascertain species composition, relative abundance, and relative occurence (animal fatality interval). The primary objectives of the study were to determine if endangered salt marsh harvest mice (Reithrodontomys raviventris), California clapper rails (Rallus longirostris), or other species of concern were represented, and to collect baseline data on transportation impacts to wildlife in the area. During 51 surveys, 291 dead birds (54.6%) and mammals (45.4%) were observed. Endangered species were not positively identified dead on the highway. In total, 28 bird, 10 mammal and 1 reptile species were positively identified along this section of highway that traverses tidal marsh and diked baylands (i.e., salt ponds, seasonal wetlands, and oat-hay agriculture fields). The mean animal fatality interval for both lanes was one road-kill every 2.1km (2.1 km SD).

Interpretation of shallow crustal structure of the Imperial Valley, California, from seismic reflection profiles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Severson, L.K.

1987-05-01

Eight seismic reflection profiles (285 km total length) from the Imperial Valley, California, were provided to CALCRUST for reprocessing and interpretation. Two profiles were located along the western margin of the valley, five profiles were situated along the eastern margin and one traversed the deepest portion of the basin. These data reveal that the central basin contains a wedge of highly faulted sediments that thins to the east. Most of the faulting is strike-slip but there is evidence for block rotations on the scale of 5 to 10 kilometers within the Brawley Seismic Zone. These lines provide insight into themore » nature of the east and west edges of the Imperial Valley. The basement at the northwestern margin of the valley, to the north of the Superstition Hills, has been normal-faulted and blocks of basement material have ''calved'' into the trough. A blanket of sediments has been deposited on this margin. To the south of the Superstition Hills and Superstition Mountain, the top of the basement is a detachment surface that dips gently into the basin. This margin is also covered by a thick sequence sediments. The basement of the eastern margin consists of metamorphic rocks of the upper plate of the Chocolate Mountain Thrust system underlain by the Orocopia Schist. These rocks dip to the southeast and extend westward to the Sand Hills Fault but do not appear to cross it. Thus, the Sand Hills Fault is interpreted to be the southern extension of the San Andreas Fault. North of the Sand Hills Fault the East Highline Canal seismicity lineament is associated with a strike-slip fault and is probably linked to the Sand Hills Fault. Six geothermal areas crossed by these lines, in agreement with previous studies of geothermal reservoirs, are associated with ''faded'' zones, Bouguer gravity and heat flow maxima, and with higher seismic velocities than surrounding terranes.« less

Waterbird habitat in California's Central Valley basins under climate, urbanization, and water management scenarios

USGS Publications Warehouse

Matchett, Elliott L.; Fleskes, Joseph

2018-01-01

California's Central Valley provides critical, but threatened habitat and food resources for migrating and wintering waterfowl, shorebirds, and other waterbirds. The Central Valley is comprised of nine basins that were defined by the Central Valley Joint Venture (CVJV) to assist in conservation planning. Basins vary in composition and extent of habitats, which primarily include croplands and wetlands that rely on water supplies shared with other competing human and environmental uses. Changes in climate, urban development, and water supply management are uncertain and could reduce future availability of water supplies supporting waterbird habitats and limit effectiveness of wetland restoration planned by the CVJV to support wintering waterbirds. We modeled 17 plausible scenarios including combinations of three climate projections, three urbanization rates, and five water supply management options to promote agricultural and urban water uses, with and without wetland restoration. Our research examines the reduction in quantity and quality of habitats during the fall migration-wintering period by basin under each scenario, and the efficacy of planned wetland restoration to compensate reductions in flooded areas of wetland habitats. Scenario combinations of projected climate, urbanization, and water supply management options reduced availability of flooded cropland and wetland habitats during fall-winter and degraded the quality of seasonal wetlands (i.e., summer-irrigation for improved forage production), though the extent and frequency of impacts varied by basin. Planned wetland restoration may substantially compensate for scenario-related effects on wetland habitats in each basin. However, results indicate that Colusa, Butte, Sutter, San Joaquin, and Tulare Basins may require additional conservation to support summer-irrigation of seasonal wetlands and winter-flooding of cropland habitats. Still further conservation may be required to provide sufficient areas of

Osmotic potential and projected drought tolerance of four phreatophytic shrub species in Owens Valley, California

USGS Publications Warehouse

Dileanis, Peter D.; Groeneveld, David P.

1989-01-01

A substantial quantity of the water used by plant communities growing on the floor of Owens Valley, California, is derived from a shallow unconfined aquifer. Fluctuations in the water table caused by ground-water withdrawal may result in periods when this water supply is not accessible to plants. The capacity of the plants to adapt to these periods of water loss depends on the availability of water stored in the soil and on physiological characteristics related to the ability of the plants to resist dehydration and wilting. Osmotic adjustment occurred in four phreatophytic shrub species at sites near Bishop, California, where the water table had been lowered by a system of pump-equipped wells installed in the vicinity of vegetation transects. The pressure-volume technique was used to determine osmotic potential and cell-wall elasticity between March 1985 and September 1986 for Atriplex torreyi, Chrysothamnus nauseosus , Sarcobatus verm iculatus , and Artemisia tridentata. Although not usually classified as a phreatophyte, Artemisia tridentata, where it grows on the valley floor, is apparently dependent on the depth to the water table. During late summer, osmotic potentials were 0.37 to 0.41 MPa (megapascal) lower in plants growing on the site where the water table had been lowered compared to an adjacent site where the water table remained at its natural levels. Measurements of soil matric potential at the two sites indicated that osmotic adjustment occurred in response to stress caused by lowering the water table. A theoretical lower limit of osmotic adjustment was determined by comparing initial cell osmotic potentials with initial xylem water potentials. These experimentally derived limits indicated that Atriplex torreyi and S. vermiculatus may maintain leaf cell turgor at significantly lower cell water potentials (about -4.5 MPa) than C. nauseosus or Artemisia tridentata (about -2.5 MPa), which allows them to function in drier soil environments.

Osmotic potential and projected drought tolerance of four phreatophytic shrub species in Owens Valley, California

USGS Publications Warehouse

Dileanis, Peter D.; Groeneveld, D.P.

1988-01-01

A large part of the water used by plant communities growing on the floor of Owens Valley, California, is derived from a shallow unconfined aquifer. Fluctuations in the water table caused by groundwater withdrawal may result in periods when this water supply is not accessible to plants. The capacity of the plants to adapt to these periods of water loss depend on the availability of water stored in the soil and on physiological characteristics related to the ability of the plants to resist dehydration and wilting. Osmotic adjustment occurred in four phreatophytic shrub species at sites near bishop, California, where the water table had been lowered by a system of pump-equipped wells installed in the vicinity of vegetation transects. The pressure-volume techniques was used to determine osmotic potential and cell-wall elasticity between March 1985 and September 1986 for Atriplex torreyi, Chrysothamnus nauseosus , Sarcobatus vermiculatus, and Artemisia tridentata. Although not usually classified as a phreatophyte, Artemisia tridentata, where it grows on the valley floor, is apparently dependent on the depth to the water table. During late summer, osmotic potentials were 0.37 to 0.41 megapascal lower in plants growing on the site where the water table had been lowered compared to an adjacent site where the water table remained at its natural levels. Measurements of soil matric potential at the two sites indicated that osmotic adjustment occurred in response to stress caused by lowering the water table. A theoretical lower limit of osmotic adjustment was determined by comparing initial cell osmotic potentials with initial xylem water potentials. These experimentally derived limits indicated that A. torreyi and S. vermiculatus may maintain leaf cell turgor at significantly lower cell water potentials (about -4.5 megapascals) than C. nauseosus or A. tridentata (about -2.5 megapascals) and allows them to function in dryer soil environments. (Author 's abstract)

Projected Impacts of Climate, Urbanization, Water Management, and Wetland Restoration on Waterbird Habitat in California's Central Valley.

PubMed

Matchett, Elliott L; Fleskes, Joseph P

2017-01-01

The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006-2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the "existing" landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

Geohydrology and water-chemistry of the Alexander Valley, Sonoma County, California

USGS Publications Warehouse

Metzger, Loren F.; Farrar, Christopher D.; Koczot, Kathryn M.; Reichard, Eric G.

2006-01-01

This study of the geohydrology and water chemistry of the Alexander Valley, California, was done to provide an improved scientific basis for addressing emerging water-management issues, including potential increases in water demand and changes in flows in the Russian River. The study tasks included (1) evaluation of existing geohydrological, geophysical, and geochemical data; (2) collection and analysis of new geohydrologic data, including subsurface lithologic data, ground-water levels, and streamflow records; and (3) collection and analysis of new water-chemistry data. The estimated total water use for the Alexander Valley for 1999 was approximately 15,800 acre-feet. About 13,500 acre-feet of this amount was for agricultural use, primarily vineyards, and about 2,300 acre-feet was for municipal/industrial use. Ground water is the main source of water supply for this area. The main sources of ground water in the Alexander Valley are the Quaternary alluvial deposits, the Glen Ellen Formation, and the Sonoma Volcanics. The alluvial units, where sufficiently thick and saturated, comprise the best aquifer in the study area. Average recharge to the Alexander Valley is estimated from a simple, basinwide water budget. On the basis of an estimated annual average of 298,000 acre-feet of precipitation, 160,000 acre-feet of runoff, and 113,000 to 133,000 acre-feet of evapotranspiration, about 5,000 to 25,000 acre-feet per year is available for ground-water recharge. Because this estimate is based on differences between large numbers, there is significant uncertainty in this recharge estimate. Long-term changes in ground-water levels are evident in parts of the study area, but because of the sparse network and lack of data on well construction and lithology, it is uncertain if any significant changes have occurred in the northern part of the study area since 1980. In the southern half of the study area, ground-water levels generally were lower at the end of the 2002 irrigation

Interpretive geologic cross sections for the Death Valley regional flow system and surrounding areas, Nevada and California

USGS Publications Warehouse

Sweetkind, D.S.; Dickerson, R.P.; Blakely, R.J.; Denning, Paul

2001-01-01

This report presents a network of 28 geologic cross sections that portray subsurface geologic relations within the Death Valley regional ground-water system, a ground-water basin that encompasses a 3? x 3? area (approximately 70,000 km2) in southern Nevada and eastern California. The cross sections transect that part of the southern Great Basin that includes Death Valley, the Nevada Test Site, and the potential high-level nuclear waste underground repository at Yucca Mountain. The specific geometric relationships portrayed on the cross sections are discussed in the context of four general sub-regions that have stratigraphic similarities and general consistency of structural style: (1) the Nevada Test Site vicinity; (2) the Spring Mountains, Pahrump Valley and Amargosa Desert region; (3) the Death Valley region; and (4) the area east of the Nevada Test Site. The subsurface geologic interpretations portrayed on the cross sections are based on an integration of existing geologic maps, measured stratigraphic sections, published cross sections, well data, and geophysical data and interpretations. The estimated top of pre-Cenozoic rocks in the cross sections is based on inversion of gravity data, but the deeper parts of the sections are based on geologic conceptual models and are more speculative. The region transected by the cross sections includes part of the southern Basin and Range Province, the northwest-trending Walker Lane belt, the Death Valley region, and the northern Mojave Desert. The region is structurally complex, where a locally thick Tertiary volcanic and sedimentary section unconformably overlies previously deformed Proterozoic through Paleozoic rocks. All of these rocks have been deformed by complex Neogene ex-tensional normal and strike-slip faults. These cross sections form a three-dimensional network that portrays the interpreted stratigraphic and structural relations in the region; the sections form part of the geologic framework that will be

Space geodetic observation of expansion of the San Gabriel Valley, California, aquifer system, during heavy rainfall in winter 2004-2005

USGS Publications Warehouse

King, N.E.; Argus, D.; Langbein, J.; Agnew, D.C.; Bawden, G.; Dollar, R.S.; Liu, Z.; Galloway, D.; Reichard, E.; Yong, A.; Webb, F.H.; Bock, Y.; Stark, K.; Barseghian, D.

2007-01-01

Starting early in 2005, the positions of GPS stations in the San Gabriel valley region of southern California showed statistically significant departures from their previous behavior. Station LONG moved up by about 47 mm, and nearby stations moved away from LONG by about 10 mm. These changes began during an extremely rainy season in southern California and coincided with a 16-m increase in water level at a nearby well in Baldwin Park and a regional uplift detected by interferometric synthetic aperture radar. No equivalent signals were seen in GPS station position time series elsewhere in southern California. Our preferred explanation, supported by the timing and by a hydrologic simulation, is deformation due to recharging of aquifers after near-record rainfall in 2004-2005. We cannot rule out an aseismic slip event, but we consider such an event unlikely because it requires slip on multiple faults and predicts other signals that are not observed. Copyright 2007 by the American Geophysical Union.

Jurassic and Cretaceous Hagiastridae from the Blake-Bahama Basin /Site 5A, JOIDES Leg I/ and the Great Valley Sequence, California Coast Ranges.

NASA Technical Reports Server (NTRS)

Pessagno, E. A., Jr.

1971-01-01

Description of a total of 24 new species and four genuses of Jurassic and Cretaceous Hagiastridae found in the Great Valley Sequence of the California Coast Ranges. Also described are four new species from the late Jurassic strata of the Blake-Bahama Basin. Spumellariina with a spongy meshwork is included in the superfamily Spongodiscacea Haeckel.

Characterizing Drought Impacted Soils in the San Joaquin Valley of California Using Remote Sensing

NASA Astrophysics Data System (ADS)

Wahab, L. M.; Miller, D.; Roberts, D. A.

2017-12-01

California's San Joaquin Valley is an extremely agriculturally productive region of the country, and understanding the state of soils in this region is an important factor in maintaining this high productivity. In this study, we quantified changing soil cover during the drought and analyzed spatial changes in salinity, organic matter, and moisture using unique soil spectral characteristics. We used data from the Airborne Visible / Infrared Imaging Spectrometer (AVIRIS) from Hyperspectral Infrared Imager (HyspIRI) campaign flights in 2013 and 2014 over the San Joaquin Valley. A mixture model was applied to both images that identified non- photosynthetic vegetation, green vegetation, and soil cover fractions through image endmembers of each of these three classes. We optimized the spectral library used to identify these classes with Iterative Endmember Selection (IES), and the images were unmixed using Multiple Endmember Spectral Mixture Analysis (MESMA). Maps of soil electrical conductivity, organic matter, soil saturated moisture, and field moisture were generated for the San Joaquin Valley based on indices developed by Ben-Dor et al. [2002]. Representative polygons were chosen to quantify changes between years. Maps of spectrally distinct soils were also generated for 2013 and 2014, in order to determine the spatial distribution of these soil types as well as their temporal dynamics between years. We estimated that soil cover increased by 16% from 2013-2014. Six spectrally distinct soil types were identified for the region, and it was determined that the distribution of these soil types was not constant for most areas between 2013 and 2014. Changes in soil pH, electrical conductivity, and soil moisture were strongly tied in the region between 2013 and 2014.

Napa River Restoration Project: Rutherford Reach Completion and Oakville to Oak Knoll Reach

EPA Pesticide Factsheets

Information about the SFBWQP Napa River Restoration Project: Rutherford Reach Completion/Oakville to Oak Knoll, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

Pyrethroid insecticide concentrations and toxicity in streambed sediments and loads in surface waters of the San Joaquin Valley, California, USA

USGS Publications Warehouse

Domagalski, Joseph L.; Weston, Donald P.; Zhang, Minghua; Hladik, Michelle L.

2010-01-01

Pyrethroid insecticide use in California, USA, is growing, and there is a need to understand the fate of these compounds in the environment. Concentrations and toxicity were assessed in streambed sediment of the San Joaquin Valley of California, one of the most productive agricultural regions of the United States. Concentrations were also measured in the suspended sediment associated with irrigation or storm‐water runoff, and mass loads during storms were calculated. Western valley streambed sediments were frequently toxic to the amphipod, Hyalella azteca, with most of the toxicity attributable to bifenthrin and cyhalothrin. Up to 100% mortality was observed in some locations with concentrations of some pyrethroids up to 20 ng/g. The western San Joaquin Valley streams are mostly small watersheds with clay soils, and sediment‐laden irrigation runoff transports pyrethroid insecticides throughout the growing season. In contrast, eastern tributaries and the San Joaquin River had low bed sediment concentrations (<1 ng/g) and little or no toxicity because of the preponderance of sandy soils and sediments. Bifenthrin, cyhalothrin, and permethrin were the most frequently detected pyrethroids in irrigation and storm water runoff. Esfenvalerate, fenpropathrin, and resmethrin were also detected. All sampled streams contributed to the insecticide load of the San Joaquin River during storms, but some compounds detected in the smaller creeks were not detected in the San Joaquin River. The two smallest streams, Ingram and Hospital Creeks, which had high sediment toxicity during the irrigation season, accounted for less than 5% of the total discharge of the San Joaquin River during storm conditions, and as a result their contribution to the pyrethroid mass load of the larger river was minimal. 

Selenium and other elements in juvenile striped bass from the San Joaquin Valley and San Francisco Estuary, California

USGS Publications Warehouse

Saiki, Michael K.; Palawski, Donald U.

1990-01-01

Concentrations of selenium and other trace elements were determined in 55 whole body samples of juvenile anadromous striped bass (Morone saxatilis) from the San Joaquin Valley and San Francisco Estuary, California. The fish (≤1 yr old—the predominant life stage in the San Joaquin Valley) were collected in September–December 1986 from 19 sites in the Valley and 3 sites in the Estuary, and analyzed for the following elements: aluminum (Al), arsenic (As), boron (B), barium (Ba), beryllium (Be), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), magnesium (Mg), molybdenum (Mo), nickel (Ni), lead (Pb), selenium (Se), strontium (Sr), vanadium (V), and zinc (Zn). When compared to concentrations in whole freshwater fish measured by surveys from other waters, a few samples contained higher levels, of As, Cd, Cu, Pb, and Se. The median concentrations of Al, As, Cu, Fe, Mg, Se, and Sr also differed significantly (P⩽0.05) among sites. However, only Se concentrations were highest (up to 7.9 μg/g dry weight) in samples from Valley sites exposed to agricultural subsurface (tile) drainwater; concentrations were lower in samples collected elsewhere. Water quality variables—especially those strongly influenced by tile drainwater (conductivity, total dissolved solids, total alkalinity, and total hardness)—were also significantly correlated (P⩽0.05) with Se concentrations in fish. Selenium concentrations in striped bass from the Estuary were only one-fourth to one-half the concentrations measured in the most contaminated fish from the San Joaquin River.

Structural controls on geothermal circulation in Surprise Valley, California: A re-evaluation of the Lake City fault zone

USGS Publications Warehouse

Anne E. Egger,; Glen, Jonathan; McPhee, Darcy K.

2014-01-01

Faults and fractures play an important role in the circulation of geothermal fluids in the crust, and the nature of that role varies according to structural setting and state of stress. As a result, detailed geologic and geophysical mapping that relates thermal springs to known structural features is essential to modeling geothermal systems. Published maps of Surprise Valley in northeastern California suggest that the “Lake City fault” or “Lake City fault zone” is a significant structural feature, cutting obliquely across the basin and connecting thermal springs across the valley. Newly acquired geophysical data (audio-magnetotelluric, gravity, and magnetic), combined with existing geochemical and geological data, suggest otherwise. We examine potential field profiles and resistivity models that cross the mapped Lake City fault zone. While there are numerous geophysical anomalies that suggest subsurface structures, they mostly do not coincide with the mapped traces of the Lake City fault zone, nor do they show a consistent signature in gravity, magnetics, or resistivities that would suggest a through-going fault that would promote connectivity through lateral fluid flow. Instead of a single, continuous fault, we propose the presence of a deformation zone associated with the growth of the range-front Surprise Valley fault. The implication for geothermal circulation is that this is a zone of enhanced porosity but lacks length-wise connectivity that could conduct fluids across the valley. Thermal fluid circulation is most likely controlled primarily by interactions between N-S–trending normal faults.

Modeling the long-term fate of agricultural nitrate in groundwater in the San Joaquin Valley, California

USGS Publications Warehouse

Chapelle, Francis H.; Campbell, Bruce G.; Widdowson, Mark A.; Landon, Mathew K.

2013-01-01

Nitrate contamination of groundwater systems used for human water supplies is a major environmental problem in many parts of the world. Fertilizers containing a variety of reduced nitrogen compounds are commonly added to soils to increase agricultural yields. But the amount of nitrogen added during fertilization typically exceeds the amount of nitrogen taken up by crops. Oxidation of reduced nitrogen compounds present in residual fertilizers can produce substantial amounts of nitrate which can be transported to the underlying water table. Because nitrate concentrations exceeding 10 mg/L in drinking water can have a variety of deleterious effects for humans, agriculturally derived nitrate contamination of groundwater can be a serious public health issue. The Central Valley aquifer of California accounts for 13 percent of all the groundwater withdrawals in the United States. The Central Valley, which includes the San Joaquin Valley, is one of the most productive agricultural areas in the world and much of this groundwater is used for crop irrigation. However, rapid urbanization has led to increasing groundwater withdrawals for municipal public water supplies. That, in turn, has led to concern about how contaminants associated with agricultural practices will affect the chemical quality of groundwater in the San Joaquin Valley. Crop fertilization with various forms of nitrogen-containing compounds can greatly increase agricultural yields. However, leaching of nitrate from soils due to irrigation has led to substantial nitrate contamination of shallow groundwater. That shallow nitrate-contaminated groundwater has been moving deeper into the Central Valley aquifer since the 1960s. Denitrification can be an important process limiting the mobility of nitrate in groundwater systems. However, substantial denitrification requires adequate sources of electron donors in order to drive the process. In many cases, dissolved organic carbon (DOC) and particulate organic carbon

California wood energy program

Treesearch

Gary Brittner

1983-01-01

Many varieties of eucalyptus adapt well to growing conditions in the coastal and central valley regions of California. The California Department of Forestry is conducting growth research on a variety of sites throughout the state with many species. Eucalyptus is an excellent fuelwood and has potential for other uses, including chemical feedstocks. Plantations...

Mono Lake excursion recorded in sediment of the Santa Clara Valley, California

USGS Publications Warehouse

Mankinen, Edward A.; Wentworth, Carl M.

2004-01-01

Two intervals recording anomalous paleomagnetic inclinations were encountered in the top 40 meters of research drill hole CCOC in the Santa Clara Valley, California. The younger of these two intervals has an age of 28,090 ± 330 radiocarbon years B.P. (calibrated age ∼32.8 ka). This age is in excellent agreement with the latest estimate for the Mono Lake excursion at the type locality and confirms that the excursion has been recorded by sediment in the San Francisco Bay region. The age of an anomalous inclination change below the Mono Lake excursion was not directly determined, but estimates of sedimentation rates indicate that the geomagnetic behavior it represents most likely occurred during the Mono Lake/Laschamp time interval (∼45–28 ka). If true, it may represent one of several recurring fluctuations of magnetic inclination during an interval of a weak geomagnetic dipole, behavior noted in other studies in the region.

Groundwater withdrawal in the Central Valley, California: implications for San Andreas Fault stressing and lithosphere rheology

NASA Astrophysics Data System (ADS)

Lundgren, P.; Liu, Z.; Ali, S. T.; Farr, T.; Faunt, C. C.

2016-12-01

Anthropogenic perturbations to crustal loading due to groundwater pumping are increasingly recognized as causing changes in nearby fault stresses. We present preliminary analysis of crustal unloading in the Central Valley (CV), California, for the period 2006-2010 to infer Coulomb stress changes on the central San Andreas Fault (CSAF), lithospheric rheology, and system memory due to more than a century of groundwater withdrawal in the southern CV. We use data-driven unloading estimates to drive three-dimensional (3-D) finite element method models and compare model vertical surface deformation rates with observed GPS uplift rates outside the CV. Groundwater level changes are observed through well water elevation changes and through the resultant surface deformation (subsidence) by interferometric synthetic aperture radar (InSAR) and through broader scale changes in gravity from the GRACE satellite time variable gravity data [Famiglietti et al., 2011] that constrain the overall water volume changes. Combining InSAR with well-water data we are able to estimate the aquifer skeletal elastic and inelastic response and through a linear inversion derive the water volume (load) changes across the Central Valley and compare them with GRACE-inferred groundwater changes. Preliminary 3-D finite element method modeling that considers elastic and viscosity structure in the lithosphere gives three interesting results: 1) elastic models poorly fit the uplift rates near the SAF; 2) viscoelastic models that simulate different unloading histories show the past history of groundwater unloading has significant residual uplift rates and fault stress changes; 3) Coulomb stress change varies from inhibited on the locked (Carrizo) section to promoted on the creeping section of the SAF north of Parkfield. Thus, 3D models that account for lithosphere rheology, loading history viscous relaxation, have significant implications for longer-term time-dependent deformation, stress perturbation, and

27 CFR 9.129 - Arroyo Grande Valley.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Grande Valley.” (b) Approved maps. The appropriate maps for determining the boundary of Arroyo Grande..., NE, California,” edition of 1965, photorevised 1978. (2) “Tar Spring Ridge, California,” edition of... of Lopez Dam in section 32, T. 31 S., R. 14 E. (see “Tar Spring Ridge” map); (12) Then, in a...

27 CFR 9.129 - Arroyo Grande Valley.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Grande Valley.” (b) Approved maps. The appropriate maps for determining the boundary of Arroyo Grande..., NE, California,” edition of 1965, photorevised 1978. (2) “Tar Spring Ridge, California,” edition of... of Lopez Dam in section 32, T. 31 S., R. 14 E. (see “Tar Spring Ridge” map); (12) Then, in a...

Perspective View, Landsat Overlay Pasadena, California

NASA Image and Video Library

2000-02-21

This image shows a perspective view of the area around Pasadena, California, just north of Los Angeles. The cluster of hills surrounded by freeways on the left is the Verdugo Hills, which lie between the San Gabriel Valley and the San Fernando Valley.

Groundwater quality in the Borrego Valley, Central Desert, and Low-Use Basins of the Mojave and Sonoran Deserts, California

USGS Publications Warehouse

Parsons, Mary C.; Belitz, Kenneth

2014-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality information. Selected groundwater basins in the Borrego Valley, Central Desert, and Low-Use Basins of the Mojave and Sonoran Deserts constitute one of the study units being evaluated.

Napa River Restoration Project: Oakville to Oak Knoll Reach, Group C Site 14

EPA Pesticide Factsheets

Information about the SFBWQP Napa River Restoration Project: Oakville to Oak Knoll Reach, Group C Site 14, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

Volatile Organic Compound Emissions from Dairy Farming and their effect on San Joaquin Valley Air Quality

NASA Astrophysics Data System (ADS)

Blake, D. R.; Yang, M.; Meinardi, S.; Krauter, C.; Rowland, F. S.

2009-05-01

The San Joaquin Valley Air Pollution Control District of California issued a report identifying dairies as a main source of Volatile Organic Compounds (VOCs). A dairy study funded by the California Air Resources Board commenced shortly after the report was issued. Our University of California Irvine group teamed with California State University Fresno to determine the major sources of VOCs from various dairy operations and from a variety of dairy types. This study identified ethanol and methanol as two gases produced in major quantities throughout the dairies in the San Joaquin valley as by-products of yeast fermentation of silage. Three different types of sampling protocols were employed in order to determine the degree of enhancement of the target oxygenates in the valley air shed. Their sources, emission profiles, and emission rates were determined from whole air samples collected at various locations at the six dairies studied. An assessment of the impact of dairy emissions in the valley was achieved by using data obtained on low altitude NASA DC-8 flights through the valley, and from ground level samples collected though out the valley in a grid like design. Our data suggest that a significant amount of O3 production in the valley may come from methanol, ethanol, and acetaldehyde (a photochemical by-product ethanol oxidation). Our findings indicate that improvement to valley air quality may be obtained by focusing on instituting new silage containment practices and regulations.

Fault-zone guided waves from explosions in the San Andreas fault at Parkfield and Cienega Valley, California

USGS Publications Warehouse

Li, Y.-G.; Ellsworth, W.L.; Thurber, C.H.; Malin, P.E.; Aki, K.

1997-01-01

Fault-zone guided waves were successfully excited by near-surface explosions in the San Andreas fault zone both at Parkfield and Cienega Valley, central California. The guided waves were observed on linear, three-component seismic arrays deployed across the fault trace. These waves were not excited by explosions located outside the fault zone. The amplitude spectra of guided waves show a maximum peak at 2 Hz at Parkfield and 3 Hz at Cienega Valley. The guided wave amplitude decays sharply with observation distance from the fault trace. The explosion-excited fault-zone guided waves are similar to those generated by earthquakes at Parkfield but have lower frequencies and travel more slowly. These observations suggest that the fault-zone wave guide has lower seismic velocities as it approaches the surface at Parkfield. We have modeled the waveforms as S waves trapped in a low-velocity wave guide sandwiched between high-velocity wall rocks, resulting in Love-type fault-zone guided waves. While the results are nonunique, the Parkfield data are adequately fit by a shallow wave guide 170 m wide with an S velocity 0.85 km/sec and an apparent Q ??? 30 to 40. At Cienega Valley, the fault-zone wave guide appears to be about 120 m wide with an S velocity 0.7 km/sec and a Q ??? 30.

Dawn in the Apollo Valley

NASA Image and Video Library

2013-12-18

Beam Wave Guide antennas at Goldstone, known as the Beam Waveguide Cluster. They are located in an area at Goldstone called Apollo Valley. The Goldstone Deep Space Communications Complex is located in the Mojave Desert in California, USA.

Evaluation of the hydrologic system and selected water-management alternatives in the Owens Valley, California

USGS Publications Warehouse

Danskin, Wesley R.

1998-01-01

The Owens Valley, a long, narrow valley along the east side of the Sierra Nevada in eastcentral California, is the main source of water for the city of Los Angeles. The city diverts most of the surface water in the valley into the Owens River?Los Angeles Aqueduct system, which transports the water more than 200 miles south to areas of distribution and use. Additionally, ground water is pumped or flows from wells to supplement the surface-water diversions to the river? aqueduct system. Pumpage from wells needed to supplement water export has increased since 1970, when a second aqueduct was put into service, and local residents have expressed concerns that the increased pumping may have a detrimental effect on the environment and the native vegetation (indigenous alkaline scrub and meadow plant communities) in the valley. Native vegetation on the valley floor depends on soil moisture derived from precipitation and from the unconfined part of a multilayered ground-water system. This report, which describes the evaluation of the hydrologic system and selected water-management alternatives, is one in a series designed to identify the effects that ground-water pumping has on native vegetation and evaluate alternative strategies to mitigate any adverse effects caused by pumping. The hydrologic system of the Owens Valley can be conceptualized as having three parts: (1) an unsaturated zone affected by precipitation and evapotranspiration; (2) a surface-water system composed of the Owens River, the Los Angeles Aqueduct, tributary streams, canals, ditches, and ponds; and (3) a saturated ground-water system contained in the valley fill. Analysis of the hydrologic system was aided by development of a ground-water flow model of the ?aquifer system,? which is defined as the most active part of the ground-water system and which includes nearly all of the Owens Valley except for the area surrounding the Owens Lake. The model was calibrated and verified for water years 1963?88 and

Spatial use by wintering greater white-fronted geese relative to a decade of habitat change in California's Central Valley

USGS Publications Warehouse

Ackerman, Joshua T.; Takekawa, John Y.; Orthmeyer, D.L.; Fleskes, J.P.; Yee, J.L.; Kruse, K.L.

2006-01-01

We investigated the effect of recent habitat changes in California's Central Valley on wintering Pacific greater white-fronted geese (Anser albifrons frontalis) by comparing roost-to-feed distances, distributions, population range sizes, and habitat use during 1987-1990 and 1998-2000. These habitat changes included wetland restoration and agricultural land enhancement due to the 1990 implementation of the Central Valley Joint Venture, increased land area used for rice (Oryza sativa) production, and the practice of flooding, rather than burning, rice straw residues for decomposition because of burning restrictions enacted in 1991. Using radiotelemetry, we tracked 192 female geese and recorded 4,516 locations. Geese traveled shorter distances between roosting and feeding sites during 1998-2000 (24.2 ?? 2.2 km) than during 1987-1990 (32.5 ?? 3.4 km); distance traveled tended to decline throughout winter during both decades and varied among watershed basins. Population range size was smaller during 1998-2000 (3,367 km2) than during 1987-1990 (5,145 km2), despite a 2.2-fold increase in the size of the Pacific Flyway population of white-fronted geese during the same time period. The population range size also tended to increase throughout winter during both decades. Feeding and roosting distributions of geese also differed between decades; geese shifted into basins that had the greatest increases in the amount of area in rice production (i.e., American Basin) and out of other basins (i.e., Delta Basin). The use of rice habitat for roosting (1987-1990: 40%, 1998-2000: 54%) and feeding (1987-1990: 57%, 1998-2000: 72%) increased between decades, whereas use of wetlands declined for roosting (1987-1990: 36%, 1998-2000: 31%) and feeding (1987-1990: 22%, 1998-2000: 12%). Within postharvested rice habitats, geese roosted and fed primarily in burned rice fields during 1987-1990 (roost: 43%, feed: 34%), whereas they used flooded rice fields during 1998-2000 (roost: 78%, feed: 64

Early results from a newly-established provenance test in Valley Oak (Quercus lobata) show significant population differentiation

Treesearch

Jessica W. Wright; Victoria L. Sork

2017-01-01

Valley oak (Quercus lobata) is a majestic, endemic California native oak, found throughout California's foothills, valleys and flood plains. It is threatened because: Contracted range due to housing and agriculture.Low recruitment in existing stands as a function of land use and...

Overwintering Biology of Culex (Diptera: Culicidae) Mosquitoes in the Sacramento Valley of California

PubMed Central

NELMS, BRITTANY M.; MACEDO, PAULA A.; KOTHERA, LINDA; SAVAGE, HARRY M.; REISEN, WILLIAM K.

2014-01-01

At temperate latitudes, Culex (Diptera: Culicidae) mosquitoes typically overwinter as adult females in reproductive arrest and also may serve as reservoir hosts for arboviruses when cold temperatures arrest viral replication. To evaluate their role in the persistence of West Nile virus (WNV) in the Sacramento Valley of California, the induction and termination of diapause were investigated for members of the Culex pipiens (L.) complex, Culex tarsalis Coquillett, and Culex stigmatosoma Dyar under field, seminatural, and experimental conditions. All Culex spp. remained vagile throughout winter, enabling the collection of 3,174 females and 1,706 males from diverse habitats during the winters of 2010–2012. Overwintering strategies included both quiescence and diapause. In addition, Cx. pipiens form molestus Forskäl females remained reproductively active in both underground and aboveground habitats. Some blood-fed, gravid, and parous Cx. tarsalis and Cx. pipiens complex females were collected throughout the winter period. Under both field and experimental conditions, Cx. tarsalis and Cx. stigmatosoma females exposed to autumnal conditions arrested primary follicular maturation at previtellogenic stage I, with primary to secondary follicular ratios <1.5 (indicative of a hormonally induced diapause). In contrast, most Cx. pipiens complex females did not enter reproductive diapause and ovarian follicles matured to ≥stage I–II (host-seeking arrest) or were found in various stages of degeneration. Diapause was initiated in the majority of Cx. tarsalis and Cx. stigmatosoma females by mid-late October and was terminated after the winter solstice, but host-seeking seemed limited by temperature. An accrual of 97.52 ± 30.7 and 162.85 ± 79.3 degree-days after the winter solstice was estimated to be necessary for diapause termination in Cx. tarsalis under field and seminatural conditions, respectively. An increase in the proportion of blood-fed Culex females in resting

An evaluation of the regional acid deposition model surface module for ozone uptake at three sites in the San Joaquin Valley of California

NASA Technical Reports Server (NTRS)

Massman, W. J.; Pederson, J.; Delany, A.; Grantz, D.; Hertog, G. Den; Neumann, H. H.; Oncley, S. P.; Pearson, R., Jr.; Shaw, R. H.

1994-01-01

Plants and soils act as major sinks for the destruction of tropospheric ozone, especially during daylight hours when plant stomata open and are thought to provide the dominant pathway for the uptake of ozone. The present study, part of the California Ozone Deposition Experiment, compares predictions of the regional acid deposition model ozone surface conductance module with surface conductance data derived from eddy covariance measurements of ozone flux taken at a grape, a cotton, and a grassland site in the San Joaquin Valley of California during the summer of 1991. Results indicate that the model (which was developed to provide long-term large-area estimates for the eastern United States) significantly overpredicts the surface conductance at all times of the day for at least two important types of plant cover of the San Joaquin Valley and that it incorrectly partitions the ozone flux between transpiring and nontranspiring components of the surface at the third site. Consequently, the model either overpredicts or inaccurately represents the observed deposition velocities. Other results indicate that the presence of dew does not reduce the rate of ozone deposition, contradicting to model assumptions, and that model assumptions involving the dependency of stomata upon environmental temperature are unnecessary. The effects of measurement errors and biases, arising from the presence of the roughness sublayer and possible photochemical reactions, are also discussed. A simpler model for ozone surface deposition (at least for the San Joaquin Valley) is proposed and evaluated.

Reexaming Owens Valley: Partitioning of Discrete and Distributed Transtension, Structural Controls on Magmatism, and Seismic Potential within an Active Rift Zone, Eastern California.

NASA Astrophysics Data System (ADS)

Levy, D. A.; Haproff, P. J.; Yin, A.

2016-12-01

Crustal-scale transtensional deformation is common in intracontinental extensional settings. However, along-strike variations in the geometry, kinematics, and linkages between rift-related faults, along with controls on local magmatic plumbing, remain inadequately examined. In this study, we conducted geologic mapping of active structures within central and northern Owens Valley of eastern California. C. Owens Valley features right-slip oblique deformation accommodated by three discrete north-south-trending faults: (1) the right-slip Owens Valley fault (OVF) and rift-bounding (2) Sierra Nevada Frontal fault (SNFF) and (3) the White-Inyo Mountains fault (WIMF). The OVF also serves as a lithospheric-scale, vertical conduit for asthenospheric-derived magma to migrate upwards and erupt at Big Pine Volcanic Field. Right-slip shear within C. Owens Valley is transferred to the SNFF of N. Owens Valley via the Poverty Hills restraining bend. In contrast to C. Owens Valley, the northern segment is dominated by distributed E-W to NE-SW-oriented extension, evidenced by normal fault scarps throughout Volcanic Tablelands and basin floor. Furthermore, the White Mountain fault which bounds N. Owens Valley to the east consists of a master west-dipping detachment fault that thinned the lithosphere, allowing for asthenospheric upwelling into the crust beneath the western rift shoulder. Subvertical, right-slip faults of the SNFF provide a conduit for magma to erupt on the surface throughout the Long Valley Caldera, Mono-Inyo Craters, and Mono Basin region. Our mapping demonstrates complex strain partitioning of discrete and distributed deformation within an alternating pure and simple shear, transtensional rift zone. Lastly, we present previously unknown relationships in Owens Valley between lithospheric-scale fault systems, seismic potential, and rift magmatism.

Ground-water quality in the southeastern Sacramento Valley aquifer, California, 1996

USGS Publications Warehouse

Milby Dawson, Barbara J.

2001-01-01

In 1996, the U.S. Geological Survey sampled 29 domestic wells and 2 monitoring wells in the southeastern Sacramento Valley as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. This area, designated as the NAWQA Sacramento subunit study area, was chosen because it had the largest amount of ground-water use in the Sacramento River Basin. The Sacramento subunit study area is about 4,400 square kilometers and includes intense agricultural and urban development. The wells sampled ranged from 14.9 to 79.2 meters deep. Ground-water samples from 31 wells were analyzed for 6 field measurements, 14 inorganic constituents, 6 nutrient constituents, organic carbon, 86 pesticides, 87 volatile organic compounds, tritium (hydrogen-3), radon-222, deuterium (hydrogen-2), and oxygen-18. Nitrate levels were lower than the 2000 drinking-water standards in all but one well, but many detections were in the range that indicated an effect by human activities on ground-water quality. Radon was detected in all wells, and was measured at levels above the proposed Federal 2000 maximum contaminant level in 90 percent of the wells. Five pesticides and one pesticide degradation product were detected in ground-water samples and concentrations were below 2000 drinking-water standards. All pesticides detected during this study have been used in the Sacramento Valley. Thirteen volatile organic compounds were detected in ground water. One detection of trichloroethene was above Federal 2000 drinking-water standards, and another, tetrachloromethane, was above California 1997 drinking-water standards; both occurred in a well that had eight volatile organic compound detections and is near a known source of ground-water contamination. Pesticides and volatile organic compounds were detected in agricultural and urban areas; both pesticides and volatile organic compounds were detected at a higher frequency in urban wells. Ground-water chemistry indicates that natural

Groundwater Quality in the Central Eastside San Joaquin Valley, California

USGS Publications Warehouse

Belitz, Kenneth; Landon, Matthew K.

2010-01-01

The Central Eastside study unit is located in California's San Joaquin Valley. The 1,695 square mile study unit includes three groundwater subbasins: Modesto, Turlock, and Merced (California Department of Water Resources, 2003). The primary water-bearing units consist of discontinuous lenses of gravel, sand, silt, and clay, which are derived largely from the Sierra Nevada Mountains to the east. Public-supply wells provide most of the drinking water supply in the Central Eastside. Consequently, the primary aquifer in the Central Eastside study unit is defined as that part of the aquifer corresponding to the perforated interval of wells listed in the California Department of Public Health database. Public-supply wells are typically drilled to depths of 200 to 350 feet, consist of solid casing from the land surface to a depth of about 100 to 200 feet, and they are perforated below the solid casing. Water quality in the shallower and deeper parts of the aquifer system may differ from that in the primary aquifer. The Central Eastside study unit has hot and dry summers and cool, moist, winters. Average annual rainfall ranges from 11 to 15 inches. The Stanislaus, Tuolumne, and Merced Rivers, with headwaters in the Sierra Nevada Mountains, are the primary streams traversing the study unit. Land use in the study unit is approximately 59 percent (%) agricultural, 34% natural (primarily grassland), and 7% urban. The primary crops are almonds, walnuts, peaches, grapes, grain, corn, and alfalfa. The largest urban areas (2003 population in parentheses) are the cities of Modesto (206,872), Turlock (63,467), and Merced (69,512). Municipal water use accounts for about 5% of the total water use in the Central Eastside study unit, with the remainder used for irrigated agriculture. Groundwater accounts for about 75% of the municipal supply, and surface water accounts for about 25%. Recharge to the groundwater flow system is primarily from percolation of irrigation return

Napa earthquake: An earthquake in a highly connected world

NASA Astrophysics Data System (ADS)

Bossu, R.; Steed, R.; Mazet-Roux, G.; Roussel, F.

2014-12-01

The Napa earthquake recently occurred close to Silicon Valley. This makes it a good candidate to study what social networks, wearable objects and website traffic analysis (flashsourcing) can tell us about the way eyewitnesses react to ground shaking. In the first part, we compare the ratio of people publishing tweets and with the ratio of people visiting EMSC (European Mediterranean Seismological Centre) real time information website in the first minutes following the earthquake occurrence to the results published by Jawbone, which show that the proportion of people waking up depends (naturally) on the epicentral distance. The key question to evaluate is whether the proportions of inhabitants tweeting or visiting the EMSC website are similar to the proportion of people waking up as shown by the Jawbone data. If so, this supports the premise that all methods provide a reliable image of the relative ratio of people waking up. The second part of the study focuses on the reaction time for both Twitter and EMSC website access. We show, similarly to what was demonstrated for the Mineral, Virginia, earthquake (Bossu et al., 2014), that hit times on the EMSC website follow the propagation of the P waves and that 2 minutes of website traffic is sufficient to determine the epicentral location of an earthquake on the other side of the Atlantic. We also compare with the publication time of messages on Twitter. Finally, we check whether the number of tweets and the number of visitors relative to the number of inhabitants is correlated to the local level of shaking. Together these results will tell us whether the reaction of eyewitnesses to ground shaking as observed through Twitter and the EMSC website analysis is tool specific (i.e. specific to Twitter or EMSC website) or whether they do reflect people's actual reactions.

Mapping playa evaporite minerals with AVIRIS data: A first report from death valley, California

USGS Publications Warehouse

Crowley, J.K.

1993-01-01

Efflorescent salt crusts in Death Valley, California, were mapped by using Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data and a recently developed least-squares spectral band-fitting algorithm. Eight different saline minerals were remotely identified, including three borates, hydroboracite, pinnoite, and rivadavite, that have not been previously reported from the Death Valley efflorescent crusts. The three borates are locally important phases in the crusts, and at least one of the minerals, rivadavite, appears to be forming directly from brine. Borates and other evaporite minerals provide a basis for making remote chemical measurements of desert hydrologic systems. For example, in the Eagle Borax Spring area, the AVIRIS mineral maps pointed to elevated magnesium and boron levels in the ground waters, and to the action of chemical divides causing subsurface fractionation of calcium. Many other chemical aspects of playa brines should have an expression in the associated evaporite assemblages. Certain anhydrous evaporites, including anhydrite, glauberite, and thenardite, lack absorption bands in the visible and near-infrared wavelength range, and crusts composed of these minerals could not be characterized by using AVIRIS. In these situations, thermal-infrared remote sensing data may complement visible and near-infrared data for mapping evaporites. Another problem occurred in wet areas of Death Valley, where water absorption caused low signal levels in the 2.0-2.5 ??m wavelength region that obscured any spectral features of evaporite minerals. Despite these difficulties, the results of this study demonstrate the potential for using AVIRIS and other imaging spectrometer data to study playa chemistry. Such data can be useful for understanding chemical linkages between evaporites and ground waters, and will facilitate studies of how desert ground-water regimes change through time in response to climatic and other variables. ?? 1993.

Delineation of faulting and basin geometry along a seismic reflection transect in urbanized San Bernardino Valley, California

USGS Publications Warehouse

Stephenson, W.J.; Odum, J.K.; Williams, R.A.; Anderson, M.L.

2002-01-01

Fourteen kilometers of continuous, shallow seismic reflection data acquired through the urbanized San Bernardino Valley, California, have revealed numerous faults between the San Jacinto and San Andreas faults as well as a complex pattern of downdropped and uplifted blocks. These data also indicate that the Loma Linda fault continues northeastward at least 4.5 km beyond its last mapped location on the southern edge of the valley and to within at least 2 km of downtown San Bernardino. Previously undetected faults within the valley northeast of the San Jacinto fault are also imaged, including the inferred western extension of the Banning fault and several unnamed faults. The Rialto-Colton fault is interpreted southwest of the San Jacinto fault. The seismic data image the top of the crystalline basement complex across 70% of the profile length and show that the basement has an overall dip of roughly 10?? southwest between Perris Hill and the San Jacinto fault. Gravity and aeromagnetic data corroborate the interpreted location of the San Jacinto fault and better constrain the basin depth along the seismic profile to be as deep as 1.7 km. These data also corroborate other fault locations and the general dip of the basement surface. At least 1.2 km of apparent vertical displacement on the basement is observed across the San Jacinto fault at the profile location. The basin geometry delineated by these data was used to generate modeled ground motions that show peak horizontal amplifications of 2-3.5 above bedrock response in the 0.05- to 1.0-Hz frequency band, which is consistent with recorded earthquake data in the valley.

Comparison of Summer and Winter California Central Valley Aerosol Distributions from Lidar and MODIS Measurements

NASA Technical Reports Server (NTRS)

Lewis, Jasper R., Jr.; DeYoung, Russell J.; Chu, D. Allen

2010-01-01

Aerosol distributions from two aircraft lidar campaigns conducted in the California Central Valley are compared in order to identify seasonal variations. Aircraft lidar flights were conducted in June 2003 and February 2008. While the PM2.5 concentration is highest in the winter, the aerosol optical depth measured from MODIS is highest in the summer. A seasonal comparison shows that PM2.5 in the winter can exceed summer PM2.5 by 55%, while summer AOD exceeds winter AOD by 43%. Higher temperatures wildfires in the summer produce elevated aerosol layers that are detected by satellite measurements, but not surface particulate matter monitors. Measurements of the boundary layer height from lidar instruments are necessary to incorporate satellite measurements with air quality measurements.

Spatial variations in fault friction related to lithology from rupture and afterslip of the 2014 South Napa, California, earthquake

USGS Publications Warehouse

Michael Floyd,; Richard Walters,; John Elliot,; Funning, Gareth J.; Svarc, Jerry L.; Murray, Jessica R.; Andy Hooper,; Yngvar Larsen,; Petar Marinkovic,; Bürgmann, Roland; Johanson, Ingrid; Tim Wright,

2016-01-01

Following earthquakes, faults are often observed to continue slipping aseismically. It has been proposed that this afterslip occurs on parts of the fault with rate-strengthening friction that are stressed by the mainshock, but our understanding has been limited by a lack of immediate, high-resolution observations. Here we show that the behavior of afterslip following the 2014 South Napa earthquake varied over distances of only a few kilometers. This variability cannot be explained by coseismic stress changes alone. We present daily positions from continuous and survey GPS sites that we re-measured within 12 hours of the mainshock, and surface displacements from the new Sentinel-1 radar mission. This unique geodetic data set constrains the distribution and evolution of coseismic and postseismic fault slip with exceptional resolution in space and time. We suggest that the observed heterogeneity in behavior is caused by lithological controls on the frictional properties of the fault plane.

California Clean Tech

EPA Pesticide Factsheets

The California Clean Air Technology Initiative is a partnership to develop clean air technologies for the San Joaquin Valley and South Coast Air Basins through collaborative projects in technology research, development, demonstration, and deployment.

Seismic imaging of the metamorphism of young sediment into new crystalline crust in the actively rifting Imperial Valley, California

USGS Publications Warehouse

Han, Liang; Hole, John; Stock, Joann; Fuis, Gary S.; Williams, Colin F.; Delph, Jonathan; Davenport, Kathy; Livers, Amanda

2016-01-01

Plate-boundary rifting between transform faults is opening the Imperial Valley of southern California and the rift is rapidly filling with sediment from the Colorado River. Three 65–90 km long seismic refraction profiles across and along the valley, acquired as part of the 2011 Salton Seismic Imaging Project, were analyzed to constrain upper crustal structure and the transition from sediment to underlying crystalline rock. Both first arrival travel-time tomography and frequency-domain full-waveform inversion were applied to provide P-wave velocity models down to ∼7 km depth. The valley margins are fault-bounded, beyond which thinner sediment has been deposited on preexisting crystalline rocks. Within the central basin, seismic velocity increases continuously from ∼1.8 km/s sediment at the surface to >6 km/s crystalline rock with no sharp discontinuity. Borehole data show young sediment is progressively metamorphosed into crystalline rock. The seismic velocity gradient with depth decreases approximately at the 4 km/s contour, which coincides with changes in the porosity and density gradient in borehole core samples. This change occurs at ∼3 km depth in most of the valley, but at only ∼1.5 km depth in the Salton Sea geothermal field. We interpret progressive metamorphism caused by high heat flow to be creating new crystalline crust throughout the valley at a rate comparable to the ≥2 km/Myr sedimentation rate. The newly formed crystalline crust extends to at least 7–8 km depth, and it is shallower and faster where heat flow is higher. Most of the active seismicity occurs within this new crust.

Seismic imaging of the metamorphism of young sediment into new crystalline crust in the actively rifting Imperial Valley, California

NASA Astrophysics Data System (ADS)

Han, Liang; Hole, John A.; Stock, Joann M.; Fuis, Gary S.; Williams, Colin F.; Delph, Jonathan R.; Davenport, Kathy K.; Livers, Amanda J.

2016-11-01

Plate-boundary rifting between transform faults is opening the Imperial Valley of southern California and the rift is rapidly filling with sediment from the Colorado River. Three 65-90 km long seismic refraction profiles across and along the valley, acquired as part of the 2011 Salton Seismic Imaging Project, were analyzed to constrain upper crustal structure and the transition from sediment to underlying crystalline rock. Both first arrival travel-time tomography and frequency-domain full-waveform inversion were applied to provide P-wave velocity models down to ˜7 km depth. The valley margins are fault-bounded, beyond which thinner sediment has been deposited on preexisting crystalline rocks. Within the central basin, seismic velocity increases continuously from ˜1.8 km/s sediment at the surface to >6 km/s crystalline rock with no sharp discontinuity. Borehole data show young sediment is progressively metamorphosed into crystalline rock. The seismic velocity gradient with depth decreases approximately at the 4 km/s contour, which coincides with changes in the porosity and density gradient in borehole core samples. This change occurs at ˜3 km depth in most of the valley, but at only ˜1.5 km depth in the Salton Sea geothermal field. We interpret progressive metamorphism caused by high heat flow to be creating new crystalline crust throughout the valley at a rate comparable to the ≥2 km/Myr sedimentation rate. The newly formed crystalline crust extends to at least 7-8 km depth, and it is shallower and faster where heat flow is higher. Most of the active seismicity occurs within this new crust.

Groundwater quality in the Southern Sierra Nevada, California

USGS Publications Warehouse

Fram, Miranda S.; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The Tehachapi-Cummings Valley and Kern River Valley basins and surrounding watersheds in the Southern Sierra Nevada constitute one of the study units being evaluated.

Texture and depositional history of near-surface alluvial deposits in the central part of the western San Joaquin Valley, California

USGS Publications Warehouse

Laudon, Julie; Belitz, Kenneth

1989-01-01

Saline conditions and associated high levels of selenium and other soluble trace elements in soil, shallow ground water, and agricultural drain water of the western San Joaquin Valley, California, have prompted a study of the texture of near-surface alluvial deposits in the central part of the western valley. Texture is characterized by the percentage of coarse-grained sediment present within a specified subsurface depth interval and is used as a basis for mapping the upper 50 feet of deposits. Resulting quantitative descriptions of the deposits are used to interpret the late Quaternary history of the area. Three hydrogeologic units--Coast Range alluvium, flood-basin deposits, and Sierran sand--can be recognized in the upper 50 feet of deposits in the central part of the western San Joaquin Valley. The upper 30 feet of Coast Range alluvium and the adjacent 5 to 35 feet of flood-basin deposits are predominantly fine grained. These fine-grained Coast Range deposits are underlain by coarse-grained channel deposits. The fine-grained flood basin deposits are underlain by coarse-grained Sierran sand. The extent and orientation of channel deposits below 20 feet in the Coast Range alluvium indicate that streams draining the Coast Range may have been tributary to the axial stream that deposited the Sierran sand and that streamflow may have been to the southeast. The fining-upward stratigraphic sequence in the upper 50 feet of deposits and the headward retreat of tributary stream channels from the valley trough with time support a recent hypothesis of climatic control of alluviation in the western San Joaquin Valley.

California's potential volcanic hazards

USGS Publications Warehouse

Jorgenson, P.

1989-01-01

This is a summary of "Potential Hazards from Future Volcanic Eruptions in California' (USGS Bulletin No. 1847: price $4.75). The chief areas of danger are Lassen Peak, Mount Shasta and Medicine Lake Highland in the north; Clear Lake, Mono Lake and Long Valley in the centre; and Owen's River-Death Valley, Amboy Crater and the Saltan Butter in the south of the State. -A.Scarth

Long-term afterslip of the M6.0, 2004 Parkfield, California, earthquake—Implications for forecasting amount and duration of afterslip on other major creeping faults

USGS Publications Warehouse

Lienkaemper, James J.; McFarland, Forrest S.

2017-01-01

We present the longest record of surface afterslip on a continental strike‐slip fault for the 2004 M 6.0 Parkfield, California, earthquake, from which we can derive critical information about the duration and predictability of afterslip relevant to urban displacement hazard applications. Surface slip associated with this event occurred entirely postseismically along the interseismically creeping (0.6–1.5  cm/yr) main trace of the San Andreas fault. Using the first year of afterslip data, the program AFTER correctly predicted the cumulative surface afterslip (maximum ∼35  cm) eventually attained. By 1 yr postearthquake, observed afterslip had accumulated to only ∼74% of its modeled final value uf in units of length. The 6‐yr data suggested final slip would be reached everywhere by ∼6–12  yrs.Parkfield’s afterslip lasted much longer (∼6–12  yrs) than afterslip following a 2014 M 6.0 event in Napa, California, where no interseismic creep was known, and its afterslip neared completion (∼97% of uf) by 1 yr. The uncertainty in uf for the Napa event fell to ≤2  cm in only three months, versus in 2 yrs for the Parkfield event, mostly because duration of the power‐law stage of afterslip at Parkfield is much longer, ∼1000 (493–1666) days versus ∼100 (35–421) days for Napa. Because the urban Hayward fault near San Francisco, California, like the Parkfield section, exhibits interseismic creep in a similar geological regime, significant afterslip might last for up to a decade following an anticipated M≥6.7 earthquake, potentially delaying postearthquake recovery.

Tomographic Rayleigh-wave group velocities in the Central Valley, California centered on the Sacramento/San Joaquin Delta

USGS Publications Warehouse

Fletcher, Jon Peter B.; Erdem, Jemile; Seats, Kevin; Lawrence, Jesse

2016-01-01

If shaking from a local or regional earthquake in the San Francisco Bay region were to rupture levees in the Sacramento/San Joaquin Delta then brackish water from San Francisco Bay would contaminate the water in the Delta: the source of fresh water for about half of California. As a prelude to a full shear-wave velocity model that can be used in computer simulations and further seismic hazard analysis, we report on the use of ambient noise tomography to build a fundamental-mode, Rayleigh-wave group velocity model for the region around the Sacramento/San Joaquin Delta in the western Central Valley, California. Recordings from the vertical component of about 31 stations were processed to compute the spatial distribution of Rayleigh wave group velocities. Complex coherency between pairs of stations were stacked over 8 months to more than a year. Dispersion curves were determined from 4 to about 18 seconds. We calculated average group velocities for each period and inverted for deviations from the average for a matrix of cells that covered the study area. Smoothing using the first difference is applied. Cells of the model were about 5.6 km in either dimension. Checkerboard tests of resolution, which is dependent on station density, suggest that the resolving ability of the array is reasonably good within the middle of the array with resolution between 0.2 and 0.4 degrees. Overall, low velocities in the middle of each image reflect the deeper sedimentary syncline in the Central Valley. In detail, the model shows several centers of low velocity that may be associated with gross geologic features such as faulting along the western margin of the Central Valley, oil and gas reservoirs, and large cross cutting features like the Stockton arch. At shorter periods around 5.5s, the model’s western boundary between low and high velocities closely follows regional fault geometry and the edge of a residual isostatic gravity low. In the eastern part of the valley, the boundaries

Tomographic Rayleigh wave group velocities in the Central Valley, California, centered on the Sacramento/San Joaquin Delta

NASA Astrophysics Data System (ADS)

Fletcher, Jon B.; Erdem, Jemile; Seats, Kevin; Lawrence, Jesse

2016-04-01

If shaking from a local or regional earthquake in the San Francisco Bay region were to rupture levees in the Sacramento/San Joaquin Delta, then brackish water from San Francisco Bay would contaminate the water in the Delta: the source of freshwater for about half of California. As a prelude to a full shear-wave velocity model that can be used in computer simulations and further seismic hazard analysis, we report on the use of ambient noise tomography to build a fundamental mode, Rayleigh wave group velocity model for the region around the Sacramento/San Joaquin Delta in the western Central Valley, California. Recordings from the vertical component of about 31 stations were processed to compute the spatial distribution of Rayleigh wave group velocities. Complex coherency between pairs of stations was stacked over 8 months to more than a year. Dispersion curves were determined from 4 to about 18 s. We calculated average group velocities for each period and inverted for deviations from the average for a matrix of cells that covered the study area. Smoothing using the first difference is applied. Cells of the model were about 5.6 km in either dimension. Checkerboard tests of resolution, which are dependent on station density, suggest that the resolving ability of the array is reasonably good within the middle of the array with resolution between 0.2 and 0.4°. Overall, low velocities in the middle of each image reflect the deeper sedimentary syncline in the Central Valley. In detail, the model shows several centers of low velocity that may be associated with gross geologic features such as faulting along the western margin of the Central Valley, oil and gas reservoirs, and large crosscutting features like the Stockton arch. At shorter periods around 5.5 s, the model's western boundary between low and high velocities closely follows regional fault geometry and the edge of a residual isostatic gravity low. In the eastern part of the valley, the boundaries of the low

An Assessment of Irrigation Technology Performance in the Southern San Joaquin Valley of California

NASA Astrophysics Data System (ADS)

Vaux, H. J., Jr.; Handley, Dale F.; Giboney, Paul M.

1990-01-01

Seasonal applied water measurements were obtained for 1710 irrigated fields in the southern San Joaquin Valley of California. Most of the fields were planted to one of five major crops: citrus, almonds, grapes, cotton, and small grains. These crops were irrigated with a wide array of irrigation technologies, including drip, sprinkler, furrows with tailwater reuse facilities, conventional furrows, and border irrigation systems. The data were analyzed within an accounting framework to standardize for a variety of climatic and cultural variations. Analyses of the mean depths of applied water by crop and irrigation technology and of the standardized results reveal that drip irrigation systems were associated with the lowest levels of applied water on permanent crops and that the levels of water applied with sprinklers did not differ significantly from those applied with surface systems on either permanent or annual crops.

Structural superposition in fault systems bounding Santa Clara Valley, California

USGS Publications Warehouse

Graymer, Russell W.; Stanley, Richard G.; Ponce, David A.; Jachens, Robert C.; Simpson, Robert W.; Wentworth, Carl M.

2015-01-01

Santa Clara Valley is bounded on the southwest and northeast by active strike-slip and reverse-oblique faults of the San Andreas fault system. On both sides of the valley, these faults are superposed on older normal and/or right-lateral normal oblique faults. The older faults comprised early components of the San Andreas fault system as it formed in the wake of the northward passage of the Mendocino Triple Junction. On the east side of the valley, the great majority of fault displacement was accommodated by the older faults, which were almost entirely abandoned when the presently active faults became active after ca. 2.5 Ma. On the west side of the valley, the older faults were abandoned earlier, before ca. 8 Ma and probably accumulated only a small amount, if any, of the total right-lateral offset accommodated by the fault zone as a whole. Apparent contradictions in observations of fault offset and the relation of the gravity field to the distribution of dense rocks at the surface are explained by recognition of superposed structures in the Santa Clara Valley region.

Liquefaction sites, Imperial Valley, California.

USGS Publications Warehouse

Youd, T.L.; Bennett, M.J.

1983-01-01

Sands that did and did not liquefy at two sites during the 1979 Imperial Valley, Calif., earthquake (ML = 6.6) are identified and their properties evaluated. SPT tests were used to evaluate liquefaction susceptibility. Loose fine sands in an abandoned channel liquefied and produced sand boils, ground fissures, and a lateral spread at the Heber Road sites. Evidence of liquefaction was not observed over moderately dense over-bank sand east of the channel nor over dense point-bar sand to the west. -from ASCE Publications Information

Heat flow and geothermal potential of the East Mesa KGRA, Imperial Valley, California

NASA Technical Reports Server (NTRS)

Swanberg, C. A.

1974-01-01

The East Mesa KGRA (Known Geothermal Resource Area) is located in the southeast part of the Imperial Valley, California, and is roughly 150 kilometers square in areal extent. A new heat flow technique which utilizes temperature gradient measurements across best clays is presented and shown to be as accurate as conventional methods for the present study area. Utilizing the best clay gradient technique, over 70 heat flow determinations have been completed within and around the East Mesa KGRA. Background heat flow values range from 1.4 to 2.4 hfu (1 hfu = .000001 cal. per square centimeter-second) and are typical of those throughout the Basin and Range province. Heat flow values for the northwest lobe of the KGRA (Mesa anomaly) are as high as 7.9 hfu, with the highest values located near gravity and seismic noise maxima and electrical resistivity minima. An excellent correlation exists between heat flow contours and faults defined by remote sensing and microearthquake monitoring.

Chronology, sedimentology, and microfauna of groundwater discharge deposits in the central Mojave Desert, Valley Wells, California

USGS Publications Warehouse

Pigati, J.S.; Miller, D.M.; Bright, J.E.; Mahan, S.A.; Nekola, J.C.; Paces, J.B.

2011-01-01

groundwater supported persistent and long-lived desert wetlands in many broad valleys and basins in the American Southwest. When active, these systems provided important food and water sources for local fauna, supported hydrophilic and phreatophytic vegetation, and acted as catchments for eolian and alluvial sediments. Desert wetlands are represented in the geologic record by groundwater discharge deposits, which are also called spring or wetland deposits. Groundwater discharge deposits contain information on the timing and magnitude of past changes in water-table levels and, thus, are a source of paleohydrologic and paleoclimatic information. Here, we present the results of an investigation of extensive groundwater discharge deposits in the central Mojave Desert at Valley Wells, California. We used geologic mapping and stratigraphic relations to identify two distinct wetland sequences at Valley Wells, which we dated using radiocarbon, luminescence, and uranium-series techniques. We also analyzed the sediments and microfauna (ostracodes and gastropods) to reconstruct the specific environments in which they formed. Our results suggest that the earliest episode of high water-table conditions at Valley Wells began ca. 60 ka (thousands of calendar yr B.P.), and culminated in peak discharge between ca. 40 and 35 ka. During this time, cold (4-12 ??C) emergent groundwater supported extensive wetlands that likely were composed of a wet, sedge-rush-tussock meadow mixed with mesic riparian forest. After ca. 35 ka, the water table dropped below the ground surface but was still shallow enough to support dense stands of phreatophytes through the Last Glacial Maximum (LGM). The water table dropped further after the LGM, and xeric conditions prevailed until modest wetlands returned briefly during the Younger Dryas cold event (13.0-11.6 ka). We did not observe any evidence of wet conditions during the Holocene at Valley Wells. The timing of these fluctuations is consistent with

Chronology, sedimentology, and microfauna of groundwater discharge deposits in the central Mojave Desert, Valley Wells, California

USGS Publications Warehouse

Pigati, Jeffrey S.; Miller, David M.; Bright, Jordon E.; Mahan, Shannon; Nekola, Jeffrey C.; Paces, James B.

2011-01-01

During the late Pleistocene, emergent groundwater supported persistent and long-lived desert wetlands in many broad valleys and basins in the American Southwest. When active, these systems provided important food and water sources for local fauna, supported hydrophilic and phreatophytic vegetation, and acted as catchments for eolian and alluvial sediments. Desert wetlands are represented in the geologic record by groundwater discharge deposits, which are also called spring or wetland deposits. Groundwater discharge deposits contain information on the timing and magnitude of past changes in water-table levels and, thus, are a source of paleohydrologic and paleoclimatic information. Here, we present the results of an investigation of extensive groundwater discharge deposits in the central Mojave Desert at Valley Wells, California. We used geologic mapping and stratigraphic relations to identify two distinct wetland sequences at Valley Wells, which we dated using radiocarbon, luminescence, and uranium-series techniques. We also analyzed the sediments and microfauna (ostracodes and gastropods) to reconstruct the specific environments in which they formed. Our results suggest that the earliest episode of high water-table conditions at Valley Wells began ca. 60 ka (thousands of calendar yr B.P.), and culminated in peak discharge between ca. 40 and 35 ka. During this time, cold (4–12 °C) emergent groundwater supported extensive wetlands that likely were composed of a wet, sedge-rush-tussock meadow mixed with mesic riparian forest. After ca. 35 ka, the water table dropped below the ground surface but was still shallow enough to support dense stands of phreatophytes through the Last Glacial Maximum (LGM). The water table dropped further after the LGM, and xeric conditions prevailed until modest wetlands returned briefly during the Younger Dryas cold event (13.0–11.6 ka). We did not observe any evidence of wet conditions during the Holocene at Valley Wells. The timing

Napa River Restoration Project: Oakville to Oak Knoll Reach, Group A Sites 21-23

EPA Pesticide Factsheets

Information about the SFBWQP Napa River Restoration Project: Oakville to Oak Knoll Reach, Group A Sites 21-23, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources

Home destruction examination: Grass Valley Fire, Lake Arrowhead, California

Treesearch

Jack D. Cohen; Richard D. Stratton

2008-01-01

The Grass Valley Fire started October 22, 2007 at approximately 0508, one-mile west of Lake Arrowhead in the San Bernardino Mountains. Fuel and weather conditions were extreme due to drought, dry Santa Ana winds, and chaparral and conifer vegetation on steep terrain. The fire proceeded south through the Grass Valley drainage one-mile before impacting an area of dense...

Potential hazards from floodflows in Grapevine Canyon, Death Valley National Monument, California and Nevada

USGS Publications Warehouse

Bowers, J.C.

1990-01-01

Grapevine Canyon is on the western slope of the Grapevine Mountains in the northern part of Death Valley National Monument , California and Nevada. Grapevine Canyon Road covers the entire width of the canyon floor in places and is a frequently traveled route to Scotty 's Castle in the canyon. The region is arid and subject to flash flooding because of infrequent but intense convective storms. When these storms occur, normally in the summer, the resulting floods may create a hazard to visitor safety and property. Historical data on rainfall and floodflow in Grapevine Canyon are sparse. Data from studies made for similar areas in the desert mountains of southern California provide the basis for estimating discharges and the corresponding frequency of floods in the study area. Results of this study indicate that high-velocity flows of water and debris , even at shallow depths, may scour and damage Grapevine Canyon Road. When discharge exceeds 4,900 cu ft/sec, expected at a recurrence interval of between 25 and 50 years, the Scotty 's Castle access road and bridge may be damaged and the parking lot partly inundated. A flood having a 100-year or greater recurrence interval probably would wash out the bridge and present a hazard to the stable and garage buildings but not to the castle buildings, whose foundations are higher than the predicted maximum flood level. (USGS)

Natural recharge estimation and uncertainty analysis of an adjudicated groundwater basin using a regional-scale flow and subsidence model (Antelope Valley, California, USA)

USGS Publications Warehouse

Siade, Adam J.; Nishikawa, Tracy; Martin, Peter

2015-01-01

Groundwater has provided 50–90 % of the total water supply in Antelope Valley, California (USA). The associated groundwater-level declines have led the Los Angeles County Superior Court of California to recently rule that the Antelope Valley groundwater basin is in overdraft, i.e., annual pumpage exceeds annual recharge. Natural recharge consists primarily of mountain-front recharge and is an important component of the total groundwater budget in Antelope Valley. Therefore, natural recharge plays a major role in the Court’s decision. The exact quantity and distribution of natural recharge is uncertain, with total estimates from previous studies ranging from 37 to 200 gigaliters per year (GL/year). In order to better understand the uncertainty associated with natural recharge and to provide a tool for groundwater management, a numerical model of groundwater flow and land subsidence was developed. The transient model was calibrated using PEST with water-level and subsidence data; prior information was incorporated through the use of Tikhonov regularization. The calibrated estimate of natural recharge was 36 GL/year, which is appreciably less than the value used by the court (74 GL/year). The effect of parameter uncertainty on the estimation of natural recharge was addressed using the Null-Space Monte Carlo method. A Pareto trade-off method was also used to portray the reasonableness of larger natural recharge rates. The reasonableness of the 74 GL/year value and the effect of uncertain pumpage rates were also evaluated. The uncertainty analyses indicate that the total natural recharge likely ranges between 34.5 and 54.3 GL/year.

Response of Grape Leaf Spectra to Phylloxera Infestation

NASA Technical Reports Server (NTRS)

Johnson, Lee F.

1999-01-01

During the 1993 growing season, leaf reflectance and chlorophyll concentrations were monitored with respect to phylloxera (root-louse) infestation in a Napa Valley (California) vineyard. Study plots were established in areas of severely infested, mildly infested, and uninfested sections of the vineyard. A handheld chlorophyll meter, measuring leaf transmittance of near-infrared and red light, confirmed that reduced foliar chlorophyll concentrations were symptomatic of phylloxera stress in the sample vines. Bidirectional reflectance measurements of green and near-infrared light, taken on fresh leaves with a laboratory spectrophotometer, were related to chlorophyll concentration but did not allow discrimination of mildly infested from uninfested vines.

Induced dynamic nonlinear ground response at Gamer Valley, California

USGS Publications Warehouse

Lawrence, Z.; Bodin, P.; Langston, C.A.; Pearce, F.; Gomberg, J.; Johnson, P.A.; Menq, F.-Y.; Brackman, T.

2008-01-01

We present results from a prototype experiment in which we actively induce, observe, and quantify in situ nonlinear sediment response in the near surface. This experiment was part of a suite of experiments conducted during August 2004 in Garner Valley, California, using a large mobile shaker truck from the Network for Earthquake Engineering Simulation (NEES) facility. We deployed a dense accelerometer array within meters of the mobile shaker truck to replicate a controlled, laboratory-style soil dynamics experiment in order to observe wave-amplitude-dependent sediment properties. Ground motion exceeding 1g acceleration was produced near the shaker truck. The wave field was dominated by Rayleigh surface waves and ground motions were strong enough to produce observable nonlinear changes in wave velocity. We found that as the force load of the shaker increased, the Rayleigh-wave phase velocity decreased by as much as ???30% at the highest frequencies used (up to 30 Hz). Phase velocity dispersion curves were inverted for S-wave velocity as a function of depth using a simple isotropic elastic model to estimate the depth dependence of changes to the velocity structure. The greatest change in velocity occurred nearest the surface, within the upper 4 m. These estimated S-wave velocity values were used with estimates of surface strain to compare with laboratory-based shear modulus reduction measurements from the same site. Our results suggest that it may be possible to characterize nonlinear soil properties in situ using a noninvasive field technique.

Comparison of estimates of evapotranspiration and consumptive use in Palo Verde Valley, California

USGS Publications Warehouse

Raymond, Lee H.; Owen-Joyce, Sandra J.

1987-01-01

Estimates of evapotranspiration and consumptive use by vegetation in Palo Verde Valley, California, were compared for calendar years 1981 to 1984. Vegetation types were classified, and the areas covered by each type were computed from Landsat satellite digital-image analysis. Evapotranspiration was calculated by multiplying the area of each vegetation type by a corresponding water use rate adjusted for year-to-year variations in climate. The vegetation classification slightly underestimates the total vegetated area when compared to crop reports, because not all multiple cropping could be identified. The accuracy of evapotranspiration calculated from vegetation classification depends primarily on the correct classification of alfalfa and cotton because alfalfa and cotton have larger acreages and use more water/acre than the other crops in the valley. Consumptive use was calculated using a water budget for each of the 4 years. Estimates of evapotranspiration and consumptive use by vegetation, respectively, were: (1) 439,400 and 483,500 acre-ft in 1981, (2) 430,700 and 452,700 acre-ft in 1982, (3) 402,000 and 364,400 acre-ft in 1983, and (4) 406,700 and 373,800 acre-ft in 1984. Evapotranspiration estimates were lower than consumptive use estimates in 1981 and 1982 and higher in 1983 and 1984. Both estimates were lower in 1983 and 1984 than in 1981 and 1982. Yearly differences in estimates correspond most closely to significant changes in stage of the lower Colorado River caused by flood control releases in 1983 and 1984 and to changes in cropping practices. (Author 's abstract)