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Sample records for central termoelectrica san

  1. 77 FR 36041 - San Antonio Central Railroad, L.L.C.-Lease Exemption-Port Authority of San Antonio

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... Surface Transportation Board San Antonio Central Railroad, L.L.C.--Lease Exemption--Port Authority of San Antonio San Antonio Central Railroad, L.L.C. (SAC), a noncarrier, has filed a verified notice of exemption... Antonio Central Railroad, L.L.C., Docket No. FD 35604, wherein Watco Holdings, Inc. has filed a...

  2. Stratigraphy, sedimentology and paleontology of lower Eocene San Jose formation, central San Juan basin, New Mexico

    SciTech Connect

    Lucas, S.G.; Smith, L.N. )

    1989-09-01

    The lower Eocene San Jose Formation in the central portion of the San Juan basin (Gobernador-Vigas Canyon area) consists of the Cuba Mesa, Regina, Llaves, and Tapicitos Members. Well log data indicate that, from its 100-m thickness, the Cuba Mesa Member thins toward the basin center and pinches out to the northeast by lat. 36{degree}40'N, long. 107{degree}19'W. The Regina Member has the most extensive outcrops in the central basin, and it decreases in sandstone/mud rock ratio to the north. The Llaves and Tapicitos Members occur only at the highest elevations, are thin due to erosion, and are not mappable as separate units. Well log data and 1,275 m of measured stratigraphic section in the Regina, Llaves, and Tapicitos Members indicate these strata are composed of approximately 35% medium to coarse-grained sandstone and 65% fine-grained sandstone and mud rock. Sedimentology and sediment-dispersal patterns indicate deposition by generally south-flowing streams that had sources to the northwest, northeast, and east. Low-sinuosity, sand-bedded, braided( ) streams shifted laterally across about 1 km-wide channel belts to produce sheet sandstones that are prominent throughout the San Jose Formation. Subtle levees separated channel environments from floodplain and local lacustrine areas. Avulsion relocated channels periodically to areas on the floodplain, resulting in the typically disconnected sheet sandstones within muddy overbank deposits of the Regina Member.

  3. Central San Juan caldera cluster: regional volcanic framework

    USGS Publications Warehouse

    Lipman, Peter W.

    2000-01-01

    Eruption of at least 8800 km3 of dacitic-rhyolitic magma as 9 major ash-slow sheets (individually 150-5000 km3) was accompanied by recurrent caldera subsidence between 28.3 and about 26.5 Ma in the central San Juan Mountains, Colorado. Voluminous andesitic-decitic lavas and breccias were erupted from central volcanoes prior to the ash-flow eruptions, and similar lava eruptions continued within and adjacent to the calderas during the period of explosive volcanism, making the central San Juan caldera cluster an exceptional site for study of caldera-related volcanic processes. Exposed calderas vary in size from 10 to 75 km in maximum diameter, the largest calderas being associated with the most voluminous eruptions. After collapse of the giant La Garita caldera during eruption if the Fish Canyon Tuff at 17.6 Ma, seven additional explosive eruptions and calderas formed inside the La Garita depression within about 1 m.y. Because of the nested geometry, maximum loci of recurrently overlapping collapse events are inferred to have subsided as much as 10-17 km, far deeper than the roof of the composite subvolcanic batholith defined by gravity data, which represents solidified caldera-related magma bodies. Erosional dissection to depths of as much as 1.5 km, although insufficient to reach the subvolcanic batholith, has exposed diverse features of intracaldera ash-flow tuff and interleaved caldera-collapse landslide deposits that accumulated to multikilometer thickness within concurrently subsiding caldera structures. The calderas display a variety of postcollapse resurgent uplift structures, and caldera-forming events produced complex fault geometries that localized late mineralization, including the epithermal base- and precious-metal veins of the well-known Creede mining district. Most of the central San Juan calderas have been deeply eroded, and their identification is dependent on detailed geologic mapping. In contrast, the primary volcanic morphology of the

  4. Foraminifera and paleoenvironments in the Etchegoin and lower San Joaquin Formations, west-central San Joaquin valley, California

    SciTech Connect

    Lagoe, M.B.; Tenison, J.A.; Buehring, R. )

    1991-02-01

    The Etchegoin and San Joaquin formations preserve a rich stratigraphic record of paleoenvironments, deposition, and tectonics during the late Miocene-Pliocene development of the San Joaquin basin. The distribution of foraminifera within these formations can help constrain this record, which includes final filling of the basin, facies responses to sea level changes, and active movement on the San Andreas fault system. The distribution of foraminifera in core samples is analyzed from seven wells along the west-central San joaquin basin - four from Buena Vista oil field, one from western Elk Hills oil field, and two from an area just south of South Belridge oil field. A model of modern, shallow- to marginal-marine foraminiferal biofacies is used to interpret the Etchegoin-San Joaquin faunal distributions. This modern model distinguishes marsh, tidal channel, intertidal, lagoonal, littoral, and shallow sublittoral environments. Ongoing work calibrating this foraminiferal record to the lithologic and macrofossil records in addition to interpreted depositional systems within these formations will further define relationships between paleoenvironments, relative sea level, and tectonics.

  5. Sediment Distribution in Central San Francisco Bay in the Vicinity of Raccoon Strait.

    NASA Astrophysics Data System (ADS)

    Parker, K. A.; White, L. D.; Vavro, M.; Tran, J.; Basconcillo, N.; Kheradyar, T.; Pestrong, R.

    2003-12-01

    We collected sediment grab samples from twenty-one sites distributed within a 2-km2 area in Central San Francisco Bay, including Raccoon Strait, which is located between the Tiburon Peninsula and Angel Island. We gathered these samples in May and August of 2003, dried and disaggregated them using a Gilson Sieve Tester, and analyzed the sediments by weight percent. Our purpose in monitoring sediment distributions over time in Central San Francisco Bay is to gain understanding of the oceanographic dynamics of the bay-delta estuarine system. Our initial results indicate that grain sizes range from > 2 millimeters to < 125 microns with coarser samples located at the entrance to Raccoon Strait. We anticipate collecting samples from these twenty-one sites in November of 2003, and eventually relating the sediment distribution patterns to seasonal variations in transport. This study is part of a larger-scale project involving bedform migration and current transport in Central San Francisco Bay.

  6. Origin and characteristics of discharge at San Marcos Springs, south-central Texas

    USGS Publications Warehouse

    Musgrove, MaryLynn; Crow, Cassi L.

    2013-01-01

    The Edwards aquifer in south-central Texas is one of the most productive aquifers in the Nation and is the primary source of water for the rapidly growing San Antonio area. Springs issuing from the Edwards aquifer provide habitat for several threatened and endangered species, serve as locations for recreational activities, and supply downstream users. Comal Springs and San Marcos Springs are major discharge points for the Edwards aquifer, and their discharges are used as thresholds in groundwater management strategies. Regional flow paths originating in the western part of the aquifer are generally understood to supply discharge at Comal Springs. In contrast, the hydrologic connection of San Marcos Springs with the regional Edwards aquifer flow system is less understood. During November 2008–December 2010, the U.S. Geological Survey, in cooperation with the San Antonio Water System, collected and analyzed hydrologic and geochemical data from springs, groundwater wells, and streams to gain a better understanding of the origin and characteristics of discharge at San Marcos Springs. During the study, climatic and hydrologic conditions transitioned from exceptional drought to wetter than normal. The wide range of hydrologic conditions that occurred during this study—and corresponding changes in surface-water, groundwater and spring discharge, and in physicochemical properties and geochemistry—provides insight into the origin of the water discharging from San Marcos Springs. Three orifices at San Marcos Springs (Deep, Diversion, and Weissmuller Springs) were selected to be representative of larger springs at the spring complex. Key findings include that discharge at San Marcos Springs was dominated by regional recharge sources and groundwater flow paths and that different orifices of San Marcos Springs respond differently to changes in hydrologic conditions; Deep Spring was less responsive to changes in hydrologic conditions than were Diversion Spring and

  7. 77 FR 36040 - Watco Holdings, Inc.-Continuance in Control Exemption-San Antonio Central Railroad, L.L.C.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... Railroad, L.L.C. Watco Holdings, Inc. (Watco), a noncarrier, has filed a verified notice of exemption pursuant to 49 CFR 1180.2(d)(2), for Watco to continue in control of San Antonio Central Railroad, L.L.C... concurrently filed verified notice of exemption in San Antonio Central Railroad, L.L.C.--Lease Exemption--...

  8. Seismic data acquisition over San Juan volcanic field, San Juan sag, south-central Colorado

    SciTech Connect

    Henkel, R.P. )

    1989-09-01

    The San Juan sag, a foreland basin along the Uncompahgre-Brazos uplift, contains Mesozoic sediments overlain by up to 10,000 ft of Tertiary volcanics. Petroleum exploration beneath thick volcanic cover requires successful acquisition of seismic data; however, experience elsewhere has generally produced only marginal results. Commencing in 1983, Meridian Oil recorded 18 seismic lines comprising 260 mi of conventional and portable data. Noise test were performed at two sites to evaluate seismic response and to determine source and receiver parameters. Vibroseis, shothole, and surface dynamite were examined as sources and gave comparable results. Coherent noise trains with velocities from 4,000 to 8,000 ft/sec and dominant frequencies of 10 to 15 Hz were generated in the Tertiary section. The predominant factor affecting data quality was outcrop lithology. Data recorded over alluvial and other Quaternary deposits tended to be good to fair. Data quality over Tertiary volcanics was variable and highly unit dependent, ranging from fair over andesites and volcaniclastics, poor over ash-flow tuffs, and uniformly very poor over basalts. Seismic source appeared to have only a minor effect on quality. Data processing involved no unusual operations. Velocity filtering was used to suppress near-surface generated coherent noise, Refraction statics were applied to lines with significant elevation or lithologic variations. A successful acquisition program helped to establish the presence of a Mesozoic sedimentary section beneath the volcanics. these data revealed large structural features within the sedimentary section as well as a dramatic angular unconformity at the top of the Cretaceous section.

  9. Fault geometry and cumulative offsets in the central Coast Ranges, California: Evidence for northward increasing slip along the San Gregorio-San Simeon-Hosgri fault

    USGS Publications Warehouse

    Langenheim, V.E.; Jachens, R.C.; Graymer, R.W.; Colgan, J.P.; Wentworth, C.M.; Stanley, R.G.

    2012-01-01

    Estimates of the dip, depth extent, and amount of cumulative displacement along the major faults in the central California Coast Ranges are controversial. We use detailed aeromagnetic data to estimate these parameters for the San Gregorio–San Simeon–Hosgri and other faults. The recently acquired aeromagnetic data provide an areally consistent data set that crosses the onshore-offshore transition without disruption, which is particularly important for the mostly offshore San Gregorio–San Simeon–Hosgri fault. Our modeling, constrained by exposed geology and in some cases, drill-hole and seismic-reflection data, indicates that the San Gregorio–San Simeon–Hosgri and Reliz-Rinconada faults dip steeply throughout the seismogenic crust. Deviations from steep dips may result from local fault interactions, transfer of slip between faults, or overprinting by transpression since the late Miocene. Given that such faults are consistent with predominantly strike-slip displacement, we correlate geophysical anomalies offset by these faults to estimate cumulative displacements. We find a northward increase in right-lateral displacement along the San Gregorio–San Simeon–Hosgri fault that is mimicked by Quaternary slip rates. Although overall slip rates have decreased over the lifetime of the fault, the pattern of slip has not changed. Northward increase in right-lateral displacement is balanced in part by slip added by faults, such as the Reliz-Rinconada, Oceanic–West Huasna, and (speculatively) Santa Ynez River faults to the east.

  10. Dual-system Tectonics of the San Luis Range and Vicinity, Coastal Central California

    NASA Astrophysics Data System (ADS)

    Hamilton, D. H.

    2010-12-01

    The M 6.5 "San Simeon" earthquake of December 22, 2003, occurred beneath the Santa Lucia Range in coastal central California, and resulted in around $250,000,000 property damage and two deaths from collapse of an historic building in the town of Paso Robles, located 40 km from the epicenter. The earthquake and more than 10,000 aftershocks were well recorded by nearby seismographs, which permitted detailed analysis of the event (eg: McLaren et al., 2008). This analysis facilitated evaluation of the hazard of the occurrence of a similar event in the nearby San Luis Range, located along the coast west of the city of San Luis Obispo some 55 km south of the San Simeon epicenter. The future occurrence of earthquakes analogous to the 2003 event in this area had been proposed in the late 1960’s (eg: Benioff and Smith, 1967; Richter, 1969) but the apparent hazard of such occurrences came to be overshadowed by the discovery of the “Hosgri” strike slip fault passing close to the area in the offshore. However data accumulated since the early 1970’s clearly demonstrate the hazard as being partitioned between nearby earthquakes of strike slip origin, and underlying earthquakes of thrust origin analogous to that of the 2003 San Simeon earthquake. And for the onshore San Luis Range area, an underlying actively seismogenic thrust wedge appears to provide the maximum potential seismic ground motion; exceeding that potentially resulting from large events on nearby strike slip faults of the San Simeon-Hosgri system, for onshore sites. Understanding and documentation of the geology, geomorphology, tectonics and seismogenesis of the San Luis Range and vicinity has recently experienced a quantum improvement as both new and accumulated data have been analysed. An integrated interpretation of all available data now clearly shows that a dual “side by side” system of active tectonics exists in the region. Essentially the most obvious evidence for this is seen simply in the

  11. Geologic Map of the Central San Juan Caldera Cluster, Southwestern Colorado

    USGS Publications Warehouse

    Lipman, Peter W.

    2006-01-01

    The San Juan Mountains are the largest erosional remnant of a composite volcanic field that covered much of the southern Rocky Mountains in middle Tertiary time. The San Juan field consists mainly of intermediate-composition lavas and breccias, erupted about 35-30 Ma from scattered central volcanoes (Conejos Formation) and overlain by voluminous ash-flow sheets erupted from caldera sources. In the central San Juan Mountains, eruption of at least 8,800 km3 of dacitic-rhyolitic magma as nine major ash flow sheets (individually 150-5,000 km3) was accompanied by recurrent caldera subsidence between 28.3 Ma and about 26.5 Ma. Voluminous andesitic-dacitic lavas and breccias erupted from central volcanoes prior to the ash-flow eruptions, and similar lava eruptions continued within and adjacent to the calderas during the period of more silicic explosive volcanism. Exposed calderas vary in size from 10 to 75 km in maximum dimension; the largest calderas are associated with the most voluminous eruptions.

  12. SEISMIC-REFRACTION PROFILE ACROSS THE SAN ANDREAS, SARGENT, AND CALAVERAS FAULTS, WEST-CENTRAL CALIFORNIA.

    USGS Publications Warehouse

    Mooney, Walter D.; Colburn, Robert H.

    1985-01-01

    Geophysical studies of the upper crustal structure of west-central California are important for the further understanding of the geologic structure and tectonics in this seismically active region. In 1981, the United States Geological Survey recorded a seismic-refraction profile across the southern Santa Cruz Mountains in west-central California to examine the shallow velocity structure of this seismogenic region. This 40-km-long profile, which consisted of three shotpoints, extended northeastward from near Watsonville, California, to Coyote Lake, crossing the San Andreas, Sargent, and Calaveras faults. Refs.

  13. Anthropogenic influence on recent bathymetric change in west-central San Francisco Bay

    USGS Publications Warehouse

    Barnard, Patrick L.; Kvitek, Rikk G.

    2010-01-01

    Two multibeam sonar surveys of west-central San Francisco Bay, California, were conducted in 1997 and 2008. Bathymetric change analysis between the two surveys indicates a loss of 14.1 million cubic meters (-3.1 cm/yr-1) of sediment during this time period, representing an approximately three-fold acceleration of the rate that was observed from prior depth change analysis from 1947 to 1979 for all of Central Bay, using more spatially coarse National Ocean Service (NOS) soundings. The portions of the overlapping survey areas between 1997 and 2008 designated as aggregate mining lease sites lost sediment at five times the rate of the remainder of west-central San Francisco Bay. Despite covering only 28% of the analysis area, volume change within leasing areas accounted for 9.2 million cubic meters of sediment loss, while the rest of the area lost 4.9 million cubic meters of sediment. The uncertainty of this recent analysis is more tightly constrained due to more stringent controls on vertical and horizontal position via tightly coupled, inertially aided differential Global Positioning Systems (GPS) solutions for survey vessel trajectory that virtually eliminate inaccuracies from traditional tide modeling and vessel motion artifacts. Further, quantification of systematic depth measurement error can now be calculated through comparison of static surfaces (e.g., bedrock) between surveys using seafloor habitat maps based on acoustic backscatter measurements and ground-truthing with grab samples and underwater video. Sediment loss in the entire San Francisco Bay Coastal System during the last half-century,as estimated from a series of bathymetric change studies, is 240 million cubic meters, and most of this is believed to be coarse sediment (i.e., sand and gravel) from Central Bay and the San Francisco Bar, which is likely to limit the sand supply to adjacent, open-coast beaches. This hypothesis is supported by a calibrated numerical model in a related study that indicates

  14. Cumulative offset of the San Andreas fault in Central California: A seismic approach

    SciTech Connect

    Revenaugh, J.; Reasoner, C.

    1997-02-01

    Scattered-wave imaging of upper crustal heterogeneity along nearly 500 km of the San Andreas fault in central California is used to estimate cumulative offset of basement rocks in the fault zone. Optimal cross-fault realignment of scattering patterns in achieved through removal of nearly 315 km of right-lateral slip. This value agrees with most previous estimates of early Miocene displacement, placing the initiation of movement on the San Andreas no earlier than ca, 23.1 Ma. Scattering along the fault correlates with segment boundaries established on the basis of historic and paleo seismicity, corroborating evidence from southern California that the upper crustal structures responsible for scattering are important in seismogenesis. 23 refs., 3 figs.

  15. Aseismic slip and seismogenic coupling along the central San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Jolivet, R.; Simons, M.; Agram, P. S.; Duputel, Z.; Shen, Z.-K.

    2015-01-01

    We use high-resolution Synthetic Aperture Radar- and GPS-derived observations of surface displacements to derive the first probabilistic estimates of fault coupling along the creeping section of the San Andreas Fault, in between the terminations of the 1857 and 1906 magnitude 7.9 earthquakes. Using a fully Bayesian approach enables unequaled resolution and allows us to infer a high probability of significant fault locking along the creeping section. The inferred discreet locked asperities are consistent with evidence for magnitude 6+ earthquakes over the past century in this area and may be associated with the initiation phase of the 1857 earthquake. As creeping segments may be related to the initiation and termination of seismic ruptures, such distribution of locked and creeping asperities highlights the central role of the creeping section on the occurrence of major earthquakes along the San Andreas Fault.

  16. Porosity evolution in reservoir sandstones in the West-Central San Joaquin basin, California

    SciTech Connect

    Horton, R.A. Jr.; McCullough, P.T.; Houghton, B.D.; Pennell, D.A.; Dunwoody, J.A. III; Menzie, R.J. Jr.

    1995-04-01

    Miocene reservoir sands (feldspathic and lithic arenites) in central San Joaquin basin oil fields show similar trends in porosity development despite differences in depositional environment, pore-fluid chemistry, and burial history. Burial and tectonic compaction caused grain rotation, deformation of altered lithics, and extensive fracturing of brittle grains, thereby eliminating most primary porosity. Diagenetic fluids, infiltrating along fractures in grains, reacted with freshly exposed mineral surfaces causing extensive leaching of framework components. All major grain types were affected but preferential removal of feldspars and lithics resulted in changes in QFL ratios. With continued compaction angular remnants of partially disolved grains were rotated and rearranged while secondary intergranular and moldic porosity collapsed to form secondary intergranular porosity. This resulted in reservoir sands that are less well sorted, more angular, and mineralogically more mature than they were at deposition. Such changes appear to widespread in the San Joaquin basin and may be more important than is generally acknowledged.

  17. The paradigm of paraglacial megafans of the San Juan river basin, Central Andes, Argentina

    NASA Astrophysics Data System (ADS)

    Suvires, Graciela M.

    2014-11-01

    The spatial distribution and several morphometric characteristics of the Quaternary alluvial fans of the San Juan River, in the province of San Juan, at the Central and Western part of Argentina, have been studied to classify them as paraglacial megafans, as well to ratify its depositional environmental conditions. The high sedimentary load exported by San Juan river from the Central Andes to the foreland depressions is estimated about 3,682,200 hm3. The large alluvial fans of Ullum-Zonda and Tulum valleys were deposited into deep tectonic depressions, during the Upper Pleistocene deglaciation stages. The outcome of collecting remotely sensed data, map and DEM data, geophysical data and much fieldwork gave access to morphometric, morphographic and morphogenetic data of these alluvial fans. The main drainage network was mapped on processed images using QGis (vers.2.0.1). Several fan morphometric parameters were measured, such as the size, the shape, the thickness, the surface areas and the sedimentary volume of exported load. The analyzed fans were accumulated in deep tectonic depressions, where the alluvium fill reaches 700 to 1200 m thick. Such fans do not reach the large size that other world megafans have, and this is due to tectonic obstacles, although the sedimentary fill average volume surpasses 514,000 hm3. The author proposes to consider Ullum-Zonda and Tulum alluvial fans as paraglacial megafans. According to the stratigraphic relationships of the tropical South American Rivers, the author considers that the San Juan paraglacial megafans would have occurred in the period before 24 ka BP , possibly corresponding to Middle Pleniglacial (ca 65-24ka BP). They record colder and more humid conditions compared with the present arid and dry conditions.

  18. Recurrence of seismic migrations along the central California segment of the San Andreas fault system

    USGS Publications Warehouse

    Wood, M.D.; Allen, S.S.

    1973-01-01

    VERIFICATIONS of tectonic concepts1 concerning seafloor spreading are emerging in a manner that has direct bearing on earthquake prediction. Although the gross pattern of worldwide seismicity contributed to the formulation of the plate tectonic hypothesis, it is the space-time characteristics of this seismicity that may contribute more toward understanding the kinematics and dynamics of the driving mechanism long speculated to originate in the mantle. If the lithosphere is composed of plates that move essentially as rigid bodies, then there should be seismic edge effects associated with this movement. It is these interplate effects, especially seismic migration patterns, that we discuss here. The unidirectional propagation at constant velocity (80 km yr-1 east to west) for earthquakes (M???7.2) on the Antblian fault for the period 1939 to 1956 (ref. 2) is one of the earliest observations of such a phenomenon. Similar studies3,4 of the Alaska Aleutian seismic zone and certain regions of the west coast of South America suggest unidirectional and recurring migrations of earthquakes (M???7.7) occur in these areas. Between these two regions along the great transform faults of the west coast of North America, there is some evidence 5 for unidirectional, constant velocity and recurrent migration of great earthquakes. The small population of earthquakes (M>7.2) in Savage's investigation5 indicates a large spatial gap along the San Andreas system in central California from 1830 to 1970. Previous work on the seismicity of this gap in central California indicates that the recurrence curves remain relatively constant, independent of large earthquakes, for periods up to a century6. Recurrence intervals for earthquakes along the San Andreas Fault have been calculated empirically by Wallace7 on the basis of geological evidence, surface measurements and assumptions restricted to the surficial seismic layer. Here we examine the evidence for recurrence of seismic migrations along

  19. Seismic images of the deep structure of the San Andreas fault system, central coast ranges, California

    SciTech Connect

    Zandt, G.

    1981-06-10

    Three-dimensional inversion of teleseimic P wave travel time residuals recorded at the U.S. Geological Survey central California array has resolved small-scale (approx.tens of kilometers) crustal and upper mantle heterogeneity down to depths of 90 km beneath the California coast ranges. Upper crustal lateral velocity variations of +- 8% correlate closely with surface geology. Lower-than-average velocities are associated with thick Tertiary sedimentary fill and higher-than-average velocities with basement exposures. Lower crustal velocity heterogeneity of +- 4% appear to reflect crustal thickness variations. A thinner crust is indicated southwest of the San Andreas fault and northwest of San Pablo Bay. A linear zone of low-velocities (0 to -40%) subparallel to the San Andreas fault was resolved in the upper mantle. The preferred interpretation is that the low-velocities indicate a narrow upwarp of asthenosphere to unusually shallow depths (approx.45 km) beneath the coast ranges. Such an unusual upper mantle structure may have been produced by the northwestward migration along the California coast of a transiently unstable Mendocino triple junction. The inversion results also indicate the possibility of partial decoupling of the crust from the upper mantle.

  20. Water Balance of the San Simon Groundwater Basin, El Salvador, Central America

    NASA Astrophysics Data System (ADS)

    Sullivan, M.; Lopez, D. L.; Matus, A.

    2008-05-01

    The Berlin hydrothermal field in El Salvador, Central America is located in the San Simon River Basin on the northwest slope of the Berlin-Tecapa volcanic complex, in the eastern portion of the country. This hydrothermal field, which has been exploited since 1992, is a liquid-dominated system governed by faults and caldera structures allowing infiltration and transport of meteoric fluids. San Simon River is a tributary of the Lempa River, the largest river in the country. Geophysical studies have found that the Berlin field is composed of three aquifers (Shallow, Intermediate, Deep). Exploitation involves the removal of hot fluids from the geothermal reservoir (deep aquifer) and re-injection of lower temperature fluids. This study analyzes the surficial hydrology and groundwater storage change (since exploitation) in the hydrothermal reservoir to produce a water budget. Field monitoring of springs, fumarolic activity, domestic wells, tributaries to the San Simon River, and meteorological data provide constraints on the hydrology. Springs occur in the system close to fault zones or at contacts between different lithologies. The water balance for the San Simon groundwater basin (July 2004 - June 2005) indicates that 2.51 - 3.46 E7 m3/yr of water are infiltrated to the ground, 1.30 - 1.45E7 m3/yr comprises the overland flow, 5.74 E6 m3/yr form the base flow of the San Simon River, and 1.54 E5 m3/yr is released thru the evaporation of Alegria Lake. The shallow aquifer is affected by pumping of 4.78 E6 m3/yr by the national water company. To complete the water balance of the San Simon Basin, a correlation between the composition of the fumarolic gases and the diffuse flux of soil CO2 was performed. The flux of water released from fumarolic areas was estimated at 1.48 E5 m3/yr. An analysis of the increase in chloride concentration with time in the deep aquifer and the net mass withdrawn from this aquifer allow an estimation of the decrease in storage in the hydrothermal

  1. A seismic refraction and reflection study across the central San Jacinto Basin, Southern California

    USGS Publications Warehouse

    Lee, T.-C.; Biehler, S.; Park, S.K.; Stephenson, W.J.

    1996-01-01

    The San Jacinto Basin is a northwest-trending, pullapart basin in the San Jacinto fault zone of the San Andreas fault system in southern California. About 24 km long and 2 to 4 km wide, the basin sits on a graben bounded by two strands of the San Jacinto fault zone: the Claremont Fault on the northeast and the Casa Loma Fault on the southwest. We present a case study of shallow structure (less than 1 km) in the central basin. A 2.75-km refraction line running from the northeast to southwest across the regional structural trend reveals a groundwater barrier (Offset I). Another line, bent southward and continued for 1.65-km, shows a crystalline basement offset (Offset III) near an inferred trace of the Casa Loma Fault. Although a basement refractor was not observed along the 2.75-km line, a mismatch between the estimate of its minimum depth and the basement depth determined for the 1.65-km line suggests that an offset in the basement (greater than 260 m) exists around the junction of the two refraction lines (Offset II). By revealing more faults and subtle sedimentary structures, the reflection stack sections confirm the two refraction offsets as faults. Offsets I and III each separate sediments of contrasting structures and, in addition. Offset III disrupts an unconformity. However, the sense and amount of the offset across Offset III contradict what may be expected across the Casa Loma Fault, which has its basinward basement down-thrown to about 2.5 km in the better defined southeastern part of the graben. The Casa Loma Fault trace has been mislinked in the existing geological maps and the trace should be remapped to Offset II where the reflector disruptions spread over a 400-m wide zone. Our Offset III is an unnamed, concealed fault.

  2. Deformation rates across the San Andreas Fault system, central California determined by geology and geodesy

    NASA Astrophysics Data System (ADS)

    Titus, Sarah J.

    The San Andreas fault system is a transpressional plate boundary characterized by sub-parallel dextral strike-slip faults separating internally deformed crustal blocks in central California. Both geodetic and geologic tools were used to understand the short- and long-term partitioning of deformation in both the crust and the lithospheric mantle across the plate boundary system. GPS data indicate that the short-term discrete deformation rate is ˜28 mm/yr for the central creeping segment of the San Andreas fault and increases to 33 mm/yr at +/-35 km from the fault. This gradient in deformation rates is interpreted to reflect elastic locking of the creeping segment at depth, distributed off-fault deformation, or some combination of these two mechanisms. These short-term fault-parallel deformation rates are slower than the expected geologic slip rate and the relative plate motion rate. Structural analysis of folds and transpressional kinematic modeling were used to quantify long-term distributed deformation adjacent to the Rinconada fault. Folding accommodates approximately 5 km of wrench deformation, which translates to a deformation rate of ˜1 mm/yr since the start of the Pliocene. Integration with discrete offset on the Rinconada fault indicates that this portion of the San Andreas fault system is approximately 80% strike-slip partitioned. This kinematic fold model can be applied to the entire San Andreas fault system and may explain some of the across-fault gradient in deformation rates recorded by the geodetic data. Petrologic examination of mantle xenoliths from the Coyote Lake basalt near the Calaveras fault was used to link crustal plate boundary deformation at the surface with models for the accommodation of deformation in the lithospheric mantle. Seismic anisotropy calculations based on xenolith petrofabrics suggest that an anisotropic mantle layer thickness of 35-85 km is required to explain the observed shear wave splitting delay times in central

  3. Fault coupling and potential for earthquakes on the creeping section of the central San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Maurer, Jeremy; Johnson, Kaj

    2014-05-01

    The 150 km long central section of the San Andreas Fault (CSAF) in central California creeps at the surface and has not produced a large earthquake historically. However, sections of the San Andreas Fault to the north and south are known to have ruptured repeatedly in M~7-8 earthquakes. It is currently unclear whether the creeping CSAF could rupture in large earthquakes, either individually or along with earthquakes on the locked sections to the north and south. We invert Global Positioning System and interferometric synthetic aperture radar data with elastic block models to estimate the degree of locking on the CSAF and place bounds on the moment accumulation rate on the fault. We find that the inferred moment accumulation rate is highly dependent on the long-term fault slip rate, which is poorly constrained along the CSAF. The inferred moment accumulation rate, normalized by shear modulus, ranges from 3.28 × 104 to 5.85 × 107 m3/yr, which is equivalent to a Mw = 5.5-7.2 earthquake every 150 years for a long-term slip rate of 26 mm/yr and Mw = 7.3-7.65 for a long-term slip rate of 34 mm/yr. The comparisons of slip distributions with microseismicity and repeating earthquakes indicate a possible locked patch between 10 and 20 km depth on the CSAF that could potentially rupture with Mw = 6.5.

  4. Evidence for Late Oligocene-Early Miocene episode of transtension along San Andreas Fault system in central California

    SciTech Connect

    Stanley, R.G.

    1986-04-01

    The San Andreas is one of the most intensely studied fault systems in the world, but many aspects of its kinematic history remain controversial. For example, the period from the late Eocene to early Miocene is widely believed to have been a time of negligible strike-slip movement along the San Andreas fault proper, based on the rough similarity of offset of the Eocene Butano-Point of rocks Submarine Fan, the early Miocene Pinnacles-Neenach volcanic center, and an early Miocene shoreline in the northern Gabilan Range and San Emigdio Mountains. Nonetheless, evidence indicates that a late Oligocene-early Miocene episode of transtension, or strike-slip motion with a component of extension, occurred within the San Andreas fault system. The evidence includes: (1) about 22-24 Ma, widespread, synchronous volcanic activity occurred at about 12 volcanic centers along a 400-km long segment of the central California coast; (2) most of these volcanic centers are located along faults of the San Andreas system, including the San Andreas fault proper, the San Gregorio-Hosgri fault, and the Zayante-Vergeles fault, suggesting that these and other faults were active and served as conduits for magmas rising from below; (3) during the late Oligocene and early Miocene, a pull-apart basin developed adjacent to the San Andreas fault proper in the La Honda basin near Santa Cruz; and (4) during the late Oligocene and early Miocene, active faulting, rapid subsidence, and marine transgression occurred in the La Honda and other sedimentary basins in central California. The amount of right-lateral displacement along the San Andreas fault proper during this transtentional episode is unknown but was probably about 7.5-35 km, based on model studies of pull-apart basin formation. This small amount of movement is well within the range of error in published estimates of the offset of the Eocene to early Miocene geologic features noted.

  5. The San Andreas Fault: A state of stress analysis in central and northern California

    NASA Astrophysics Data System (ADS)

    Provost, Ann-Sophie

    The San Andreas Fault system is a network of faults extending from the Gulf of California to the Mendocino Triple Junction that accommodates the motion between the North American and Pacific tectonic plates. The faults' types, slip rates and distributions of seismicity varies from south to north; the question addressed by this dissertation is whether or not the mechanical behavior of this plate boundary varies as well. We used suites of fault plane solutions of earthquakes occurring in central and northern California, and inverted them for the best stress tensors. We obtained a map of stress orientations close to and far away from the major strands of the San Andreas Fault system in these areas. In the creeping zone on the central San Andreas the maximum horizontal compression, S H, is oriented almost perpendicular to the fault trend far away from it and as close as 2 km from it, whereas in the fault zone itself SH lies at a smaller angle to the fault (˜50°). In northern California there is no clear difference between on-fault and off-fault orientations and SH orientations are on average at 55° from the trend of major faults. The Bay Area shows an intermediate behavior between the two just mentioned. This difference in the orientation of SH from central to northern California suggest a change in the mechanical behavior of the plate boundary between these two regions. This situation could be related to the "young and multiple stranded" SAF system in northern California compared to the "old" SAF in central California where much more slip has accumulated on this one fault strand. Using the same data we investigated possible temporal variations in the orientation of SH before and after the occurrence of a major earthquake. Such variations could be related to the stress release produced by the mainshock. For the four events studied, 1986 Mt. Lewis, 1984 Morgan Hill, 1979 Coyote Lake, and 1989 Loma Prieta earthquakes, a rotation of SH to an orientation more normal to

  6. Estuarine sedimentation, sediment character, and foraminiferal distribution in central San Francisco Bay, California

    USGS Publications Warehouse

    Chin, John L.; Woodrow, Donald L.; McGann, Mary; Wong, Florence L.; Fregoso, Theresa; Jaffe, Bruce E.

    2010-01-01

    Central San Francisco Bay is the deepest subembayment in the San Francisco Bay estuary and hence has the largest water volume of any of the subembayments. It also has the strongest tidal currents and the coarsest sediment within the estuary. Tidal currents are strongest over the west-central part of central bay and, correspondingly, this area is dominated by sand-size sediment. Much of the area east of a line from Angel Island to Alcatraz Island is characterized by muddy sand to sandy mud, and the area to the west of this line is sandy. The sand-size sediment over west-central bay furthermore is molded by the energetic tidal currents into bedforms of varying sizes and wavelengths. Bedforms typically occur in water depths of 15-25 m. High resolution bathymetry (multibeam) from 1997 and 2008 allow for subdivision of the west-central bayfloor into four basic types based on morphologic expression: featureless, sand waves, disrupted/man-altered, and bedrock knobs. Featureless and sand-wave morphologies dominate the bayfloor of west-central bay. Disrupted bayfloor has a direct association with areas that are undergoing alteration due to human activities, such as sand-mining lease areas, dredging, and disposal of dredge spoils. Change detection analysis, comparing the 1997 and 2008 multibeam data sets, shows that significant change has occurred in west-central bay during the roughly 10 years between surveys. The surveyed area lost about 5.45 million m3 of sediment during the decade. Sand-mining lease areas within west-central bay lost 6.77 million m3 as the bayfloor deepened. Nonlease areas gained 1.32 million m3 of sediment as the bayfloor shallowed slightly outside of sand-mining lease areas. Furthermore, bedform asymmetry did not change significantly, but some bedforms did migrate some tens of meters. Gravity cores show that the area east of Angel and Alcatraz Islands is floored by clayey silts or silty sand whereas the area to the west of the islands is floored

  7. [Effects of Kaixin San formulas on behavioristics and central monoamine neurotransmitters of chronic stress rats].

    PubMed

    Liu, Wan-wan; Xu, Lu; Dong, Xian-zhe; Tan, Xiao; Wang, Shi; Zhu, Wei-yu; Liu, Ping

    2015-06-01

    The efficacy of Chinese herbal formula in treating depression has been proved in many studies. In this study, six different Kaixin San formulas were compared to investigate their effects on central monoamine neurotransmitters of chronic stress rats and against depression based on their different components in plasma, in order to discuss the efficacy-comparability relationship and the possible efficacy mechanism. The classic isolation method and the chronic unpredictable mild stress (CUMS) depression model were combined to investigate the changes in contents in hippocampus and monoamine neurotransmitters (NE, DA, 5-HT) and the components of some formulas in plasma with HPLC and UPLC-Q-TOF-MSE methods. As a result, Dingzhi Xiaowan recorded in Essential Recipes for Emergent Use Worth A Thousand significantly increased the behavioral scores, NE and 5-HT contents in hippocampus and NE, DA and 5-HT contents in cortex, with the best anti-depressant effect. Dingzhi Xiaowan recorded in Complete Records of Ancient and Modern Medical Works showed a notable increase in sucrose preference and open field score in model rats, NE content in hippocampus and NE, DA and 5-HT contents in cortex, with a certain anti anti-depressant effect. Kaixin San recorded in Ishinpo showed remarkable rise in weight of model rats. NE content in hippocampus and DA content in cortex. Puxin Decoction recorded in A Supplement to Recipes Worth A Thousand Gold showed 5-HT content in hippocampus and DA content in cortex. Kaixin San recorded in Yimenfang only showed DA content in cortex. Kaixin Wan recorded in Essential Recipes for Emergent Use Worth A Thousand did not mention the antidepressant effect. According to the results, the formulas' different anti-depressant effects may be related to the different plasma components. PMID:26552177

  8. Ground-squirrel mounds and related patterned ground along the San Andreas Fault in Central California

    USGS Publications Warehouse

    Wallace, Robert E.

    1991-01-01

    Extensive areas of mound topography and related patterned ground, apparently derived from the mounds of the California Ground Squirrel (Spermophilus beecheyi beecheyi), are in central California.  The relation of patterned ground to the San Andreas fault west of Bakersfield may provide insight into the timing of deformation along the fault as well as the history of ground squirrels.  Mound topography appears to have evolved through several stages from scattered mounds currently being constructed on newly deposited alluvial surfaces, to saturation of areas by mounds, followed by coalescence, elongation and lineation of the mounds.  Elongation, coalescence and modification of the mounds has been primarily by wind, but to a lesser extent by drainage and solifluction.  A time frame including ages of 4,000, 10,500, 29,000, and 73,000 years BP is derived by relating the patterns to slip on the San Andreas fault.  Further relating of the patterns to faulting, tilting, and warping may illuminate details of the rates and history of deformation.  Similarly, relating the patterns to the history of ground squirrel activity may help answer such problems as rates of dispersal and limits on population density.

  9. Paleoclimatic inferences from an isotopic investigation of groundwater in the central San Juan Basin, New Mexico

    NASA Astrophysics Data System (ADS)

    Phillips, Fred M.; Peeters, Leslie A.; Tansey, Michael K.; Davis, Stanley N.

    1986-09-01

    Groundwater from the Ojo Alamo and Nacimiento aquifers in the central San Juan Basin. New Mexico, has yielded 14C ages ranging from modern to 35,000 yr B.P. The Pleistocene-age samples are characterized by a stable isotope content about 25‰ lighter in D and 3‰ lighter in 18O than modern precipitation and groundwater. We attribute this difference to a colder mean annual temperature and perhaps increased winter precipitation. Consideration of various factors controlling the stable isotope composition of the groundwater allows estimation of a 5° to 7°C temperature decrease during the late Wisconsin, accompanied by increased effective precipitation. A similar estimate of the temperature change is obtained from noble-gas paleothermometry. These data support a model of moderately cooler late Pleistocene climate in the American Southwest characterized by summers with less precipitation than today, but wetter winters.

  10. Geodetic measurement of deformation east of the San Andreas Fault in Central California

    NASA Technical Reports Server (NTRS)

    Sauber, Jeanne; Solomon, Sean C.; Lisowski, Michael

    1988-01-01

    The shear strain rates in the Diablo Range of California have been calculated, and the slip rate along the Calaveras and Paicines faults in Central California have been estimated, on the basis of triangulation and trilateration data from two geodetic networks located between the western edge of the Great Valley and the San Andreas Fault. The orientation of the principal compressive strain predicted from the azimuth of the major structures in the region is N 25 deg E, leading to an average shear strain value that corresponds to a relative shortening rate of 4.5 + or - 2.4 mm/yr. It is inferred that the measured strain is due to compression across the fold of this area. The hypothesized uniform, fault-normal compression within the Coast Ranges is not supported by these results.

  11. Fault coupling and potential for earthquakes on the creeping section of the Central San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Maurer, J.; Johnson, K. M.; Segall, P.

    2013-12-01

    The San Andreas Fault (SAF) has been known historically to produce large earthquakes in northern California along the northern coast section and in southern California along the Carrizo and Mojave sections. However, it is currently unclear whether the 150-km long central creeping section between these two sections could also rupture in large earthquakes. This section of the fault is known to be creeping at the surface, and in some areas may creep at nearly the long-term slip rate. We invert Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data to estimate the degree of locking on the central San Andreas Fault (CSAF) that place bounds on potential moment release. We use an elastic block model to compute present-day creep rates on the CSAF and compare these rates to seismicity patterns and observed surface creep rates. We find the inferred moment accumulation rate on the fault is highly dependent on the long-term fault slip rate, which is poorly constrained along the CSAF. The inferred potency accumulation rates on the creeping section, defined to be the seismic moment rate divided by shear modulus, range from 3.28x10^4 to 5.85x10^7 m^3/yr. The equivalent 150-year recurring earthquake magnitude is Mw = 5.5 - 7.2 for a long-term slip rate of 26 mm/yr and Mw = 7.3-7.65 for a long-term slip rate of 34 mm/yr. Although it is unclear how much of the accumulating moment would be released in future earthquakes, comparisons of slip distributions with seismicity indicate a possible locked patch between 10 and 20 km depth on the CSAF that could potentially rupture with Mw=6.5.

  12. Fault coupling and potential for earthquakes on the creeping section of the Central San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Maurer, Jeremy Lee

    The San Andreas Fault (SAF) has been known historically to produce large earthquakes in northern California along the northern coast section and in southern California along the Carrizo and Mojave sections. However, it is currently unclear whether the 150-km long central creeping section between these two sections could also rupture in large earthquakes. This section of the fault is known to be creeping at the surface, and in some areas may creep at nearly the long-term slip rate. We invert Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data to estimate the degree of locking on the central San Andreas Fault (CSAF) that place bounds on potential moment release. We use an elastic block model to compute present-day creep rates on the CSAF and compare these rates to seismicity patterns and observed surface creep rates. We find the inferred moment accumulation rate on the fault is highly dependent on the long-term fault slip rate, which is poorly constrained along the CSAF. The inferred potency accumulation rates on the creeping section, defined to be the seismic moment rate divided by shear modulus, range from 3.28x104 to 5.85x107m 3/yr. The equivalent 150-year recurring earthquake magnitude is M w = 5.5 - 7.2 for a long-term slip rate of 26 mm/yr and Mw = 7.3-7.65 for a long-term slip rate of 34 mm/yr. Although it is unclear how much of the accumulating moment would be released in future earthquakes, comparisons of slip distributions with seismicity indicate a possible locked patch between 10 and 20 km depth on the CSAF that could potentially rupture with M w=6.5.

  13. Seismicity at Fuego, Pacaya, Izalco, and San Cristobal Volcanoes, Central America, 1973-1974

    USGS Publications Warehouse

    McNutt, S.R.; Harlow, D.H.

    1983-01-01

    Seismic data collected at four volcanoes in Central America during 1973 and 1974 indicate three sources of seismicity: regional earthquakes with hypocentral distances greater than 80 km, earthquakes within 40 km of each volcano, and seismic activity originating at the volcanoes due to eruptive processes. Regional earthquakes generated by the underthrusting and subduction of the Cocos Plate beneath the Caribbean Plate are the most prominent seismic feature in Central America. Earthquakes in the vicinity of the volcanoes occur on faults that appear to be related to volcano formation. Faulting near Fuego and Pacaya volcanoes in Guatemala is more complex due to motion on a major E-W striking transform plate boundary 40 km north of the volcanoes. Volcanic activity produces different kinds of seismic signatures. Shallow tectonic or A-type events originate on nearby faults and occur both singly and in swarms. There are typically from 0 to 6 A-type events per day with b value of about 1.3. At very shallow depths beneath Pacaya, Izalco, and San Cristobal large numbers of low-frequency or B-type events are recorded with predominant frequencies between 2.5 and 4.5 Hz and with b values of 1.7 to 2.9. The relative number of B-type events appears to be related to the eruptive states of the volcanoes; the more active volcanoes have higher levels of seismicity. At Fuego Volcano, however, low-frequency events have unusually long codas and appear to be similar to tremor. High-amplitude volcanic tremor is recorded at Fuego, Pacaya, and San Cristobal during eruptive periods. Large explosion earthquakes at Fuego are well recorded at five stations and yield information on near-surface seismic wave velocities (??=3.0??0.2 km/sec.). ?? 1983 Intern. Association of Volcanology and Chemistry of the Earth's Interior.

  14. Estimation of streamflow gains and losses in the lower San Antonio River watershed, south-central Texas, 2006-10

    USGS Publications Warehouse

    Lizarraga, Joy S.; Wehmeyer, Loren L.

    2012-01-01

    The U.S. Geological Survey (USGS), in cooperation with the San Antonio River Authority, the Evergreen Underground Water Conservation District, and the Goliad County Groundwater Conservation District, investigated streamflow gains and losses during 2006-10 in the lower San Antonio River watershed in south-central Texas. Streamflow gains and losses were estimated using 2006-10 continuous streamflow records from 11 continuous streamflow-gaging stations, and discrete streamflow measurements made at as many as 20 locations on the San Antonio River and selected tributaries during four synoptic surveys during 2006-7. From the continuous streamflow records, the greatest streamflow gain on the lower San Antonio River occurred in the reach from Falls City, Tex., to Goliad, Tex. The greatest streamflow gain on Cibolo Creek during 2006-10 occurred in the reach from near Saint Hedwig, Tex., to Sutherland Springs, Tex. The San Antonio River between Floresville, Tex., and Falls City was the only reach that had an estimated streamflow loss during 2006-10. During all four synoptic streamflow measurement surveys, the only substantially flowing tributary reach to the main stem of the lower San Antonio River was Cibolo Creek. Along the main stem of the lower San Antonio River, verifiable gains larger than the potential measurement error were estimated in two of the four synoptic streamflow measurement surveys. These gaining reaches occurred in the two most downstream reaches of the San Antonio River between Goliad and Farm Road (FM) 2506 near Fannin, Tex., and between FM 2506 near Fannin to near McFaddin. There were verifiable gains in streamflow in Cibolo Creek, between La Vernia, Tex., and the town of Sutherland Springs during all four surveys, estimated at between 4.8 and 14 ft3/s.

  15. Maps of Quaternary Deposits and Liquefaction Susceptibility in the Central San Francisco Bay Region, California

    USGS Publications Warehouse

    Witter, Robert C.; Knudsen, Keith L.; Sowers, Janet M.; Wentworth, Carl M.; Koehler, Richard D.; Randolph, Carolyn E.; Brooks, Suzanna K.; Gans, Kathleen D.

    2006-01-01

    This report presents a map and database of Quaternary deposits and liquefaction susceptibility for the urban core of the San Francisco Bay region. It supercedes the equivalent area of U.S. Geological Survey Open-File Report 00-444 (Knudsen and others, 2000), which covers the larger 9-county San Francisco Bay region. The report consists of (1) a spatial database, (2) two small-scale colored maps (Quaternary deposits and liquefaction susceptibility), (3) a text describing the Quaternary map and liquefaction interpretation (part 3), and (4) a text introducing the report and describing the database (part 1). All parts of the report are digital; part 1 describes the database and digital files and how to obtain them by downloading across the internet. The nine counties surrounding San Francisco Bay straddle the San Andreas fault system, which exposes the region to serious earthquake hazard (Working Group on California Earthquake Probabilities, 1999). Much of the land adjacent to the Bay and the major rivers and streams is underlain by unconsolidated deposits that are particularly vulnerable to earthquake shaking and liquefaction of water-saturated granular sediment. This new map provides a consistent detailed treatment of the central part of the 9-county region in which much of the mapping of Open-File Report 00-444 was either at smaller (less detailed) scale or represented only preliminary revision of earlier work. Like Open-File Report 00-444, the current mapping uses geomorphic expression, pedogenic soils, inferred depositional environments, and geologic age to define and distinguish the map units. Further scrutiny of the factors controlling liquefaction susceptibility has led to some changes relative to Open-File Report 00-444: particularly the reclassification of San Francisco Bay mud (Qhbm) to have only MODERATE susceptibility and the rating of artificial fills according to the Quaternary map units inferred to underlie them (other than dams - adf). The two colored

  16. Geodetic Measurement of Deformation East of the San Andreas Fault in Central California

    NASA Technical Reports Server (NTRS)

    Sauber, Jeanne M.; Lisowski, Michael; Solomon, Sean C.

    1988-01-01

    Triangulation and trilateration data from two geodetic networks located between the western edge of the Great Valley and the San Andreas fault have been used to calculate shear strain rates in the Diablo Range and to estimate the slip rate along the Calaveras and Paicines faults in Central California. Within the Diablo Range the average shear strain rate was determined for the time period between 1962 and 1982 to be 0.15 + or - 0.08 microrad/yr, with the orientation of the most compressive strain at N 16 deg E + or - 14 deg. The orientation of the principal compressive strain predicted from the azimuth of the major structures in the region is N 25 deg E. It is inferred that the measured strain is due to compression across the folds of this area: the average shear straining corresponds to a relative shortening rate of 4.5 + or - 2.4 mm/yr. From an examination of wellbore breakout orientations and the azimuths of P-axes from earthquake focal mechanisms the inferred orientation of maximum compressive stress was found to be similar to the direction of maximum compressive strain implied by the trend of local fold structures. Results do not support the hypothesis of uniform fault-normal compression within the Coast Ranges. From trilateration measurements made between 1972 and 1987 on lines that are within 10 km of the San Andreas fault, a slip rate of 10 to 12 mm/yr was calculated for the Calaveras-Paicines fault south of Hollister. The slip rate of the Paicines fault decreases to 4 mm/yr near Bitter.

  17. Catalog of earthquakes along the San Andreas fault system in Central California, July-September 1972

    USGS Publications Warehouse

    Wesson, R.L.; Meagher, K.L.; Lester, F.W.

    1973-01-01

    Numerous small earthquakes occur each day in the coast ranges of Central California. The detailed study of these earthquakes provides a tool for gaining insight into the tectonic and physical processes responsible for the generation of damaging earthquakes. This catalog contains the fundamental parameters for earthquakes located within and adjacent to the seismograph network operated by the National Center for Earthquake Research (NCER), U.S. Geological Survey, during the period July - September, 1972. The motivation for these detailed studies has been described by Pakiser and others (1969) and by Eaton and others (1970). Similar catalogs of earthquakes for the years 1969, 1970 and 1971 have been prepared by Lee and others (1972 b, c, d). Catalogs for the first and second quarters of 1972 have been prepared by Wessan and others (1972 a & b). The basic data contained in these catalogs provide a foundation for further studies. This catalog contains data on 1254 earthquakes in Central California. Arrival times at 129 seismograph stations were used to locate the earthquakes listed in this catalog. Of these, 104 are telemetered stations operated by NCER. Readings from the remaining 25 stations were obtained through the courtesy of the Seismographic Stations, University of California, Berkeley (UCB), the Earthquake Mechanism Laboratory, National Oceanic and Atmospheric Administration, San Francisco (EML); and the California Department of Water Resources, Sacramento. The Seismographic Stations of the University of California, Berkeley, have for many years published a bulletin describing earthquakes in Northern California and the surrounding area, and readings at UCB Stations from more distant events. The purpose of the present catalog is not to replace the UCB Bulletin, but rather to supplement it, by describing the seismicity of a portion of central California in much greater detail.

  18. Catalog of earthquakes along the San Andreas fault system in Central California, April-June 1972

    USGS Publications Warehouse

    Wesson, R.L.; Bennett, R.E.; Lester, F.W.

    1973-01-01

    Numerous small earthquakes occur each day in the coast ranges of Central California. The detailed study of these earthquakes provides a tool for gaining insight into the tectonic and physical processes responsible for the generation of damaging earthquakes. This catalog contains the fundamental parameters for earthquakes located within and adjacent to the seismograph network operated by the National Center for Earthquake Research (NCER), U.S. Geological Survey, during the period April - June, 1972. The motivation for these detailed studies has been described by Pakiser and others (1969) and by Eaton and others (1970). Similar catalogs of earthquakes for the years 1969, 1970 and 1971 have been prepared by Lee and others (1972 b, c, d). A catalog for the first quarter of 1972 has been prepared by Wesson and others (1972). The basic data contained in these catalogs provide a foundation for further studies. This catalog contains data on 910 earthquakes in Central California. A substantial portion of the earthquakes reported in this catalog represents a continuation of the sequence of earthquakes in the Bear Valley area which began in February, 1972 (Wesson and others, 1972). Arrival times at 126 seismograph stations were used to locate the earthquakes listed in this catalog. Of these, 101 are telemetered stations operated by NCER. Readings from the remaining 25 stations were obtained through the courtesy of the Seismographic Stations, University of California, Berkeley (UCB); the Earthquake Mechanism Laboratory, National Oceanic and Atmospheric Administration, San Francisco (EML); and the California Department of Water Resources, Sacramento. The Seismographic Stations of the University of California, Berkeley, have for many years published a bulletin describing earthquakes in Northern California and the surrounding area, and readings at UCB Stations from more distant events. The purpose of the present catalog is not to replace the UCB Bulletin, but rather to supplement

  19. Catalog of earthquakes along the San Andreas fault system in Central California: January-March, 1972

    USGS Publications Warehouse

    Wesson, R.L.; Bennett, R.E.; Meagher, K.L.

    1973-01-01

    Numerous small earthquakes occur each day in the Coast Ranges of Central California. The detailed study of these earthquakes provides a tool for gaining insight into the tectonic and physical processes responsible for the generation of damaging earthquakes. This catalog contains the fundamental parameters for earthquakes located within and adjacent to the seismograph network operated by the National Center for Earthquake Research (NCER), U.S. Geological Survey, during the period January - March, 1972. The motivation for these detailed studies has been described by Pakiser and others (1969) and by Eaton and others (1970). Similar catalogs of earthquakes for the years 1969, 1970 and 1971 have been prepared by Lee and others (1972 b,c,d). The basic data contained in these catalogs provide a foundation for further studies. This catalog contains data on 1,718 earthquakes in Central California. Of particular interest is a sequence of earthquakes in the Bear Valley area which contained single shocks with local magnitudes of S.O and 4.6. Earthquakes from this sequence make up roughly 66% of the total and are currently the subject of an interpretative study. Arrival times at 118 seismograph stations were used to locate the earthquakes listed in this catalog. Of these, 94 are telemetered stations operated by NCER. Readings from the remaining 24 stations were obtained through the courtesy of the Seismographic Stations, University of California, Berkeley (UCB); the Earthquake Mechanism Laboratory, National Oceanic and Atmospheric Administration, San Francisco (EML); and the California Department of Water Resources, Sacramento. The Seismographic Stations of the University of California, Berkeley,have for many years published a bulletin describing earthquakes in Northern California and the surrounding area, and readings at UCB Stations from more distant events. The purpose of the present catalog is not to replace the UCB Bulletin, but rather to supplement it, by describing the

  20. Shifting shoals and shattered rocks : How man has transformed the floor of west-central San Francisco Bay

    USGS Publications Warehouse

    Chin, John L.; Wong, Florence L.; Carlson, Paul R.

    2004-01-01

    subembayments--north bay (San Pablo and Suisun Bays), central bay, and south bay--each characterized by a central area of open water surrounded by intertidal mudflats and marshes. Central bay includes Alcatraz and Angel Islands and also a number of submerged bedrock knobs that protrude through the sediment of the bay floor and rise to within about 40 feet (12 m) of the water surface. The most prominent of these are Harding, Shag, Arch, and Blossom Rocks. These rocks have been lowered by blasting several times in the past, but they remain a potential hazard to shipping because newer cargo vessels are designed with increasingly deeper drafts. Central bay's location adjacent to two major population and commerce centers, San Francisco and Oakland, subjects it to greater human influences than less developed parts of the estuary. The western part of central San Francisco Bay is adjacent to the Golden Gate, the estuary's outlet to the Pacific Ocean. The changing submarine topography of the west-central bay, as well as its geology, form the main focus of this book.

  1. Sequence stratigraphy of the Lower Triassic Sinbad Formation, San Rafael Swell, east-central, Utah

    SciTech Connect

    Goodspeed, T.H.; Elrick, M. . Dept. of Earth and Planetary Sciences); Lucas, S.G. )

    1993-04-01

    The Lower Triassic Sinbad Fm (20--30 m thick) in the San Rafael Swell of east-central Utah is high energy carbonate deposits that conformably overlie tidal flat/fluvial channel deposits of the Black Dragon Fm. The Torrey Fm conformably overlies the Sinbad Fm and consists primarily of siliciclastic tidal flat and fluvial deposits. Five facies (in ascending order) are characteristic of the Sinbad Fm: (1) bioturbated calcisiltite with calcite-replaced evaporite nodules and ripple laminations, (2) skeletal-oolitic-intraclastic packstone and grainstone, (3) slightly bioturbated, mechanically laminated, pelletal calcisiltite (5) trough cross-bedded, peloidal to oolitic grainstone, and (5) thin-bedded, skeletal-pelletal-oolitic grainstone with mud to wackestone drapes. Regional facies relationships of the Sinbad Fm indicate initial deepening followed by shallowing. The skeletal-intraclastic packstone and grainstone facies represents maximum flooding. This facies thickens to the northwest and contains an open marine molluscan fauna of ammonites, bivalves, gastropods and scaphopods. The ammonites are indicative of the Tardus Zone of late Smithian age. Deposits above the maximum flooding zone (MFZ) are restricted foreshoal, pelletal calcisiltite, oolitic shoal, and backshoal skeletal-oolitic (with a restricted fauna of molluscs and ostracods) deposits. This shallowing-upward sequence represents the early HST. The Sinbad Fm represents the MFZ and early HST of a 150-m-thick depositional sequence of rocks with the Black Dragon FM representing the TST, and the Torrey Fm representing the late HST.

  2. Anomalous hydrogen emissions from the San Andreas fault observed at the Cienega Winery, central California

    USGS Publications Warehouse

    Sato, M.; Sutton, A.J.; McGee, K.A.

    1985-01-01

    We began continuous monitoring of H2 concentration in soil along the San Andreas and Calaveras faults in central California in December 1980, using small H2/O2 fuel-cell sensors. Ten monitoring stations deployed to date have shown that anomalous H2 emissions take place occasionally in addition to diurnal changes. Among the ten sites, the Cienega Winery site has produced data that are characterized by very small diurnal changes, a stable baseline, and remarkably distinct spike-like H2 anomalies since its installation in July 1982. A major peak appeared on 1-10 November 1982, and another on 3 April 1983, and a medium peak on 1 November 1983. The occurrences of these peaks coincided with periods of very low seismicity within a radius of 50 km from the site. In order to methodically assess how these peaks are related to earthquakes, three H2 degassing models were examined. A plausible correlational pattern was obtained by using a model that (1) adopts a hemicircular spreading pattern of H2 along an incipient fracture plane from the hypocenter of an earthquake, (2) relies on the FeO-H2O reaction for H2 generation, and (3) relates the accumulated amount of H2 to the mass of serpentinization of underlying ophiolitic rocks; the mass was tentatively assumed to be proportional to the seismic energy of the earthquake. ?? 1985 Birkha??user Verlag.

  3. Potential field studies of the central San Luis Basin and San Juan Mountains, Colorado and New Mexico, and southern and western Afghanistan

    NASA Astrophysics Data System (ADS)

    Drenth, Benjamin John

    This dissertation includes three separate chapters, each demonstrating the interpretive utility of potential field (gravity and magnetic) geophysical datasets at various scales and in various geologic environments. The locations of these studies are the central San Luis Basin of Colorado and New Mexico, the San Juan Mountains of southwestern Colorado, and southern and western Afghanistan. The San Luis Basin is the northernmost of the major basins that make up the Rio Grande rift, and interpretation of gravity and aeromagnetic data reveals patterns of rifting, rift-sediment thicknesses, distribution of pre-rift volcanic and sedimentary rocks, and distribution of syn-rift volcanic rocks. Syn-rift Santa Fe Group sediments have a maximum thickness of ˜2 km in the Sanchez graben near the eastern margin of the basin along the central Sangre de Cristo fault zone. Under the Costilla Plains, thickness of these sediments is estimated to reach ˜1.3 km. The Santa Fe Group sediments also reach a thickness of nearly 1 km within the Monte Vista graben near the western basin margin along the San Juan Mountains. A narrow, north-south-trending structural high beneath San Pedro Mesa separates the graben from the structural depression beneath the Costilla Plains. Aeromagnetic anomalies are interpreted to mainly reflect variations of remanent magnetic polarity and burial depth of the 5.3-3.7 Ma Servilleta basalt of the Taos Plateau volcanic field. Magnetic-source depth estimates indicate patterns of subsidence following eruption of the basalt and show that the Sanchez graben has been the site of maximum subsidence. One of the largest and most pronounced gravity lows in North America lies over the rugged San Juan Mountains in southwestern Colorado. A buried, low-density silicic batholith related to an Oligocene volcanic field coincident with the San Juan Mountains has been the accepted interpretation of the source of the gravity low since the 1970s. However, this interpretation was

  4. Evolution of the east-central San Jose del Cabo basin, Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    McTeague, M. S.; Umhoefer, P. J.; Schwennicke, T.; Ingle, J. C.; Cortes Martinez, M.

    2006-12-01

    The San Jose del Cabo basin at the southern tip of the Baja California peninsula records the early tectonic evolution of the west side of the Gulf of California. This study focused on the east central margin of the basin. The basal La Calera Formation unconformably overlies Cretaceous granite and consists of conglomerate, pebbly sandstone and conglomerate, and sandstone deposited in alluvial fans and fan-deltas. Deposition of the La Calera Formation was from ca. 9-14 Ma. The lower member of the Trinidad Formation was deposited beginning ca. 9-13 Ma and consists of sandstone, mudstone, and shelly mudstone deposited in nearshore and estuarine environments. These age estimates are based on sedimentation rates and foraminifera and coccoliths from the NN 11A nannozone (7.4 8.6 Ma, GTS 2004). The middle member of the Trinidad Formation consists of deeper water mudstones deposited by turbidity currents and suspension settling in a shelf to slope and conglomerates deposited by submarine debris flows on the shelf. The basin began earlier than previously thought. The oldest marine rocks are ca.9-13 Ma, while sedimentation on the east side began at ca. 9-14 Ma, synchronous with estimates of initiation of offset on the San Jose del Cabo fault. The Zapote fault is a down-to-the-east normal and sinistral-oblique fault that exposes a wedge of granite and older strata in the footwall to the west. The fault was active during sedimentation in the late Miocene and possibly later. The fault divides the study area into an eastern hanging wall subbasin and western footwall subbasin. The eastern subbasin formed an embayment in the eastern margin of the Cabo basin. A regional flooding surface (ca. 8 Ma) can be correlated across the fault that marks a major marine incursion. Depositional systems evolved rapidly from coarse-grained terrestrial systems to fine-grained marine and estuarine systems. The Cabo basin provides an excellent analogue for comparison with offshore basins, which are

  5. Geology, thermal maturation, and source rock geochemistry in a volcanic covered basin: San Juan sag, south-central Colorado

    USGS Publications Warehouse

    Gries, R.R.; Clayton, J.L.; Leonard, C.

    1997-01-01

    The San Juan sag, concealed by the vast San Juan volcanic field of south-central Colorado, has only recently benefited from oil and gas wildcat drilling and evaluations. Sound geochemical analyses and maturation modeling are essential elements for successful exploration and development. Oil has been produced in minor quantities from an Oligocene sill in the Mancos Shale within the sag, and major oil and gas production occurs from stratigraphically equivalent rocks in the San Juan basin to the south-west and in the Denver basin to the northeast. The objectives of this study were to identify potential source rocks, assess thermal maturity, and determine hydrocarbon-source bed relationships. Source rocks are present in the San Juan sag in the upper and lower Mancos Shale (including the Niobrara Member), which consists of about 666 m (2184 ft) of marine shale with from 0.5 to 3.1 wt. % organic carbon. Pyrolysis yields (S1 + S2 = 2000-6000 ppm) and solvent extraction yields (1000-4000 ppm) indicate that some intervals within the Mancos Shale are good potential source rocks for oil, containing type II organic matter, according to Rock-Eval pyrolysis assay. Oils produced from the San Juan sag and adjacent part of the San Juan basin are geochemically similar to rock extracts obtained from these potential source rock intervals. Based on reconstruction of the geologic history of the basin integrated with models of organic maturation, we conclude that most of the source rock maturation occurred in the Oligocene and Miocene. Little to no maturation took place during Laramide subsidence of the basin, when the Animas and Blanco Basin formations were deposited. The timing of maturation is unlike that of most Laramide basins in the Rocky Mountain region, where maturation occurred as a result of Paleocene and Eocene basin fill. The present geothermal gradient in the San Juan sag is slightly higher (average 3.5??C/100 m; 1.9??F/100 ft) than the regional average for southern Rocky

  6. Creep avalanches on the Central San Andreas Fault: Clues and Causes

    NASA Astrophysics Data System (ADS)

    Khoshmanesh, M.; Shirzaei, M.; Nadeau, R. M.

    2015-12-01

    The Central segment of San Andreas Fault (CSAF) is characterized by a nearly continuous right-lateral aseismic slip. However, observations of the creep rate obtained using Characteristically Repeating Earthquakes (CREs) show a quasi-periodic temporal variation, which is recently confirmed using both InSAR surface deformation time series and geodetic-based time-dependent kinematic model of creep along the CSAF. Here, we show that the statistical analysis of creep fronts along the CSAF indicates a sporadic behavior, signature of a burst-like creep dynamics. Moreover, the probability of creep velocities follows a Gumbel distribution characterized by longer tail toward the extreme positive rates. Fourier analysis of the time series of surface creep rate indicates a self-affine regime with Hurst exponent altering between 0.6 and 0.9 during the observation period of 2003-2011. The variable Hurst component is an indicator for temporal variation in the roughness of the fault zone. To explain the causes of creep avalanches, two possible mechanisms are considered, including temporal variation in: 1) fault geometry, and 2) Ambient normal stress. We find that the overall statistical dependence between the pattern of surface creep rate and the fault geometry is insignificant. To investigate the effect of ambient normal stress, primarily due to variation in pore pressure, we implement a rate and state friction law to link the time-dependent kinematic creep model to the spatiotemporal variations of the normal stress on the velocity-strengthening fault zones. These observations and models help to understand the driving mechanisms that govern the creep rate variations at short spatial length and low velocities. Under these circumstances, the other mechanisms such as thermal pressurization are not feasible.

  7. Geology, thermal maturation, and source rock geochemistry in a volcanic covered basin: San Juan sag, south-central Colorado

    SciTech Connect

    Gries, R.R.; Clayton, J.L.; Leonard, C.

    1997-07-01

    The San Juan sag, concealed by the vast San Juan volcanic field of south-central Colorado, has only recently benefited from oil and gas wildcat drilling and evaluations. Sound geochemical analyses and maturation modeling are essential elements for successful exploration and development. Oil has been produced in minor quantities from an Oligocene sill in the Mancos Shale within the sag, and major oil and gas production occurs from stratigraphically equivalent rocks in the San Juan basin to the southwest and in the Denver basin to the northeast. The objectives of this study were to identify potential source rocks, assess thermal maturity, and determine hydrocarbon-source bed relationships. Source rocks are present in the San Juan sag in the upper and lower Mancos Shale (including the Niobrara Member), which consists of about 666 m (2184 ft) of marine shale with from 0.5 to 3.1 wt. % organic carbon. Pyrolysis yields (S{sub 1} + S{sub 2} = 2000-6000 ppm) and solvent extraction yields (1000-4000 ppm) indicate that some intervals within the Mancos Shale are good potential source rocks for oil, containing type II organic matter, according to Rock-Eval pyrolysis assay.

  8. Spatial variations in slip deficit on the central San Andreas Fault from InSAR

    NASA Astrophysics Data System (ADS)

    Ryder, Isabelle; Bürgmann, Roland

    2008-12-01

    We use ERS InSAR measurements to record spatial variations in creep rate along the creeping segment of the San Andreas Fault (SAF), California, between 1992 and 2001. Inversion of geodetic data yields a slip rate distribution along the creeping segment, which is used for first-order moment release and deficit calculations. We present a time-averaged spatial picture of surface deformation and associated subsurface creep. An interferometric stack is constructed from 12 interferograms that show good coherence. For the decade of observation, the total right-lateral offset spanned by the data is ~34 mmyr-1. Along most of the length of the creeping segment, this offset occurs within a narrow (<2 km) zone close to the fault trace. In the northern part, a minor part of the offset is taken up by the nearby Calaveras-Paicines Fault. In general, the observed rates of surface creep are consistent with those obtained by several other studies for a longer and/or earlier period of time, using different geodetic methods. This suggests that the average creep rate has been constant over a period of almost four decades. A joint GPS-InSAR inversion implies that the shallow creep rate is variable along strike, reaching up to 31.5 +/- 1 mmyr-1 in the central section of the creeping segment, tapering off along-strike to the south and becoming partitioned across two subparallel faults in the north. The deep slip rate beneath the seismogenic layer is 33 +/- 3 mmyr-1. The difference between shallow and deep slip rates suggests that there is a shallow slip deficit on the creeping segment of the SAF (CSAF). Moment release rate due to aseismic slip is approximately three orders of magnitude greater than seismic moment release. The annual creep on the CSAF is equivalent to the moment released in a M 6 earthquake. The equivalent moment of the slip deficit relative to the deep slip rate is between 4.1 × 1017 and 8.4 × 1017 N myr-1, which is equivalent to a magnitude 5.7-5.9 earthquake. Over a

  9. A rheologically layered three-dimensional model of the San Andreas fault in central and southern California

    NASA Technical Reports Server (NTRS)

    Williams, Charles A.; Richardson, Randall M.

    1991-01-01

    The effects of rheological parameters and the fault slip distribution on the horizontal and vertical deformation in the vicinity of the fault are investigated using 3D kinematic finite element models of the San Andreas fault in central and southern California. It is shown that fault models with different rheological stratification schemes and slip distributions predict characteristic deformation patterns. Models that do not include aseismic slip below the fault locking depth predict deformation patterns that are strongly dependent on time since the last earthquake, while models that incorporate the aseismic slip below the locking depth depend on time to a significantly lesser degree.

  10. 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

  11. Correlation between deep fluids, tremor and creep along the central San Andreas fault.

    PubMed

    Becken, Michael; Ritter, Oliver; Bedrosian, Paul A; Weckmann, Ute

    2011-12-01

    The seismicity pattern along the San Andreas fault near Parkfield and Cholame, California, varies distinctly over a length of only fifty kilometres. Within the brittle crust, the presence of frictionally weak minerals, fault-weakening high fluid pressures and chemical weakening are considered possible causes of an anomalously weak fault northwest of Parkfield. Non-volcanic tremor from lower-crustal and upper-mantle depths is most pronounced about thirty kilometres southeast of Parkfield and is thought to be associated with high pore-fluid pressures at depth. Here we present geophysical evidence of fluids migrating into the creeping section of the San Andreas fault that seem to originate in the region of the uppermost mantle that also stimulates tremor, and evidence that along-strike variations in tremor activity and amplitude are related to strength variations in the lower crust and upper mantle. Interconnected fluids can explain a deep zone of anomalously low electrical resistivity that has been imaged by magnetotelluric data southwest of the Parkfield-Cholame segment. Near Cholame, where fluids seem to be trapped below a high-resistivity cap, tremor concentrates adjacent to the inferred fluids within a mechanically strong zone of high resistivity. By contrast, subvertical zones of low resistivity breach the entire crust near the drill hole of the San Andreas Fault Observatory at Depth, northwest of Parkfield, and imply pathways for deep fluids into the eastern fault block, coincident with a mechanically weak crust and the lower tremor amplitudes in the lower crust. Fluid influx to the fault system is consistent with hypotheses of fault-weakening high fluid pressures in the brittle crust. PMID:22129729

  12. Correlation between deep fluids, tremor and creep along the central San Andreas fault

    USGS Publications Warehouse

    Becken, M.; Ritter, O.; Bedrosian, P.A.; Weckmann, U.

    2011-01-01

    The seismicity pattern along the San Andreas fault near Parkfield and Cholame, California, varies distinctly over a length of only fifty kilometres. Within the brittle crust, the presence of frictionally weak minerals, fault-weakening high fluid pressures and chemical weakening are considered possible causes of an anomalously weak fault northwest of Parkfield. Non-volcanic tremor from lower-crustal and upper-mantle depths is most pronounced about thirty kilometres southeast of Parkfield and is thought to be associated with high pore-fluid pressures at depth. Here we present geophysical evidence of fluids migrating into the creeping section of the San Andreas fault that seem to originate in the region of the uppermost mantle that also stimulates tremor, and evidence that along-strike variations in tremor activity and amplitude are related to strength variations in the lower crust and upper mantle. Interconnected fluids can explain a deep zone of anomalously low electrical resistivity that has been imaged by magnetotelluric data southwest of the Parkfield-Cholame segment. Near Cholame, where fluids seem to be trapped below a high-resistivity cap, tremor concentrates adjacent to the inferred fluids within a mechanically strong zone of high resistivity. By contrast, subvertical zones of low resistivity breach the entire crust near the drill hole of the San Andreas Fault Observatory at Depth, northwest of Parkfield, and imply pathways for deep fluids into the eastern fault block, coincident with a mechanically weak crust and the lower tremor amplitudes in the lower crust. Fluid influx to the fault system is consistent with hypotheses of fault-weakening high fluid pressures in the brittle crust. ?? 2011 Macmillan Publishers Limited. All rights reserved.

  13. Paleobathymetric maps of tertiary La Honda Basin and implications for offset along San Andreas fault in central California

    SciTech Connect

    Stanley, R.G.

    1987-05-01

    Paleobathymetric maps of the La Honda basin of central California were constructed for ten intervals of geologic time from late Paleocene (Nezian) to middle Miocene (Luisian). The maps are based on analyses of benthic foraminiferal biofacies in more than 800 faunal lists compiled from the literature and from subsurface data provided by oil companies. The sequence of paleobathymetric maps shows the paleogeographic evolution of the La Honda basin. From the late Paleocene (Ynezian) to the early Oligocene (early Zemorrian), deep-sea sands and muds accumulated at water depths of 2000 m and more on a surface that sloped gently to the north and northeast. Striking changes in the configuration of the La Honda basin occurred during the late Oligocene and early Miocene (late Zemorrian). Much of the basin floor remained at water depths of 2000 m and greater, but submarine volcanic rocks locally built up to form seamounts, and movement along the Zayante-Vergeles fault led to shoaling and development of a narrow shelf and very steep slope along the southwestern margin of the basin. During the early and middle Miocene (Relizian and Luisian), the entire basin shoaled to depths of less than 1500 m. Comparison of paleobathymetric maps of the La Honda and San Joaquin basins lends support to the notion that the two basins were once contiguous but have been separated by about 320 to 330 km of right-lateral displacement along the San Andreas fault since the earliest Miocene (late Zemorrian and Saucesian).

  14. LiDAR and Field Observations of Earthquake Slip Distribution for the central San Jacinto fault

    NASA Astrophysics Data System (ADS)

    Salisbury, J. B.; Rockwell, T. K.; Middleton, T.; Hudnut, K. W.

    2010-12-01

    We mapped the tectonic geomorphology of 80 km of the Clark strand of the San Jacinto fault to determine slip per event for the past several surface ruptures. From the southeastern end of Clark Valley (east of Borrego Springs) northwest to the mouth of Blackburn Canyon (near Hemet), we identify 203 offset geomorphic features from which we make over 560 measurements on channel margins, channel thalwegs, ridge noses, and bar crests using filtered B4 LiDAR imagery, aerial photography, and field observations. Displacement estimates show that the most recent large event (MRE) produced an average of 2.5-2.9 m of right-lateral slip, with maximum slip of 3.5 to 4 m at Anza. Double-event offsets for the same 80 km section average ~5.5 m of right-lateral slip. Maximum values near Anza are estimated to be close to 3 m for the penultimate event, suggesting that the penultimate event was similar in size to the MRE. The third event is also similar in size, with cumulative displacement of 9-10 m through Anza for the past three events. Magnitude estimates for the MRE range from Mw 7.2 to Mw 7.5, depending on how far north the rupture continued. Historically, no earthquakes reported along the Clark fault are large enough to have produced the offset geomorphology we observe. However, recent paleoseismic work at Hog Lake dates the most recent surface rupture event at ca. 1790, potentially placing this event in the historic period. A poorly located, large earthquake occurred on November 22, 1800, and is reported to have caused extensive damage (MMI VII) at the San Diego and San Juan Capistrano missions. We infer slightly lower intensity values for the two missions (MMI VI-VII instead of VII) and relocate this event on the Clark fault based on dating of the MRE at Hog Lake. We also recognize the occurrence of a younger offset along ~15-20 km of the fault in Blackburn Canyon, apparently due to lower slip in that area in the November 22, 1800 event. With average displacement of ~1.25 m

  15. Crustal structure of a transform plate boundary: San Francisco Bay and the central California continental margin

    USGS Publications Warehouse

    Holbrook, W.S.; Brocher, T.M.; ten Brink, U.S.; Hole, J.A.

    1996-01-01

    Wide-angle seismic data collected during the Bay Area Seismic Imaging Experiment provide new glimpses of the deep structure of the San Francisco Bay Area Block and across the offshore continental margin. San Francisco Bay is underlain by a veneer (<300 m) of sediments, beneath which P wave velocities increase rapidly from 5.2 km/s to 6.0 km/s at 7 km depth, consistent with rocks of the Franciscan subduction assemblage. The base of the Franciscan at-15-18 km depth is marked by a strong wide-angle reflector, beneath which lies an 8- to 10-km-thick lower crust with an average velocity of 6.75??0.15 km/s. The lower crust of the Bay Area Block may be oceanic in origin, but its structure and reflectivity indicate that it has been modified by shearing and/or magmatic intrusion. Wide-angle reflections define two layers within the lower crust, with velocities of 6.4-6.6 km/s and 6.9-7.3 km/s. Prominent subhorizontal reflectivity observed at near-vertical incidence resides principally in the lowermost layer, the top of which corresponds to the "6-s reflector" of Brocher et al. [1994]. Rheological modeling suggests that the lower crust beneath the 6-s reflector is the weakest part of the lithosphere; the horizontal shear zone suggested by Furlong et al. [1989] to link the San Andreas and Hayward/Calaveras fault systems may actually be a broad zone of shear deformation occupying the lowermost crust. A transect across the continental margin from the paleotrench to the Hayward fault shows a deep crustal structure that is more complex than previously realized. Strong lateral variability in seismic velocity and wide-angle reflectivity suggests that crustal composition changes across major transcurrent fault systems. Pacific oceanic crust extends 40-50 km landward of the paleotrench but, contrary to prior models, probably does not continue beneath the Salinian Block, a Cretaceous arc complex that lies west of the San Andreas fault in the Bay Area. The thickness (10 km) and high

  16. Crustal structure of a transform plate boundary: San Francisco Bay and the central California continental margin

    NASA Astrophysics Data System (ADS)

    Holbrook, W. Steven; Brocher, Thomas M.; ten Brink, Uri S.; Hole, John A.

    1996-10-01

    Wide-angle seismic data collected during the Bay Area Seismic Imaging Experiment provide new glimpses of the deep structure of the San Francisco Bay Area Block and across the offshore continental margin. San Francisco Bay is underlain by a veneer (<300 m) of sediments, beneath which P wave velocities increase rapidly from 5.2 km/s to 6.0 km/s at 7 km depth, consistent with rocks of the Franciscan subduction assemblage. The base of the Franciscan at 15-18 km depth is marked by a strong wide-angle reflector, beneath which lies an 8- to 10-km-thick lower crust with an average velocity of 6.75 ± 0.15 km/s. The lower crust of the Bay Area Block may be oceanic in origin, but its structure and reflectivity indicate that it has been modified by shearing and/or magmatic intrusion. Wide-angle reflections define two layers within the lower crust, with velocities of 6.4-6.6 km/s and 6.9-7.3 km/s. Prominent subhorizontal reflectivity observed at near-vertical incidence resides principally in the lowermost layer, the top of which corresponds to the "6-s reflector" of Brocher et al. [1994]. Rheological modeling suggests that the lower crust beneath the 6-s reflector is the weakest part of the lithosphere; the horizontal shear zone suggested by Furlong et al. [1989] to link the San Andreas and Hayward/Calaveras fault systems may actually be a broad zone of shear deformation occupying the lowermost crust. A transect across the continental margin from the paleotrench to the Hayward fault shows a deep crustal structure that is more complex than previously realized. Strong lateral variability in seismic velocity and wide-angle reflectivity suggests that crustal composition changes across major transcurrent fault systems. Pacific oceanic crust extends 40-50 km landward of the paleotrench but, contrary to prior models, probably does not continue beneath the Salinian Block, a Cretaceous arc complex that lies west of the San Andreas fault in the Bay Area. The thickness (10 km) and high

  17. Database compilation for the geologic map of the San Francisco volcanic field, north-central Arizona

    USGS Publications Warehouse

    Bard, Joseph A.; Ramsey, David W.; Wolfe, Edward W.; Ulrich, George E.; Newhall, Christopher G.; Moore, Richard B.; Bailey, Norman G.; Holm, Richard F.

    2015-01-01

    The orignial geologic maps were prepared under the Geothermal Research Program of the U.S. Geological Survey as a basis for interpreting the history of magmatic activity in the volcanic field. The San Francisco field, which is largely Pleistocene in age, is in northern Arizona, just north of the broad transition zone between the Colorado Plateau and the Basin and Range province. It is one of several dominantly basaltic volcanic fields of the late Cenozoic age situated near the margin of the Colorado Plateau. The volcanic field contains rocks ranging in composition from basalt to rhyolite—the products of eruption through Precambrian basement rocks and approximately a kilometer of overlying, nearly horizontal, Paleozoic and Mesozoic sedimentary rocks. About 500 km3 of erupted rocks cover about 5,000 km2 of predominantly Permian and locally preserved Triassic sedimentary rocks that form the erosionally stripped surface of the Colorado Plateau in Northern Arizona.

  18. Potential of public lands in California's central valley as habitat for the endangered San Joaquin kit fox. [Vulpes macrotis mutica

    SciTech Connect

    O'Farrell, T.P.; McCue, P.; Sauls, M.L.; Kato, T.

    1982-01-01

    As part of an assessment of the impacts of their activities on the endangered San Joaquin kit fox and its essential habitat, the Department of Energy and Bureau of Land Management investigated the potential of public lands in the San Joaquin Valley as suitable habitat for the San Joaquin kit fox. (ACR)

  19. Retardations in fault creep rates before local moderate earthquakes along the San Andreas fault system, central California

    USGS Publications Warehouse

    Burford, R.O.

    1988-01-01

    Records of shallow aseismic slip (fault creep) obtained along parts of the San Andreas and Calaveras faults in central California demonstrate that significant changes in creep rates often have been associated with local moderate earthquakes. An immediate postearthquake increase followed by gradual, long-term decay back to a previous background rate is generally the most obvious earthquake effect on fault creep. This phenomenon, identified as aseismic afterslip, usually is characterized by above-average creep rates for several months to a few years. In several cases, minor step-like movements, called coseismic slip events, have occurred at or near the times of mainshocks. One extreme case of coseismic slip, recorded at Cienega Winery on the San Andreas fault 17.5 km southeast of San Juan Bautista, consisted of 11 mm of sudden displacement coincident with earthquakes of ML=5.3 and ML=5.2 that occurred 2.5 minutes apart on 9 April 1961. At least one of these shocks originated on the main fault beneath the winery. Creep activity subsequently stopped at the winery for 19 months, then gradually returned to a nearly steady rate slightly below the previous long-term average. The phenomena mentioned above can be explained in terms of simple models consisting of relatively weak material along shallow reaches of the fault responding to changes in load imposed by sudden slip within the underlying seismogenic zone. In addition to coseismic slip and afterslip phenomena, however, pre-earthquake retardations in creep rates also have been observed. Onsets of significant, persistent decreases in creep rates have occurred at several sites 12 months or more before the times of moderate earthquakes. A 44-month retardation before the 1979 ML=5.9 Coyote Lake earthquake on the Calaveras fault was recorded at the Shore Road creepmeter site 10 km northwest of Hollister. Creep retardation on the San Andreas fault near San Juan Bautista has been evident in records from one creepmeter site for

  20. San Ignacio (La Tembladera) geothermal site, Departamento de Francisco Morazan, Honduras, Central America: Geological field report

    SciTech Connect

    Aldrich, M.J.; Eppler, D.; Heiken, G.; Flores, W.; Ramos, N.; Ritchie, A.

    1987-06-01

    The San Ignacio (La Tembladera) geothermal site is located on the north side of the Siria Valley, Departamento de Francisco Morazan, near the village of Barrosa. Hot springs are located along a northwest-trending fault scarp at the edge of the valley and along north-trending faults that cross the scarp. The rocks in the area are primarily Paleozoic metamorphic rocks, overlain by patches of Tertiary Padre Miguel Group tuffs and alluvial deposits. Movement probably occurred along several faults during latest Tertiary and possibly early Quaternary times. Four spring areas were mapped. Area 1, the largest, is associated with a sinter mound and consists of 40 spring groups. About half of the springs, aligned along a north-south trend, are boiling. Area 2 is a small sinter mound with several seeps. Area 3 consists of a group of hot and boiling springs aligned along a north-trending fault. The springs rise through fractured schists and a thin cover of alluvium. Area 4 is located at the intersection of several faults and includes one of the largest boiling springs in the area.

  1. Comparison of sediment supply to San Francisco Bay from watersheds draining the Bay Area and the Central Valley of California

    USGS Publications Warehouse

    McKee, L.J.; Lewicki, M.; Schoellhamer, D.H.; Ganju, N.K.

    2013-01-01

    Quantifying suspended sediment loads is important for managing the world's estuaries in the context of navigation, pollutant transport, wetland restoration, and coastal erosion. To address these needs, a comprehensive analysis was completed on sediment supply to San Francisco Bay from fluvial sources. Suspended sediment, optical backscatter, velocity data near the head of the estuary, and discharge data obtained from the output of a water balance model were used to generate continuous suspended sediment concentration records and compute loads to the Bay from the large Central Valley watershed. Sediment loads from small tributary watersheds around the Bay were determined using 235 station-years of suspended sediment data from 38 watershed locations, regression analysis, and simple modeling. Over 16 years, net annual suspended sediment load to the head of the estuary from its 154,000 km2 Central Valley watershed varied from 0.13 to 2.58 (mean = 0.89) million metric t of suspended sediment, or an average yield of 11 metric t/km2/yr. Small tributaries, totaling 8145 km2, in the nine-county Bay Area discharged between 0.081 and 4.27 (mean = 1.39) million metric t with a mean yield of 212 metric t/km2/yr. The results indicate that the hundreds of urbanized and tectonically active tributaries adjacent to the Bay, which together account for just 5% of the total watershed area draining to the Bay and provide just 7% of the annual average fluvial flow, supply 61% of the suspended sediment. The small tributary loads are more variable (53-fold between years compared to 21-fold for the inland Central Valley rivers) and dominated fluvial sediment supply to the Bay during 10 out of 16 yr. If San Francisco Bay is typical of other estuaries in active tectonic or climatically variable coastal regimes, managers responsible for water quality, dredging and reusing sediment accumulating in shipping channels, or restoring wetlands in the world's estuaries may need to more carefully

  2. Aseismic slip and fault-normal strain along the central creeping section of the San Andreas fault

    NASA Astrophysics Data System (ADS)

    Rolandone, F.; Bürgmann, R.; Agnew, D. C.; Johanson, I. A.; Templeton, D. C.; d'Alessio, M. A.; Titus, S. J.; DeMets, C.; Tikoff, B.

    2008-07-01

    We use GPS data to measure the aseismic slip along the central San Andreas fault (CSAF) and the deformation across adjacent faults. Comparison of EDM and GPS data sets implies that, except for small-scale transients, the fault motion has been steady over the last 40 years. We add 42 new GPS velocities along the CSAF to constrain the regional strain distribution. Shear strain rates are less than 0.083 +/- 0.010 μstrain/yr adjacent to the creeping SAF, with 1-4.5 mm/yr of contraction across the Coast Ranges. Dislocation modeling of the data gives a deep, long-term slip rate of 31-35 mm/yr and a shallow (0-12 km) creep rate of 28 mm/yr along the central portion of the CSAF, consistent with surface creep measurements. The lower shallow slip rate may be due to the effect of partial locking along the CSAF or reflect reduced creep rates late in the earthquake cycle of the adjoining SAF rupture zones.

  3. Aseismic slip and fault-normal strain along the central creeping section of the San Andreas fault

    USGS Publications Warehouse

    Rolandone, F.; Burgmann, R.; Agnew, D.C.; Johanson, I.A.; Templeton, D.C.; d'Alessio, M. A.; Titus, S.J.; DeMets, C.; Tikoff, B.

    2008-01-01

    We use GPS data to measure the aseismic slip along the central San Andreas fault (CSAF) and the deformation across adjacent faults. Comparison of EDM and GPS data sets implies that, except for small-scale transients, the fault motion has been steady over the last 40 years. We add 42 new GPS, velocities along the CSAF to constrain the regional strain distribution. Shear strain rates are less than 0.083 ?? 0.010 ??strain/yr adjacent to the creeping SAF, with 1-4.5 mm/yr of contraction across the Coast Ranges. Dislocation modeling of the data gives a deep, long-term slip rate of 31-35 mm/yr and a shallow (0-12 km) creep rate of 28 mm/yr along the central portion of the CSAF, consistent with surface creep measurements. The lower shallow slip rate may be due to the effect of partial locking along the CSAF or reflect reduced creep rates late in the earthquake cycle of the adjoining SAF rupture zones. Copyright 2008 by the American Geophysical Union.

  4. Tectonic framework of the Parkfield-Cholame area, central San Andreas fault zone, California

    SciTech Connect

    Sims, J.D.; Ross, D.C.; Irwin, W.P.

    1985-01-01

    Recent geologic mapping of the NW-trending San Andreas fault zone (SAFZ) in the southern Diablo Range reveals details of this structurally complex region. Movement on the fault juxtaposes dissimilar tectonic terranes. The region on the NE side is characterized by complexly folded and faulted rocks of the Franciscan assemblage, the Coast Range ophiolite, and sedimentary rocks of the Great Valley sequence and younger formations. The region on the SW side is characterized by crystalline basement rocks of the Salinia terrane overlain by slightly deformed Pliocene and Pleistocene gravel and Miocene and Pliocene sedimentary rocks. The active trace of the SAFZ is along the SW side of a belt of melange that separates the Salinia terrane from the terranes to the NE. The active main trace is notable for a right step over of about 1 km in the southern part of the area and a 5/sup 0/ left bend in the northern part of the area. The melange consists of highly sheared and deformed rocks of late Cenozoic units, and exotic blocks of granite, gabbro, and marble. Deformation of Late Cretaceous and younger rocks east of the SAFZ varies with their age as follows: 1) Late Cretaceous rocks are strongly deformed and overlain by late Cenozoic rocks with angular unconformity, 2) early(.) and middle Miocene rocks are the most complexly folded, 3) late Miocene and early Pliocene strata are less complexly deformed, and 4) Pliocene and Pleistocene rocks the least deformed. Folding resulted from north-south compression across the SAFZ since early (.) Miocene time.

  5. High-resolution electromagnetic imaging of the San Andreas fault in Central California

    SciTech Connect

    Unsworth, M.; Egbert, G.; Booker, J.

    1999-01-01

    Although there is increasing evidence that fluids may play a significant role in the earthquake rupture process, direct observation of fluids in active fault zones remains difficult. Since the presence of an electrically conducting fluid, such as saline pore water, strongly influences the overall conductivity of crustal rocks, electrical and electromagnetic methods offer great potential for overcoming this difficulty. Here we present and compare results from high-resolution magnetotelluric (MT) profiles across two segments of the San Andreas Fault (SAF) which exhibit very different patterns of seismicity: Parkfield, which has regular small earthquakes and creep events, and in the Carrizo Plain, where the fault is seismically quiescent and apparently locked. In both surveys, electric fields were sampled continuously, with 100 m long dipoles laid end-to-end across the fault. From 100 to 0.1 Hz the data from both profiles are consistent with a two-dimensional (2-D) fault-parallel resistivity model. When both transverse electric and magnetic (TE and TM) mode data are included in the interpretation, narrow ({approximately}300{endash}600 m wide) zones of low resistivity extending to depths of 2{endash}4 km in the core of the fault are required at both locations. However, at Parkfield the conductance (conductivity thickness product) of the anomalous region is an order of magnitude larger than at Carrizo Plain, suggesting much higher concentrations of fluids for the more seismically active Parkfield segment. We also image structural differences between the two segments. At Carrizo Plain, resistive, presumably crystalline, rocks are present on both sides of the fault at depths below 3{endash}4 km. In particular, we clearly image resistive basement extending {approximately}10 km or more east of the SAF, beneath the Elkhorn Hills and Temblor Range. At Parkfield the situation is quite different with a resistive block of Salinian granite west of the fault and an electrically

  6. Zongo-San Gaban zone: Eocene foreland boundary of the Central Andean orogen, northwest Bolivia and southeast Peru

    SciTech Connect

    Farrar, E.; Clark, A.H.; Kontak, D.J.; Archibald, D.A.

    1988-01-01

    Discordant muscovite and biotite K-Ar dates of samples taken in six transects through the Cordillera Oriental of southeast Peru and northwest Bolivia, combined with /sup 40/Ar//sup 39/Ar age spectra, reveal a northwest-trending, structurally cryptic, tectonothermal zone of late Eocene age (ca. 38 Ma) that overprints Triassic and older igneous and metamorphic rocks. The zone is at least 450 km long but is less than 25 km wide; temperatures along its northeast boundary are estimated to have reached 350/sup 0/C. No Paleogene magmatism has been recognized that could account for the thermal resetting of the K-Ar isotopic system. Uplift, erosion, and southwest-verging thrusting accompanied the development of this domain, which defined the foreland boundary of the orogen prior to inception of northeast-verging Andean thrusting in Miocene time. It is proposed that this tectonothermal zone, the Zongo-San Gaban zone (ZSGZ), which involves thrusting and basement shortening, is the southerly manifestation of the Incaic compressional deformation, which produced the thin-skinned Maranon thrust and fold belt (MTFB) north of the Abancay deflection of central Peru.

  7. Upper-Crustal Reflectivity of the Central California Coast Range Near the San Andreas Fault Observatory at Depth (SAFOD), USA

    NASA Astrophysics Data System (ADS)

    Ryberg, T.; Fuis, G. S.; Bauer, K.; Hole, J. A.; Bleibinhaus, F.

    2005-12-01

    We describe a new method of extracting seismic reflections that are visually evident in shot gathers but which may or may not come into focus in an image processed using conventional CDP reflection processing. This method has proven extremely useful in the central California Coast Range, near the San Andreas Fault Observatory at Depth (SAFOD), where conventional CDP processing has thus far produced an image that has few to no clear reflections, although special processing has imaged a couple of steeply dipping reflectors. The image described here includes both gently and steeply dipping reflections that combine to produce an interpretable image of the subsurface. Our data was recorded along a 46-km profile centered on SAFOD and perpendicular to the San Andreas Fault (SAF), with 62 shots and 912 recorders (shot spacing 0.5 to 1 km; receiver spacing 25 to 50 m). Although conventional CDP processing produced an image with few to no clear reflections, reflections are definitely visible in shot gathers. Using our new method, coherent energy (reflections and other phases) are picked on shot gathers and converted automatically to line drawings, and then the line drawings are migrated in a tomographic velocity model. The final image has clear reflectivity, including both gently and steeply dipping events. We see subhorizontal to gently west-dipping reflective bands within the granitic Salinian block at depths of 6 to 14 km, beginning at approximately the SAF. Within the Franciscan melange east of the fault, we see diffuse gently west-dipping reflectivity at depths of 4 to 10 km. Near the Coast Range (or here Waltham Canyon) fault (CRF), we see a sharp, steeply east-dipping reflector that begins approximately 2 km below the surface and 2 km west of the surface trace of the CRF. At approximately 4 km depth this reflector bends to become gently east dipping. A short but clear zone of west-dipping reflectors connects the top of this curved reflector to the surface trace of the

  8. Crustal structure of the Central Precordillera of San Juan, Argentina (31°S) using teleseismic receiver functions

    NASA Astrophysics Data System (ADS)

    Ammirati, Jean-Baptiste; Alvarado, Patricia; Perarnau, Marcelo; Saez, Mauro; Monsalvo, Guillermo

    2013-10-01

    The subduction of the Nazca plate under the South American plate around 31°S is characterized by flat slab geometry. The (Chilean) Pampean flat slab of Argentina associated with the subduction of the Juan Fernandez ridge lies in a region of a series of foreland uplifts corresponding to the thin-skinned Precordillera and basement cored Sierras Pampeanas ranges. The SIEMBRA project deployed 40 broadband stations in 2008-2009 in both the Precordillera and the Sierras Pampeanas with the aim to foster the understanding of the entire central Andean flat slab region. One of the SIEMBRA station (DOCA) located on the western flank of Sierra de la Invernada in the Central Precordillera appears particularly appropriate to study the crustal structure and eventually detect discontinuities related to terranes establishment. We thus performed a receiver function analysis using teleseismic data recorded at the DOCA station during the SIEMBRA project and from October 2011 to June 2012 using a broadband UNSJ (National University of San Juan) seismic station with the purpose to obtain crustal images with details of the intracrustal structure consistent with a mechanism that could explains both the observed earthquake depths and the uplift pattern in the Central Precordillera. Our results show that the Moho beneath the Precordillera lies at a depth of about 66 km. The Moho signal appears diminished and behaves irregularly as a function of azimuthal orientations. Although this observation could be the result of an irregular geometry it also correlates with the hypothesis of partial eclogitisation in the lower crust. Two mid-crustal discontinuities have also been revealed. The shallower one could correspond to a décollement level between the Precordilleran strata and the Cuyania basement at 21 km depth. The deeper one which the presence has been matched with a sharp decrease of the crustal seismic activity drove us to the hypothesis of a major change in crustal composition at 36 km

  9. Imaging fault slip variation along the central San Andreas fault from satellite, airborne InSAR and GPS

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Lundgren, P.; Fielding, E. J.; Hensley, S.

    2011-12-01

    The improved spatiotemporal resolution of surface deformation from recent satellite and airborne InSAR measurements provides great potential to improve our understanding of faulting processes and earthquake hazard for a given fault system. A major plate boundary fault in central California, the central San Andreas fault (CSAF) displays a spectrum of complex fault slip behaviors with creeping in its central segment that decreases towards its northwest and southeast ends where the fault transitions to being locked. In the north the CSAF branches into two sub-parallel faults that are both actively accommodating plate motion. To the south, near the Parkfield transition, large earthquakes have occurred with at least six Mw ~6.0 events since 1857, most recently in 2004. To understand the complexity and variety of fault slip behaviors and fault mechanics, we integrate satellite and airborne synthetic aperture radar (SAR) repeat pass interferometry (RPI) observations, with GPS measurements from the Plate Boundary Observatory (PBO) and regional campaign networks to estimate fault slip and shallow slip deficits along the CSAF. Existing C-band ERS-1/2, Envisat and Radarsat SAR data provide long archives of SAR data over the region but are subject to severe decorrelation. The Japan Aerospace Exploration Agency's ALOS satellite has made less frequent acquisitions (5-6/yr per track) since 2006 but its PALSAR L-band sensor provides much improved coherence compared to shorter wavelength radar data. More recently, the NASA UAVSAR airborne SAR has repeated fault perpendicular adjacent swaths imaged from opposing look directions and fault parallel swath flights over the CSAF over the past three years and provides an improved imaging of fault slip related deformation at finer spatial resolution than previous platforms (~6m at 12 azimuth x 3 range looks). Compared to C-band instruments, the UAVSAR provides nearly complete spatial coverage. Compared to the ALOS mission, the UAVSAR

  10. Forward and Reverse Modeling Compressive Deformation in a 3D Geologic Model along the Central San Andreas Fault Zone

    NASA Astrophysics Data System (ADS)

    Roberts, M. A.; Graymer, R. W.; McPhee, D.

    2015-12-01

    During the late Miocene, a small change in the relative motion of the Pacific plate resulted in compressive as well as translational deformation along the central San Andreas Fault (SAF), creating thrust faults and folds throughout this region of California. We constructed a 3D model of an upper crustal volume between Pinnacles National Park and Gold Hill by assembling geologic map data and cross sections, geophysical data, and petroleum well logs in MoveTm, software which has the ability to forward and reverse model movement along faults and folds. For this study, we chose a blind thrust fault west of the SAF near Parkfield to compare deformation produced by MoveTm's forward modeling algorithm with that observed. We chose various synclines east of the SAF to explore the software's ability to unfold (reverse model) units. For the initial round of modeling, strike-slip movement has been omitted as the fault algorithm was designed primarily for extensional or compressional environments. Preliminary forward modeling of originally undeformed strata along the blind thrust produced geometries similar to those in the present-day 3D geologic model. The modeled amount of folding produced in hanging wall strata was less severe, suggesting these units were slightly folded before displacement. Based on these results, the algorithm shows potential in predicting deformation related to blind thrusts. Contraction in the region varies with fold axis location and orientation. MoveTm's unfolding algorithm can allow researchers to measure the amount of contraction a fold represents, and compare that amount across the modeled area as a way of observing regional stress patterns. The unfolding algorithm also allows for passive deformation of strata unconformably underlying the fold; one example reveals a steeper orientation of Cretaceous units prior to late Miocene deformation. Such modeling capabilities can allow for a better understanding of the structural history of the region.

  11. Micromechanisms of creep in clay-rich gouge from the Central Deforming Zone of the San Andreas Fault

    NASA Astrophysics Data System (ADS)

    French, M. E.; Chester, F. M.; Chester, J. S.

    2015-02-01

    We report the strength and constitutive behavior of gouge sampled from the Central Deforming Zone (CDZ) of the San Andreas Fault. Layers of flaked CDZ gouge were sheared in the triaxial saw cut configuration using the stress relaxation technique to measure the gouge strength over 4 orders of magnitude in shear strain rate and at rates as low as 5 × 10-10s-1 and within an order of magnitude of in situ rates. Deformation conditions correspond to the in situ effective normal stress (100 MPa) and temperature (65 to 120°C) at the sampling depth of 2.7 km. Gouge was sheared dry and with brine pore fluid at 25 MPa pore pressure. Dry gouge is stronger and more rate strengthening than brine-saturated gouge. Brine-saturated CDZ gouge strengthens with increasing strain rate and decreasing temperature, and the dependencies of strength on strain rate and temperature increase at rates below ˜5 × 10-9s-1. At strain rates greater than ˜5 × 10-9s-1, the rate dependence is consistent with previous studies on the CDZ gouge conducted at even higher rates. The increase in rate dependence below ˜5 × 10-9s-1 indicates a change in the rate-controlling deformation mechanism. The magnitude of the friction rate dependence parameter, a, and the temperature sensitivity of a are consistent with crystal plasticity of the phyllosilicates. We hypothesize a micromechanical model for the CDZ gouge whereby a transition from fracture and delamination-accommodated frictional flow to crystal plasticity-accommodated frictional flow occurs with decreasing strain rate.

  12. Marine neotectonic investigation of the San Gregorio Fault Zone on the northern flank of Monterey Canyon, offshore central California

    NASA Astrophysics Data System (ADS)

    Maier, K. L.; Paull, C. K.; Brothers, D. S.; McGann, M.; Caress, D. W.; Lundsten, E. M.; Anderson, K.; Gwiazda, R.

    2014-12-01

    The San Gregorio Fault Zone (SGFZ) is part of the North American-Pacific plate boundary and is thought to accommodate right-lateral offset up to 10 mm/yr. Because much of the SGFZ in Monterey Bay, central California, lies offshore in steep submarine canyon bathymetry, little is known of its recent activity. We provide initial direct evidence for faulting where the SGFZ has been interpreted based on canyon morphology to cross the northern flank of Monterey Canyon. High-resolution multibeam bathymetry and chirp subbottom profiles were acquired during 13 dives with the Monterey Bay Aquarium Research Institute's (MBARI) Autonomous Underwater Vehicle (AUV) from 2009-2014 on the northern flank of Monterey Canyon, extending from the shelf edge ~15 km offshore Santa Cruz to ~1850 m water depth. Chirp profiles resolve layered sediments up to ~40 m subsurface in this region, and no fault scarps or seafloor lineaments are visible in the 1-m resolution multibeam bathymetry. At least one subsurface fault is identified within the SGFZ by offset reflections across a discrete, nearly vertical fault. However, this fault is only imaged where mass wasting has exhumed older strata to within ~25 m of the seafloor. Numerous slumps scars on the seafloor and packages of chaotic internal reflectivity in chirp profiles suggest that submarine landslide processes dominate the study area. To constrain the age of reflections offset by the fault, MBARI's Remotely Operated Vehicle (ROV) Doc Ricketts, sampled faces of slump scars where the offset reflections crop out using vibracores and horizontal push cores. Radiocarbon dating of foraminifera within these core samples is being used to constrain the last recorded movement on the fault. Application of AUV and ROV methods allows detailed neotectonic investigation of significant offshore structures, like the SGFZ, that contribute to hazard assessment.

  13. Correlation of coal beds in the Fruitland Formation as interpreted from geophysical logs, east-central San Juan County, New Mexico

    USGS Publications Warehouse

    Sandberg, Dorothy T.

    1986-01-01

    Correlation of coal beds in the Fruitland Formation (Upper Cretaceous) in the subsurface, from interpretation of geophysical logs, is an outgrowth of unpublished studies of deep coal on the Navajo Reservation by the author in the Toadlena 30 x 60 minute quadrangle, New Mexico, and by W. J. Mapel in the Farmington 30 x 60 minute quadrangle, New Mexico.  The lines of sections of this report extend eastward from the reservation into east-central San Juan County, which is in the western part of the San Juan Basin.  In this area, the rocks dip gently northeast toward the central part of the basin.  The thick coal is less than 1,500 feet beneath the surface.  Of the 53 logs in the sections, 48 are from oil- and gas-test holes, and 5 are from coal-test holes (see table 1).  Stratigraphic relations of the Upper Cretaceous Lewis Shale, Pictured Cliffs Sandstone, and Fruitland Formation, shown on the cross sections and briefly reviewed below, have been previously described for this or other parts of the San Juan Basin by Hayes and Zapp (1955), Beaumont (1971), Fassett and hinds (1971), O;Sullivan and other (1972), and Molenaar (1983), among others.

  14. Status and Understanding of Groundwater Quality in the Central-Eastside San Joaquin Basin, 2006: California GAMA Priority Basin Project

    USGS Publications Warehouse

    Landon, Matthew K.; Belitz, Kenneth; Jurgens, Bryant C.; Justin T. Kulongoski, Justin T.; Johnson, Tyler D.

    2010-01-01

    Groundwater quality in the approximately 1,695-square-mile Central Eastside San Joaquin Basin (Central Eastside) study unit was investigated as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001, and 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 GAMA Central Eastside study unit was designed to provide a spatially unbiased assessment of untreated-groundwater quality, as well as a statistically consistent basis for comparing water quality throughout California. During March through June 2006, samples were collected from 78 wells in Stanislaus and Merced Counties, 58 of which were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and 20 of which were sampled to evaluate changes in water chemistry along groundwater-flow paths (understanding wells). Water-quality data from the California Department of Public Health (CDPH) database also were used for the assessment. An assessment of the current status of the groundwater quality included collecting samples from wells for analysis of anthropogenic constituents such as volatile organic compounds (VOCs) and pesticides, as well as naturally occurring constituents such as major ions and trace elements. The assessment of status is intended to characterize the quality of untreated-groundwater resources within the primary aquifer system, not the treated drinking water delivered to consumers by water purveyors. The primary aquifer system (hereinafter, primary aquifer) is defined as that part of the aquifer corresponding to the perforation interval of wells listed in the CDPH database for the Central Eastside study unit. The quality of groundwater in shallower or

  15. Sea level fluctuations in central California at subtidal to decadal and longer time scales with implications for San Francisco Bay, California

    NASA Astrophysics Data System (ADS)

    Ryan, H. F.; Noble, M. A.

    2007-07-01

    Sea level elevations from near the mouth of San Francisco Bay are used to describe the low-frequency variability of forcing of the coastal ocean on the Bay at a variety of temporal scales. About 90% of subtidal fluctuations in sea level in San Francisco Bay are driven by the sea level variations in the coastal ocean that propagate into the Bay at the estuary mouth. We use the 100-year sea level record available at San Francisco to document a 1.9 mm/yr mean sea level rise, and to determine fluctuations related to El Nino-Southern Oscillation (ENSO) and other climatic events. At time scales greater than 1 year, ENSO dominates the sea level signal and can result in fluctuations in sea level of 10-15 cm. Alongshore wind stress data from central California are also analyzed to determine the impact of changes in coastal elevation at the mouth of San Francisco Bay within the synoptic wind band of 2-30 days. At least 40% of the subtidal fluctuations in sea level of the Bay are tied to the large-scale regional wind field affecting sea level variations in the coastal ocean, with little local, direct wind forcing of the Bay itself. The majority of the subtidal sea level fluctuations within the Bay that are not related to the coastal ocean sea level signal are forced by an east-west sea level gradient resulting from tidally induced variations in sea level at specific beat frequencies that are enhanced in the northern reach of the Bay. River discharge into the Bay through the Sacramento and San Joaquin River Delta also contributes to the east-west gradient, but to a lesser degree.

  16. Central San Francisco Bay suspended-sediment transport processes study and comparison of continuous and discrete measurements of suspended-solids concentrations

    USGS Publications Warehouse

    Schoellhamer, David H.

    1994-01-01

    Sediments are an important component of the San Francisco Bay estuarine system. Potentially toxic substances, such as metals and pesticides, adsorb to sediment particles. The sediments on the bottom of the Bay provide the habitat for benthic communities which can ingest these substances and introduce them into the food web. The bottom sediments are also a reservoir of nutrients. The transport and fate of suspended sediment is an important factor in determining the transport and fate of the constituents adsorbed on the sediment. Suspended sediments also limit light availability in the bay, which limits photosynthesis and primary production, and deposit in ports and shipping channels, which require dredging. Dredged materials are disposed in Central San Francisco Bay.

  17. San Marino.

    PubMed

    1985-02-01

    San Marino, an independent republic located in north central Italy, in 1983 had a population of 22,206 growing at an annual rate of .9%. The literacy rate is 97% and the infant mortality rate is 9.6/1000. The terrain is mountainous and the climate is moderate. According to local tradition, San Marino was founded by a Christian stonecutter in the 4th century A.D. as a refuge against religious persecution. Its recorded history began in the 9th century, and it has survived assaults on its independence by the papacy, the Malatesta lords of Rimini, Cesare Borgia, Napoleon, and Mussolini. An 1862 treaty with the newly formed Kingdom of Italy has been periodically renewed and amended. The present government is an alliance between the socialists and communists. San Marino has had its own statutes and governmental institutions since the 11th century. Legislative authority at present is vested in a 60-member unicameral parliament. Executive authority is exercised by the 11-member Congress of State, the members of which head the various administrative departments of the goverment. The posts are divided among the parties which form the coalition government. Judicial authority is partly exercised by Italian magistrates in civil and criminal cases. San Marino's policies are tied to Italy's and political organizations and labor unions active in Italy are also active in San Marino. Since World War II, there has been intense rivalry between 2 political coalitions, the Popular Alliance composed of the Christian Democratic Party and the Independent Social Democratic Party, and the Liberty Committee, coalition of the Communist Party and the Socialist Party. San Marino's gross domestic product was $137 million and its per capita income was $6290 in 1980. The principal economic activities are farming and livestock raising, along with some light manufacturing. Foreign transactions are dominated by tourism. The government derives most of its revenue from the sale of postage stamps to

  18. Application of high resolution DEM data to detect rock damage from geomorphic signals along the central San Jacinto Fault

    NASA Astrophysics Data System (ADS)

    Wechsler, Neta; Rockwell, Thomas K.; Ben-Zion, Yehuda

    2009-12-01

    We analyze geomorphic properties extracted from LiDAR and SRTM (Shuttle Radar Topography Mission) data to test whether the damage zone along the central San Jacinto Fault (SJF) zone can be resolved with remotely-sensed data in a quantitative fashion. The SJF is one of the most active faults in southern California, with well expressed geomorphology and a fast slip rate, as seen in the geology and by GPS. We use ArcMap and the TauDEM toolbox to compare several morphometric parameters, including drainage density (Dd), on both sides of the fault, using a 1 km and a 5 km buffer for the LiDAR and SRTM data, respectively. We also analyze the spatial patterns of Dd near the fault, using two different definitions of spatial Dd. The high resolution of the LiDAR data allows us to focus on a single fault, eliminating the effects of parallel nearby faults. From the LiDAR data we find that the highest Dd values occur in areas between two fault strands, followed generally by rocks on the northeast side of the fault, with the lowest Dd values occurring on the southwest side of the fault. The SRTM data shows a band of high Dd values centered on the main fault trace with ~ 1 km width. Our results indicate that there is a strong correlation between drainage density and proximity to the fault, with zones of structural complexity along the fault displaying the highest Dd. We interpret this to largely be an effect of degree of rock damage, as these are areas that are expected to be more damaged, and field observations support this contention. If we are correct, then it appears that the northeast side of the SJF is generally more damaged. South of the trifurcation area there is evidence that the signal is reversed on the larger scale, with more damage on the southwest side of the fault inferred from the SRTM data, possibly caused by extension between the Coyote Creek and Clark faults. The implications of the observed asymmetry could be geological evidence for rupture propagation

  19. 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.

  20. Continuation of the San Andreas fault system into the upper mantle: Evidence from spinel peridotite xenoliths in the Coyote Lake basalt, central California

    NASA Astrophysics Data System (ADS)

    Titus, Sarah J.; Medaris, L. Gordon; Wang, Herbert F.; Tikoff, Basil

    2007-01-01

    The Coyote Lake basalt, located near the intersection of the Hayward and Calaveras faults in central California, contains spinel peridotite xenoliths from the mantle beneath the San Andreas fault system. Six upper mantle xenoliths were studied in detail by a combination of petrologic techniques. Temperature estimates, obtained from three two-pyroxene geothermometers and the Al-in-orthopyroxene geothermometer, indicate that the xenoliths equilibrated at 970-1100 °C. A thermal model was used to estimate the corresponding depth of equilibration for these xenoliths, resulting in depths between 38 and 43 km. The lattice preferred orientation of olivine measured in five of the xenolith samples show strong point distributions of olivine crystallographic axes suggesting that fabrics formed under high-temperature conditions. Calculated seismic anisotropy values indicate an average shear wave anisotropy of 6%, higher than the anisotropy calculated from xenoliths from other tectonic environments. Using this value, the anisotropic layer responsible for fault-parallel shear wave splitting in central California is less than 100 km thick. The strong fabric preserved in the xenoliths suggests that a mantle shear zone exists below the Calaveras fault to a depth of at least 40 km, and combining xenolith petrofabrics with shear wave splitting studies helps distinguish between different models for deformation at depth beneath the San Andrea fault system.

  1. 9. Partial elevation of west side showing pillar, central and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Partial elevation of west side showing pillar, central and southern sections, from San Antonio Highway Bridge. - Puente Ferroviario San Antonio, Spanning San Antonio Channel at PR-1, San Juan, San Juan Municipio, PR

  2. Preliminary Results from SAFOD Phase 3: Implications for the state of stress and shear localization in and near the San Andreas Fault at depth in central California

    NASA Astrophysics Data System (ADS)

    Zoback, M. D.; Hickman, S. H.; Ellsworth, W.; Kirschner, D.; Pennell, N. B.; Chery, J.; Sobolev, S.

    2007-12-01

    Strain localization along the San Andreas fault system in central California appears to result from both a thermally-weak lower crust and upper mantle (reflecting northward migration of the Mendocino triple junction and its associated slab window) and a fault zone in the upper brittle crust that is distinctly weaker than the surrounding crust. Geophysical logs and cuttings analyses from SAFOD Phase 2 (completed in 2005) revealed the San Andreas Fault Zone at approximately 2.7 km depth to be relatively broad (about 250 m), with several discrete, localized zones only 2-3 m wide with very low P- and S-wave velocities and low resistivity. Since 2005, fault creep at two of these localized zones has deformed the casing and thus demonstrates that these zones are actively creeping faults. During SAFOD Phase 3, continuous cores were obtained across these two actively creeping faults. Another core was obtained near the geologic boundary between the Salinian terrane (Pacific plate) and Great Valley/Franciscan terrane (North American plate). Each set of cores reveal zones of profound strain localization and probable weakening. These include ultracataclasites, highly-foliated shear zones (some containing veined serpentine) and intervals that appear to be cohesionless, compacted fault gouges which are likely composed of minerals with low frictional strength. No evidence of significantly elevated fluid pressure is observed within the fault zone. Information about the state of stress in the fault zone and adjacent crust comes from observations and modeling of wellbore failures, direct measurements of the magnitude of the least principal stress and the direction of stress-induced shear wave velocity anisotropy. Observations made after rotary drilling through the fault in 2005 indicate that the San Andreas is a weak fault imbedded in a strong crust. These observations made within about 100 m of the active fault zone at 2.7 km include i) stress orientations that are nearly

  3. Structure and composition of the San Andreas Fault in central California: Recent results from SAFOD sample analyses

    NASA Astrophysics Data System (ADS)

    Hickman, S.; Zoback, M.; Ellsworth, W.; Chester, J.; Chester, F.; Evans, J.; Moore, D.; Kirschner, D.; Schleicher, A.; van der Pluijm, B.; Solum, J.

    2008-12-01

    The San Andreas Fault Observatory at Depth (SAFOD) was drilled to study the physical and chemical processes controlling faulting and earthquake generation along an active, plate-bounding fault at depth. SAFOD is located near Parkfield, California, and penetrates a section of the fault that is moving through a combination of repeating microearthquakes and fault creep. In 2004 and 2005, SAFOD was drilled vertically to a depth of 1.5 km and then deviated across the entire San Andreas Fault Zone to a vertical depth of 3.1 km. In 2007, cores were acquired from holes branching off the main hole to sample directly the country rock and actively deforming traces of the fault. Geophysical logs define the San Andreas Fault Zone to be about 200 m wide, containing several discrete zones only 2-3 m wide with very low P- and S-wave velocities and low resistivity. Two of these zones have progressively deformed the cemented well casing at measured depths of 3194 m and 3301 m (corresponding to vertical depths of 2.6 - 2.7 km), indicating that they are actively creeping shear zones. The 3194 m casing deformation zone lies about 100 m above a cluster of repeating M2 earthquakes along the southwestern boundary of the active fault zone. Talc and serpentine discovered in drill cuttings associated with the deepest casing deformation zone may be responsible for the predominantly creeping behavior and anomalously low shear strength of the San Andreas Fault at this location. Hydrous clay minerals found as thin-film coatings on polished slip surfaces in cuttings may also be important in controlling fault strength and stability of sliding. Core was obtained in 2007 across the active deformation zones at 3194 and 3301 m and from just outside the geologically defined San Andreas Fault Zone. Cores crossing the two deformation zones are composed of shales, siltstones and mudstones and contain 1-2 m of a highly foliated, relatively incohesive fault gouge. In both cases, this fault gouge exactly

  4. Anomalous Change of Diffuse CO2 Emission Rates at San Salvador volcano, El Salvador, Central America: a premonitory geochemical signature of magmatic and/or tectonic reactivation?

    NASA Astrophysics Data System (ADS)

    Perez, N.; Salazar, J.; Hernandez, P.; Soriano, T.; Barahona, F.; Cartagena, R.; Olmos, R.; Lopez, D.

    2002-12-01

    San Salvador volcano is located towards the southern part of the Central American graben. The most recent magmatic activity was mainly focused on the volcano NW flank forming monogenetic explosion craters, cinder cones, and lava flows. Flank vents continue to erupt at a rate of once every 82 yrs with the last eruption in 1917 (Sofield, 1999). The city of San Salvador, with a population 1.7 million located at the skirts of the volcano, will be at high risk if an eruption occurs. The purpose of this work is to provide a multidisciplinary approach for the volcanic surveillance by means of introducing geochemical continuous monitoring of diffuse CO2 and H2S emission rates. Soil CO2 and H2S efflux are continuously monitored at Cerro La Hoya, which is located at San Salvador volcano southern flank, by means of a soil gas efflux continuous monitoring station. Since Nov.11, 2001, until Aug.30, 2002, about 6,800 observations of soil gas efflux and meteorological measurements had been recorded. Soil H2S efflux values were negligible during this period. On the contrary, two distinct diffuse CO2 degassing periods have been observed: (1) a stationary period from Nov. 11 to Dec. 27, 2001, and (2) a clear increasing trend period from Dec. 28, 2001, up to date. From Nov.11 to Dec.27, 2001, CO2 efflux showed an average of 700 gm-2d-1 peaking values up to 1,194 gm-2d-1. From Dec.28, 2001, to Aug.30, 2002, CO2 efflux showed an average of 7,435 gm-2d-1 peaking values up to 45,285 gm-2d-1. Soil temperature showed similar average and peak values for both periods. It is quite evident that this anomalous change of CO2 efflux rate at San Salvador is not driven by meteorological fluctuations. Therefore, this anomalous change of diffuse CO2 emission should be related to an increase of CO2 pressure in the volcanic-hydrothermal system. This increase of fluid pressure could be related to subsurface strain/stress changes, which might be taking place due to either magmatic or tectonic

  5. Nd- and Pb-isotope variations in the multicyclic central caldera cluster of the San Juan volcanic field, Colorado, and implications for crustal hybridization

    SciTech Connect

    Riciputi, L.R.; Johnson, C.M. )

    1990-10-01

    The {epsilon}{sub Nd} values for six large-volume (100-3000 km{sup 3}) ash-flow tuffs and associated lavas from the multicyclic central caldera cluster of the San Juan volcanic field in south-central Colorado are between those of Proterozoic crust in the region and mantle-derived basaltic magmas, and the values generally become progressively higher in progressively younger tuffs and lavas. The increase in the {epsilon}{sub Nd} values of the tuffs, from -8.0 to -6.0 with decreasing age, can be modeled by assimilation and crystal fractionation of a mantle-derived magma, accompanied by an increase of {approx} 4 units in {epsilon}{sub Nd} values of the assimilated crust. The postulated increase in {epsilon}{sub Nd} values of the crust is envisioned to have occurred by hybridization of the crust through continued injection of mantle-derived magmas during the life of the magmatic system. Decreasing {sup 206}Pb/{sup 204}Pb ratios observed in progressively younger tuffs following the initiation of caldera-related volcanism cannot, however, be solely explained by addition of mantle-derived magmas to the crust, but are more likely to reflect the transfer of lower-crustal Pb into the upper crust as the magmatic system evolved. Input of large volumes (> 300,000 km{sup 3} in the San Juan volcanic field) of mantle-derived magma resulted in extensive hybridization of preexisting crust, suggesting that large-scale silicic volcanism involves generation of large quantities of new crust.

  6. Origin of the San Pedro-Linzor volcanic chain and its relation with the Altiplano-Puna Volcanic Complex, Central Andes

    NASA Astrophysics Data System (ADS)

    Godoy, B.; Wörner, G.; Kojima, S.; Aguilera, F.

    2011-12-01

    Mantle-derived magmas at the Central Andean magmatic province (26 Ma - Recent) had been generated by hydration of the asthenospheric mantle below this zone (Davidson, 1996). After generation, these magmas ascent through a thick continental crust (up to ~70 km) that mostly thickened by crustal shortening of the Andes during this time. The magmatic products erupted during this period of time are characterised by incresingly "crustal isotopic signatures" related with increased crustal assimilation of mantle-derived magmas. However, lavas with 87Sr/86Sr ratios higher than 0,708 indicate not only assimilation but rather attest to a large contribution of anatectic melts that are located at the upper crust. The existence of large volumes of such melts in the upper crust has been proposed by geophysical methods (i.e. the Altiplano-Puna magmatic body; Zandt, et al., 2003) and are related with voluminous silicic volcanism observed in the area (de Silva, 1989). In this work, we present new isotopic data from lavas with SiO2 from 56 to 70 wt. %. These lavas belong to volcanoes distributed in San Pedro-Linzor volcanic chain (22°-22°30'S, northern Chile) which is located completely within the APVC. Upper Pleistocene volcanoes that belong to this volcanic chain are aligned in a NW-SE trend and show 87Sr/86Sr ratios up to 0,709 at 65 to 68 % SiO2. These ratios are at the upper end of isotopic variation in Central Andean andesites (typically 0,706 to 0,708). Moreover, only low Sm/Yb ratios are observed (1,48 - 4,5) in the San Pedro-Linzor volcanic chain compared to Sm/Yb in other Quaternary Central Andean volcanics, which range from 5 to 10 (Mamani et al., 2010). High Sm/Yb are generally related to garnet during high-pressure magma evolution. High Sr isotope ratios unusually large degrees of contamination of primary magmas by anatectic melts from the Altiplano-Puna magmatic body in the upper crust. Low Sm/Yb ratios are not consistent with magma evolution at great depth even

  7. The Point Sal–Point Piedras Blancas correlation and the problem of slip on the San Gregorio–Hosgri fault, central California Coast Ranges

    USGS Publications Warehouse

    Colgan, Joseph P.; Stanley, Richard G.

    2016-01-01

    Existing models for large-magnitude, right-lateral slip on the San Gregorio–Hosgri fault system imply much more deformation of the onshore block in the Santa Maria basin than is supported by geologic data. This problem is resolved by a model in which dextral slip on this fault system increases gradually from 0–10 km near Point Arguello to ∼150 km at Cape San Martin, but such a model requires abandoning the cross-fault tie between Point Sal and Point Piedras Blancas, which requires 90–100 km of right-lateral slip on the southern Hosgri fault. We collected stratigraphic and detrital zircon data from Miocene clastic rocks overlying Jurassic basement at both localities to determine if either section contained unique characteristics that could establish how far apart they were in the early Miocene. Our data indicate that these basins formed in the early Miocene during a period of widespread transtensional basin formation in the central Coast Ranges, and they filled with sediment derived from nearby pre-Cenozoic basement rocks. Although detrital zircon data do not indicate a unique source component in either section, they establish the maximum depositional age of the previously undated Point Piedras Blancas section to be 18 Ma. We also show that detrital zircon trace-element data can be used to discriminate between zircons of oceanic crust and arc affinity of the same age, a potentially useful tool in future studies of the California Coast Ranges. Overall, we find no characteristics in the stratigraphy and provenance of the Point Sal and Point Piedras Blancas sections that are sufficiently unique to prove whether they were far apart or close together in the early Miocene, making them of questionable utility as piercing points.

  8. Heat flow, strong near-fault seismic waves, and near-fault tectonics on the central San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Sleep, Norman H.

    2016-05-01

    The main San Andreas Fault strikes subparallel to compressional folds and thrust faults. Its fault-normal traction is on average a factor of γ=1+2μthr>(√(1+μthr2)+μthr>), where μthr is the coefficient of friction for thrust faults, times the effective lithostatic pressure. A useful upper limit for μthr of 0.6 (where γ is 3.12) is obtained from the lack of heat flow anomalies by considering off-fault convergence at a rate of 1 mm/yr for 10 km across strike. If the fault-normal traction is in fact this high, the well-known heat flow constraint of average stresses of 10-20 MPa during strike slip on the main fault becomes more severe. Only a few percent of the total slip during earthquakes can occur at the peak stress before dynamic mechanisms weaken the fault. The spatial dimension of the high-stress rupture-tip zone is ˜10 m for γ = 3.12 and, for comparison, ˜100 m for γ = 1. High dynamic stresses during shaking occur within these distances of the fault plane. In terms of scalars, fine-scale tectonic stresses cannot exceed the difference between failure stress and dynamic stress. Plate-scale slip causes stresses to build up near geometrical irregularities of the fault plane. Strong dynamic stresses near the rupture tip facilitate anelastic deformation with the net effects of relaxing the local deviatoric tectonic stress and accommodating deformation around the irregularities. There also is a mild tendency for near-fault material to extrude upward. Slip on minor thrust faults causes the normal traction on the main fault to be spatially variable.

  9. Borehole geophysical, fluid, and hydraulic properties within and near the freshwater/saline-water transition zone, San Antonio segment of the Edwards aquifer, south-central Texas, 2010-11

    USGS Publications Warehouse

    Thomas, Jonathan V.; Stanton, Gregory P.

    2013-01-01

    The freshwater zone of the San Antonio segment of the Edwards aquifer is used by residents of San Antonio and numerous other rapidly growing communities in south-central Texas as their primary water supply source. This freshwater zone is bounded to the south and southeast by a saline-water zone with an intermediate zone transitioning from freshwater to saline water (transition zone). As demands on this water supply increase, there is concern that the transition zone could potentially move, resulting in more saline water in current freshwater supply wells. Since 1985, the U.S. Geological Survey, San Antonio Water System, and other Federal and State agencies have conducted studies to better understand the transition zone.

  10. Stress orientations in northern and central California: Evidence for the evolution of frictional strength along the San Andreas plate boundary system

    NASA Astrophysics Data System (ADS)

    Provost, Ann-Sophie; Houston, Heidi

    2003-03-01

    We determined orientations of principal stresses around the San Andreas fault (SAF) system in the greater San Francisco Bay Area and regions farther north along the strike-slip plate boundary. Stress orientations, as well as a ratio between principal stress magnitudes, were determined by inversions of ˜6000 earthquake fault plane solutions, divided into ˜100 groups based on the spatial distribution of seismicity with respect to major regional fault strands (i.e., the SAF, the Hayward-Rodgers Creek-Maacama fault zone, and the Calaveras-Green Valley-Bartlett Springs fault zone). The stress orientations, while spatially variable, reveal several features; to describe them, it is useful to distinguish between groups of events occurring on and off the major fault strands. First, for off-fault groups, the angle between major fault strands and the maximum horizontal compression SH decreases systematically to the north. This contrasts with the high angles of SH (˜80°) found immediately adjacent to, as well as farther from, the creeping segment of the SAF in central California by [2001]. Second, for on-fault groups, the angle that SH makes with major fault strands changes little along strike, averaging 50° to 55° in the creeping segment, the Bay area, and the northernmost part of our study area. Third, as in the vicinity of the creeping segment of the SAF in central California, the majority of both the off-fault groups, and the on-fault groups, are in a strike-slip, rather than thrust, tectonic regime. Finally, anomalous east-west SH orientations are seen in the vicinity of Sutter Buttes. In the north, multiple strands of the strike-slip fault system have accumulated little slip, dip relatively shallowly and are composed of short, complex en échelon segments, suggesting that they originated as thrust faults in the accretionary prism associated with the Farallon subduction and have been subsequently reactivated in a strike-slip sense following the northward passage of

  11. Simulation of Streamflow, Evapotranspiration, and Groundwater Recharge in the Lower San Antonio River Watershed, South-Central Texas, 2000-2007

    USGS Publications Warehouse

    Lizarraga, Joy S.; Ockerman, Darwin J.

    2010-01-01

    The U.S. Geological Survey (USGS), in cooperation with the San Antonio River Authority, the Evergreen Underground Water Conservation District, and the Goliad County Groundwater Conservation District, configured, calibrated, and tested a watershed model for a study area consisting of about 2,150 square miles of the lower San Antonio River watershed in Bexar, Guadalupe, Wilson, Karnes, DeWitt, Goliad, Victoria, and Refugio Counties in south-central Texas. The model simulates streamflow, evapotranspiration (ET), and groundwater recharge using rainfall, potential ET, and upstream discharge data obtained from National Weather Service meteorological stations and USGS streamflow-gaging stations. Additional time-series inputs to the model include wastewater treatment-plant discharges, withdrawals for cropland irrigation, and estimated inflows from springs. Model simulations of streamflow, ET, and groundwater recharge were done for 2000-2007. Because of the complexity of the study area, the lower San Antonio River watershed was divided into four subwatersheds; separate HSPF models were developed for each subwatershed. Simulation of the overall study area involved running simulations of the three upstream models, then running the downstream model. The surficial geology was simplified as nine contiguous water-budget zones to meet model computational limitations and also to define zones for which ET, recharge, and other water-budget information would be output by the model. The model was calibrated and tested using streamflow data from 10 streamflow-gaging stations; additionally, simulated ET was compared with measured ET from a meteorological station west of the study area. The model calibration is considered very good; streamflow volumes were calibrated to within 10 percent of measured streamflow volumes. During 2000-2007, the estimated annual mean rainfall for the water-budget zones ranged from 33.7 to 38.5 inches per year; the estimated annual mean rainfall for the entire

  12. Social vulnerability as a contributing factor to disasters in Central America: A case study at San Vicente volcano, El Salvador

    NASA Astrophysics Data System (ADS)

    Bowman, L. J.; Henquinet, K. B.; Gierke, J. S.; Rose, W. I.

    2012-12-01

    El Salvador's geographic location on the Pacific Ring of Fire at the juncture of the Caribbean and Cocos plates exposes its population to various natural hazards, including volcanic eruptions (e.g., Santa Ana in 2005), earthquakes (e.g., January 13 and February 13, 2001), and landslides and flooding due to tropical rainfall events (e.g., Hurricane Mitch in 1998, Hurricane Stan in 2005). Such hazards can be devastating anywhere, but the condition of social vulnerability in which many Salvadorans currently live exacerbates the impacts of these hazards. Aspects contributing to most rural Salvadorans being marginalized include a colonial history marked by ethnic discrimination and laws prohibiting land ownership, lack of access to desirable land in an agrarian society, a poor education system, global economic policies that foster inequality, political marginalization, a bloody civil conflict, and rampant criminality and violence. In November 2009, an extreme rainfall event triggered landslides and lahars killing over 200 people at San Vicente volcano. This disaster brought to light weaknesses in disaster preparedness and response plans. Despite the existence of recent hazard maps and lahar inundation models (2001), and the occurrence of a similar, deadly event in 1934, the population appeared to be unaware of the risk, and lacked the organization and decision-making protocols to adequately deal with the emergency. Therefore, in the aftermath of the 2009 lahars, much of the focus on disaster risk reduction (DRR) initiatives has been aimed at the communities affected by this most recent event. Our study examines root causes of social vulnerability and assesses the apparent impacts of these interventions on the population, including individual's perceptions regarding these risk-reducing interventions. Two years after the event, though aid abounds, many people remain vulnerable to hazards in this area. Semi-structured interviews were completed with survivors of the 2009

  13. Two-dimensional seismic image of the San Andreas Fault in the Northern Gabilan Range, central California: Evidence for fluids in the fault zone

    USGS Publications Warehouse

    Thurber, C.; Roecker, S.; Ellsworth, W.; Chen, Y.; Lutter, W.; Sessions, R.

    1997-01-01

    A joint inversion for two-dimensional P-wave velocity (Vp), P-to-S velocity ratio (Vp/Vs), and earthquake locations along the San Andreas fault (SAF) in central California reveals a complex relationship among seismicity, fault zone structure, and the surface fault trace. A zone of low Vp and high Vp/Vs lies beneath the SAF surface trace (SAFST), extending to a depth of about 6 km. Most of the seismic activity along the SAF occurs at depths of 3 to 7 km in a southwest-dipping zone that roughly intersects the SAFST, and lies near the southwest edge of the low Vp and high Vp/Vs zones. Tests indicate that models in which this seismic zone is significantly closer to vertical can be confidently rejected. A second high Vp/Vs zone extends to the northeast, apparently dipping beneath the Diablo Range. Another zone of seismicity underlies the northeast portion of this Vp/Vs high. The high Vp/Vs zones cut across areas of very different Vp values, indicating that the high Vp/Vs values are due to the presence of fluids, not just lithology. The close association between the zones of high Vp/Vs and seismicity suggests a direct involvement of fluids in the faulting process. Copyright 1997 by the American Geophysical Union.

  14. Estimates of flow direction for calc-alkaline welded tuffs and paleomagnetic data reliability from anisotropy of magnetic susceptibility measurements: Central San Juan Mountains, southwest Colorado

    NASA Astrophysics Data System (ADS)

    Ellwood, Brooks B.

    1982-07-01

    Flow directions are estimated from the measurement of the magnetic fabric of 106 samples, collected at 18 sites in four welded tuff units in the central San Juan Mountains of southern Colorado. The estimates assume that the tuffs generally flowed directly away from the extrusive vents and that the lineations of magnetic grains within the tuffs represent the flow direction at individual sites. Errors in the estimation may arise from topographic variation, rheomorphism (post-emplacement mass flow) within the tuff, and other factors. Magnetic lineation is defined as the site mean anisotropy of magnetic susceptibility maximum azimuth. A test on the flow directions for individual units is based on the projection of lineation azimuths and their intersection within or near the known source caldera for the tuff. This test is positive for the four units examined. Paleomagnetic results for these tuffs are probably reliable indicators of the geomagnetic field direction in southwest Colorado, during the time (28.2-26.5 Ma) of emplacement.

  15. Time-dependent model of aseismic slip on the central San Andreas Fault from InSAR time series and repeating earthquakes

    NASA Astrophysics Data System (ADS)

    Khoshmanesh, M.; Shirzaei, M.; Nadeau, R. M.

    2015-09-01

    The Central segment of San Andreas Fault (CSAF) is characterized by a nearly continuous right-lateral aseismic slip. However, observations of the creep rate obtained using small characteristically repeating earthquakes (CREs) show pulses of creep along the CSAF, which may indicate spatially and temporally variable seismic hazard along the CSAF. Therefore, the goal of this study is to obtain a high-resolution time-dependent model of creep along the CSAF to examine this hypothesis. To this end, we apply a time-dependent creep modeling approach, which combines interferometric synthetic aperture radar (InSAR) surface deformation time series and observations of fault creep obtained from CREs. The SAR data set includes C band scenes acquired by the ERS-2 and Envisat satellites between 2003 and 2011. The resulting creep rate distribution implies a peak rate up to 32 mm/yr along the central part of the CSAF. Afterslip due to the 2004 Parkfield earthquake on the southeastern segment of the CSAF is also manifest in the model, and there is clear evidence of creep pulsing along strike and depth of the CSAF. Estimated annual rate of slip deficit accumulation is equivalent to a magnitude 5.6-5.7 earthquake. Taking advantage of the time-dependence of our model, we also refine the scaling relationship, which associates the released seismic moment due to a CRE event with the amount of creep on the fault, surrounding the CRE patches. This study provides the first kinematic model of creep pulsing, constrained using geodetic and seismic data, which can enhance time-dependent seismic hazard maps and improve earthquake operational forecast models.

  16. High-resolution seismic-reflection and marine-magnetic data from offshore central California--San Gregorio to Point Sur

    USGS Publications Warehouse

    Sliter, Ray W.; Johnson, Samuel Y.; Watt, Janet T.; Scheirer, Daniel S.; Allwardt, Parker; Triezenberg, Peter J.

    2013-01-01

    The U.S. Geological Survey collected high-resolution seismic-reflection data on four surveys (S-N1-09-MB, S-15-10-NC, S-06-11-MB, and S-04-12-MB) and marine-magnetic data on one survey (S-06-11-MB) between 2009 and 2012, offshore of central California between San Gregorio and Point Sur. This work was supported in part by the California Seafloor Mapping Program. The survey areas span about 120 km of California's coast (including Monterey Bay). Most data were collected aboard the U.S. Geological Survey R/V Parke Snavely. Cumulatively, approximately 1,410 km of single-channel seismic-reflection data were acquired, mainly using a SIG 2mille minisparker. About 44 km of data were collected simultaneously using an EdgeTech Chirp 512. Subbottom acoustic penetration spanned tens to several hundreds of meters, variable by location. Marine magnetic data were collected on approximately 460 km of track lines (mainly in southern Monterey Bay) using a Geometrics G882 cesium-vapor marine magnetometer. This report includes maps and navigation files of the surveyed transects, linked to Google Earth™ software, as well as digital data files showing images of each transect in SEG-Y and JPEG formats. The images of bedrock, sediment deposits, and tectonic structure provide geologic information that is essential to hazard assessment, regional sediment management, and coastal and marine spatial planning at Federal, State and local levels, as well as to future research on the geomorphic, sedimentary, tectonic, and climatic record of central California.

  17. Character and evolution of the ground-water flow system in the central part of the western San Joaquin Valley, California

    USGS Publications Warehouse

    Belitz, K.R.

    1988-01-01

    The occurrence of selenium in agricultural drain water derived from the western San Joaquin Valley, California, has focused concern on the groundwater flow system of the western valley. Previous work and recently collected texture and water level data were used to evaluate the character and evolution of the regional groundwater flow system in the central part of the western valley, with particular emphasis on the deposits overlying the Corcoran Clay Member of the Tulane Formation. The Corcoran Clay Member, where present, divides the flow system into an upper semiconfined zone and a lower confined zone. Above the Corcoran, three geohydrologic units can be recognized: Coast Range alluvium, Sierran sand, and flood-basin deposits. These units differ in texture, hydrologic properties, and oxidation state. The development of irrigated agriculture in the central part of the western valley has significantly altered the flow system. Percolation of irrigation water past crop roots has caused a rise in the altitude of the water table in mid-fan and distal-fan areas. Pumpage of groundwater from wells has caused a lowering of the water table beneath parts of the fanheads and a lowering of the potentiometric surface of the confined zone over much of the western valley. The combination of percolation and pumpage has resulted in development of a large downward hydraulic head gradient in the semi-confined zone and has created a groundwater divide along the western margin of the valley. Surface water deliveries from the California Aqueduct have allowed a decrease in pumpage and a consequent recovery in hydraulic head throughout the system. (Author 's abstract)

  18. Geophysical Exploration of Fractured-Media Aquifers at the Mexican Mesa Central: Satellite City, San Luis Potosí, Mexico

    NASA Astrophysics Data System (ADS)

    López Loera, Héctor; Ramos Leal, José Alfredo; Dávila Harris, Pablo; Torres Gaytan, David Ernesto; Martinez Ruiz, Victor Julian; Gogichaishvili, Avto

    2015-01-01

    Groundwater is scarce in arid and semi-arid zones in the Mexican Mesa Central. It is found at depths over 200 m, and its movement is primarily through fractures. This work aims to present a geophysical methodology, which shows the potential of combining natural and induced methods to locate confined aquifers in fault zones. The studies begin by interpreting the aeromagnetic survey, mainly by seeking lineaments associated with low magnetic anomalies, which are correlated with fault zones, and/or fractures and/or geological contacts where ferromagnetic minerals have undergone oxidation due to their association with recharge zones. These aeromagnetic lineaments are confirmed on land by a ground magnetic survey. After locating these areas, interpreted as permeability zones, their possible association with moist zones is confirmed by applying the vertical electrical sounding (VES) technique. H-type curve is associated with the presence of saturated zones. This study used the proposed methodology to interpret four main aeromagnetic lineaments and 12 main ground magnetic lineaments in a 36 km2 (6 km × 6 km) area. Twenty-six SEV were performed over these magnetic lineaments, of which about 50 % were associated with H-type resistivity curves, interpreted as being associated with moisture. Of the 12 VES with inferred groundwater potential, two wells have been drilled to date, one having an extraction flow of 70 lps.

  19. Geophysical Exploration of Fractured-Media Aquifers at the Mexican Mesa Central: Satellite City, San Luis Potosí, Mexico

    NASA Astrophysics Data System (ADS)

    López Loera, Héctor; Ramos Leal, José Alfredo; Dávila Harris, Pablo; Torres Gaytan, David Ernesto; Martinez Ruiz, Victor Julian; Gogichaishvili, Avto

    2014-09-01

    Groundwater is scarce in arid and semi-arid zones in the Mexican Mesa Central. It is found at depths over 200 m, and its movement is primarily through fractures. This work aims to present a geophysical methodology, which shows the potential of combining natural and induced methods to locate confined aquifers in fault zones. The studies begin by interpreting the aeromagnetic survey, mainly by seeking lineaments associated with low magnetic anomalies, which are correlated with fault zones, and/or fractures and/or geological contacts where ferromagnetic minerals have undergone oxidation due to their association with recharge zones. These aeromagnetic lineaments are confirmed on land by a ground magnetic survey. After locating these areas, interpreted as permeability zones, their possible association with moist zones is confirmed by applying the vertical electrical sounding (VES) technique. H-type curve is associated with the presence of saturated zones. This study used the proposed methodology to interpret four main aeromagnetic lineaments and 12 main ground magnetic lineaments in a 36 km2 (6 km × 6 km) area. Twenty-six SEV were performed over these magnetic lineaments, of which about 50 % were associated with H-type resistivity curves, interpreted as being associated with moisture. Of the 12 VES with inferred groundwater potential, two wells have been drilled to date, one having an extraction flow of 70 lps.

  20. Structure and geomorphology of the "big bend" in the Hosgri-San Gregorio fault system, offshore of Big Sur, central California

    NASA Astrophysics Data System (ADS)

    Johnson, S. Y.; Watt, J. T.; Hartwell, S. R.; Kluesner, J. W.; Dartnell, P.

    2015-12-01

    The right-lateral Hosgri-San Gregorio fault system extends mainly offshore for about 400 km along the central California coast and is a major structure in the distributed transform margin of western North America. We recently mapped a poorly known 64-km-long section of the Hosgri fault offshore Big Sur between Ragged Point and Pfieffer Point using high-resolution bathymetry, tightly spaced single-channel seismic-reflection and coincident marine magnetic profiles, and reprocessed industry multichannel seismic-reflection data. Regionally, this part of the Hosgri-San Gregorio fault system has a markedly more westerly trend (by 10° to 15°) than parts farther north and south, and thus represents a transpressional "big bend." Through this "big bend," the fault zone is never more than 6 km from the shoreline and is a primary control on the dramatic coastal geomorphology that includes high coastal cliffs, a narrow (2- to 8-km-wide) continental shelf, a sharp shelfbreak, and a steep (as much as 17°) continental slope incised by submarine canyons and gullies. Depth-converted industry seismic data suggest that the Hosgri fault dips steeply to the northeast and forms the eastern boundary of the asymmetric (deeper to the east) Sur Basin. Structural relief on Franciscan basement across the Hosgri fault is about 2.8 km. Locally, we recognize five discrete "sections" of the Hosgri fault based on fault trend, shallow structure (e.g., disruption of young sediments), seafloor geomorphology, and coincidence with high-amplitude magnetic anomalies sourced by ultramafic rocks in the Franciscan Complex. From south to north, section lengths and trends are as follows: (1) 17 km, 312°; (2) 10 km, 322°; (3)13 km, 317°; (4) 3 km, 329°; (5) 21 km, 318°. Through these sections, the Hosgri surface trace includes several right steps that vary from a few hundred meters to about 1 km wide, none wide enough to provide a barrier to continuous earthquake rupture.

  1. Regression models of monthly water-level change in and near the Closed Basin Division of the San Luis Valley, south-central Colorado

    USGS Publications Warehouse

    Watts, Kenneth R.

    1995-01-01

    The Bureau of Reclamation is developing a water-resource project, the Closed Basin Division, in the San Luis Valley of south-central Colorado that is designed to salvage unconfined ground water that currently is discharged as evapotranspiration. The water table in and near the 130,000-acre Closed Basin Division area will be lowered by an annual withdrawal of as much as 100,000 acre-feet of ground water from the unconfined aquifer. The legislation authorizing the project limits resulting drawdown of the water table in preexisting irrigation and domestic wells outside the Closed Basin Division to a maximum of 2 feet. Water levels in the closed basin in the northern part of the San Luis Valley historically have fluctuated more than 2 feet in response to water-use practices and variation of climatically controlled recharge and discharge. Declines of water levels in nearby wells that are caused by withdrawals in the Closed Basin Division can be quantified if water-level fluctuations that result from other water-use practices and climatic variations can be estimated. This study was done to evaluate water-level change at selected observation wells in and near the Closed Basin Division. Regression models of monthly water-level change were developed to predict monthly water-level change in 46 selected observation wells. Predictions of monthly water-level change are based on one or more of the following: elapsed time, cosine and sine functions with an annual period, streamflow depletion of the Rio Grande, electrical use for agricultural purposes, runoff into the closed basin, precipitation, and mean air temperature. Regression models for five of the wells include only an intercept term and either an elapsed-time term or terms determined by the cosine and sine functions. Regression models for the other 41 wells include 1 to 4 of the 5 other variables, which can vary from month to month and from year to year. Serial correlation of the residuals was detected in 24 of the

  2. Estimation of a water budget for 1972-2000 for the Grasslands Area, central part of the Western San Joaquin Valley, California

    USGS Publications Warehouse

    Brush, Charles F.; Belitz, Kenneth; Phillips, Steven P.

    2004-01-01

    Equitable implementation of regulations restricting discharges from agricultural drains into the San Joaquin River requires a greater understanding of the influence of extreme precipitation events on the ground-water flow system. As part of a larger investigation, this study estimated ground-water recharge and ground-water pumpage, two important components of the water budget in the Grasslands drainage area in the central part of the western San Joaquin Valley, California, for the water years 1972 through 2000. These estimates will be used as inputs to a numerical simulation model of the regional ground-water flow system in the continuing investigation. Crop-acreage and surface-water delivery data were compiled for 14 water districts and 6 other areas comprising approximately 97 percent of the 600-square-mile study area. Little ground-water pumpage data exists for the study area. A climate-based approach was employed to estimate annual water-table recharge flux and ground-water pumpage for 11 water-budget areas. Ground-water pumpage was estimated from the residual irrigation demand after crop consumption of surface water. Estimated recharge flux to the water table for the entire study area averaged 0.8 ft/yr, and estimated ground-water pumpage per unit area for the entire study area averaged 0.5 ft/yr. Increased discharges from agricultural drains in the late 1990s may have been due partly to 4 years of high recharge from precipitation over the 6-year period from 1993 to 1998. Knowledge of the ratio of annual crop water demand to annual potential evapotranspiration, expressed as an aggregate crop coefficient, Kd, will facilitate estimation of annual water-budget components in future studies. Annual aggregate crop coefficients, calculated each year for the entire study area, were nearly constant at 0.59 from 1983 to 2000, and reasonably constant at 0.53 prior to 1983. The overall trend suggests continuous reductions in recharge from irrigation over time. This

  3. 19. REGIONAL MAP, SALINAS RIVER PROJECT, CAMP SAN LUIS OBISPO, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. REGIONAL MAP, SALINAS RIVER PROJECT, CAMP SAN LUIS OBISPO, IN CENTRAL PORTION OF SAN LUIS OBISPO, CALIFORNIA. Leeds Hill Barnard & Jewett - Consulting Engineers, February 1942. - Salinas River Project, Cuesta Tunnel, Southeast of U.S. 101, San Luis Obispo, San Luis Obispo County, CA

  4. Constitutive behavior of gouge from the Central Deforming Zone of the San Andreas Fault approaching in-situ strain-rates

    NASA Astrophysics Data System (ADS)

    French, M. E.; Chester, F. M.; Chester, J. S.

    2013-12-01

    Well-foliated smectite-rich fault gouge was recovered from the actively creeping Southwest Deforming Zone (SDZ) and the Central Deforming Zone (CDZ) during drilling of the San Andreas Fault Observatory at Depth (SAFOD). The SDZ and CDZ have a combined thickness of ~4m and are believed to accommodate the majority of aseismic creep (20 mm/yr) along the central segment of the San Andreas Fault (SAF). Assuming distributed shear, the in-situ shear-strain rate here is ~10 -10 s-1. This study investigates the constitutive behavior of the well-foliated Mg-smectite CDZ gouge recovered from 2.7 km depth. Previously published laboratory friction experiments and microstructural studies of CDZ gouge have proposed several explanations for the fault creep including: inherently low strength of saponite, slip along films of nanometer sized clay-particles that line the clasts and shear surfaces that define a scaly fabric, and pressure solution creep. To test these hypotheses, we conducted stress-relaxation experiments on the CDZ gouge; stress-relaxation allows measurement of strength over several orders magnitude of strain-rate, and at strain-rates lower than typically achieved in constant stress or constant displacement-rate experiments. The gouge was gently fragmented to ~800 micrometers to preserve the clay microfabric. Gouge layers ~2 mm thick were sheared at 100° C and 100 MPa effective normal stress between sawcut cylinders using a triaxial deformation apparatus. We report the results of 5 experiments during which we conducted 17 stress-relaxation tests lasting from 1 to 30 days. Relaxation tests achieved strain rates from 10-9 to 10-5 s-1 (approaching in-situ rates). The gouge was deformed either room-dry or saturated with a brine similar in composition to the in-situ pore fluid chemistry at SAFOD; for one experiment temperature was stepped between 60-100° C. Future experiments will be conducted on finely powdered gouge to test the effects of microstructure. In order to

  5. Diagenetic resetting of Sm-Nd isotope systematics in Wilcox Group sandstones and shales, San Marcos Arch, south-central Texas

    SciTech Connect

    Awwiller, D.N.; Mack, L.E. )

    1989-09-01

    Preliminary Sm-Nd analyses of sandstones and shales from the Wilcox Group (upper Paleocene-lower Eocene) suggest that the whole-rock Sm-Nd signature is changed by diagenesis. Samples are obtained from the San Marcos arch, south-central Texas, at depths ranging from outcrop to 15,000 ft. Samples from above the depth of intense illitization and feldspar reactions (about 10,000 ft) have whole-rock Nd model ages of about 1,500-1,400 Ma, whereas samples buried deeper than 13,000 ft have Nd model ages of about 1,700-1,500 Ma. The similar depositional age of all samples makes change in provenance an unlikely cause of the variation. Diagenetic modification is the only reasonable explanation for the observed differences. Sm and Nd reservoirs within the shale change considerably with progressive diagenesis. Outcrop samples contain subequal concentrations of Sm and Nd in the acid-soluble and silicate fractions. The acid-soluble reservoir in deeper samples contains progressively less Sm and Nd and higher Sm/Nd ratios. In all samples, the acid-soluble Nd is more radiogenic than the Nd in the corresponding silicate fraction; the difference between the two reservoirs increases with depth. Preferential loss of Nd relative to Sm in the silicate reservoir during diagenetic crystallization of illite and albite is the most likely explanation for the observed trend in Nd model age. These data imply that the earlier assumption that no fractionation takes place in the Sm-Nd system during diagenesis is incorrect.

  6. Effects of reservoir installation, San Juan-Chama Project water, and reservoir operations on streamflow and water quality in the Rio Chama and Rio Grande, northern and central New Mexico, 1938-2000

    USGS Publications Warehouse

    Langman, Jeff B.; Anderholm, Scott K.

    2004-01-01

    The coordinated operation of Heron, El Vado, and Abiquiu Dams on the Rio Chama and Cochiti Dam on the Rio Grande and the importation of Colorado River Basin water by the San Juan-Chama Project have altered streamflow and water quality of the Rio Chama and Rio Grande in northern and central New Mexico. The coordinated retention of streamflow in the four reservoirs increased median streamflows, decreased extreme flows, and decreased periods of small streamflow; inflow of San Juan-Chama Project water increased overall streamflow in the Rio Chama and Rio Grande. These changes to streamflow decreased specific conductance and suspended-sediment concentration and increased pH in the Rio Chama and the Rio Grande. Following construction of Heron and Cochiti Dams and integration of reservoir operations on the Rio Chama and the Rio Grande, the inflow of San Juan-Chama Project water and retention of snowmelt runoff influenced water quality. These influences varied by season because reservoir releases fluctuated according to downstream user needs and annual streamflow variation. The influences of San Juan-Chama Project water and retained snowmelt on water quality diminished with downstream flow as the Rio Grande was subjected to various natural and anthropogenic inflows. Because of the variability and type of seasonal influences, streamflow did not have a strong annual correlation with water quality in the Rio Chama or the Rio Grande.

  7. Time-dependent Model of Aseismic slip on the Central San Andreas Fault from InSAR Time Series and Repeating Earthquakes

    NASA Astrophysics Data System (ADS)

    Khoshmanesh, M.; Shirzaei, M.; Nadeau, R. M.

    2014-12-01

    The Central segment of the San Andreas Fault (CSAF) is characterized by a nearly continuous right-lateral aseismic slip. Geodetic observations of surface deformation along CSAF indicate interseismic strain accumulation with a rate of about 10 mm/yr. The creep rates obtained using Characteristic Repeating Earthquakes (CRE) show pulses of creep affecting most of the CSAF, suggesting spatiotemporal variability of seismic hazard. Therefore, a high resolution time-dependent model of creep on the CSAF can greatly enhance the knowledge of aseismic and seismic faulting processes as well as the seismic hazard estimates. We used InSAR surface deformation time series in conjunction with observations of fault creep obtained from CRE. The SAR data set includes C-band scenes acquired by the ERS-2 and Envisat during period 2003-2011, comprising 46 images, resulted in about 150 interferograms. Within the same observation period, the CRE data set includes more than 630 repeating sequences. Understanding the spatiotemporal distribution of creep, we implement a time-dependent modeling scheme, allowing us to jointly invert the surface deformation time series and CRE estimates of the fault creep.The distribution of obtained creep rate on the CSAF includes features similar to that reported in earlier works. The map of long-term slip rate reveals that fastest creep rate occurs at the central part of CSAF with an average rate of 27 mm/yr, which is less than the long-term shearing rate. Moving northwestward, the slip rate gradually drops to less than half of its long-term rate. The spatiotemporal map of the creep includes unique features such as afterslip due to the 2004 Parkfield earthquake affecting the southeastern part of the CSAF and the clear evidence of creep pulsing along strike and depth of the CSAF with a period of 1.5 to 2 years. Considering 34.5 mm/yr as the long-term shearing rate, the zone of afterslip is characterized by relaxation time of about 16.35 years. The moment

  8. Morphotectonic analysis of the long-term surface expression of the Paganica - San Demetrio Fault System (2009 L'Aquila earthquake, Central Italy)

    NASA Astrophysics Data System (ADS)

    Civico, Riccardo; Pucci, Stefano; Pantosti, Daniela; De Martini, Paolo Marco

    2013-04-01

    On April 6, 2009 a Mw6.1 earthquake struck a densely populated area in the Abruzzi Apennines (central Italy), causing heavy damage in the town of L'Aquila and surrounding villages and resulting in ~300 fatalities and thousands of injured. Seismological and geodetic data all converge in identifying a ~15km-long, NW-SE oriented, SW-dipping normal structure, coincident with the Paganica-San Demetrio fault system (PSDFS, hereinafter) as the 2009 earthquake causative fault. We performed a detailed morphotectonic analysis on the surface expression of the PSDFS, mainly based on the availability of high-resolution LiDAR topographic data. The extent of the long-term morphological expression of the PSDFS (characterized by the presence of pre-existing composite fault scarps with throws of several meters) and of the modeled seismologic/geodetic coseismic fault contrasts with the limited size of the primary coseismic surface ruptures (~3km-long with maximum throw of 0.15m). This discrepancy raises two main questions: (1) are repeated coseismic centimetric displacements at the surface able to build the decametric-high long-term composite fault scarps, or there is need for larger coseismic slip at the surface? (2) how does the PSDFS cumulate slip over time and space? Both these questions represent serious caveats for the assessment of the seismic hazard of the area and envisage the hypothesis that the PSDFS can generate larger magnitude events, with respect to that of April 2009. Through our detailed morphotectonic analysis we imaged the long-term morphological expression of the PSDFS and highlighted its complex geometrical arrangement (length, number of fault splays and boundaries) at the surface. We also defined a first-order hierarchy among the numerous fault splays across the fault system. The PSDFS appears to be a ~19km-long structure comprising two main sectors: (1) the Paganica sector to the NW, characterized by a narrow deformation zone and a relatively small Quaternary

  9. Ecological and water quality impairment resulting from the New Idria Mercury Mine and natural sources in the San Carlos and Silver Creek watersheds, central California

    NASA Astrophysics Data System (ADS)

    Rytuba, J. J.; Hothem, R.; Goldstein, D.; Brussee, B.

    2011-12-01

    The New Idria Mercury Mine in central California is the second largest mercury (Hg) deposit in North America and has been proposed as a US EPA Superfund Site based on ecological impairment to the San Carlos and Silver Creek watersheds. Water, sediment, and biota were sampled in San Carlos Creek in the mine area and downstream for 25 km into the watershed termed Silver Creek. Release of acid rock drainage (ARD) and erosion of mine tailings have impacted the watershed during 120 years of mining and since the mine was closed in 1972. The watershed can be divided into three segments based on water and sediment composition, Hg sources and concentrations, and biodiversity of aquatic invertebrates. Creek waters in segment no. 1 above the mine area consist of Mg-Ca-CO3 meteoric water with pH 8.73. Hg concentrations are elevated in both sediment (100μg/g), and in waters (60 ng/L) because of erosion of Hg mine tailings in the upper part of the watershed. Invertebrate biodiversity is the highest of the sites sampled in the watershed, with seven families (six orders) of aquatic invertebrates collected and six other families observed. In the mine area isotopically heavy ARD (pH 2.7) with high levels of Fe(II), SO4, and total Hg (HgT: 76.7 ng/L) enters and mixes with meteoric creek water, constituting from 10-15% of the water in the 10-km long second creek segment downstream from the mine. Oxidation of Fe(II) from ARD results in precipitation of FeOOH which is transported and deposited as an Fe precipitate that has high Hg and MMeHg concentration (Hg: 15.7-79 μg/g, MMeHg: 0.31 - 1.06 ng/g). Concentrations of HgT are uniformly high (1530-2890 ng/L) with particulate Hg predominant. MMeHg ranges from 0.21-0.99 ng/L. In the area just downstream from the ARD source, biodiversity of invertebrates was low, with only one taxa (water striders) available in sufficient numbers and mass (> 1 g)_to be sampled. Biodiversity further downstream was also low, with only up to 2 families present

  10. Simulation of streamflow and estimation of recharge to the Edwards aquifer in the Hondo Creek, Verde Creek, and San Geronimo Creek watersheds, south-central Texas, 1951-2003

    USGS Publications Warehouse

    Ockerman, Darwin J.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the San Antonio Water System, constructed three watershed models using the Hydrological Simulation Program—FORTRAN (HSPF) to simulate streamflow and estimate recharge to the Edwards aquifer in the Hondo Creek, Verde Creek, and San Geronimo Creek watersheds in south-central Texas. The three models were calibrated and tested with available data collected during 1992–2003. Simulations of streamflow and recharge were done for 1951–2003. The approach to construct the models was to first calibrate the Hondo Creek model (with an hourly time step) using 1992–99 data and test the model using 2000–2003 data. The Hondo Creek model parameters then were applied to the Verde Creek and San Geronimo Creek watersheds to construct the Verde Creek and San Geronimo Creek models. The simulated streamflows for Hondo Creek are considered acceptable. Annual, monthly, and daily simulated streamflows adequately match measured values, but simulated hourly streamflows do not. The accuracy of streamflow simulations for Verde Creek is uncertain. For San Geronimo Creek, the match of measured and simulated annual and monthly streamflows is acceptable (or nearly so); but for daily and hourly streamflows, the calibration is relatively poor. Simulated average annual total streamflow for 1951–2003 to Hondo Creek, Verde Creek, and San Geronimo Creek is 45,400; 32,400; and 11,100 acre-feet, respectively. Simulated average annual streamflow at the respective watershed outlets is 13,000; 16,200; and 6,920 acre-feet. The difference between total streamflow and streamflow at the watershed outlet is streamflow lost to channel infiltration. Estimated average annual Edwards aquifer recharge for Hondo Creek, Verde Creek, and San Geronimo Creek watersheds for 1951–2003 is 37,900 acrefeet (5.04 inches), 26,000 acre-feet (3.36 inches), and 5,940 acre-feet (1.97 inches), respectively. Most of the recharge (about 77 percent for the three watersheds

  11. San Antonio, Texas, USA

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This sharp, cloud free view of San Antonio, Texas (29.5N, 98.5W) illustrates the classic pattern of western cities. The city has a late nineteenth century Anglo grid pattern overlaid onto an earlier, less regular Hispanic settlement. A well marked central business district having streets laid out north/south and east/west is surrounded by blocks of suburban homes and small businesses set between the older colonial radial transportation routes.

  12. Insights into Surface Manifestation of Aseismic vs. Coseismic Strike-Slip Faulting from UAV Imagery of Creep-Induced Surface Fracturing Along the Central San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Bunds, M. P.; Toke, N. A.; Lawrence, A.; Arrowsmith, R.; Salisbury, J. B.

    2015-12-01

    Left-stepping en echelon fractures formed at the Dry Lake Valley paleoseismic site (DLV, 36.470N, 121.057W) on the central creeping segment of the San Andreas Fault (SAF) during the 2012-14 drought. The fractures were investigated using high resolution DEMs and orthophotos made by applying Structure from Motion processing to photos taken using a UAV and handheld cameras on 9/20/2014. At DLV the SAF is marked by a distinctive 2-7 m high west-facing scarp that extends northwestward from a dilational step-over. The orthophotos and DEMs were used to measure 110 fractures along a 37 m section of scarp and 15 additional fracture sets along a further 79 m of scarp. The fractures averaged 54 cm long by 1.8 cm wide with 22% overlap, and were mode 1 opening fractures that on average trended 184o, nearly perpendicular to the maximum extension direction for right-lateral slip along the 144o - trending SAF. The fractures occurred in ~5 m long sets that were themselves left-stepping, on average trended 159o, and were confined to a 3-4 m wide zone along the fault scarp. We interpret the fracture sets to be incipient Riedel shears with a component of extension across them based on the orientation of the sets relative to the SAF, the obliquity of the individual fractures to the trend of the sets, and the presence of topographic lows along them. We conservatively estimate 2.5 ± 1 cm of right-lateral creep on the SAF was recorded in the opening of the fractures, which probably began forming at most 21 months before the photographic survey based on precipitation records and prior site inspection. From these results and the 2.5-3.2 cm/yr creep rate for the SAF, we infer that at least ~30%, and probably 50-80% or more of creep occurs along the narrow 5-50 m wide primary geomorphic expression of the fault, and that the same amount of creep can be accommodated by brittle fracturing in a narrow 3-4 m wide zone along the fault scarp during drought periods. In comparison to seismically

  13. Improving the Flash Flood Frequency Analysis using dendrogeomorphological evidences in the Arenal River crossing Arenas de San Pedro Village (Spanish Central System)

    NASA Astrophysics Data System (ADS)

    Ruiz-Villanueva, V.; Ballesteros, J. A.; Díez-Herrero, A.; Bodoque, J. M.

    2009-04-01

    The flash flood frequency analysis in mountainous catchments presents specific scientific challenges. One of the challenges is the relevant gradient in precipitation intensity with altitude. Another challenge is the lack of information from rainfall or discharge gauge stations or from documentary sources. Dendrogeomorphology studies the response in the wood growth pattern and the botanical signs on the trees affected by geomorphological processes. With regard to the flood frequency, the dendrogeomorphological evidences bring forward valuable infomation about single past events (with annual or even seasonal precision) and their occurrence periodicity. The main macro-evidence that we can find in the tree trunk is a stem scar originated by a wound in the bark of the tree. When the tree grows, this wound remains reflected in the tree ring sequence. The best way to analyze the tree ring sequence is by using a complete section of the trunk, this couldn't be possible unless the tree is cut down. Due to the unfeasibility of cutting down the trees, in Dendrogeomorphology is enough to obtain an increment core, using a Pressler borer. Nevertheless, this study has been based on complete stem sections analysis facilitated for the felling works in the riverine vegetation in the Arenal River, carried out by the Tagus River Water Authority. These felling works have allowed us to obtain sections and to analyze the stump of the tree in situ. On this way, 100 samples of Alnus glutinosa and Fraxinus angustifolia located by the river along the Arenal River crossing Arenas de San Pedro Village (Ávila, northern slopes of the Gredos Mountain Range in the Spanish Central System) have been analyzed. This village is known for its historical problems of flood during extreme events. A meticulous fieldwork has been carried out. Every sample was analyzed locating its geomorphological position, the distance to the riverbed and the height of the stump in which the evidences were observed. Using a

  14. Apparent stable isotope heterogeneities in gangue carbonates of the Mississippi Valley-type Zn-Pb deposit of San Vicente, central Peru

    NASA Astrophysics Data System (ADS)

    Spangenberg, J.; Sharp, Z. D.; Fontboté, L.

    1995-02-01

    The aim of the present communication is to emphasize that some variations of the measured δ 13C and δ 18O values are apparent, and due to analytical interferences caused by the presence of sulfur and organosulfur compounds in the analyzed carbonates. This is particularly relevant for isotopic studies on carbonate-hosted mineral deposits, where the nearly ubiquitous association of the host carbonates with organic matter and sulfides can certainly affect the metallogenetic interpretations. In this work two methods were used to overcome the disturbing effects of sulfides and organic matter: (1) sample pretreatment following the method proposed by Charef and Sheppard (1984), combining the oxidation of organic matter with sodium hypochlorite and trapping of the sulfur species with silver phosphate; and (2) laser-based microprobe extraction. Apparent isotopic variations in sparry dolomite from a single hand sample of zebra ore from the MVT Zn-Pb deposit, San Vicente, central Peru, are as large as 6‰ δ 13C and 4‰ δ 18O. These variations are reduced to several tenths of a per mil when the samples are pretreated. A careful examination of the effects of treatment with NaOCl and/or Ag3PO4 in relation to the concentration of sulfide inclusions indicates that the main disturbing effects for δ 13C values are the presence of sulfur species and organic matter, whereas the δ 18O values are mainly affected by the presence of sulfides. Fine- and medium-grained replacement carbonates from MVT and other sediment-hosted base metal deposits are potentially the most affected during isotope analysis, due to the common presence of organic matter and sulfides. Using in situ laser microprobe techniques, it is possible to determine isotopic variations at a sub-millimeter scale. Our results show that laser extraction analysis allows a more precise sampling of the carbonate minerals, and minimizes contamination of the sample with sulfides and to some extent with intergrown organic

  15. Digital data and derivative products from a high-resolution aeromagnetic survey of the central San Luis basin, covering parts of Alamosa, Conejos, Costilla, and Rio Grande counties, Colorado, and Taos county, New Mexico

    USGS Publications Warehouse

    Bankey, Viki; Grauch, V.J.S.; Webbers, Ank; PRJ, Inc

    2005-01-01

    This report describes data collected from a high-resolution aeromagnetic survey flown over the central San Luis basin during October, 2004, by PRJ, Inc., on contract to the U.S. Geological Survey (USGS). The survey extends from just north of Alamosa, Colorado, southward to just northwest of Taos, New Mexico. It covers large parts of the San Luis Valley in Alamosa, Conejos, Costilla, and Rio Grande Counties, southern Colorado, and the Taos Plateau in Taos County, northern New Mexico. The survey was designed to complement two surveys previously acquired along the eastern borders of the San Luis Basin over the vicinities of Taos, New Mexico (Bankey and others, 2004a) and Blanca, Colorado (Bankey and others, 2004b). Our overall objective in conducting these surveys is to improve knowledge of the subsurface geologic framework in order to understand ground-water systems in populated alluvial basins along the Rio Grande. These USGS efforts are conducted in collaboration with other federal, state, and local governmental entities where possible.

  16. Three thousand years of flank and central vent eruptions of the San Salvador volcanic complex (El Salvador) and their effects on El Cambio archeological site: a review based on tephrostratigraphy

    NASA Astrophysics Data System (ADS)

    Ferrés, D.; Delgado Granados, H.; Hernández, W.; Pullinger, C.; Chávez, H.; Castillo Taracena, C. R.; Cañas-Dinarte, C.

    2011-09-01

    The volcanic events of the last 3,000 years at San Salvador volcanic complex are reviewed using detailed stratigraphic records exposed in new excavations between 2005 and 2007, at El Cambio archeological site (Zapotitán Valley, El Salvador), and in other outcrops on the northern and northwestern sectors of the complex. The sequences that overlie Tierra Blanca Joven (cal. 429 ± 107 ad), from the Ilopango caldera, comprise the Loma Caldera (cal. 590 ± 90 ad) and El Playón (1658-1671) deposits and the San Andrés Tuff (cal. 1031 ± 29 ad), related to El Boquerón Volcano. The surge deposits within the El Playón, San Andrés Tuff and overlying Talpetate II sequences indicate the significance of phreatomagmatic phases in both central vent and flank eruptions during the last 1,600 years. Newly identified volcanic deposits underlying Tierra Blanca Joven at El Cambio extend the stratigraphic record of the area to 3,000 years bp. Paleosols interstratified with those deposits contain cultural artifacts which could be associated with the Middle Preclassic period (900-400 bc). If correct, human occupation of the site during the Preclassic period was more intense than previously known and volcanic eruptions must have affected prehistoric settlements. The archeological findings provide information on how prehistoric populations dealt with volcanic hazards, thousands of years ago in the eastern Zapotitán Valley, where several housing projects are currently being developed. The new stratigraphic and volcanological data can be used as a basis for local and regional hazard assessment related to future secondary vent activity in the San Salvador Volcanic Complex.

  17. Cyanobacteria/Foraminifera Association from Anoxic/Dysoxic Beds of the Agua Nueva Formation (Upper Cretaceous - Cenomanian/Turonian) at Xilitla, San Luis Potosi, Central Mexico

    NASA Astrophysics Data System (ADS)

    Blanco-Piñón, A.; Maurrasse, F. J.; Rojas-León, A.; Duque-Botero, F.

    2008-05-01

    The Agua Nueva Formation in the vicinity of Xilitla, State of San Luis Potosí, Central Mexico, consists of interbedded brown shale (Grayish orange 10YR 7/4 to Moderate yellowish brown 10YR 5/4) and dark-gray fossiliferous limestone (Bluish gray 5B 6/1 to Dark bluish gray 5B 4/1), varying between 10 and 20 cm in thickness. The sequence also includes 2 to 4 cm- thick intermittent bentonite layers (Moderate greenish yellow 10Y 7/4, to dark greenish yellow 10Y 6/6 and Light olive 10Y 5/4). At the field scale, shaly intervals show no apparent internal structures, whereas most limestone beds show primary lamination at the millimeter scale (1-2 mm), and intermittent layers of black chert of about 5 cm thick. Pyrite is present as disseminated crystals and as 2 cm-thick layers. Bioturbation or macrobenthic organisms other than inoceramids do not occur in the Agua Nueva Formation at Xilitla. Unusual macrofossils are present only in limestone strata, and consist of well- preserved diverse genera of fishes such as sharks, Ptychodus sp. and teleosteans, Rhynchodercetis sp., Tselfatia sp., Goulmimichthys sp., and scales of Ichtyodectiformes, as well as ammonites and inoceramids (Blanco et al., 2006). The presence of Inoceramus (Mytyloides) labiatus (Maldonado-Koederll, 1956) indicates an Early Turonian age for the sequence. Total carbonate content (CaCO3 = TIC) varies between 62 and 94% in the Limestone beds, which yield Total Organic Carbon (TOC) from 0.4% to 2.5%; the shale intervals contain TIC values consistently lower than 33% and TOC lower than 0.8% Microscopically the limestone beds vary from mudstone to packstone composed essentially of coccoid cyanobacteria similar to coeval deposits in northeastern Mexico, Coahuila State, at Parras de La Fuente (Duque- Botero 2006). Similarly, the microspheroids are spherical to sub-spherical, and occur as isolated elements or aggregates forming series of chains of parallel-packed light lamina 1-2 mm thick. Filamentous cyanobacteria

  18. 75 FR 53332 - San Carlos Irrigation Project, Arizona

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... Bureau of Reclamation San Carlos Irrigation Project, Arizona AGENCY: Bureau of Reclamation, Interior... of San Carlos Irrigation Project (SCIP) water delivery facilities near the communities of Casa Grande... and Central Arizona Project (CAP) to agricultural lands in the San Carlos Irrigation and...

  19. Radon emanation on San Andreas Fault

    USGS Publications Warehouse

    King, C.-Y.

    1978-01-01

    Subsurface radon emanation monitored in shallow dry holes along an active segment of the San Andreas fault in central California shows spatially coherent large temporal variations that seem to be correlated with local seismicity. ??1978 Nature Publishing Group.

  20. A new Eimeria sP. from the plumbeous Central American caecilian, Dermophis mexicanus (amphibia: gymnophiona) from Volcán Tajumulco, Department of San Marcos, Guatemala.

    PubMed

    Asmundsson, I M; Campbell, J A; Duszynski, D W

    2000-04-01

    Fresh fecal samples from 5 caecilians (Dermophis mexicanus) were collected and examined for coccidia in the summer of 1998. The caecilians were collected in the Department of San Marcos, Guatemala. Two of the 5 (40%) specimens of caecilians contained an Eimeria species that is described here as new. This represents the first coccidia described from a gymnophionian host. Sporulated oocysts are spheroidal to subspheroidal, 19.5 X 17.7 (16-23 x 15-21) microm, micropyle and oocyst residuum are absent, and 3 (or more) polar granules are always present. Sporocysts are ovoidal, 11.0 X 7.2 (10-12 x 6-9); a Stieda body and sporocyst residuum are present. PMID:10780555

  1. Central San Francisco Bay suspended-sediment transport processes and comparison of continuous and discrete measurements of suspended-solids concentrations

    USGS Publications Warehouse

    Schoellhamer, David H.

    1996-01-01

    Sediments are an important component of the San Francisco Bay estuarine system. Potentially toxic substances, such as metals and pesticides, adsorb to sediment particles (Kuwabara and others, 1989; Domagalski and Kuivila, 1993). Sediments on the bottom of the bay provide the habitat for benthic communities that can ingest these substances and introduce them into the food web (Luoma and others, 1985). Nutrients, metals, and other substances are stored in bottom sediments and pore water in which chemical reactions occur and which provide an important source and/or sink to the water column (Hammond and others, 1985; Flegal and others, 1991). The transport and fate of suspended sediment is an important factor in determining the transport and fate of the constituents adsorbed on the sediment. Seasonal changes in sediment erosion and deposition patterns contribute to seasonal changes in the abundance of benthic macroinvertebrates (Nichols and Thompson, 1985). Tidal marshes are an ecologically important habitat that were created and are maintained by sedimentation processes (Atwater and others, 1979). In Suisun Bay, the maximum suspended-sediment concentration marks the position of the turbidity maximum, which is a crucial ecological region in which suspended sediment, nutrients, phytoplankton, zooplankton, larvae, and juvenile fish accumulate (Peterson and others, 1975; Arthur and Ball, 1979; Kimmerer, 1992; Jassby and Powell, 1994). Suspended sediments confine the photic zone to the upper part of the water column, and this limitation on light availability is a major control on phytoplankton production in San Francisco Bay (Cloern, 1987; Cole and Cloern, 1987). Suspended sediments also deposit in ports and shipping channels, which must be dredged to maintain navigation (U.S. Environmental Protection Agency, 1992).

  2. Emission of gas and atmospheric dispersion of SO2 during the December 2013 eruption at San Miguel volcano (El Salvador, Central America)

    NASA Astrophysics Data System (ADS)

    Granieri, Domenico; Salerno, Giuseppe; Liuzzo, Marco; La Spina, Alessandro; Giuffrida, Giovanni; Caltabiano, Tommaso; Giudice, Gaetano; Gutierrez, Eduardo; Montalvo, Francisco; Burton, Michael R.; Papale, Paolo

    2015-07-01

    San Miguel volcano, El Salvador, erupted on 29 December 2013, after a 46 year period characterized by weak activity. Prior to the eruption a trend of increasing SO2 emission rate was observed, with all values measured after mid-November greater than the average value of the previous year (~310 t d-1). During the eruption, SO2 emissions increased from the level of ~330 t d-1 to 2200 t d-1, dropping after the eruption to an average level of 680 t d-1. Wind measurements and SO2 emission rates during the preeruptive, syneruptive, and posteruptive stages were used to model SO2 dispersion around the volcano. Atmospheric SO2 concentration exceeded the dangerous threshold of 5 ppm in the crater region and in some sectors with medium elevation of the highly visited volcanic cone. Combining the SO2 emission rate with measured CO2/SO2, HCl/SO2, and HF/SO2 plume gas ratios, we estimate the CO2, HCl, and HF outputs for the first time on this volcano.

  3. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Landon, Matthew K.; Green, Christopher T.; Belitz, Kenneth; Singleton, Michael J.; Esser, Bradley K.

    2011-09-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated >5 mg/L NO3-N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use.

  4. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Landon, Matthew K.; Green, Christopher T.; Belitz, Kenneth; Singleton, Michael J.; Esser, Bradley K.

    2011-01-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated >5 mg/L NO3–N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use.

  5. The unrest of the San Miguel volcano (El Salvador, Central America): installation of the monitoring network and observed volcano-tectonic ground deformation

    NASA Astrophysics Data System (ADS)

    Bonforte, Alessandro; Hernandez, Douglas Antonio; Gutiérrez, Eduardo; Handal, Louis; Polío, Cecilia; Rapisarda, Salvatore; Scarlato, Piergiorgio

    2016-08-01

    On 29 December 2013, the Chaparrastique volcano in El Salvador, close to the town of San Miguel, erupted suddenly with explosive force, forming a column more than 9 km high and projecting ballistic projectiles as far as 3 km away. Pyroclastic density currents flowed to the north-northwest side of the volcano, while tephras were dispersed northwest and north-northeast. This sudden eruption prompted the local Ministry of Environment to request cooperation with Italian scientists in order to improve the monitoring of the volcano during this unrest. A joint force, made up of an Italian team from the Istituto Nazionale di Geofisica e Vulcanologia and a local team from the Ministerio de Medio Ambiente y Recursos Naturales, was organized to enhance the volcanological, geophysical and geochemical monitoring system to study the evolution of the phenomenon during the crisis. The joint team quickly installed a multiparametric mobile network comprising seismic, geodetic and geochemical sensors (designed to cover all the volcano flanks from the lowest to the highest possible altitudes) and a thermal camera. To simplify the logistics for a rapid installation and for security reasons, some sensors were colocated into multiparametric stations. Here, we describe the prompt design and installation of the geodetic monitoring network, the processing and results. The installation of a new ground deformation network can be considered an important result by itself, while the detection of some crucial deforming areas is very significant information, useful for dealing with future threats and for further studies on this poorly monitored volcano.

  6. Flow characteristics of streams that drain the Fort Apache and San Carlos Indian reservations, east-central Arizona, 1930-86

    USGS Publications Warehouse

    Baldys, Stanley; Bayles, J.A.

    1990-01-01

    Streamflow characteristics of the Salt River and Gila River basins in the Fort Apache and San Carlos Indian Reservations, were studied in response to pending adjudication of water resources in those basins. Statistical summaries were compiled for 28 streamflow-gaging stations in and near the reservation. Mean annual streamflow for 1930-86 was computed for stations with complete records for the period; for those stations with records that did not completely cover the 1930-86 period, record extension techniques were used. Mean annual streamflow for ungaged sites on streams with gaging stations was estimated by interpolation between data points using drainage-area ratios. Two regional-regression equations were derived to estimate mean annual streamflow at sites on ungaged natural streams. The standard error of the regression for estimation of mean annual flow for sites in the Salt River basin is -37 to +59%. The standard error of the regression for estimation of mean annual flow for sites in the Gila River basins is -18 to +21%. (USGS)

  7. Geochemical, petrographic and physical characterizations and associated alterations of the volcanic rocks of the Romanesque San Nicola Church (Ottana, central Sardinia, Italy)

    NASA Astrophysics Data System (ADS)

    Columbu, Stefano; Palomba, Marcella; Sitzia, Fabio

    2015-04-01

    In this research, the volcanic rocks belonging to the Sardinia Oligo-Miocene volcanic cycle (32 - 11 Ma) and building up the structure of the San Nicola church, one of the most representative churches of the Romanesque architecture, were studied. These stones were widely used in medieval architecture for the excellent workability, but they present some disadvantages, since they are greatly affected by alteration phenomena. The main objectives of this research are i) to focus the mineral, chemical and petrographic compositions of the San Nicola stones, ii) the chemical and physical alteration processes affecting these materials, and iii) to establish the exactly provenance of the volcanic rocks. Furthermore, a comparative study between the rocks from the ancient quarries and those forming the structure of the church was performed. In the ancient quarries, where presumably a more advanced alteration occurs due to the vertical alteration gradient, different facies of the same volcanic lithology, characterized by macroscopical evidences of chemical-physical degradation degree, were sampled. Petrographic, geochemical (both major elements that the traces) and physical-mechanical features of the collected samples were determined to highlight the compositional differences (density, porosity, water-absorption kinetics, mechanical resistance) as a function of the different alteration degree. Moreover, chemical-mineralogical analysis of the sample surfaces from the church, was performed, to highlight possible presence and nature of secondary newly-formed phases (e.g., salt efflorescence). Several methodologies were applied to carry out physical-chemical and petrographic analysis: X-Ray fluorescence (XRF) and Inductively Coupled Mass Spectrometry (ICP-MS), X-Ray Diffractometry (XRD) for chemical and mineral composition; Optical and Scanning Electron Microscopy (SEM) for textures, mineral assemblages and microstructures studies; He-picnometry, water-absorption and mechanical

  8. Morphotectonic and neotectonic control on river pattern in the Sierra de la Cantera piedmont, Central Precordillera, province of San Juan, Argentina

    NASA Astrophysics Data System (ADS)

    Perucca, Laura P.; Rothis, Martín; Vargas, Horacio N.

    2014-01-01

    The drainage pattern on the western piedmont of the Sierra de La Cantera is divergent, typical of alluvial fans and showing anomalies that are directly related to the trace of La Cantera thrust. In previous studies, two types of anomalies were identified: upstream of the fault scarp, rivers have a broom-shaped pattern, while downstream - in the hanging block - streams become denser, more sinuous and incised. In this contribution, these morphotectonic aspects were analyzed in detail, making direct and indirect analysis to quantify the relationship between these anomalies and the faults affecting alluvial fans. In addition, the influence of neotectonic activity on smaller water course patterns in the alluvial fan areas was investigated in order to find indicators of on-going vertical movements, since the spatial arrangements of these piedmont channels are determined by slope and structure, where active faults cause diversions or anomalies. Topographic profiles in two selected channels cutting across the trace of the fault were performed using a differential GPS in order to establish the relationship between the sinuosity and slope of these rivers. The results obtained allow us to state that the most sinuous channels have lower slopes and are located in the hanging wall of the fault. Morphometric analysis of scarps stated that active tectonics have played an essential role in controlling the drainage pattern in the piedmont, leading the rivers to adjust to these slope variations. Finally, based on the geomorphologic, stratigraphic, structural and seismological characteristics and parameters analyzed, La Cantera Thrust is considered a seismogenic source of significance to the nearby towns (> 700,000 inhabitants) and also to the large-scale dams built downstream along the San Juan River.

  9. LiDAR and field observations of slip distribution for the most recent surface ruptures along the central San Jacinto fault

    USGS Publications Warehouse

    J.B. Salisbury; T.K. Rockwell; T.J. Middleton; Hudnut, Kenneth W.

    2012-01-01

    We measured offsets on tectonically displaced geomorphic features along 80 km of the Clark strand of the San Jacinto fault (SJF) to estimate slip‐per‐event for the past several surface ruptures. We identify 168 offset features from which we make over 490 measurements using B4 light detection and ranging (LiDAR) imagery and field observations. Our results suggest that LiDAR technology is an exemplary supplement to traditional field methods in slip‐per‐event studies. Displacement estimates indicate that the most recent surface‐rupturing event (MRE) produced an average of 2.5–2.9 m of right‐lateral slip with maximum slip of nearly 4 m at Anza, a Mw 7.2–7.5 earthquake. Average multiple‐event offsets for the same 80 kms are ∼5.5  m, with maximum values of 3 m at Anza for the penultimate event. Cumulative displacements of 9–10 m through Anza suggest the third event was also similar in size. Paleoseismic work at Hog Lake dates the most recent surface rupture event at ca. 1790. A poorly located, large earthquake occurred in southern California on 22 November 1800; we relocate this event to the Clark fault based on the MRE at Hog Lake. We also recognize the occurrence of a younger rupture along ∼15–20  km of the fault in Blackburn Canyon with ∼1.25  m of average displacement. We attribute these offsets to the 21 April 1918 Mw 6.9 event. These data argue that much or all of the Clark fault, and possibly also the Casa Loma fault, fail together in large earthquakes, but that shorter sections may fail in smaller events.

  10. The Purisima Formation and related rocks (upper Miocene - Pliocene), greater San Francisco Bay area, central California; review of literature and USGS collection now housed at the Museum of Paleontology, University of California, Berkeley

    USGS Publications Warehouse

    Powell, C.L., II

    1998-01-01

    Sedimentary rocks more than 1.6 kilometers thick are attributed to the upper Miocene to upper Pliocene Purisima Formation in the greater San Francisco Bay area. These rocks occur as scattered, discontinuous outcrops from Point Reyes National Seashore in the north to south of Santa Cruz. Lithologic divisions of the Formation appear to be of local extent and are of limited use in correlating over this broad area. The Purisima Formation occurs in several fault-bounded terranes which demonstrate different stratigraphic histories and may be found to represent more than a single depositional basin. The precise age and stratigraphic relationship of these scattered outcrops are unresolved and until they are put into a stratigraphic and paleogeographic context the tectonic significance of the Purisima Foramtion can only be surmised. This paper will attempt to resolve some of these problems. Mollusks and echinoderms are recorded from the literature and more than 70 USGS collections that have not previously been reported. With the exception of one locality, the faunas suggest deposition in normal marine conditions at water depths of less than 50 m and with water temperatures the same or slightly cooler than exist along the present coast of central California. The single exception is a fauna from outcrops between Seal Cove and Pillar Point, where both mollusks and foraminifers suggest water depths greater than 100 m. Three molluscan faunas, the La Honda, the Pillar Point, and the Santa Cruz, are recognized based on USGS collections and published literature for the Purisima Formation. These biostratigraphically distinct faunas aid in the correlation of the scattered Purisima Formation outcrops. The lowermost La Honda fauna suggests shallow-water depths and an age of late Miocene to early Pliocene. This age is at odds with a younger age determination from an ash bed in the lower Purisima Formation along the central San Mateo County coast. The Pillar Point fauna contains only a

  11. Geochemical constraints on the origin of mafic and silicic magmas at Cordón El Guadal, Tatara-San Pedro Complex, central Chile

    NASA Astrophysics Data System (ADS)

    Feeley, T. C.; Dungan, M. A.; Frey, F. A.

    The aim of this study is to quantify the crustal differentiation processes and sources responsible for the origin of basaltic to dacitic volcanic rocks present on Cordón El Guadal in the Tatara-San Pedro Complex (TSPC). This suite is important for understanding the origin of evolved magmas in the southern Andes because it exhibits the widest compositional range of any unconformity-bound sequence of lavas in the TSPC. Major element, trace element, and Sr-isotopic data for the Guadal volcanic rocks provide evidence for complex crustal magmatic histories involving up to six differentiation mechanisms. The petrogenetic processes for andesitic and dacitic lavas containing undercooled inclusions of basaltic andesitic and andesitic magma include: (1) assimilation of garnet-bearing, possibly mafic lower continental crust by primary mantle-derived basaltic magmas; (2) fractionation of olivine + clinopyroxene + Ca-rich plagioclase + Fe-oxides in present non-modal proportions from basaltic magmas at 4-8kbar to produce high-Al basalt and basaltic andesitic magmas; (3) vapor-undersaturated (i.e., PH2O

  12. Planned updates and refinements to the Central Valley hydrologic model with an emphasis on improving the simulation of land subsidence in the San Joaquin Valley

    USGS Publications Warehouse

    Faunt, Claudia C.; Hanson, Randall T.; Martin, Peter; Schmid, Wolfgang

    2011-01-01

    California's Central Valley has been one of the most productive agricultural regions in the world for more than 50 years. To better understand the groundwater availability in the valley, the U.S. Geological Survey (USGS) developed the Central Valley hydrologic model (CVHM). Because of recent water-level declines and renewed subsidence, the CVHM is being updated to better simulate the geohydrologic system. The CVHM updates and refinements can be grouped into two general categories: (1) model code changes and (2) data updates. The CVHM updates and refinements will require that the model be recalibrated. The updated CVHM will provide a detailed transient analysis of changes in groundwater availability and flow paths in relation to climatic variability, urbanization, stream flow, and changes in irrigated agricultural practices and crops. The updated CVHM is particularly focused on more accurately simulating the locations and magnitudes of land subsidence. The intent of the updated CVHM is to help scientists better understand the availability and sustainability of water resources and the interaction of groundwater levels with land subsidence.

  13. The geometry of the active strike-slip El Tigre Fault, Precordillera of San Juan, Central-Western Argentina: integrating resistivity surveys with structural and geomorphological data

    NASA Astrophysics Data System (ADS)

    Fazzito, Sabrina Y.; Cortés, José M.; Rapalini, Augusto E.; Terrizzano, Carla M.

    2013-07-01

    The geometry and related geomorphological features of the right-lateral strike-slip El Tigre Fault, one of the main morphostructural discontinuities in the Central-Western Precordillera of Argentina, were investigated. Achievements of this survey include: recognition of structural and geometrical discontinuities along the fault trace, identification and classification of landforms associated with local transpressional and transtensional sectors, observation of significant changes in the fault strike and detection of right and left bends of different wavelength. In the Central Segment of the El Tigre Fault, 2D electrical resistivity tomography surveys were carried out across the fault zone. The resistivity imaging permitted to infer the orientation of the main fault surface, the presence of blind fault branches along the fault zone, tectonic tilting of the Quaternary sedimentary cover, subsurface structure of pressure ridges and depth to the water table. Based on this information, it is possible to characterize the El Tigre Fault also as an important hydro-geological barrier. Our survey shows that the main fault surface changes along different segments from a high-angle to a subvertical setting whilst the vertical-slip component is either reverse or normal, depending on the local transpressive or transtensive regime induced by major bends along the trace. These local variations are expressed as sections of a few kilometres in length with relatively homogeneous behaviour and frequently separated by oblique or transversal structures.

  14. Water level, specific conductance, and water temperature data, San Francisco Bay, California, for Water Year 2000

    USGS Publications Warehouse

    Buchanan, P.A.

    2002-01-01

    Time series of water-level, specific-conductance, and watertemperature data were collected at seven sites in San Francisco Bay during water year 2000 (October 1, 1999 through September 30, 2000). Water-level data were recorded only at Point San Pablo. Specific-conductance and water-temperature data were recorded at 15-minute intervals at the following locations (Figure 1): • Carquinez Strait at Carquinez Bridge • Napa River at Mare Island Causeway near Vallejo • San Pablo Bay at Petaluma River Channel Marker 9 • San Pablo Strait at Point San Pablo • Central San Francisco Bay at Presidio Military Reservation • Central San Francisco Bay at Pier 24 • South San Francisco Bay at San Mateo Bridge near Foster City.

  15. 78 FR 53243 - Safety Zone; TriRock San Diego, San Diego Bay, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking A... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; TriRock San Diego, San Diego Bay, San Diego... Safety Zone; TriRock San Diego, San Diego Bay, San Diego, CA. (a) Location. The limits of the safety...

  16. 8. VIEW LOOKING NORTHWEST DOWN CENTRAL AXIS OF ROOM 110. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW LOOKING NORTHWEST DOWN CENTRAL AXIS OF ROOM 110. NOTE CHANGE IN CEILING TREATMENT: WOOD PLANKS IN CENTER, ALL OTHER AREAS ARE GYPSUM BOARD. FLOOR IN CENTRAL AREA IS CONCRETE. POSTS AND BEAMS ARE ALL WOOD CONSTRUCTION. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

  17. 29. Photocopy of photograph (from San Francisco Chronicle Library, San ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Photocopy of photograph (from San Francisco Chronicle Library, San Francisco, California, c. 1930 (?) EXTERIOR, GENERAL VIEW OF CONVENTO, FRONT VIEW, AFTER RESTORATION - Mission San Francisco Solano de Sonoma, First & Spain Streets, Sonoma, Sonoma County, CA

  18. 40. Historic American Buildings Survey San Francisco Chronicle Collection San ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. Historic American Buildings Survey San Francisco Chronicle Collection San Francisco, California March 24, 1924 VIEW OF HIGH ALTAR - Mission San Carlos Borromeo, Rio Road & Lausen Drive, Carmel-by-the-Sea, Monterey County, CA

  19. Specific conductance, water temperature, and water level data, San Francisco Bay, California, water year 1998

    USGS Publications Warehouse

    Buchanan, Paul A.

    1999-01-01

    Specific conductance and water temperature data are continuously recorded at four sites in San Francisco Bay, California: San Pablo Strait at Point San Pablo, Central San Francisco Bay at Presidio Military Reservation, Pier 24 at Bay Bridge, and South San Francisco Bay at San Mateo Bridge near Foster City (Figure 1). Water level data are recorded only at San Pablo Strait at Point San Pablo. These data were recorded by the Department of Water Resources (DWR) before 1988, by the US Geological Survey (USGS) National Research Program from 1988 to 1989, and by the USGS-DWR cooperative program since 1990. This article presents time-series plots of data from the four sites in San Francisco Bay during water year 1998 (1 October 1997 through 30 September 1998).

  20. San Francisco floating STOLport study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The operational, economic, environmental, social and engineering feasibility of utilizing deactivated maritime vessels as a waterfront quiet short takeoff and landing facility to be located near the central business district of San Francisco was investigated. Criteria were developed to evaluate each site, and minimum standards were established for each criterion. Predicted conditions at the two sites were compared to the requirements for each of the 11 criteria as a means of evaluating site performance. Criteria include land use, community structure, economic impact, access, visual character, noise, air pollution, natural environment, weather, air traffic, and terminal design.

  1. /S/ in Central American Spanish.

    ERIC Educational Resources Information Center

    Lipski, John M.

    1985-01-01

    Describes the behavior of the phoneme /s/ in Central American Spanish by comparing the speech patterns of residents of Guatemala City, San Salvador, Tegucigalpa, San Jose, and Managua. Considers the possible diachronic processes which could have given rise to the current configurations and the theoretical consequences implied by the…

  2. 24. INTERIOR OF CENTRAL ROOM. BASE POWER PANEL VISIBLE ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. INTERIOR OF CENTRAL ROOM. BASE POWER PANEL VISIBLE ON RIGHT WALL OF HALLWAY. - Chollas Heights Naval Radio Transmitting Facility, Transmitter Building, 6410 Zero Road, San Diego, San Diego County, CA

  3. California: San Joaquin Valley

    Atmospheric Science Data Center

    2014-05-15

    article title:  Fog and Haze in California's San Joaquin Valley   ... 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 ... 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, ...

  4. Plankton studies in San Francisco Bay; II, Phytoplankton abundance and species composition, July 1977-December 1979

    USGS Publications Warehouse

    Wong, Raymond L. J.; Cloern, James E.

    1981-01-01

    Data are presented on the phytoplankton species composition and abundance in San Francisco Bay from July 1977 through December 1979. Phytoplankton identification and enumerations were made at selected stations. Sample collections were made at selected stations in the main channel of the Bay from Rio Vista on the Sacramento River to Calaveras Point in South San Francisco Bay, and at shoal stations in the central portion of South San Francisco Bay, San Pablo Bay, and Suisun Bay. Also reported, from October 1978 through December 1979, are the calculated phytoplankton carbon and percent nondiatom carbon, and the species list. This study is one component of an ongoing interdisciplinary study of San Francisco Bay. (USGS)

  5. Neogene geomorphic and climatic evolution of the central San Juan Mountains, Colorado: K/Ar age and stable isotope data on supergene alunite and jarosite from the Creede mining district

    USGS Publications Warehouse

    Rye, Robert O.; Bethke, Philip M.; Lanphere, Marvin A.; Steven, Thomas A.

    2000-01-01

    K/Ar age determinations or supergene alunite and jarosite, formed during Neogene weathering of the epithermal silver and base-metal ores of the Creede mining district, have been combined with geologic evidence to estimate the timing of regional uplift of the southern Rocky Mountains and related canyon cutting. In addition, oxygen and hydrogen isotopic studies suggest climate changes in the central San Juan Mountains during the past 5 m.y. Alunite [ideally (K,Na)Al3(SO4)2(OH)6] and jarosite [ideally KFe3(SO4)2(OH)6] can be dated by K/Ar or 40Ar/39Ar techniques and both contain OH and SO4 sites that enable four stable isotope analyses (δD, δ18OOH, and δ34S) to be made. This supergene alunite and jarosite formed by weathering of sulfide-rich ore bodies may record the evolution of the chemical and hydrologic processes affecting ancient oxidized acid ground water, as well as details of climate history and geomorphic evolution. Fine-grained (1-10 μm) supergene alunite and jarosite occur in minor fractures in the upper, oxidized parts of the 25 Ma sulfide-bearing veins of the Creede mining district, and jarosite also occurs in adjacent oxidized Ag-bearing clastic sediments. K/Ar ages for alunite range from 4.8 to 3.1 Ma, and for jarosite range from 2.6 to 0.9 Ma. The δD values for alunite and jarosite show opposite correlations with elevation, and values for jarosite correlate with age. Calculated δDH2O values of alunite fluids approach but are larger than those of present-day meteoric water. Calculated δDH2O values for jarosite fluids are more variable; the values of the youngest jarosites are lowest and are similar to those of present-day meteoric water in the district. The narrow δD-δ18OSO4 values of alunites reflects oxidation of sulfide below the water table. The greater range in these values for jarosites reflects oxidation of sulfide under vadose conditions. The ages of alunite mark the position of the paleo-water table at the end of a period of moderate

  6. 16. OVERALL VIEW TO THE NORTH OVER THE CENTRAL PART ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. OVERALL VIEW TO THE NORTH OVER THE CENTRAL PART OF THE INTERIOR, RECENTLY USED FOR A BASKETBALL, LOOKING NORTH TOWARDS THE ROLL-UP DOOR. - U.S. Coast Guard Air Station San Francisco, Warehouse, 1020 North Access Road, San Francisco, San Francisco County, CA

  7. 2. Historic American Buildings Survey San Francisco Chronicle Library San ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Historic American Buildings Survey San Francisco Chronicle Library San Francisco, California Year Built: 1834 Photo Taken: About 1925 VIEW FROM EAST - General Sherman Quarters, 464 Calle Principal, Monterey, Monterey County, CA

  8. History of San Marco

    NASA Technical Reports Server (NTRS)

    Caporale, A. J.

    1968-01-01

    A brief history is reported of the first San Marco project, a joint program of the United States and Italy. The Project was a three phase effort to investigate upper air density and associated ionosphere phenomena. The initial phase included the design and development of the spacecraft, the experiments, the launch complex, and a series of suborbital flights, from Wallops Island. The second phase, consisting of designing, fabricating, and testing a spacecraft for the first orbital mission, culminated in an orbital launch also from Wallops Island. The third phase consisted of further refining the experiments and spacecraft instrumentation and of establishing a full-bore scout complex in Kenya. The launch of San Marco B, in April 1967, from this complex into an equatorial orbit, concluded the initial San Marco effort.

  9. New evidence on the state of stress of the san andreas fault system.

    PubMed

    Zoback, M D; Zoback, M L; Mount, V S; Suppe, J; Eaton, J P; Healy, J H; Oppenheimer, D; Reasenberg, P; Jones, L; Raleigh, C B; Wong, I G; Scotti, O; Wentworth, C

    1987-11-20

    Contemporary in situ tectonic stress indicators along the San Andreas fault system in central California show northeast-directed horizontal compression that is nearly perpendicular to the strike of the fault. Such compression explains recent uplift of the Coast Ranges and the numerous active reverse faults and folds that trend nearly parallel to the San Andreas and that are otherwise unexplainable in terms of strike-slip deformation. Fault-normal crustal compression in central California is proposed to result from the extremely low shear strength of the San Andreas and the slightly convergent relative motion between the Pacific and North American plates. Preliminary in situ stress data from the Cajon Pass scientific drill hole (located 3.6 kilometers northeast of the San Andreas in southern California near San Bernardino, California) are also consistent with a weak fault, as they show no right-lateral shear stress at approximately 2-kilometer depth on planes parallel to the San Andreas fault. PMID:17839366

  10. Diazinon concentrations in the Sacramento and San Joaquin Rivers and San Francisco Bay, California, February 1993

    USGS Publications Warehouse

    Kuivila, Kathryn M.

    1993-01-01

    The distribution and possible biological effects of a dormant spray pesticide, diazinon, were examined by measuring pesticide concentrations and estimating toxicity using bioassays at a series of sites in the Sacramento-San Joaquin Delta and San Francisco Bay. Pulses of diazinon were observed in early February 1993 in the Sacramento and San Joaquin Rivers after heavy rains, with elevated concentrations measured for a few days to weeks at a time. The pulse of diazinon in the Sacramento River was followed from Sacramento through Suisun Bay, the eastward embayment of San Francisco Bay. In the central delta, well-defined pulses of diazinon were not observed at the Old and Middle River sites; instead, the concentrations steadily increased throughout February. Ceriodaphnia dubia mortality was 100% in water samples collected for 12 consecutive days (February 8-19) from the San Joaquin River at Vernalis. The bioassay mortality corresponded with the peak diazinon concentrations. Conversely, no toxicity was observed in water collected before or after peaks of diazinon concentration. Other pesticides present also could contribute to the toxicity.

  11. Plankton studies in San Francisco Bay; IV, Phytoplankton abundance and species composition, January 1980 - February 1981

    USGS Publications Warehouse

    Wong, R.L.; Cloern, J.E.

    1982-01-01

    Data are presented on the phytoplankton species composition and abundance in San Francisco Bay from January 1980 through February 1981. Phytoplankton were identified and enumerated in surface samples collected approximately every two weeks at selected stations in the main channel of the Bay, and at shoal stations in the central portion of South San Francisco Bay, San Pablo Bay, and Suisun Bay. Also reported are separate species lists for microphytoplankton (< 60 micrometers) and macrophytoplankton (> 60 micrometers). (Author 's abstract)

  12. SAN PEDRO WATERSHED DATABASE

    EPA Science Inventory

    The San Pedro River Geo-Data Browser was jointly developed by the Landscape Ecology Branch of the U.S. Environmental Protection Agency and the U.S. Department of Agriculture, Agricultural Research Service (Tucson, AZ). Since 1995, U.S. Environmental Protection Agency (EP A) and U...

  13. SAN PEDRO GEODATA BROWSER

    EPA Science Inventory

    The San Pedro Data Browser was developed by the Landscape Ecology Branch of the U.S. Environmental Protection Agency (Las Vegas, NV). The goal of the Landscape Sciences Program is to improve decision-making relative to natural and human resource management through the development...

  14. San Rafael Schools Exhibit.

    ERIC Educational Resources Information Center

    San Rafael City Schools, CA.

    The San Rafael City Schools' exhibit which was displayed at the 1983 Marin County Fair (California) is described. The exhibit, entitled "Education - A Real Winner," consisted of 12 display panels illustrating the following aspects of the school system: (1) early history from 1861; (2) present board and administration; (3) present schools and…

  15. Innovation in san francisco.

    PubMed

    Travis, J

    1992-08-01

    In San Francisco 2 weeks ago, AAAS and Science sponsored a new meeting, Science Innovation '92. The unusual gathering focused not on research results but on new techniques and instruments, particularly for biomedical science. As seen in the stories below, some of the most eye-catching innovations emerged at the intersection of physics and biology. PMID:17736460

  16. The Influence of the Geometry of the San Andreas Fault System on Earthquakes in California

    NASA Astrophysics Data System (ADS)

    Li, Q.; Liu, M.

    2004-12-01

    The San Andreas Fault is believed to be the main surface trace of the plate boundary between the North American and the Pacific plates. From 1800 to present, three large historical earthquakes (1857 M7.9, 1906 M8.25, and 1989 M7.1) ruptured the San Andreas Fault. At the same time, more than a dozen M>7.0 earthquakes occurred outside the main trace of the San Andreas Fault. Most of the off-main-trace large earthquakes were scattered in Southern California, whereas in northern and central California, earthquakes were clustered along the main trace of the San Andreas Fault. Such a seismic distribution may be related to the geometry of the San Andreas Fault, which is curved with a major bending in southern California. In this study, we constructed a finite element model to explore the influence of the geometry of the San Andreas Fault system on stress distribution and seismicity in California. In the model, the San Andreas Fault is simulated with a weak zone that obeys the Coulomb Friction Law. The model results show that along relative straight segments of the San Andreas Fault in northern and central California, fault slip on the main fault trace causes low level stresses in nearby regions. Along the bended San Andreas Fault in southern California, however, the relative plate motion causes significant off-main-trace stress buildup, consistent with the distribution of large historical earthquakes outside the San Andreas Fault.

  17. San Jose, Costa Rica

    NASA Technical Reports Server (NTRS)

    2007-01-01

    San Jose, capital city of Costa Rica, fills the valley between two steep mountain ranges. In this image made from data collected by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra satellite, visible, shortwave, and near-infrared wavelengths of light that the sensor observed have been combined to produce a false-color version of the scene in which vegetation is red, urban areas are silvery gray, water is dark blue, and clouds are white. The image was captured on February 8, 2007. San Jose is in the center of the image. The Rio Torres winds through downtown San Jose. Cartago, the much smaller colonial capital, sits in the lower right corner, while the city of Alajuela appears across the river, northwest of San Jose. The cities' manmade surfaces contrast sharply with the lushly vegetated landscape surrounding the city. Greenhouses are common in the region, and their glass roofs may be the brilliant white spots around the outer edges the cities. The long, straight runway of the Tobias Bolanos International Airport is visible as a dark line southeast of Alajuela. The landscape around the two cities shown here is rugged. Steep mountain peaks cast dark shadows across their leeward slopes. Patches of dark red vegetation on the mountains north of San Jose may be rainforest. Coffee plantations also cover the slopes of the mountains around the city. February is the dry season in Costa Rica. During the rainy season, from about April to November, clouds usually block the satellite's view of this tropical location. NASA image created by Jesse Allen, using data provided courtesy of Asaf Ullah and Tim Gubbels, SERVIR project.

  18. 77 FR 54811 - Safety Zone; TriRock San Diego, San Diego Bay, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    .... SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; TriRock San Diego, San Diego Bay, San Diego... Competitor Group is sponsoring the TriRock Triathlon, consisting of 2000 swimmers swimming a...

  19. 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.

  20. 1. Historic American Buildings Survey San Francisco Examiner Library EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey San Francisco Examiner Library EAST ELEVATION - Presidio of San Francisco, Old Station Hospital, Funston Avenue & Lincoln Boulevard, San Francisco, San Francisco County, CA

  1. A Study of Equality of Educational Opportunity for Mexican Americans in Nine School Districts of the San Antonio Area. United States Commission on Civil Rights, Staff Report.

    ERIC Educational Resources Information Center

    Commission on Civil Rights, Washington, DC.

    The report is the result of a study that investigated the extent to which Mexican American students in 9 independent school districts in metropolitan San Antonio, Texas, were afforded equal educational opportunities. The districts were Alamo Heights, East Central, Edgewood, Harlandale, North East, Northside, San Antonio, South San Antonio, and…

  2. BACTERIOPLANKTON DYNAMICS IN NORTHERN SAN FRANCISCO BAY: ROLE OF PARTICLE ASSOCIATION AND SEASONAL FRESHWATER FLOW

    EPA Science Inventory

    Bacterioplankton abundance and metabolic characteristics were observed in northern San Francisco Bay, California, during spring and summer 1996 at three sites: Central Bay, Suisun Bay, and the Sacramento River. These sites spanned a salinity gradient from marine to freshwater, an...

  3. 77 FR 34988 - Notice of Inventory Completion: San Diego State University, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    ... National Park Service Notice of Inventory Completion: San Diego State University, San Diego, CA AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: San Diego State University Archeology Collections... associated funerary objects may contact San Diego State University Archeology Collections Management...

  4. Photocopy of drawing located at National Archives, San Bruno, California ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of drawing located at National Archives, San Bruno, California (Navy # 121-A-23). PW Minsy Building 121 record ground floor plan; N.D. - Mare Island Naval Shipyard, Central Power Plant, California Avenue, norhtwest corner of California Avenue & Seventh Street, Vallejo, Solano County, CA

  5. High-resolution marine seismic reflection data from the San Francisco Bay area

    USGS Publications Warehouse

    Childs, Jonathan R.; Hart, Patrick; Bruns, Terry R.; Marlow, Michael S.; Sliter, Ray

    2000-01-01

    Between 1993 and 1997, the U.S. Geological Survey acquired high-resolution, marine seismic-reflection profile data across submerged portions of known and inferred upper crustal fault zones throughout the greater San Francisco Bay area. Surveys were conducted oversouth San Francisco Bay in the vicinity of the San Bruno shoal (roughly between the San Francisco and Oakland airports), over the offshore extension of the San Andreas fault system west of the Golden Gate, over the Hayward fault to Rodgers Creek fault step-over in San Pablo Bay, and over the Kirby Hills fault where it crosses the western Sacramento Delta. Reconnaissance profiles were acquired elsewhere throughout the San Francisco and San Pablo Bays. These data were acquired by the U.S. Geological Survey, Western Coastal and Marine Geology Team, under the auspices of the Central California/San Francisco Bay Earthquake Hazards Project. Analysis and interpretation of some of these profiles has been published by Marlow and others (1996, 1999). Further analysis and interpretation of these data are available in a USGS. Professional Paper Crustal Structure of the Coastal and Marine San Francisco Bay Region, T. Parsons, editor, http://geopubs.wr.usgs.gov/prof-paper/pp1658/ [link added 2012 mfd].

  6. SAN PEDRO PARKS WILDERNESS, NEW MEXICO.

    USGS Publications Warehouse

    Santos, Elmer S.; Weisner, Robert C.

    1984-01-01

    The San Pedro Parks Wilderness occupies 62. 7 sq mi of the Santa Fe National Forest in north-central New Mexico. Several copper mines, many copper prospects, and a few uranium prospects occur in sedimentary units in the vicinity of the wilderness. These units, where they extend into the wilderness, constitute only a small volume of rock and, judging from analyses of samples and from field observations, are devoid of copper and uranium concentration. Prospects on several of about 65 mining claims within the wilderness revealed concentrations of manganese or barite but only in volumes too small to be considered a demonstrated resource.

  7. SAN DIEGO ZOO EDUCATIONAL PROGRAM.

    ERIC Educational Resources Information Center

    San Diego County Dept. of Education, CA.

    A BROCHURE GEARED TO HELP TEACHERS AND STUDENTS IN THE SAN DIEGO AREA TAKE FULL ADVANTAGE OF THE EDUCATIONAL RESOURCES OF THE SAN DIEGO ZOO IS PRESENTED. THE EDUCATION DEPARTMENT OF THE ZOO EMPLOYS TWO FULL-TIME TEACHERS AND A DRIVER-GUIDE. THE PROGRAM OFFERED IS BRIEFLY DESCRIBED--(1) IN "PRESCHOOL AND FIRST GRADE," INTRODUCTIONS ARE MADE TO…

  8. Sources of groundwater based on Helium analyses in and near the freshwater/saline-water transition zone of the San Antonio segment of the Edwards Aquifer, South-Central Texas, 2002-03

    USGS Publications Warehouse

    Hunt, Andrew G.; Lambert, Rebecca B.; Fahlquist, Lynne

    2010-01-01

    This report evaluates dissolved noble gas data, specifically helium-3 and helium-4, collected by the U.S. Geological Survey, in cooperation with the San Antonio Water System, during 2002-03. Helium analyses are used to provide insight into the sources of groundwater in the freshwater/saline-water transition zone of the San Antonio segment of the Edwards aquifer. Sixty-nine dissolved gas samples were collected from 19 monitoring wells (categorized as fresh, transitional, or saline on the basis of dissolved solids concentration in samples from the wells or from fluid-profile logging of the boreholes) arranged in five transects, with one exception, across the freshwater/saline-water interface (the 1,000-milligrams-per-liter dissolved solids concentration threshold) of the Edwards aquifer. The concentration of helium-4 (the dominant isotope in atmospheric and terrigenic helium) in samples ranged from 63 microcubic centimeters per kilogram at standard temperature (20 degrees Celsius) and pressure (1 atmosphere) in a well in the East Uvalde transect to 160,587 microcubic centimeters per kilogram at standard temperature and pressure in a well in the Kyle transect. Helium-4 concentrations in the 10 saline wells generally increase from the western transects to the eastern transects. Increasing helium-4 concentrations from southwest to northeast in the transition zone, indicating increasing residence time of groundwater from southwest to northeast, is consistent with the longstanding conceptualization of the Edwards aquifer in which water recharges in the southwest, flows generally northeasterly (including in the transition zone, although more slowly than in the fresh-water zone), and discharges at major springs in the northeast. Excess helium-4 was greater than 1,000 percent for 60 of the 69 samples, indicating that terrigenic helium is largely present and that most of the excess helium-4 comes from sources other than the atmosphere. The helium data of this report cannot be

  9. Perspective View, San Andreas Fault

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The prominent linear feature straight down the center of this perspective view is California's famous San Andreas Fault. The image, created with data from NASA's Shuttle Radar Topography Mission (SRTM), will be used by geologists studying fault dynamics and landforms resulting from active tectonics. This segment of the fault lies west of the city of Palmdale, Calif., about 100 kilometers (about 60 miles) northwest of Los Angeles. The fault is the active tectonic boundary between the North American plate on the right, and the Pacific plate on the left. Relative to each other, the Pacific plate is moving away from the viewer and the North American plate is moving toward the viewer along what geologists call a right lateral strike-slip fault. Two large mountain ranges are visible, the San Gabriel Mountains on the left and the Tehachapi Mountains in the upper right. Another fault, the Garlock Fault lies at the base of the Tehachapis; the San Andreas and the Garlock Faults meet in the center distance near the town of Gorman. In the distance, over the Tehachapi Mountains is California's Central Valley. Along the foothills in the right hand part of the image is the Antelope Valley, including the Antelope Valley California Poppy Reserve. The data used to create this image were acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000.

    This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

    SRTM uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space

  10. 78 FR 58878 - Safety Zone; San Diego Shark Fest Swim; San Diego Bay, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking A... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego Shark Fest Swim; San Diego Bay... Diego Shark Fest Swim. This safety zone is necessary to provide for the safety of the participants,...

  11. 78 FR 34895 - Safety Zone; San Francisco Independence Day Fireworks Display, San Francisco Bay, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; San Francisco Independence Day Fireworks Display, San.... SUMMARY: The Coast Guard will enforce the safety zones for the San Francisco Independence Day Fireworks... INFORMATION: The Coast Guard will enforce the San Francisco Independence Day Fireworks Display safety...

  12. 75 FR 55975 - Safety Zone; San Diego Harbor Shark Fest Swim; San Diego Bay, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-15

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego Harbor Shark Fest Swim; San Diego... of a bay swim in San Diego Harbor. This temporary safety zone is necessary to provide for the safety... of the San Diego Bay swim in sufficient time to issue an NPRM without delaying this rulemaking....

  13. Central California Action Associates, Inc.

    ERIC Educational Resources Information Center

    Sortor, Maia, Comp.

    The overall goal of the Central California Action Associates Inc. (CCAA) program is to provide basic education and pre-vocational training so that migrant and seasonal adult farm workers will be able to upgrade their economic and social lives. Without increased educational attainment, the San Joaquin Valley farm workers face a grim future because…

  14. Geologic Map of the San Luis Quadrangle, Costilla County, Colorado

    USGS Publications Warehouse

    Machette, Michael N.; Thompson, Ren A.; Drenth, Benjamin J.

    2008-01-01

    The map area includes San Luis and the primarily rural surrounding area. San Luis, the county seat of Costilla County, is the oldest surviving settlement in Colorado (1851). West of the town are San Pedro and San Luis mesas (basalt-covered tablelands), which are horsts with the San Luis fault zone to the east and the southern Sangre de Cristo fault zone to the west. The map also includes the Sanchez graben (part of the larger Culebra graben), a deep structural basin that lies between the San Luis fault zone (on the west) and the central Sangre de Cristo fault zone (on the east). The oldest rocks exposed in the map area are the Pliocene to upper Oligocene basin-fill sediments of the Santa Fe Group, and Pliocene Servilleta Basalt, a regional series of 3.7?4.8 Ma old flood basalts. Landslide deposits and colluvium that rest on sediments of the Santa Fe Group cover the steep margins of the mesas. Rare exposures of the sediment are comprised of siltstones, sandstones, and minor fluvial conglomerates. Most of the low ground surrounding the mesas and in the graben is covered by surficial deposits of Quaternary age. The alluvial deposits are subdivided into three Pleistocene-age units and three Holocene-age units. The oldest Pleistocene gravel (unit Qao) forms extensive coalesced alluvial fan and piedmont surfaces, the largest of which is known as the Costilla Plain. This surface extends west from San Pedro Mesa to the Rio Grande. The primary geologic hazards in the map area are from earthquakes, landslides, and localized flooding. There are three major fault zones in the area (as discussed above), and they all show evidence for late Pleistocene to possible Holocene movement. The landslides may have seismogenic origins; that is, they may be stimulated by strong ground shaking during large earthquakes. Machette and Thompson based this geologic map entirely on new mapping, whereas Drenth supplied geophysical data and interpretations.

  15. Continuity of the San Andreas Fault at San Gorgonio Pass

    NASA Astrophysics Data System (ADS)

    Carena, S.; Suppe, J.

    2002-12-01

    The San Andreas fault at San Gorgonio Pass does not have a clear surface trace and is considered aseismic. Our findings suggest in fact that the existence of a through-going vertical or near-vertical San Andreas fault between Yucaipa and North Palm Springs is highly unlikely. We mapped over 70 faults in the San Gorgonio Pass-San Bernardino Mountains region using the catalog of 43,500 relocated 1975-1998 earthquakes of Richards-Dinger and Shearer (2000). A clustering algorithm was applied to the relocated earthquakes in order to obtain tighter earthquake clouds and thus better-defined fault surfaces. The earthquakes were then imported into Gocad, a 3D modeling software that allowed us to separate earthquakes into coplanar clusters associated with different faults and fault strands and to fit optimized surfaces to them. We also used the catalog of 13,000 focal mechanisms of Hauksson (2000) to confirm the nature of the mapped faults. We were able to constrain the 3D geometry of the San Andreas fault near San Gorgonio Pass from the 3D geometry of the fault network surrounding it. None of these faults show any displacement due to an hypothetical sub-vertical San Andreas. The San Andreas fault must therefore rotate to much shallower dips, or lose its continuity at depths between 3 and 15 km The most likely configuration is the one where the San Andreas fault merges into the shallow-dipping San Gorgonio Pass thrust W of North Palm Springs. Strike-slip motion is taken up by both the thrust (the slip vector on the N. Palm Springs segment is reverse/right-lateral strike-slip) and by a series of NW striking faults in the footwall of the thrust. The W termination of the most active part of the San Gorgonio Pass thrust coincides with one of these footwall faults at depth, and with the south bend in the San Andreas fault strand N of Banning. This boundary also marks a change in the stress field, with a dominant strike-slip regime to the E (and localized thrusting between San

  16. San Francisco Bay Sediment Concentration

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This March 3, 2000 image of the San Francisco Bay region shows a 60 by 75 kilometer Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image in band 1 (near infrared, 0.52-0.60 microns). The color coded suspended sediment image was created from band 1 by blacking out the land, and assigning colors to the relative brightnesses in the water. High values were colored white, then red, yellow, green, and blue. Brighter values in band 1 indicate higher sediment load in the water. The highest values are in Suisun and San Pablo Bays, into which the Sacramento River empties, and along the coast of the San Francisco Peninsula. The Pacific Ocean and San Francisco Bay water are relatively clear. Image courtesy ASTER Science Team

  17. Jean Parker School, San Francisco.

    ERIC Educational Resources Information Center

    Larson, Soren

    1999-01-01

    Describes the post-earthquake renovation of a San Francisco urban elementary school that preserved its historical detail within a modern replacement. Design features are detailed; photos and a floorplan are included. (GR)

  18. 1974 meeting in san antonio.

    PubMed

    Bowden, V

    1974-01-01

    San Antonio will be the site of the 1974 MLA Annual Meeting, and the program will emphasize expanding the role of health science libraries. Tours, as well as activities available in San Antonio, are described. The Convention Center itself, and the convention hotel, the Hilton Palacio del Rio, are mentioned, and other accommodations are listed. Social events are discussed, and the city's many interesting restaurants are noted. PMID:16017664

  19. South Central California Coastline and Channel Islands

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This distant and very oblique image of the south Central California Coastline and Channel Islands (35.0N, 119.0W) offers a spectacular and scenic view of the southern west coast, the central San Joaquin Valley, the entire Sierra Nevada Range and across the southwest to the Rocky Mountains on the horizon.

  20. Northern California near San Francisco

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A part of northern California centered near San Francisco Bay (38.0N, 122.0W) photographed at 3 p.m. January 1, 1974, from the Skylab space station in Earth orbit. This near vertical view encompasses the coastline from Monteray Bay (right) to about 50 miles north of Point Reyes (left) and includes, from bottom to top, San Francisco Bay (center), Sacramento Valley (left center), San Joaquin Valley (right center), and the snow-covered Sierra Nevada. Afternoon shadows sharply delineate a valley which parallels San Francisco Bay, crosses Point Reyes, and lies between the Bay and the Pacific coastline. This valley marks the location of the San Andreas Fault. Forces acting on the crust are causing the land west (bottom) of the fault line to move north relative to land on the east side. Agricultural areas in the Sacramento and San Joaquin Valleys are indicated by the tan areas which are easily discerned in contrast to the green-gray background.

  1. 41. Historic American Buildings Survey San Francisco CallBulletin Library San ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. Historic American Buildings Survey San Francisco Call-Bulletin Library San Francisco, California INTERIOR VIEW OF CHURCH BEFORE RESTORATION - 1934 - Mission San Carlos Borromeo, Rio Road & Lausen Drive, Carmel-by-the-Sea, Monterey County, CA

  2. DISTRIBUTION AND COMPOSITION OF DISSOLVED AND PARTICULATE ORGANIC CARBON IN NORTHERN SAN FRANCISCO BAY DURING LOW FRESHWATER FLOW CONDITIONS

    EPA Science Inventory

    The distribution of organic matter was studied in northern San Francisco Bay monthly through spring and summer 1996 along the salinity gradient from the Sacramento River to Central Bay. Dissolved constituents included monosaccharides (MONO), total carbohydrates (TCHO), dissolved ...

  3. Interior, view of central hall staircase showing bracketed stair, square ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior, view of central hall staircase showing bracketed stair, square balusters and fluted newel post, camera facing southwest - Naval Training Station, Senior Officers' Quarters District, Quarters No. 4, Naval Station Treasure Island, 4 Whiting Way, Yerba Buena Island, San Francisco, San Francisco County, CA

  4. Environmental setting of the San Joaquin-Tulare basins, California

    USGS Publications Warehouse

    Gronberg, JoAnn A.; Dubrovsky, Neil M.; Kratzer, Charles R.; Domagalski, Joseph L.; Brown, Larry R.; Burow, Karen R.

    1998-01-01

    The National Water-Quality Assessment Program for the San Joaquin- Tulare Basins began in 1991 to study the effects of natural and anthropogenic influences on the quality of ground water, surface water, biology, and ecology. The San Joaquin-Tulare Basins study unit, which covers approximately 31,200 square miles in central California, is made up of the San Joaquin Valley, the eastern slope of the Coast Ranges to the west, and the western slope of the Sierra Nevada to the east. The sediments of the San Joaquin Valley can be divided into alluvial fans and basin deposits. The San Joaquin River receives water from tributaries draining the Sierra Nevada and Coast Ranges, and except for streams discharging directly to the Sacramento-San Joaquin Delta, is the only surface- water outlet from the study unit. The surface-water hydrology of the San Joaquin-Tulare Basins study unit has been significantly modified by development of water resources. Almost every major river entering the valley from the Sierra Nevada has one or more reservoirs. Almost every tributary and drainage into the San Joaquin River has been altered by a network of canals, drains, and wasteways. The Sierra Nevada is predominantly forested, and the Coast Ranges and the foothills of the Sierra Nevada are predominately rangeland. The San Joaquin Valley is dominated by agriculture, which utilized approximately 14.7 million acre-feet of water and 597 million pounds active ingredient of nitrogen and phosphorus fertilizers in 1990, and 88 million pounds active ingredient of pesticides in 1991. In addition, the livestock industry contributed 318 million pounds active ingredient of nitrogen and phosphorus from manure in 1987. This report provides the background information to assess the influence of these and other factors on water quality and to provide the foundation for the design and interpretation of all spatial data. These characterizations provide a basis for comparing the influences of human activities

  5. Sand waves at the mouth of San Francisco Bay, California

    USGS Publications Warehouse

    Gibbons, Helen; Barnard, Patrick L.

    2007-01-01

    The U.S. Geological Survey; California State University, Monterey Bay; U.S. Army Corps of Engineers; National Oceanic and Atmospheric Administration; and Center for Integrative Coastal Observation, Research and Education partnered to map central San Francisco Bay and its entrance under the Golden Gate Bridge using multibeam echosounders. View eastward, through the Golden Gate into central San Francisco Bay. Depth of sea floor color coded: red (less than 10 m deep) to purple (more than 100 m deep). Land from USGS digital orthophotographs (DOQs) overlaid on USGS digital elevation models (DEMs). Sand waves in this view average 6 m in height and 80 m from crest to crest. Golden Gate Bridge is about 2 km long. Vertical exaggeration is approximately 4x for sea floor, 2x for land.

  6. Perspective View, San Andreas Fault

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The prominent linear feature straight down the center of this perspective view is the San Andreas Fault in an image created with data from NASA's shuttle Radar Topography Mission (SRTM), which will be used by geologists studying fault dynamics and landforms resulting from active tectonics. This segment of the fault lies west of the city of Palmdale, California, about 100 kilometers (about 60 miles) northwest of Los Angeles. The fault is the active tectonic boundary between the North American plate on the right, and the Pacific plate on the left. Relative to each other, the Pacific plate is moving away from the viewer and the North American plate is moving toward the viewer along what geologists call a right lateral strike-slip fault. This area is at the junction of two large mountain ranges, the San Gabriel Mountains on the left and the Tehachapi Mountains on the right. Quail Lake Reservoir sits in the topographic depression created by past movement along the fault. Interstate 5 is the prominent linear feature starting at the left edge of the image and continuing into the fault zone, passing eventually over Tejon Pass into the Central Valley, visible at the upper left.

    This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (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 the Space Shuttle Endeavour in 1994

  7. Mantle fluids in the San Andreas fault system, California

    USGS Publications Warehouse

    Kennedy, B.M.; Kharaka, Y.K.; Evans, William C.; Ellwood, A.; DePaolo, D.J.; Thordsen, J.; Ambats, G.; Mariner, R.H.

    1997-01-01

    Fluids associated with the San Andreas and companion faults n central and south-central California have high 3He/4He ratios. The lack of correlation between helium isotopes and fluid chemistry or local geology requires that fluids enter the fault system from the mantle. Mantle fluids passing through the ductile lower crust must enter the brittle fault zone at or near lithostatic pressures; estimates of fluid flux based on helium isotopes suggest that they may thus contribute directly to fault-weakening high-fluid pressures at seismogenic depths.

  8. Mantle fluids in the San Andreas fault system, California

    SciTech Connect

    Kennedy, B.M.; Kharaka, Y.K.; Evans, W.C.

    1997-11-14

    Fluids associated with the San Andreas and companion faults in central and south-central California have high {sup 3}He/{sup 4}He ratios. The lack of correlation between helium isotopes and fluid chemistry or local geology requires that fluids enter the fault system from the mantle. Mantle fluids passing through the ductile lower crust must enter the brittle fault zone at or near lithostatic pressures; estimates of fluid flux based on helium isotopes suggest that they may thus contribute directly to fault-weakening high-fluid pressures at seismogenic depths. 31 refs., 4 figs.

  9. California State Waters Map Series: offshore of San Francisco, California

    USGS Publications Warehouse

    Cochrane, Guy R.; Johnson, Samuel Y.; Dartnell, Peter; Greene, H. Gary; Erdey, Mercedes D.; Golden, Nadine E.; Hartwell, Stephen R.; Endris, Charles A.; Manson, Michael W.; Sliter, Ray W.; Kvitek, Rikk G.; Watt, Janet Tilden; Ross, Stephanie L.; Bruns, Terry R.

    2015-01-01

    Circulation over the continental shelf in the Offshore of San Francisco map area is dominated by the southward-flowing California Current, an eastern limb of the North Pacific Gyre that flows from Oregon to Baja California. At its midpoint offshore of central California, the California Current transports subarctic surface waters southeastward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the California Current, generate coastal upwelling. Ocean temperatures offshore of central California have increased over the past 50 years, driving an ecosystem shift from the productive subarctic regime towards a depopulated subtropical environment.

  10. 1. VIEW LOOKING SOUTHWEST AT TURNOUT ON SAN TAN FLOODWATER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW LOOKING SOUTHWEST AT TURNOUT ON SAN TAN FLOOD-WATER CANAL TO SAN TAN INDIAN CANAL - San Carlos Irrigation Project, San Tan Flood Water Canal, North Side of Gila River, Coolidge, Pinal County, AZ

  11. South San Francisco Bay, California

    USGS Publications Warehouse

    Dartnell, Peter; Gibbons, Helen

    2007-01-01

    View eastward. Elevations in mapped area color coded: purple (approx 15 m below sea level) to red-orange (approx 90 m above sea level). South San Francisco Bay is very shallow, with a mean water depth of 2.7 m (8.9 ft). Trapezoidal depression near San Mateo Bridge is where sediment has been extracted for use in cement production and as bay fill. Land from USGS digital orthophotographs (DOQs) overlaid on USGS digital elevation models (DEMs). Distance across bottom of image approx 11 km (7 mi); vertical exaggeration 1.5X.

  12. Update: San Andreas Fault experiment

    NASA Technical Reports Server (NTRS)

    Christodoulidis, D. C.; Smith, D. E.

    1984-01-01

    Satellite laser ranging techniques are used to monitor the broad motion of the tectonic plates comprising the San Andreas Fault System. The San Andreas Fault Experiment, (SAFE), has progressed through the upgrades made to laser system hardware and an improvement in the modeling capabilities of the spaceborne laser targets. Of special note is the launch of the Laser Geodynamic Satellite, LAGEOS spacecraft, NASA's only completely dedicated laser satellite in 1976. The results of plate motion projected into this 896 km measured line over the past eleven years are summarized and intercompared.

  13. Resistance Management for San Jose Scale (Hemiptera: Diaspididae).

    PubMed

    Buzzetti, K; Chorbadjian, R A; Nauen, R

    2015-12-01

    The San Jose scale Diaspidiotus perniciosus Comstock is one of the most important pests of deciduous fruit trees. The major cause of recent outbreaks in apple orchards is thought to be the development of insecticide resistance, specifically organophosphates. The first report was given in North America, and now, in Chile. In the present study, San Jose scale populations collected from two central regions of Chile were checked for their susceptibility to different mode of action insecticides in order to establish alternatives to manage this pest. No evidence of cross resistance between organophosphates insecticides and acetamiprid, buprofezin, pyriproxyfen, spirotetramat, sulfoxaflor, or thiacloprid was found. Baselines of LC50-LC95 for different life stages of San Jose scale are given, as reference to future studies of resistance monitoring. The systemic activity of acetamiprid, spirotetramat, and thiacloprid was higher than the contact residue effect of these compounds. For sulfoxaflor, both values were similar. Program treatments including one or more of these compounds are compared in efficacy and impact on resistance ratio values. In order to preserve new insecticides as an important tool to control San Jose scale, resistance management programs should be implemented, considering insecticide mode of action classes alternated or mixed. PMID:26470382

  14. 77 FR 28771 - Safety Zone; San Francisco Giants Fireworks Display, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-16

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; San Francisco Giants Fireworks Display, San Francisco, CA... enforce the safety zone for the San Francisco Giants Fireworks Display in the Captain of the Port, San... life and property of the maritime public from the hazards associated with the fireworks display....

  15. 78 FR 20792 - Safety Zone; San Francisco Giants Fireworks Display, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; San Francisco Giants Fireworks Display, San Francisco, CA... enforce the safety zone for the San Francisco Giants Fireworks Display in the Captain of the Port, San... life and property of the maritime public from the hazards associated with the fireworks display....

  16. 77 FR 15260 - Safety Zone; San Francisco Fireworks Display, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-15

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; San Francisco Fireworks Display, San Francisco, CA AGENCY... safety zone for the San Francisco Giants Fireworks Display in the Captain of the Port, San Francisco area... and property of the maritime public from the hazards associated with the fireworks display. During...

  17. 76 FR 38305 - Safety Zone; San Francisco Chronicle Fireworks Display, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-30

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; San Francisco Chronicle Fireworks Display, San Francisco... will enforce the safety zones for the annual San Francisco Chronicle Fireworks Display (Independence Day Celebration for the City of San Francisco Fireworks). This action is necessary to control...

  18. 77 FR 42647 - Safety Zone: San Diego Symphony POPS Fireworks; San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    ... FR Federal Register NPRM Notice of Proposed Rulemaking A. Regulatory History and Information The... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone: San Diego Symphony POPS Fireworks; San... establishing a safety zone on the navigable waters of San Diego Bay in support of the San Diego Symphony...

  19. 75 FR 77756 - Safety Zone; San Diego Parade of Lights Fireworks, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-14

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego Parade of Lights Fireworks, San... San Diego Parade of Lights Fireworks Displays on December 12 and December 19, 2010. This safety zone... San Diego Parade of Lights Fireworks Displays, which will include two fireworks...

  20. 75 FR 39166 - Safety Zone; San Francisco Giants Baseball Game Promotion, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-08

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Francisco Giants Baseball Game... Bay off San Francisco, CA in support of the San Francisco Giants Baseball Game Promotion. This safety... Giants will sponsor the San Francisco Giants Baseball Game Promotion on July 16, 2010, on the...

  1. 77 FR 37603 - Safety Zone; San Francisco Independence Day Fireworks Display, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-22

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; San Francisco Independence Day Fireworks Display, San... Guard will enforce the safety zones for the San Francisco Independence Day Fireworks Display in the... INFORMATION: The Coast Guard will enforce the San Francisco Independence Day Fireworks Display safety...

  2. 406. Delineator Unknown April 19, 1933 ELEVATION STUDY FOR SAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    406. Delineator Unknown April 19, 1933 ELEVATION STUDY FOR SAN FRANCISCO ANCHORAGE; SAN FRANCISCO - OAKLAND BAY BRIDGE; BOARD OF CONSULTING ARCHITECTS; TIMOTHY L. PFLUEGER, ARTHUR BROWN JR., JOHN J. DONOVAN; SHEET 23 - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  3. A Spanish Borderlands Community: San Antonio.

    ERIC Educational Resources Information Center

    Teja, Jesus F. de la

    2000-01-01

    Discusses the founding of San Antonio, originally San Antonio de Bexar, which, in 1718, came into being as a military settlement involved in Spanish imperial defensive measures. Focuses on the development and continued growth of San Antonio, Texas's most populous city in the 19th century. (CMK)

  4. San Francisco Bay Sand Mining Resource Evaluation and Impact Analysis

    NASA Astrophysics Data System (ADS)

    Fenical, S.; Tirindelli, M.; Sicular, D.; Gragg, J.; Huitt, C.

    2012-12-01

    This paper presents results of the evaluation of potential future sand resources within certain Central San Francisco Bay (Central Bay) sand mining lease areas, as well as the potential impacts of further mining these areas for a ten-year period. The study consisted of morphological analysis using field measurements and hydrodynamic modeling, and covered a wide spectrum of physical processes including tidal and river circulation, salinity, sediment transport, and morphology. The study was conducted within the framework of an Environmental Impact Report (EIR) prepared by the California State Lands Commission (CSLC) as part of the discretionary approval process for issuing new mining leases. The results of the morphological analysis indicate a measurable depletion of sand resources in the Central Bay lease areas during the period 1997-2008, and that for the purposes of the proposed ten-year mining lease renewal, sand mining resources in Central Bay are largely limited to material already in place. The morphological analysis results also indicate that the proposed additional ten years of sand mining in the Central Bay lease areas are not likely to cause a significant impact on sediment transport and budgets in areas outside the vicinity of the lease areas, such as the San Francisco Bar, Ocean Beach, etc. Numerical modeling results, including particle tracking exercises, do indicate a net seaward transport of sand, and that a linkage exists between the mining areas and offshore areas (San Francisco Bar, Ocean Beach, etc). However, the modeling results demonstrate that the linkage is weak, and that any measurable changes in hydrodynamics, salinity and sediment transport/morphology caused by the mining activities are likely to be confined to the vicinity of the mining areas.

  5. Seeking Justice in San Francisco

    ERIC Educational Resources Information Center

    Pascopella, Angela

    2010-01-01

    This article discusses the life of Carlos A. Garcia, superintendent at the San Francisco Unified School District. Garcia was born in Chicago, but his parents shortly thereafter moved back to their homeland of Mexico for a few years. When Garcia was almost 5, his family moved to Los Angeles, where his parents worked in factories and Garcia was…

  6. 33 CFR 165.1185 - Regulated Navigation Area; San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin River, and..., Sacramento River, San Joaquin River, and connecting waters in California. (a) Location. All waters of San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin River,...

  7. 33 CFR 165.1185 - Regulated Navigation Area; San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin River, and..., Sacramento River, San Joaquin River, and connecting waters in California. (a) Location. All waters of San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin River,...

  8. 33 CFR 165.1185 - Regulated Navigation Area; San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin River, and..., Sacramento River, San Joaquin River, and connecting waters in California. (a) Location. All waters of San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin River,...

  9. 33 CFR 165.1185 - Regulated Navigation Area; San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin River, and..., Sacramento River, San Joaquin River, and connecting waters in California. (a) Location. All waters of San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin River,...

  10. Danggui-Shaoyao-San: New Hope for Alzheimer's Disease.

    PubMed

    Fu, Xin; Wang, QiuHong; Wang, ZhiBin; Kuang, HaiXue; Jiang, Pinghui

    2016-08-01

    Danggui-Shaoyao-San (DSS), also called Toki-shakuyaku-san (TJ-23) or Dangguijakyak-san (DJS), is a well-known herbal formula (Angelica sinensis (Oliv.) Diels., Ligusticum chuanxiong Hort., Paeonia lactiflora pall., Poria cocos (Schw.) Wolf, Alisma orientalis (Sam.) Juzep., Atractylodes macrocephala Koidz.), which has been widely used in oriental countries for the treatment of various gynecological diseases. Recent studies show that DSS has an effect on free radical-mediated neurological diseases and exhibits anti-inflammatory and antioxidant activities and reduces cell apoptosis in the hippocampus. In addition, DSS mediates the modulation of central monoamine neurotransmitter systems and ameliorates dysfunction of the central cholinergic nervous system and scopolamine-induced decrease in ACh levels. DSS improves the function of the dopaminergic, adrenergic, and serotonergic nervous systems. Interestingly, DSS can alleviate cognitive dysfunction of Alzheimer's disease (AD) patients, suggesting that it is a useful therapeutic agent for AD. This paper reviews the mechanism of DSS for the treatment of AD. PMID:27493835

  11. Danggui-Shaoyao-San: New Hope for Alzheimer's Disease

    PubMed Central

    Fu, Xin; Wang, QiuHong; Wang, ZhiBin; Kuang, HaiXue; Jiang, Pinghui

    2016-01-01

    Danggui-Shaoyao-San (DSS), also called Toki-shakuyaku-san (TJ-23) or Dangguijakyak-san (DJS), is a well-known herbal formula (Angelica sinensis (Oliv.) Diels., Ligusticum chuanxiong Hort., Paeonia lactiflora pall., Poria cocos (Schw.) Wolf, Alisma orientalis (Sam.) Juzep., Atractylodes macrocephala Koidz.), which has been widely used in oriental countries for the treatment of various gynecological diseases. Recent studies show that DSS has an effect on free radical-mediated neurological diseases and exhibits anti-inflammatory and antioxidant activities and reduces cell apoptosis in the hippocampus. In addition, DSS mediates the modulation of central monoamine neurotransmitter systems and ameliorates dysfunction of the central cholinergic nervous system and scopolamine-induced decrease in ACh levels. DSS improves the function of the dopaminergic, adrenergic, and serotonergic nervous systems. Interestingly, DSS can alleviate cognitive dysfunction of Alzheimer's disease (AD) patients, suggesting that it is a useful therapeutic agent for AD. This paper reviews the mechanism of DSS for the treatment of AD. PMID:27493835

  12. ASTER Flyby of San Francisco

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Advanced Spaceborne Thermal Emission and Reflection radiometer, ASTER, is an international project: the instrument was supplied by Japan's Ministry of International Trade and Industry. A joint US/Japan science team developed algorithms for science data products, and is validating instrument performance. With its 14 spectral bands, extremely high spatial resolution, and 15 meter along-track stereo capability, ASTER is the zoom lens of the Terra satellite. The primary mission goals are to characterize the Earth's surface; and to monitor dynamic events and processes that influence habitability at human scales. ASTER's monitoring and mapping capabilities are illustrated by this series of images of the San Francisco area. The visible and near infrared image reveals suspended sediment in the bays, vegetation health, and details of the urban environment. Flying over San Francisco (3.2MB) (high-res (18.3MB)), we see the downtown, and shadows of the large buildings. Past the Golden Gate Bridge and Alcatraz Island, we cross San Pablo Bay and enter Suisun Bay. Turning south, we fly over the Berkeley and Oakland Hills. Large salt evaporation ponds come into view at the south end of San Francisco Bay. We turn northward, and approach San Francisco Airport. Rather than landing and ending our flight, we see this is as only the beginning of a 6 year mission to better understand the habitability of the world on which we live. For more information: ASTER images through Visible Earth ASTER Web Site Image courtesy of MITI, ERSDAC, JAROS, and the U.S./Japan ASTER Science Team

  13. Summary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2005

    USGS Publications Warehouse

    Buchanan, Paul A.; Lionberger, Megan A.

    2007-01-01

    Suspended-sediment concentration data were collected by the U.S. Geological Survey in San Francisco Bay during water year 2005 (October 1, 2004-September 30, 2005). Optical sensors and water samples were used to monitor suspended-sediment concentration at two sites in Suisun Bay, three sites in San Pablo Bay, two sites in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned at two depths at most sites. Water samples were collected periodically and analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the output of the optical sensors so that a record of suspended-sediment concentrations could be derived. This report presents the data-collection methods used and summarizes, in graphs, the suspended-sediment concentration data collected from October 2004 through September 2005. Calibration curves and plots of the processed data for each sensor also are presented.

  14. Ancient blue oaks reveal human impact on San Francisco Bay salinity

    USGS Publications Warehouse

    Stahle, David W.; Therrell, Matthew D.; Cleaveland, Malcolm K.; Cayan, Daniel R.; Dettinger, Michael D.; Knowles, Noah

    2001-01-01

    San Francisco Bay is one of the most important estuaries on the west coast of the Americas. Its water quality is controlled primarily by streamflow from the Sacramento and San Joaquin rivers. In fact, freshwater inflow from the Sacramento-San Joaquin Delta explains 86% of the salinity variability at the mouth of the San Francisco Bay estuary [Peterson et al., 1989]. The massive diversion of streamflow by the California State Water Project and the Central Valley Project, part of the largest manmade water control system on Earth [Reisner, 1988], has raised salinity in the estuary on daily, seasonal, and annual timescales [Nichols et al., 1986; Peterson et al., 1989].

  15. Lithologic and physicochemical properties and hydraulics of flow in and near the freshwater/saline-water transition zone, San Antonio segment of the Edwards aquifer, south-central Texas, based on water-level and borehole geophysical log data, 1999-2007

    USGS Publications Warehouse

    Lambert, Rebecca B.; Hunt, Andrew G.; Stanton, Gregory P.; Nyman, Michael B.

    2010-01-01

    The freshwater zone of the San Antonio segment of the Edwards aquifer in south-central Texas (hereinafter, the Edwards aquifer) is bounded to the south and southeast by a zone of transition from freshwater to saline water (hereinafter, the transition zone). The boundary between the two zones is the freshwater/saline-water interface (hereinafter, the interface), defined as the 1,000-milligrams per liter dissolved solids concentration threshold. This report presents the findings of a study, done by the U.S. Geological Survey in cooperation with the San Antonio Water System, to obtain lithologic properties (rock properties associated with known stratigraphic units) and physicochemical properties (fluid conductivity and temperature) and to analyze the hydraulics of flow in and near the transition zone of the Edwards aquifer on the basis of water-level and borehole geophysical log data collected from 15 monitoring wells in four transects during 1999-2007. No identifiable relation between conductivity values from geophysical logs in monitoring wells in all transects and equivalent freshwater heads in the wells at the times the logs were run is evident; and no identifiable relation between conductivity values and vertical flow in the boreholes concurrent with the times the logs were run is evident. The direction of the lateral equivalent freshwater head gradient and thus the potential lateral flow at the interface in the vicinity of the East Uvalde transect fluctuates between into and out of the freshwater zone, depending on recharge and withdrawals. Whether the prevailing direction on average is into or out of the freshwater zone is not clearly indicated. Equivalent freshwater head data do not indicate a prevailing direction of the lateral gradient at the interface in the vicinity of the Tri-County transect. The prevailing direction on average of the lateral gradient and thus potential lateral flow at the interface in the vicinity of the Kyle transect likely is from the

  16. Microbial biogeography of San Francisco Bay sediments

    NASA Astrophysics Data System (ADS)

    Lee, J. A.; Francis, C. A.

    2014-12-01

    The largest estuary on the west coast of North America, San Francisco Bay is an ecosystem of enormous biodiversity, and also enormous human impact. The benthos has experienced dredging, occupation by invasive species, and over a century of sediment input as a result of hydraulic mining. Although the Bay's great cultural and ecological importance has inspired numerous surveys of the benthic macrofauna, to date there has been almost no investigation of the microbial communities on the Bay floor. An understanding of those microbial communities would contribute significantly to our understanding of both the biogeochemical processes (which are driven by the microbiota) and the physical processes (which contribute to microbial distributions) in the Bay. Here, we present the first broad survey of bacterial and archaeal taxa in the sediments of the San Francisco Bay. We conducted 16S rRNA community sequencing of bacteria and archaea in sediment samples taken bimonthly for one year, from five sites spanning the salinity gradient between Suisun and Central Bay, in order to capture the effect of both spatial and temporal environmental variation on microbial diversity. From the same samples we also conducted deep sequencing of a nitrogen-cycling functional gene, nirS, allowing an assessment of evolutionary diversity at a much finer taxonomic scale within an important and widespread functional group of bacteria. We paired these sequencing projects with extensive geochemical metadata as well as information about macrofaunal distribution. Our data reveal a diversity of distinct biogeographical patterns among different taxa: clades ubiquitous across sites; clades that respond to measurable environmental drivers; and clades that show geographical site-specificity. These community datasets allow us to test the hypothesis that salinity is a major driver of both overall microbial community structure and community structure of the denitrifying bacteria specifically; and to assess

  17. San Jose Accord: energy aid or petroleum-marketing strategy

    SciTech Connect

    Not Available

    1982-09-30

    The San Jose Accord was signed in San Jose, Costa Rica on August 3, 1980 by the Presidents of Venezuela and Mexico, whereby the two countries mutually committed to supply the net imported domestic oil consumption of several Central American and Caribbean countries. Countries initially participating in the program are: Barbados, Costa Rica, Dominican Republic, El Salvador, Guatemala, Honduras, Jamaica, Nicaragua, and Panama. Seven eastern Caribbean countries were to meet on October 7 to petition for inclusion in the Accord, namely: Antigua, St. Kitt/Nevis, Montserrat, Dominica, St. Lucia, St. Vincent, and Grenada. The official language of the Accord is presented, and the operative status of the Accord two years after signing is discussed. Specific briefs about some of the individual countries in the Accord are included. The fuel price/tax series for the Western Hemisphere countries is updated.

  18. The paleoseismology of the San Andreas fault at Pitman Canyon, San Bernadino, California

    SciTech Connect

    Seitz, G.; Weldon, R.J. . Dept. of Geological Sciences)

    1993-04-01

    The San Andreas fault at Pitman Canyon creates a well-defined downhill-facing scarp in young alluvium deposited mainly as debris flows. Groundwater rising on the uphill side of the scarp produces marshes that accumulate peat deposits. Trench exposures and C-14 dates confirm that this depositional environment, resulting in a datable section of inter-layered debris flows and peats, has existed for at least 1,400 years. The scarp extends across the entire canyon floor with the exception of a central shutterridge, offset along the fault, and the active channel. At the shutterridge this datable section overlies the fault and is involved in the faulting. A debris flow levee is offset approximately 4 meters and is inferred to be caused by the 1812 earthquake. To the northwest similar 4 meter offsets exist in Purdue and Lone Pine Canyons (Weldon and Sieh, 1985). An older debris flow lobe which postdates 1659 AD, the earliest possible age of a directly underlying C-14 dated peat is offset 7--8 meter indicating a similar size event post 1659 AD. Up to three additional events prior to 1280 AD were recognized in trench exposures based upon the upward termination of fault breaks, facies mismatches, and folding. Further study of offset buried debris flows and channels should allow determination of displacement per event. This preliminary record suggests extending the 1812 rupture into the San Bernadino region and is compatible with extending an approximately 1700 AD event from Indio to Wrightwood.

  19. Has the San Gabriel fault been offset

    SciTech Connect

    Sheehan, J.R.

    1988-03-01

    The San Gabriel fault (SGF) in southern California is a right-lateral, strike-slip fault extending for 85 mi in an arcuate, southwestward-bowing curve from near the San Andreas fault at Frazier Mountain to its intersection with the left-lateral San Antonio Canyon fault (SACF) in the eastern San Gabriel Mountains. Termination of the SGF at the presently active SACF is abrupt and prompts the question Has the San Gabriel Fault been offset. Tectonic and geometric relationships in the area suggest that the SGF has been offset approximately 6 mi in a left-lateral sense and that the offset continuation of the SGF, across the SACF, is the right-lateral, strike-slip San Jacinto fault (SJF), which also terminates at the SACF. Reversing the left-lateral movement on the SACF to rejoin the offset ends of the SGF and SJF reveals a fault trace that is remarkably similar in geometry and movement (and perhaps in tectonic history), to the trace of the San Andreas fault through the southern part of the San Bernardino Mountains. The relationship of the Sierra Madre-Cucamonga fault system to the restored SGF-SJF fault is strikingly similar to the relationship of the Banning fault to the Mission Creek-Mill Creek portion of the San Andreas fault. Structural relations suggest that the San Gabriel-San Jacinto system predates the San Andreas fault in the eastern San Gabriel Mountains and that continuing movement on the SACF is currently affecting the trace of the San Andreas fault in the Cajon Pass area.

  20. California State Waters Map Series: offshore of San Gregorio, California

    USGS Publications Warehouse

    Cochrane, Guy R.; Dartnell, Peter; Greene, H. Gary; Watt, Janet T.; Golden, Nadine E.; Endris, Charles A.; Phillips, Eleyne L.; Hartwell, Stephen R.; Johnson, Samuel Y.; Kvitek, Rikk G.; Erdey, Mercedes D.; Bretz, Carrie K.; Manson, Michael W.; Sliter, Ray W.; Ross, Stephanie L.; Dieter, Bryan E.; Chin, John L.; Cochran, Susan A.

    2014-01-01

    the northern and southern parts of the map area are the result of right-lateral motion on strands of the San Gregorio Fault system. In the south, headlands near Pescadero Point have been uplifted by motion along the west strand of the San Gregorio Fault (also called the Frijoles Fault), which separates rocks of the Pigeon Point Formation south of the fault from rocks of the Purisima Formation north of the fault. The regional uplift in this map area has caused relatively shallow water depths within California's State Waters and, thus, little accommodation space for sediment accumulation. Sediment is observed offshore in the central part of the map area, in the shelter of the headlands north of the east strand of the San Gregorio Fault (also called the Coastways Fault) around Miramontes Point (about 5 km north of the map area) and also on the outer half of the California's State Waters shelf in the south where depths exceed 40 m. Sediment in the outer shelf of California's State Waters is rippled, indicating some mobility. The Offshore of San Gregorio map area lies within the cold-temperate biogeographic zone that is called either the "Oregonian province" or the "northern California ecoregion." This biogeographic province is maintained by the long-term stability of the southward-flowing California Current, an eastern limb of the North Pacific subtropical gyre that flows from Oregon to Baja California. At its midpoint off central California, the California Current transports subarctic surface (0–500 m deep) waters southward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the California Current, generate coastal upwelling. The south end of the Oregonian province is at Point Conception (about 350 km south of the map area), although its associated phylogeographic group of marine fauna may extend beyond to the area offshore of Los Angeles in southern California. The ocean off of central California has experienced a warming

  1. Three-dimensional upper crustal velocity structure beneath San Francisco Peninsula, California

    NASA Astrophysics Data System (ADS)

    Parsons, Tom; Zoback, Mary Lou

    1997-03-01

    This paper presents new seismic data from, and crustal models of the San Francisco Peninsula. In much of central California the San Andreas fault juxtaposes the Cretaceous granitic Salinian terrane on its west and the Late Mesozoic/Early Tertiary Franciscan Complex on its east. On San Francisco Peninsula, however, the present-day San Andreas fault is completely within a Franciscan terrane, and the Pilarcitos fault, located southwest of the San Andreas, marks the Salinian-Franciscan boundary. This circumstance has evoked two different explanations: either the Pilarcitos is a thrust fault that has pushed Franciscan rocks over Salinian rocks or the Pilarcitos is a transform fault that has accommodated significant right-lateral slip. In an effort to better resolve the subsurface structure of the peninsula faults, we established a temporary network of 31 seismographs arrayed across the San Andreas fault and the subparallel Pilarcitos fault at ˜1-2 km spacings. These instruments were deployed during the first 6 months of 1995 and recorded local earthquakes, air gun sources set off in San Francisco Bay, and explosive sources. Travel times from these sources were used to augment earthquake arrival times recorded by the Northern California Seismic Network and were inverted for three-dimensional velocity structure. Results show lateral velocity changes at depth (˜0.5-7 km) that correlate with downward vertical projections of the surface traces of the San Andreas and Pilarcitos faults. We thus interpret the faults as high-angle to vertical features (constrained to a 70°-110° dip range). From this we conclude that the Pilarcitos fault is probably an important strike-slip fault that accommodated much of the right-lateral plate boundary strain on the peninsula prior to the initiation of the modern-day San Andreas fault in this region sometime after about 3.0 m.y. ago.

  2. Soil degradation in farmlands of California’s San Joaquin Valley resulting from drought-induced land-use changes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation in California’s Central Valley (USA) has decreased significantly due to water shortages resulting from the current drought, which began in 2010. In particular, fallow fields in the west side of the San Joaquin Valley (WSJV), which is the southwest portion of the Central Valley, increased ...

  3. Mineral resources of the San Rafael Swell Wilderness Study Areas, including Muddy Creek, Crack Canyon, San Rafael Reef, Mexican Mountain, and Sids Mountain Wilderness Study Areas, Emery County, Utah

    SciTech Connect

    Bartsch-Winkler, S.; Dickerson, R.P.; Barton, H.W.; McCafferty, A.E.; Grauch, V.J.S.; Koyuncu, H.; Lee, K.; Duval, J.S. ); Munts, S.R.; Benjamin, D.A.; Close, T.J.; Lipton, D.A.; Neumann, T.R.; Willet, S.L. )

    1990-09-01

    This paper reports on the San Rafael Swell Wilderness Study areas, which includes the Muddy Creek, Crack Canyon, San Rafael Reef, Mexican Mountain, and Sids Mountain Wilderness Study Areas, in Emery County, south-central Utah. Within and near the Crack Canyon Wilderness Study Area are identified subeconomic uranium and vanadium resources. Within the Carmel Formation are inferred subeconomic resources of gypsum in the Muddy Creek, San Rafael Reef, and Sids Mountain Wilderness Study Areas. Other commodities evaluated include geothermal energy, gypsum, limestone, oil and gas, sand and gravel, sandstone, semiprecious gemstones, sulfur petrified wood, and tar sand.

  4. South elevation and main floor plan. San Bernardino Valley Union ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    South elevation and main floor plan. San Bernardino Valley Union Junior College, Science Building. Includes chemistry and botany departments. Howard E. Jones, Architect, San Bernardino, California. Sheet 2, job no. 311. Scale 1/8 inch to the foot. February 15, 1927. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  5. 10. Office of the Post Engineer, Presidio of San Francisco. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Office of the Post Engineer, Presidio of San Francisco. Location of Water Lines, Presidio of San Francisco. Sheet 30. November 1943. SHOWING EASTERN PORTION OF CRISSY FIELD AND AREA A. - Presidio of San Francisco, Storehouse & Administration, Crissy Field North cantonment, Allen Street, San Francisco, San Francisco County, CA

  6. 9. Office of the Post Engineer, Presidio of San Francisco. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Office of the Post Engineer, Presidio of San Francisco. Location of Water Lines, Presidio of San Francisco. Sheet 29. June 1944. SHOWING EASTERN PORTION OF CRISSY FIELD. - Presidio of San Francisco, Storehouse & Administration, Crissy Field North cantonment, Allen Street, San Francisco, San Francisco County, CA

  7. 111. Frank Deras Jr., Photographer April 1998 VIEW OF SAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    111. Frank Deras Jr., Photographer April 1998 VIEW OF SAN FRANCISCO VIADUCT WITH BUS RAMP TO TRANSBAY TERMINAL BUS LOOP IN FOREGROUND, NEAR SECOND STREET, FACING SOUTH. - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  8. Shelving plans, elevations, and sections. San Bernardino Valley Union Junior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Shelving plans, elevations, and sections. San Bernardino Valley Union Junior College, Science Building. Howard E. Jones, Architect, San Bernardino, California. Sheet 9, job no. 311. Scale 1.2 inch to the foot. February 15, 1927. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  9. South entrance, plan, section, & detail. San Bernardino Valley Union ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    South entrance, plan, section, & detail. San Bernardino Valley Union Junior College, Science Building. Detailed drawings of tile work, wrought iron, and art stone, Howard E. Jones, Architect, San Bernardino, California. Sheet 6, job no. 311. Scale 1.2 inch to the foot. February 15, 1927. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  10. 36. Post Engineer Office, Presidio of San Francisco. Plot Plan, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. Post Engineer Office, Presidio of San Francisco. Plot Plan, Letterman Army Hospital, San Francisco, Calif. 1958. SHOWING LOCATION OF BUILDINGS 1006 AND 1049 IN LETTERMAN HOSPITAL COMPLEX IN 1958. - Presidio of San Francisco, Letterman General Hospital, Building No. 27, Letterman Hospital Complex, Edie Road, San Francisco, San Francisco County, CA

  11. Elevations, plan and section PP of main entrance. San Bernardino ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevations, plan and section PP of main entrance. San Bernardino Valley Union Junior College, Library Building. Howard E. Jones, Architect, San Bernardino, California. Sheet 9, job no. 315. Scale 1/2 inch to the foot. No date given on sheet (probably March or April, 1927). - San Bernardino Valley College, Library, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  12. An Analysis of Certain Selected Causes of Poverty in San Miguel County.

    ERIC Educational Resources Information Center

    Knowlton, Clark S.

    San Miguel County, one of the larger, older, and more predominantly Spanish American counties in New Mexico, is located in the north central section of the State. Marked by varied topographical and climatic characteristics, the county was once one of the more prosperous and densely populated areas of the State. Today it suffers from high rates of…

  13. Long Range Development Plan, University of California, San Diego, October 1963.

    ERIC Educational Resources Information Center

    Alexander, Robert E.

    The academic and physical development plans of the University of California at San Diego are outlined. Facilities for 27,500 anticipated students are divided into twelve colleges of about 2300 students each. The twelve colleges are arranged into three clusters of four each, grouped around the central academic and administrative facilities, in…

  14. San Juan School Evaluation. Research and Evaluation Report Series No. 27.

    ERIC Educational Resources Information Center

    Bureau of Indian Affairs (Dept. of Interior), Albuquerque, NM.

    The San Juan School (Espanola, New Mexico) was evaluated by a team from the Bureau of Indian Affairs' Central Office staff in Albuquerque. Team members assisted the Division of Program Review as representatives from other divisions, using the expertise in their respective fields. The methodology and techniques, which were left to the evaluator's…

  15. San Diego: Public Attitudes About Crime. A National Crime Survey Report.

    ERIC Educational Resources Information Center

    Paez, Adolfo L., Ed.

    The National Crime Survey program has conducted a continuous national survey and separate surveys in 26 central cities to study the impact of crime on American society. Attitudinal information obtained from a 1974 survey of occupants of 4,906 housing units (9,125 residents age 16 and over) in San Diego reflects crime trends, fear of crime,…

  16. POINT-OF-USE TREATMENT OF DRINKING WATER IN SAN YSIDRO, NM

    EPA Science Inventory

    This study was conducted to determine whether point-of-use (POU) reverse osmosis (RO) units could satisfactorily function in lieu of central treatment to remove arsenic and fluoride from the drinking water supply of San Ysidro, NM. POU treatment was evaluated for removal efficien...

  17. The San Francisco Peace Treaty: The Cold War and the Peace Process.

    ERIC Educational Resources Information Center

    Brunette, Rachel

    International treaties have played a central role in diplomatic history since the rise of the modern nation state. Since the end of World War II, more treaties have been formed than in the preceding four centuries. The year 2001 marks the 50th anniversary of the San Francisco Peace Treaty. This unit provides students with historical knowledge of…

  18. San Francisco and Bay Area, CA, USA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Although clouds obscure part of the city of San Francisco and the mouth of the Bay (37.5N, 122.0W), many cultural and natural features in the immediate vicinity are obvious. The Bay Bridge which was damaged in the 1989 earthquake, Candlestick Park, San Mateo and Dumbarton Bridges as well as the various colored settling ponds rimming the south end of the Bay, the San Andreas and Calaveras faults and many of the major highways can be seen.

  19. Deformation across the Pacific-North America plate boundary near San Francisco, California

    USGS Publications Warehouse

    Prescott, W.H.; Savage, J.C.; Svarc, J.L.; Manaker, D.

    2001-01-01

    We have detected a narrow zone of compression between the Coast Ranges and the Great Valley, and we have estimated slip rates for the San Andreas, Rodgers Creek, and Green Valley faults just north of San Francisco. These results are based on an analysis of campaign and continuous Global Positioning System (GPS) data collected between 1992 and 2000 in central California. The zone of compression between the Coast Ranges and the Great Valley is 25 km wide. The observations clearly show 3.8??1.5 mm yr-1 of shortening over this narrow zone. The strike slip components are best fit by a model with 20.8??1.9 mm yr-1 slip on the San Andreas fault, 10.3??2.6 mm yr-1 on the Rodgers Creek fault, and 8.1??2.1 mm yr-1 on the Green Valley fault. The Pacific-Sierra Nevada-Great Valley motion totals 39.2??3.8 mm yr-1 across a zone that is 120 km wide (at the latitude of San Francisco). Standard deviations are one ??. The geodetic results suggest a higher than geologic rate for the Green Valley fault. The geodetic results also suggest an inconsistency between geologic estimates of the San Andreas rate and seismologic estimates of the depth of locking on the San Andreas fault. The only convergence observed is in the narrow zone along the border between the Great Valley and the Coast Ranges.

  20. Interseismic strain accumulation and the earthquake potential on the southern San Andreas fault system.

    PubMed

    Fialko, Yuri

    2006-06-22

    The San Andreas fault in California is a mature continental transform fault that accommodates a significant fraction of motion between the North American and Pacific plates. The two most recent great earthquakes on this fault ruptured its northern and central sections in 1906 and 1857, respectively. The southern section of the fault, however, has not produced a great earthquake in historic times (for at least 250 years). Assuming the average slip rate of a few centimetres per year, typical of the rest of the San Andreas fault, the minimum amount of slip deficit accrued on the southern section is of the order of 7-10 metres, comparable to the maximum co-seismic offset ever documented on the fault. Here I present high-resolution measurements of interseismic deformation across the southern San Andreas fault system using a well-populated catalogue of space-borne synthetic aperture radar data. The data reveal a nearly equal partitioning of deformation between the southern San Andreas and San Jacinto faults, with a pronounced asymmetry in strain accumulation with respect to the geologically mapped fault traces. The observed strain rates confirm that the southern section of the San Andreas fault may be approaching the end of the interseismic phase of the earthquake cycle. PMID:16791192

  1. Periodic pulsing of characteristic microearthquakes on the San Andreas fault.

    PubMed

    Nadeau, Robert M; McEvilly, Thomas V

    2004-01-01

    Deep fault slip information from characteristically repeating microearthquakes reveals previously unrecognized patterns of extensive, large-amplitude, long-duration, quasiperiodic repetition of aseismic events along much of a 175-kilometer segment of the central San Andreas fault. Pulsing occurs both in conjunction with and independent of transient slip from larger earthquakes. It extends to depths of approximately 10 to 11 kilometers but may be deeper, and it may be related to similar phenomena occurring in subduction zones. Over much of the study area, pulse onset periods also show a higher probability of larger earthquakes, which may provide useful information for earthquake forecasting. PMID:14716011

  2. Heat flow and energetics of the San Andreas fault zone.

    USGS Publications Warehouse

    Lachenbruch, A.H.; Sass, J.H.

    1980-01-01

    Approximately 100 heat flow measurements in the San Andreas fault zone indicate 1) there is no evidence for local frictional heating of the main fault trace at any latitude over a 1000-km length from Cape Mendocino to San Bernardino, 2) average heat flow is high (ca.2 HFU, ca.80 mW m-2) throughout the 550-km segment of the Coast Ranges that encloses the San Andreas fault zone in central California; this broad anomaly falls off rapidly toward the Great Valley to the east, and over a 200-km distance toward the Mendocino Triple Junction to the northwest. As others have pointed out, a local conductive heat flow anomaly would be detectable unless the frictional resistance allocated to heat production on the main trace were less than 100 bars. Frictional work allocated to surface energy of new fractures is probably unimportant, and hydrologic convection is not likely to invalidate the conduction assumption, since the heat discharge by thermal springs near the fault is negligible. -Authors

  3. 75 FR 35651 - Safety Zone; San Francisco Chronicle Fireworks Display, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; San Francisco Chronicle Fireworks Display, San Francisco... will enforce the Independence Day Celebration for the City of San Francisco Fireworks safety zone from 11 a.m. through 10 p.m. on July 4, 2010. The fireworks will be fired simultaneously from two...

  4. 78 FR 18238 - Safety Zone; SFPD Training Safety Zone; San Francisco Bay, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ... of Homeland Security FR Federal Register SFPD San Francisco Police Department NPRM Notice of Proposed... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; SFPD Training Safety Zone; San Francisco... Guard is establishing a temporary safety zone in the navigable waters of the San Francisco Bay...

  5. 77 FR 57494 - Safety Zone; Fleet Week Fireworks, San Francisco Bay, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-18

    ... SECURITY Coast Guard 33 CFR Part 165 Safety Zone; Fleet Week Fireworks, San Francisco Bay, San Francisco... will enforce the safety zone for the Fleet Week Fireworks in the Captain of the Port, San Francisco...'' W (NAD83) for the Fleet Week Fireworks in 33 CFR 165.1191, Table 1, item number 25. This safety...

  6. Pathology of Central American refugees.

    PubMed

    Molesky, J

    1986-01-01

    Almost every city in the US has Central American refugees; Houston has 150,000 Salvadorans; San Francisco has 80,000-150,000; and Los Angeles has more than 250,000. There are over 1/2 million Salvadorans in the US, and the number of Guatemalans increases every year. Suffering many losses and burdened in a shadowed life, the refugee is angry, frustrated, and depressed. Mental health specialists in San Francisco observe how similar the refugees symptoms seem to post-traumatic stress disorder (PTSD), the psychological syndrome 1st described among Viet Nam veterans and disaster victims in the 1970s. An informal survey of 50 Salvadoran clients in an out-patient program at San Fernando Valley Community Mental Health in Southern California found that PTSD was prevalent in most cases, with 19% of the group reporting depression as a major symptom and 54% seriously ill enough to require medication. There seems to be a consensus among many mental health workers that one way out of PTSD is group work with fellow victims. When Central American refugees find themselves in an emotional crisis, there are few resources of mental health aid for them. Support groups help replicate the organic family support system that so many refugees left behind in their own countries. PMID:12341433

  7. Late Cenozoic geology of Cajon Pass: implications for tectonics and sedimentation along the San Andreas fault

    SciTech Connect

    Weldon, R.J. II

    1986-01-01

    The geology in Cajon Pass, southern California, provides a detailed history of strike-slip activity on the San Andreas fault, compressional deformation associated with the uplift of the central Transverse Ranges and an excellent Cenozoic record of syntectonic sedimentation. Age control was established in all of the sediments deposited since the Early Miocene, using biostratigraphy, magnetostratigraphy, fission-track dating of volcanic ashes, radiocarbon dating, soil development, and the relative stratigraphic and geomorphic position of the units. Detailed mapping revealed that tectonic deformation and sedimentation styles varied through time, reflecting the evolution of the San Andreas fault zone within the Pacific-North American plate boundary and climatic changes. Three distinct phases of the uplift of the San Bernardino Mountains have been recognized, suggesting a long-term interaction between the strike-slip activity on the San Andreas system and the compressional tectonics of the Transverse Ranges. Uplift began in the late Miocene, paused during the Pliocene, recommenced in the earliest Pleistocene and culminated in the late Pleistocene. The average slip rate across the combined San Andreas and San Jacinto faults was 37.5 +/- 2 mm/yr during the Quaternary Period. The Holocene slip rate on the San Andreas fault in Cajon Pass was determined to be 24.5 +/- 3.5 mm/yr. This investigation indicates that the last earthquake associated wit rupture on the San Andreas fault in Cajon Pass occurred around 1700 AD and that the average recurrence interval between earthquakes is between 150 and 200 years. A kinematic model was constructed from the structural and slip rate data developed here that produces internally consistent motions for all of the fault-bounded blocks in southern California.

  8. Metamorphism of San Antonio Terrane metapelites, San Gabriel Mountains, California

    SciTech Connect

    Archuleta, L.; Ishimatsu, J.; Schneiderman, J.S. . Geology Dept.)

    1993-04-01

    Pelitic schists and gneisses from the San Antonio terrane in the eastern San Gabriel Mountains consist of garnet, biotite, plagioclase, quartz, sillimanite, cordierite, hercynite [+-] alkali feldspar. Large garnet porphyroblasts contain quartz, plagioclase and sillimanite inclusions. Cordierite occurs as haloes around garnet porphyroblasts and as small subgrains always associated with hercynite and together replacing sillimanite blades. Hercynite additionally appears to have nucleated on the edges of sillimanite blades. Contrary to previous investigations, hercynite appears to be a late mineral phase. Reaction textures described above have been used to calculate a set of net-transfer reactions that can be used (1) to characterize all possible exchanges of matter between minerals in the system and (2) to construct a reaction space for the system. Fourteen thin sections with large garnet porphyroblasts and abundant biotite were used for microprobe analysis. Detailed probe analyses show well-developed zoning in the plagioclase and alkali feldspar whose character varies depending on location in the thin section relative to neighboring minerals. Generally, large plagioclase porphyroblasts display normal zoning and are not as calcium-rich as plagioclase inclusions in the garnet. Garnet porphyroblasts have flat zoning profiles due to high temperatures of metamorphism. Pressures and temperatures of metamorphism have been calculated from these assemblages using garnet-biotite geothermometry and quartz-garnet-aluminosilicate-plagioclase geobarometry.

  9. SAN RAFAEL PRIMITIVE AREA, CALIFORNIA.

    USGS Publications Warehouse

    Gower, H.D.

    1984-01-01

    No mineral-resource potential was identified during studies of the San Rafael Primitive Area, located at the southern end of the Coast Ranges of California. No petroleum has been produced from the area and there is little promise for the occurrence of energy resources. Limestone occurs in the area but also is found in abundance outside the area. Inasmuch as sampling and analytical techniques have improved significantly since this study was completed a restudy of the area using new methodology is possibly warranted.

  10. 8. GENERAL VIEW FROM SOUTHEAST (Title Insurance Co. collection, San ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. GENERAL VIEW FROM SOUTHEAST (Title Insurance Co. collection, San Diego Historical Society). Historical view, no date, photocopied for HABS, 1975 - Long-Waterman House, 2408 First Avenue, San Diego, San Diego County, CA

  11. 2. Historic American Buildings Photo by Muybridge, Gleason Collection San ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Historic American Buildings Photo by Muybridge, Gleason Collection San Francisco College for Women Ca. 1870 CONSTRUCTION VIEW FROM SOUTH - U. S. Branch Mint, Mission & Fifth Streets, San Francisco, San Francisco County, CA

  12. 1. GENERAL VIEW OF COMPLEX (drawing from History of San ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. GENERAL VIEW OF COMPLEX (drawing from History of San Diego County, California, published 1883. Photocopy 1975 by Bert Shankland, San Diego). - Johnson-Taylor Ranch House, Black Mountain Road vicinity, Rancho Penasquitos, San Diego County, CA

  13. Space Radar Image of San Francisco, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This image of San Francisco, California shows how the radar distinguishes between densely populated urban areas and nearby areas that are relatively unsettled. Downtown San Francisco is at the center and the city of Oakland is at the right across the San Francisco Bay. Some city areas, such as the South of Market, called the SOMA district in San Francisco, appear bright red due to the alignment of streets and buildings to the incoming radar beam. Various bridges in the area are also visible including the Golden Gate Bridge (left center) at the opening of San Francisco Bay, the Bay Bridge (right center) connecting San Francisco and Oakland, and the San Mateo Bridge (bottom center). All the dark areas on the image are relatively smooth water: the Pacific Ocean to the left, San Francisco Bay in the center, and various reservoirs. Two major faults bounding the San Francisco-Oakland urban areas are visible on this image. The San Andreas fault, on the San Francisco peninsula, is seen in the lower left of the image. The fault trace is the straight feature filled with linear reservoirs which appear dark. The Hayward fault is the straight feature on the right side of the image between the urban areas and the hillier terrain to the east. The image is about 42 kilometers by 58 kilometers (26 miles by 36 miles) with north toward the upper right. This area is centered at 37.83 degrees north latitude, 122.38 degrees east longitude. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR-C/X-SAR) imaging radar when it flew aboard the space shuttle Endeavour on October 3, 1994. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth.

  14. Emplacement, offset history, and recent uplift of basement within the San Andreas Fault System, northeast San Gabriel Mountains, California

    NASA Astrophysics Data System (ADS)

    Kenney, Miles Douglas

    1999-11-01

    Mapping, petrography, cross-sections, structure contours, earthquake locations, and focal mechanism analogues of summed moment tensors have provided insights into the reconstruction and deformation associated with the San Andreas Fault System in the San Gabriel and Western San Bernardino Mountains (WSBM) of the Central Transverse Ranges. The San Gabriel Mountains (SGM) represent a Quaternary 'arch' that extends across the northwest trending San Andreas Fault (SAF). Mechanisms to explain the relatively large magnitudes of uplift on both sides of this relatively straight strike slip fault have been problematical. The uplift results from the interactions between the right lateral San Jacinto Fault (SJF) and SAF, and the thrust Cucamonga-Sierra Madre Faults (CF-SMF). Uplift south of the SAF occurs as the SGM Block propagates through the restraining bend at the intersection of the SJF and SAF at the surface, which has produced an antiform in the topography of the range and in the Vincent Thrust. Uplift is also due to motion on the CF-SMF. Uplift north of the SAF is attributed to an upper-crustal north-dipping subsurface restraining bend in the SAF due to the projected intersection of the CF-SMF and SJF, with the SAF. Northwest migration of the restraining bend in the Quaternary has produced a ˜1.5 km high, northeast dipping monocline in crystalline basement which is adjacent and parallel to the SAF. Reverse faults and deformation of alluvial terraces document a northwest migrating locus of compression and uplift. Toward the southeast, the subsurface restraining bend becomes a subsurface lateral ramp where the SJF intersects the SAF at depth. Crystalline basement of the Holcomb Ridge-Table Mountain 'slice' consists of a syntectonically emplaced, intercalated, north-dipping, igneous and metamorphic suite. Cretaceous igneous rocks were emplaced as tabular bodies, which now strike eastwest, and are concordant with a relatively older metasedimentary screen and para

  15. 78 FR 21414 - Central Valley Project Improvement Act, Water Management Plans

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-10

    ... available for review: Carpinteria Valley Water District Gravelly Ford Water District Hills Valley Irrigation District San Juan Water District San Luis Water District Shafter-Wasco Irrigation District Tea Pot Dome Irrigation District To meet the requirements of the Central Valley Project Improvement Act of 1992 and...

  16. MAPP in action in San Antonio, Texas.

    PubMed

    Shields, Kathleen M; Pruski, Charles E

    2005-01-01

    San Antonio was selected as an official Mobilizing for Action through Planning and Partnerships (MAPP) demonstration site by National Association of County and City Officials in 2000. The San Antonio Metropolitan Health District, under the leadership of Dr Fernando A. Guerra, agreed to facilitate the process. The MAPP process provided the San Antonio Metropolitan Health District, the local public health authority, a defined process for community health improvement, as well as a mechanism to help bridge the gap between public health and the community. The San Antonio Metropolitan Health District organized a Core Planning Team to lead the MAPP process in April 2001. By October 2002, the Core Planning Team was expanded to a full community working group named the Alliance for Community Health in San Antonio and Bexar County (Alliance). The Alliance identified six strategic issues, which eventually became the basis of the San Antonio Community Health Improvement Plan. The strategic issues are Public Policy, Data Tracking, Healthy Lifestyles, Promoting a Sense of Community, Access to Care, and Safe Environment. San Antonio's MAPP experience has been successful in bringing together the public health system partners, and establishing public health priorities collectively. The MAPP process has resulted in the development of many new initiatives, and, most important, has opened the door to many partnership opportunities in the future. The work of the Alliance, through the MAPP process, has helped to leverage resources for public health improvement in San Antonio, and has the potential to effect positive change in public health in the future. PMID:16103814

  17. San Diego's High School Dropout Crisis

    ERIC Educational Resources Information Center

    Wilson, James C.

    2012-01-01

    This article highlights San Diego's dropout problem and how much it's costing the city and the state. Most San Diegans do not realize the enormous impact high school dropouts on their city. The California Dropout Research Project, located at the University of California at Santa Barbara, has estimated the lifetime cost of one class or cohort of…

  18. Trouble Brewing in San Francisco. Policy Brief

    ERIC Educational Resources Information Center

    Buck, Stuart

    2010-01-01

    The city of San Francisco will face enormous budgetary pressures from the growing deficits in public pensions, both at a state and local level. In this policy brief, the author estimates that San Francisco faces an aggregate $22.4 billion liability for pensions and retiree health benefits that are underfunded--including $14.1 billion for the city…

  19. San Diego City College Accreditation Survey Report.

    ERIC Educational Resources Information Center

    Takahata, Gail M.; Armstrong, William B.

    In fall, 1996, the San Diego Community College District undertook a self-study period to prepare for the Accrediting Commission for Community and Junior Colleges (ACCJC) visit in 1998. Faculty, staff, and students at San Diego City College were asked if the College met the ten standards of the ACCJC as evidence of "good educational practices."…

  20. Jack London and the San Francisco earthquake

    USGS Publications Warehouse

    Sachs, J.S.

    1982-01-01

    After it was over, it seemed to many, and especially to eyewitnesses like Jack London, that the earthquake and fire had devastated San Francisco. However people were confident that, like the phoeniz, San Francisco would rise from the ashes and regain her palce as the "Imperial City of the West." 

  1. Lithosphere-Asthenosphere interactions near the San Andreas fault.

    NASA Astrophysics Data System (ADS)

    Houlie, N.

    2015-12-01

    We decipher the strain history of the upper mantle in California through the comparison of the long-term finite strain field in the mantle and the surface strain-rate field, respectively inferred from fast polarization directions of seismic phases (SKS and SKKS), and Global Positioning System (GPS) surface velocity fields. We show that mantle strain and surface strain-rate fields are consistent in the vicinity of San Andreas Fault (SAF) in California. Such an agreement suggests that the lithosphere and strong asthenosphere have been deformed coherently and steadily since >1 Ma. We find that the crustal stress field rotates (up to 40 degrees of rotation across a 50 km distance from 50 degrees relative to the strike of the SAF, in the near-field of SAF) from San Francisco to the Central Valley. Both observations suggest that the SAF extends to depth, likely through the entire lithosphere. From Central Valley towards the Basin and Range, the orientations of GPS strain-rates, shear wave splitting measurements and seismic stress fields diverge indicating reduced coupling or/and shallow crustal extension and/or presence of frozen anisotropy.

  2. Summary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2007

    USGS Publications Warehouse

    Buchanan, Paul A.; Morgan, Tara L.

    2010-01-01

    Suspended-sediment concentration data were collected by the U.S. Geological Survey in San Francisco Bay during water year 2007 (October 1, 2006-September 30, 2007). Optical sensors and water samples were used to monitor suspended-sediment concentration at two sites in Suisun Bay, two sites in Central San Francisco Bay, and one site in South San Francisco Bay. Sensors were positioned at two depths at most sites to help define the vertical variability of suspended sediments.Water samples were collected periodically and analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the output of the optical sensors so that a record of suspended-sediment concentrations could be derived. This report presents the data-collection methods used and summarizes, in graphs, the suspended-sediment concentration data collected from October 2006 through September 2007. Calibration curves and plots of the processed data for each sensor also are presented.

  3. Summary of suspended-sediment concentration data, San Francisco Bay, California, water year 2008

    USGS Publications Warehouse

    Buchanan, Paul A.; Morgan, Tara L.

    2011-01-01

    Suspended-sediment concentration data were collected by the U.S. Geological Survey in San Francisco Bay during water year 2008 (October 1, 2007–September 30, 2008). Optical sensors and water samples were used to monitor suspended-sediment concentration at two sites in Suisun Bay, two sites in Central San Francisco Bay, and one site in South San Francisco Bay. Sensors were positioned at two depths at most sites to help define the vertical variability of suspended sediments. Water samples were collected periodically and analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the output of the optical sensors so that a record of suspended-sediment concentrations could be derived. This report presents the data-collection methods used and summarizes, in graphs, the suspended-sediment concentration data collected from October 2007 through September 2008. Calibration curves and plots of the processed data for each sensor also are presented.

  4. Middle Cenozoic depositional, tectonic, and sea level history of southern San Joaquin basin, California

    SciTech Connect

    Decelles, P.G.

    1988-11-01

    As a prolific producer of hydrocarbons, the San Joaquin basin in south-central California has been the subject of geological research since the late nineteenth century. Much of this research has focused on the subsurface Eocene to lower Miocene succession because of its attractive reservoir potential. Although seismic and well-log data are available in profuse quantities, the complex sedimentary architecture of the basin fill, the application of local and inconsistent stratigraphic nomenclature, and the inherent limitations of subsurface data have led to much confusion concerning the middle Cenozoic history of the basin. This paper presents a sedimentological analysis of the depositional systems in the Eocene to lower Miocene strata of the San Emigdio and Tehachapi Mountains. The various depositional systems are considered within the contexts of encompassing depositional sequences to reconstruct the middle Cenozoic depositional, tectonic, and sea level history of the southern San Joaquin basin. 14 figures, 1 table.

  5. Talc-bearing serpentinite and the creeping section of the San Andreas fault

    USGS Publications Warehouse

    Moore, Diane E.; Rymer, M.J.

    2007-01-01

    The section of the San Andreas fault located between Cholame Valley and San Juan Bautista in central California creeps at a rate as high as 28 mm yr -1 (ref. 1), and it is also the segment that yields the best evidence for being a weak fault embedded in a strong crust. Serpentinized ultramafic rocks have been associated with creeping faults in central and northern California, and serpentinite is commonly invoked as the cause of the creep and the low strength of this section of the San Andreas fault. However, the frictional strengths of serpentine minerals are too high to satisfy the limitations on fault strength, and these minerals also have the potential for unstable slip under some conditions. Here we report the discovery of talc in cuttings of serpentinite collected from the probable active trace of the San Andreas fault that was intersected during drilling of the San Andreas Fault Observatory at Depth (SAFOD) main hole in 2005. We infer that the talc is forming as a result of the reaction of serpentine minerals with silica-saturated hydrothermal fluids that migrate up the fault zone, and the talc commonly occurs in sheared serpentinite. This discovery is significant, as the frictional strength of talc at elevated temperatures is sufficiently low to meet the constraints on the shear strength of the fault, and its inherently stable sliding behaviour is consistent with fault creep. Talc may therefore provide the connection between serpentinite and creep in the San Andreas fault, if shear at depth can become localized along a talc-rich principal-slip surface within serpentinite entrained in the fault zone. ??2007 Nature Publishing Group.

  6. Talc-bearing serpentinite and the creeping section of the San Andreas fault.

    PubMed

    Moore, Diane E; Rymer, Michael J

    2007-08-16

    The section of the San Andreas fault located between Cholame Valley and San Juan Bautista in central California creeps at a rate as high as 28 mm yr(-1) (ref. 1), and it is also the segment that yields the best evidence for being a weak fault embedded in a strong crust. Serpentinized ultramafic rocks have been associated with creeping faults in central and northern California, and serpentinite is commonly invoked as the cause of the creep and the low strength of this section of the San Andreas fault. However, the frictional strengths of serpentine minerals are too high to satisfy the limitations on fault strength, and these minerals also have the potential for unstable slip under some conditions. Here we report the discovery of talc in cuttings of serpentinite collected from the probable active trace of the San Andreas fault that was intersected during drilling of the San Andreas Fault Observatory at Depth (SAFOD) main hole in 2005. We infer that the talc is forming as a result of the reaction of serpentine minerals with silica-saturated hydrothermal fluids that migrate up the fault zone, and the talc commonly occurs in sheared serpentinite. This discovery is significant, as the frictional strength of talc at elevated temperatures is sufficiently low to meet the constraints on the shear strength of the fault, and its inherently stable sliding behaviour is consistent with fault creep. Talc may therefore provide the connection between serpentinite and creep in the San Andreas fault, if shear at depth can become localized along a talc-rich principal-slip surface within serpentinite entrained in the fault zone. PMID:17700697

  7. San Francisco and Bay Area, CA, USA

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Although clouds obscure part of the city of San Francisco and the mouth of the Bay (37.5N, 122.0W), many cultural and natural features in the immediate vicinity are obvious. The Bay Bridge which was damaged in the 1989 earthquake, Candlestick Park, San Mateo and Dumbarton Bridges as well as the various colored settling ponds rimming the south end of the Bay, the San Andreas and Calaveras faults and many of the major highways can be seen. Color infrared photography is very useful for haze penetration and greater definition of the imagery as well as vegetation detection, depicted as shades of red.

  8. San Francisco and Bay Area, CA, USA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This cloud free color infrared view of San Francisco and Bay Area, CA (38.0N, 122.5W) is unusual because the city is normally concealed from view by clouds and fog. Gray tones represent urban areas and the red toned areas are vegetated. Within the city, parks easily stand out from the well-developed parts of the city as enclaves of color. The trace of the San Andreas fault shows as a straight valley running across the San Francisco peninsula.

  9. CIRSS vertical data integration, San Bernardino study

    NASA Technical Reports Server (NTRS)

    Hodson, W.; Christenson, J.; Michel, R. (Principal Investigator)

    1982-01-01

    The creation and use of a vertically integrated data base, including LANDSAT data, for local planning purposes in a portion of San Bernardino County, California are described. The project illustrates that a vertically integrated approach can benefit local users, can be used to identify and rectify discrepancies in various data sources, and that the LANDSAT component can be effectively used to identify change, perform initial capability/suitability modeling, update existing data, and refine existing data in a geographic information system. Local analyses were developed which produced data of value to planners in the San Bernardino County Planning Department and the San Bernardino National Forest staff.

  10. SANS studies of micellar and magnetic fluids

    SciTech Connect

    Hayter, J.B,

    1985-08-01

    Small-angle neutron scattering (SANS) has proved to be an excellent technique for the study of complex fluids. This article introduces SANS from the viewpoint of such studies. The use of SANS to determine the structures of concentrated micellar fluids is then discussed within the framework of current one-component macrofluid (OCM) models, and experimental examples are taken from several contemporary studies. Finally, the discussion is extended to magnetic fluids (ferrofluids) in which the neutron magnetic interaction plays an important experimental role. 25 refs., 11 figs., 1 tab.

  11. 42. Post Engineer Office, Presidio of San Francisco, Letterman Army ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. Post Engineer Office, Presidio of San Francisco, Letterman Army Hospital, X-Ray Department and Second Floor Plan, X-Ray Department Plan, Building 1006. no date. BUILDING 1006. - Presidio of San Francisco, Letterman General Hospital, Building No. 27, Letterman Hospital Complex, Edie Road, San Francisco, San Francisco County, CA

  12. 21. Post Engineer Office, Presidio of San Francisco, Letterman Army ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Post Engineer Office, Presidio of San Francisco, Letterman Army Hospital. EKG Cardiology Clinic, Building 1049. December 1955. BUILDING 1049. - Presidio of San Francisco, Letterman General Hospital, Building No. 12, Letterman Hospital Complex, Edie Road, San Francisco, San Francisco County, CA

  13. 22. Post Engineer Office, Presidio of San Francisco, Building # ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Post Engineer Office, Presidio of San Francisco, Building # 1049 Letterman General Hospital. Alterations to EKG Cardiology Clinic. November 1963. BUILDING 1049. - Presidio of San Francisco, Letterman General Hospital, Building No. 12, Letterman Hospital Complex, Edie Road, San Francisco, San Francisco County, CA

  14. 1. ABANDONED TURNOUT (CALLED CAPTAIN WHEEL) TO SAN TAN INDIAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. ABANDONED TURN-OUT (CALLED CAPTAIN WHEEL) TO SAN TAN INDIAN CANAL OFF OF SAN TAN FLOOD-WATER CANAL, T4S, R6E, S11/12. VIEW LOOKING SOUTHWEST. - San Carlos Irrigation Project, San Tan Indian Canal, North of Gila River, Coolidge, Pinal County, AZ

  15. Complexity of the deep San Andreas Fault zone defined by cascading tremor

    NASA Astrophysics Data System (ADS)

    Shelly, David R.

    2015-02-01

    Weak seismic vibrations--tectonic tremor--can be used to delineate some plate boundary faults. Tremor on the deep San Andreas Fault, located at the boundary between the Pacific and North American plates, is thought to be a passive indicator of slow fault slip. San Andreas Fault tremor migrates at up to 30 m s-1, but the processes regulating tremor migration are unclear. Here I use a 12-year catalogue of more than 850,000 low-frequency earthquakes to systematically analyse the high-speed migration of tremor along the San Andreas Fault. I find that tremor migrates most effectively through regions of greatest tremor production and does not propagate through regions with gaps in tremor production. I interpret the rapid tremor migration as a self-regulating cascade of seismic ruptures along the fault, which implies that tremor may be an active, rather than passive participant in the slip propagation. I also identify an isolated group of tremor sources that are offset eastwards beneath the San Andreas Fault, possibly indicative of the interface between the Monterey Microplate, a hypothesized remnant of the subducted Farallon Plate, and the North American Plate. These observations illustrate a possible link between the central San Andreas Fault and tremor-producing subduction zones.

  16. Does centennial morphodynamic evolution lead to higher channel efficiency in San Pablo Bay, California?

    USGS Publications Warehouse

    van der Wegen, M.; Jaffe, B.E.

    2013-01-01

    Measured bathymetries on 30 year interval over the past 150 years show that San Pablo Bay experienced periods of considerable deposition followed by periods of net erosion. However, the main channel in San Pablo Bay has continuously narrowed. The underlying mechanisms and consequences of this tidal channel evolution are not well understood. The central question of this study is whether tidal channels evolve towards a geometry that leads to more efficient hydraulic conveyance and sediment throughput. We applied a hydrodynamic process-based, numerical model (Delft3D), which was run on 5 San Pablo Bay bathymetries measured between 1856 and 1983. Model results shows increasing energy dissipation levels for lower water flows leading to an approximately 15% lower efficiency in 1983 compared to 1856. During the same period the relative seaward sediment throughput through the San Pablo Bay main channel increased by 10%. A probable explanation is that San Pablo Bay is still affected by the excessive historic sediment supply. Sea level rise and Delta surface water area variations over 150 years have limited effect on the model results. With expected lower sediment concentrations in the watershed and less impact of wind waves due to erosion of the shallow flats, it is possible that energy dissipations levels will decrease again in future decades. Our study suggests that the morphodynamic adaptation time scale to excessive variations in sediment supply to estuaries may be on the order of centuries.

  17. Sediment conditions in the San Antonio River Basin downstream from San Antonio, Texas, 2000-13

    USGS Publications Warehouse

    Ockerman, Darwin J.; Banta, J. Ryan; Crow, Cassi L.; Opsahl, Stephen P.

    2015-01-01

    Sediment plays an important role in the ecological health of rivers and estuaries and consequently is an important issue for water-resource managers. To better understand sediment characteristics in the San Antonio River Basin, the U.S. Geological Survey, in cooperation with the San Antonio River Authority, completed a two-part study in the San Antonio River Basin downstream from San Antonio, Texas, to (1) collect and analyze sediment data to characterize sediment conditions and (2) develop and calibrate a watershed model to simulate hydrologic conditions and suspended-sediment loads during 2000–12.

  18. Underwater gravity meter survey of San Francisco and San Pablo bays, California, 1982

    USGS Publications Warehouse

    Childs, Jonathan R.; Beyer, L.A.; McCulloch, D.S.; McHendrie, G.A.; Steele, W.C.

    1983-01-01

    Seafloor gravity measurements were made at 281 bottom stations in San Francisco and San Pablo Bays, California, on a series of lines oriented approximately NNE.. Line spacing was approximately 2.8 km and stations along the lines mere spaced 0.5 to 1.5 km apart, between 0.5 and 1.5 km perpendicular to the axis. Sample Bouguer anomalies in the San Francisco Bay range from -15 to +15 mGals (?0.1 mgal), while anomalies in the San Pablo Bay are consistently negative, ranging from +4.0 to -40.0 mGal (?0.2 mGal).

  19. 76 FR 10945 - San Luis Trust Bank, FSB, San Luis Obispo, CA; Notice of Appointment of Receiver

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY Office of Thrift Supervision San Luis Trust Bank, FSB, San Luis Obispo, CA; Notice of Appointment of... Corporation as sole Receiver for San Luis Trust Bank, FSB, San Luis Obispo, California, (OTS No. 15051)...

  20. A Community Stormwater Investigation, San Francisco, CA

    NASA Astrophysics Data System (ADS)

    Chio, J.; Garcia, E.; Hernandez, M.; Devine, M.; Isip, N.; Jiang, J.; Li, A.; Li, D.; Lopez, J.; Mark, J.; McGuire, S.; Navarro, K.; Negrete, R.; Orellana, S.; Yun, C.; Bissell, M.; Neiss, J.

    2008-12-01

    The San Francisco Bay watershed covers 40% of the State of California. Nonpoint source pollutants from cars, lawns, houses, parks and people residing within the watershed contribute contamination into San Francisco Bay. To measure the contribution from our neighborhoods we collected runoff from storm-drains at 10 different sites around San Francisco and tested them for heavy metals, Total Organic Carbons (TOC), and Methylene Blue Active Substances (MBAS) during a six-month period. Each sample site location is situated within one block of each participant's home. The goal of this study was to determine the contaminants contributed as nonpoint source pollution into San Francisco Bay. Our results show that a variety of contaminants are entering the Bay's ecosystem via sources in our residential settings. While this contribution may be thought of as unsubstantial, our results show that our neighborhoods are significant sources of watershed pollution.

  1. Suicide Among Chinese in San Francisco

    ERIC Educational Resources Information Center

    Bourne, Peter G.

    1973-01-01

    Reports on a study which investigated suicide among Chinese in San Francisco, its relationship to age and sex distribution, place of birth, marital status, occupation, and methods and causes of suicide. (SF)

  2. Computerized Bus Routing in San Francisco.

    ERIC Educational Resources Information Center

    Caswell, Peter J.; Jungherr, J. Anton

    1979-01-01

    A computerized routing and scheduling system for the San Francisco Public Schools includes the batch processing of bus route assignments and schedules for all schools and the online terminal processing of daily changes. (Author/MLF)

  3. Foundation plan. San Bernardino Valley Union Junior College, Library Building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Foundation plan. San Bernardino Valley Union Junior College, Library Building. Also includes sections A through MM. Howard E. Jones, Architect, San Bernardino, California. Sheet 1, job no. 315. Scales 1/8 inch to the foot (plan) and 1/2 inch to the foot (sections). No date given on sheet (probably March or April, 1927). - San Bernardino Valley College, Library, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  4. East and west elevations. San Berardino Valley Union Junior College, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    East and west elevations. San Berardino Valley Union Junior College, Library Building. Also includes miscellaneous full size details. Howard E. Jones, Architect, San Bernardino, California. Sheet 4, Job no. 315. Scales 1/8 inch to the foot (elevations). No date given on sheet (probably March or April, 1927). - San Bernardino Valley College, Library, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  5. 2. SAN FRANCISCO STREET PROFILES: Photocopy of engraving, c. 1880, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. SAN FRANCISCO STREET PROFILES: Photocopy of engraving, c. 1880, showing street profiles of two San Francisco cable railroads. Figure 10 illustrates the mainline of the Sutter Street Railroad on Sutter Street, while Figure 11 shows the route of the Presidio & Ferries Railroad along Union Street. Note the lack of significant grades along the Sutter Street route. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  6. 1. SAN FRANCISCO STREET PROFILES: Photocopy of engraving, c. 1880, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SAN FRANCISCO STREET PROFILES: Photocopy of engraving, c. 1880, showing street profiles of three San Francisco cable lines. Figure 7, at bottom of engraving, is the profile of Hallidie's Clay Street Hill Railroad. Figures 8 and 9 show the grades for the California Street Cable Railroad and the Geary Street Park & Ocean Railroad respectively. Note the lack of significant grades along Geary Street. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  7. East and west elevations. San Berardino Valley Union Junior College, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    East and west elevations. San Berardino Valley Union Junior College, Science Building. Also includes elevations and sections of chemistry department shelving. Howard E. Jones, Architect, San Bernardino, California. Sheet 4, Job no. 311. Scales 1/8 inch to the foot (elevations) and 1/2 inch t other foot (shelving). February 15, 1927. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  8. West elevation. San Bernardino Valley Union Junior College, Science Building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    West elevation. San Bernardino Valley Union Junior College, Science Building. Also includes plan of entrance, section EE showing tiling and typical transom design, and a full size detail of a door jamb for inside concrete walls. Howard E. Jones, Architect, San Bernardino, California. Sheet 7, job no. 311. Scale 1.2 inch to the foot. February 15, 1927. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  9. Section AA through main entrance gates & west stairs. San ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Section AA through main entrance gates & west stairs. San Bernardino Valley Union Junior College, Science Building. Also includes plans and sections of boys' and girls' toilets. Howard E. Jones, Architect, San Bernardino, California. Sheet 5, job no. 311. Scales 1/4 inch to the foot (section AA) and 1/2 inch to the foot (toilet rooms). February 15, 1927. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  10. North elevation and second floor plan. San Bernardino Valley Union ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    North elevation and second floor plan. San Bernardino Valley Union Junior College, Science Building. Includes physics, geology, and zoology departments shelving. Howard E. Jones, Architect, San Bernardino, California. Sheet 4, job no. 311. Scales 1/8 inch to the foot (elevations) and 1/2 inch to the foot (shelving). February 15, 1927. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  11. Elevation and plan of east side entrance. San Bernardino Valley ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevation and plan of east side entrance. San Bernardino Valley Union Junior College, Library Building. Also includes sections II and SS of entrance hall; and a stress diagram of steel truss. Howard E. Jones, Architect, San Bernardino, California. Sheet 7, job no. 315. Scale 1/2 inch to the foot. No date given on sheet (probably March or April, 1927). - San Bernardino Valley College, Library, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  12. 11. Office of the Post Engineer, Presidio of San Francisco. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Office of the Post Engineer, Presidio of San Francisco. Location of Water Lines, Presidio of San Francisco. Sheet 31. November 1943. SHOWING EASTERN PORTION OF AREA A; BUILDINGS 274, 275, AND 277; AND POST ENGINEER'S SHOP AND YARDS INCLUDING BUILDINGS 280, 282-285, AND 288. - Presidio of San Francisco, Storehouse & Administration, Crissy Field North cantonment, Allen Street, San Francisco, San Francisco County, CA

  13. Plot plan & miscellaneous details. San Bernardino Valley Union Junior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Plot plan & miscellaneous details. San Bernardino Valley Union Junior College, Classics Building. Includes map drawers, surveying equipment lockers, counters, platforms, etc. Howard E. Jones, Architect, San Bernardino, California. Sheet 8, job no. 312. Scales 1/2 inch to the foot (details) and 1/64 inch to the foot (plot plan). February 15, 1927. - San Bernardino Valley College, Classics Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  14. Foundation plan. San Bernardino Valley Union Junior College, Classics Building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Foundation plan. San Bernardino Valley Union Junior College, Classics Building. Also includes sections AA-KK (except DD). Howard E. Jones, Architect, San Bernardino, California. Sheet 1, job no. 312. Scales 1/8 inch to the foot (plan) and 1/2 inch to the foot (sections). February 15, 1927. - San Bernardino Valley College, Classics Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  15. Trouble Brewing in San Diego. Policy Brief

    ERIC Educational Resources Information Center

    Buck, Stuart

    2010-01-01

    The city of San Diego will face enormous budgetary pressures from the growing deficits in public pensions, both at a state and local level. In this policy brief, the author estimates that San Diego faces total of $45.4 billion, including $7.95 billion for the county pension system, $5.4 billion for the city pension system, and an estimated $30.7…

  16. Children and the San Fernando earthquake

    USGS Publications Warehouse

    Howard, S. J.

    1980-01-01

    Before dawn, on February 9, 1971, a magnitude 6.4 earthquake occurred in the San Fernando Valley of California. On the following day, theSan Fernando Valley Child Guidance Clinic, through radio and newspapers, offered mental health crises services to children frightened by the earthquake. Response to this invitation was immediate and almost overwhelming. During the first 2 weeks, the Clinic's staff counseled hundreds of children who were experiencing various degrees of anxiety. 

  17. Tracer study of San Vicente reservoir

    SciTech Connect

    Williams, R.T.

    1996-11-01

    The City of San Diego remains on the cutting edge of water conservation. With an unwavering commitment to maintain an adequate water supply for the future, water repurification is now being considered. The City of San Diego and San Diego Water Authority (CWA) have proposed to recycle repurified water through San Vicente Reservoir. A key component of assessing the feasibility of such a project is to calculate the retention time of repurified water in the reservoir. Working with engineering consultant team (Montgomery-Watson Engineers and Flow Science, Incorporated) two tracer studies were conducted to model the circulation and mixing of repurified water introduced into the reservoir. The goal was to determine whether repurified water recycled through San Vicente will meet the retention time criteria established by the Department of Health Services. This presentation however, will not attempt to interpret the results of the study, that aspect will be evaluated by the Flow Scientist. The objective here is to explain how the project was carried out and to focus mostly on the analytical work performed on the samples by the chemist in the City of San Diego Water Quality Laboratory.

  18. Toxic phytoplankton in San Francisco Bay

    USGS Publications Warehouse

    Rodgers, Kristine M.; Garrison, David L.; Cloern, James E.

    1996-01-01

    The Regional Monitoring Program (RMP) was conceived and designed to document the changing distribution and effects of trace substances in San Francisco Bay, with focus on toxic contaminants that have become enriched by human inputs. However, coastal ecosystems like San Francisco Bay also have potential sources of naturally-produced toxic substances that can disrupt food webs and, under extreme circumstances, become threats to public health. The most prevalent source of natural toxins is from blooms of algal species that can synthesize metabolites that are toxic to invertebrates or vertebrates. Although San Francisco Bay is nutrient-rich, it has so far apparently been immune from the epidemic of harmful algal blooms in the world’s nutrient-enriched coastal waters. This absence of acute harmful blooms does not imply that San Francisco Bay has unique features that preclude toxic blooms. No sampling program has been implemented to document the occurrence of toxin-producing algae in San Francisco Bay, so it is difficult to judge the likelihood of such events in the future. This issue is directly relevant to the goals of RMP because harmful species of phytoplankton have the potential to disrupt ecosystem processes that support animal populations, cause severe illness or death in humans, and confound the outcomes of toxicity bioassays such as those included in the RMP. Our purpose here is to utilize existing data on the phytoplankton community of San Francisco Bay to provide a provisional statement about the occurrence, distribution, and potential threats of harmful algae in this Estuary.

  19. Abrupt along-strike change in tectonic style: San Andreas fault zone, San Francisco Peninsula

    USGS Publications Warehouse

    Zoback, M.L.; Jachens, R.C.; Olson, J.A.

    1999-01-01

    Seismicity and high-resolution aeromagnetic data are used to define an abrupt change from compressional to extensional tectonism within a 10- to 15-km-wide zone along the San Andreas fault on the San Francisco Peninsula and offshore from the Golden Gate. This 100-km-long section of the San Andreas fault includes the hypocenter of the Mw = 7.8 1906 San Francisco earthquake as well as the highest level of persistent microseismicity along that ???470-km-long rupture. We define two distinct zones of deformation along this stretch of the fault using well-constrained relocations of all post-1969 earthquakes based a joint one-dimensional velocity/hypocenter inversion and a redetermination of focal mechanisms. The southern zone is characterized by thrust- and reverse-faulting focal mechanisms with NE trending P axes that indicate "fault-normal" compression in 7- to 10-km-wide zones of deformation on both sides of the San Andreas fault. A 1- to 2-km-wide vertical zone beneath the surface trace of the San Andreas is characterized by its almost complete lack of seismicity. The compressional deformation is consistent with the young, high topography of the Santa Cruz Mountains/Coast Ranges as the San Andreas fault makes a broad restraining left bend (???10??) through the southernmost peninsula. A zone of seismic quiescence ???15 km long separates this compressional zone to the south from a zone of combined normal-faulting and strike-slip-faulting focal mechanisms (including a ML = 5.3 earthquake in 1957) on the northernmost peninsula and offshore on the Golden Gate platform. Both linear pseudo-gravity gradients, calculated from the aeromagnetic data, and seismic reflection data indicate that the San Andreas fault makes an abrupt ???3-km right step less than 5 km offshore in this northern zone. A similar right-stepping (dilatational) geometry is also observed for the subparallel San Gregorio fault offshore. Persistent seismicity and extensional tectonism occur within the San

  20. Chronology of eclipse "San Miao"

    NASA Astrophysics Data System (ADS)

    Liu, Ci-Yuan

    2001-06-01

    The ancient book "Mozi" (5th century BC) records: "In ancient times, the San Miao tribes were in disarray. The sun rose in the evening...King Yu vanquished them. "King Yu is a prehistoric person living in 23-19th century BC. The strange phenomena "sun rose in evening" was explained as a large solar eclipse at sunset by Pang. Therefore investigations on it may lead to an important progress of Chinese chronology. After an analysis on all similar records in Chinese history, we pay main attention to the relationship of eclipse computations with parameter "c", the long term of earth's rotation rate. We have computed all the solar eclipses in that period by the way similar to that used for investigating the "double dawn" eclipse. By change parameter "c" in reasonable range (28-36 sec/cy2), we have found 11 possible results listed in a table. One figure shows the eclipse maps and relative "double dawn/dusk" areas while another one illustrates how the parameter "c" affects the result. For an exact conclusion of King Yu's chronology, we need further progress from both side: history which may limit the King Yu's period and astronomy which may limit the possible range of parameter "c".

  1. Anthropogenic influences on shoreline and nearshore evolution in the San Francisco Bay coastal system

    USGS Publications Warehouse

    Dallas, K.L.; Barnard, P.L.

    2011-01-01

    Analysis of four historical bathymetric surveys over a 132-year period has revealed significant changes to the morphology of the San Francisco Bar, an ebb-tidal delta at the mouth of San Francisco Bay estuary. From 1873 to 2005 the San Francisco Bar vertically-eroded an average of 80 cm over a 125 km2 area, which equates to a total volume loss of 100 ± 52 million m3 of fine- to coarse-grained sand. Comparison of the surveys indicates the entire ebb-tidal delta contracted radially, with the crest moving landward an average of 1 km. Long-term erosion of the ebb-tidal delta is hypothesized to be due to a reduction in the tidal prism of San Francisco Bay and a decrease in coastal sediment supply, both as a result of anthropogenic activities. Prior research indicates that the tidal prism of the estuary was reduced by 9% from filling, diking, and sedimentation. Compilation of historical records dating back to 1900 reveals that a minimum of 200 million m3 of sediment has been permanently removed from the San Francisco Bay coastal system through dredging, aggregate mining, and borrow pit mining. Of this total, ~54 million m3 of sand-sized or coarser sediment was removed from central San Francisco Bay. With grain sizes comparable to the ebb-tidal delta, and its direct connection to the bay mouth, removal of sediments from central San Francisco Bay may limit the sand supply to the delta and open coast beaches. SWAN wave modeling illustrates that changes to the morphology of the San Francisco Bar have altered the alongshore wave energy distribution at adjacent Ocean Beach, and thus may be a significant factor in a persistent beach erosion ‘hot spot’ occurring in the area. Shoreline change analyses show that the sandy shoreline in the shadow of the ebb-tidal delta experienced long-term (1850s/1890s to 2002) and short-term (1960s/1980s to 2002) accretion while the adjacent sandy shoreline exposed to open-ocean waves experienced long-term and short-term erosion. Therefore

  2. Simulations of the 1906 San Francisco Earthquake and Scenario Earthquakes in Northern California

    NASA Astrophysics Data System (ADS)

    Larsen, S.; Dreger, D.; Dolenc, D.

    2006-12-01

    3-D simulations of seismic ground motions are performed to better characterize the 1906 San Francisco earthquake and to investigate the seismic consequences from scenario events in northern California. Specifically, we perform simulations of: 1) the 1906 earthquake, which bilaterally ruptured a 480-km segment of the San Andreas fault from San Juan Bautista to Cape Mendocino (epicenter a few kilometers off the coast of San Francisco); 2) large scenario San Andreas events with different epicentral locations; and 3) smaller scenario events along faults local to the San Francisco Bay Area. Simulations of the 1906 earthquake indicate that significant ground motion occurred up and down the northern California coast and out into the Central Valley. Comparisons between the simulated motions and observed data (e.g., shaking intensities, Boatwright and Bundock, 2005), suggest that the moment magnitude of this event was between M7.8 and M7.9. Simulations of 1906-like scenario events along the San Andreas fault reveal that ground motions in the San Francisco Bay Area and in the Sacramento Delta region would be significantly stronger for earthquakes initiating along the northern section of the fault and rupturing to the southeast. Simulations of smaller scenario events in the San Francisco Bay Area indicate areas of concentrated shaking. These simulations are performed using a recently developed 3-D geologic model of northern California (Brocher and Thurber, 2005; Jachens et al., 2005), together with finite-difference codes (E3D and a new public domain package). The effects of topography and attenuation are included. The full computational domain spans most of the geologic model and is 630x320x50 km3. The minimum S-wave velocity is constrained to 500 m/s, except in water. Frequencies up to 1.0 Hz are modeled. The grid spacing ranges from 75 m to 200 m. High performance supercomputers are used for the simulations, which include models of over 23 billion grid nodes using 2000

  3. Commercial production of ethanol in the San Luis Valley, Colorado. Final Report

    SciTech Connect

    Hewlett, E.M.; Erickson, M.V.; Ferguson, C.D.; Sherwood, P.B.; Boswell, B.S.; Walter, K.M.; Hart, M.L.

    1983-07-01

    The purpose of this study is to assess the commercial feasibility of producing between 76 and 189 million liters (20 and 50 million gallons) of ethanol annually in the San Luis Valley, Colorado using geothermal energy as the primary heat source. The San Luis Valley is located in south-central Colorado. The valley is a high basin situated approximately 2316 meters (7600 feet) above sea level which contains numerous warm water wells and springs. A known geothermal resource area (KGRA) is located in the east-central area of the valley. The main industry in the valley is agriculture, while the main industry in the surrounding mountains is lumber. Both of these industries can provide feedstock for the production of ethanol.

  4. Commercial production of ethanol in the San Luis Valley, Colorado. Final report

    SciTech Connect

    Hewlett, E.M.; Erickson, M.V.; Ferguson, C.D.; Boswell, B.S.; Walter, K.M.; Hart, M.L.; Sherwood, P.B.

    1983-07-01

    The commercial feasibility of producing between 76 and 189 million liters (20 to 50 million gallons) of ethanol annually in the San Luis Valley, Colorado using geothermal energy as the primary heat source was assessed. The San Luis Valley is located in south-central Colorado. The valley is a high basin situated approximately 2316 meters (7600 feet) above sea level which contains numerous warm water wells and springs. A known geothermal resource area (IGRA) is located in the east-central area of the valley. The main industry in the valley is agriculture, while the main industry in the surrounding mountains is lumber. Both of these industries can provide feedstocks for the production of ethanol.

  5. Slip in the 1857 and earlier large earthquakes along the Carrizo Plain, San Andreas Fault.

    PubMed

    Zielke, Olaf; Arrowsmith, J Ramón; Grant Ludwig, Lisa; Akçiz, Sinan O

    2010-02-26

    The moment magnitude (Mw) 7.9 Fort Tejon earthquake of 1857, with a approximately 350-kilometer-long surface rupture, was the most recent major earthquake along the south-central San Andreas Fault, California. Based on previous measurements of its surface slip distribution, rupture along the approximately 60-kilometer-long Carrizo segment was thought to control the recurrence of 1857-like earthquakes. New high-resolution topographic data show that the average slip along the Carrizo segment during the 1857 event was 5.3 +/- 1.4 meters, eliminating the core assumption for a linkage between Carrizo segment rupture and recurrence of major earthquakes along the south-central San Andreas Fault. Earthquake slip along the Carrizo segment may recur in earthquake clusters with cumulative slip of approximately 5 meters. PMID:20093436

  6. Sans Spring Field Exploration Model, Nye County, Nevada

    SciTech Connect

    Mitchell, M.H.

    1995-06-01

    The existing model for Oligocene volcanic reservoir production in Railroad Valley was expanded with the discovery of oil at Sans Spring field by CENEX, et. al in March, 1993. Prior to drilling the CENEX No. 5-14 Federal (SWNW, section 14, T7N-R56E), economic production had only been established along the east and west borders of the valley, in structures associated with large offset normal faults. The location of Sans Spring field is on an east-west structural high that separates the productive central Railroad Valley sub-basin from the as yet unproductive southern sub-basin. Gravity, regional and detailed conventional 2-D seismic data coverage was employed to define the structure. This geophysical data further suggested that the structure had remained relatively undeformed, providing seal and trap integrity, during the post Oligocene extensional structural development of Railroad Valley. The location also met a critical criterion of being along a potential hydrocarbon migration pathway for oil generated by the Mississippian Chainman shale source rocks. The discovery well found reservoir development in a moderately welded and altered rhyolitic ignimbrite, with an IPF 1253 BOPD. The trap is an angular unconformity, with truncation to the west that has been modified and complicated by cut and fill channeling and faulting. Definition of the structural configuration, fault geometries and offsets has been greatly enhanced with the acquisition of a 3-D seismic survey. However, the data volume does not as yet provide an unambiguous solution to stratigraphic variations.

  7. Strain accumulation and surface deformation along the San Andreas, California

    NASA Technical Reports Server (NTRS)

    Li, Victor C.

    1986-01-01

    Stressing and rupture of a locked zone adjacent to a creeping fault segment was studied with special reference to strength heterogeneity depthwise and along-strike. The resulting precursory temporal and spatial variations of surface strain rate profiles were compared to geodetic measurements on the San Andreas fault in central California. Crustal deformation in great California earthquake cycles was also studied with special reference to the temporal decay of strain rate observed since the 1957 and 1906 great earthquakes, and comtemporary surface strain rate and velocity profiles at several locations along the San Andreas. The effect of viscoelastic response in the deep aseismic shear zone on the surface deformation behavior was examined. Work was begun on a fundamental reformulation of the crustal deformation problem focusing on the crustal deformation process affected by deep aseismic slip as the slip zone progresses toward an instability and as deep seismic slip continues postseismically, the 3-D nature of the problem due to geometry and material heterogeneity, and the time-dependent source coming from the lithosphere/astenospheric coupling process.

  8. Designing and application of SAN extension interface based on CWDM

    NASA Astrophysics Data System (ADS)

    Qin, Leihua; Yu, Shengsheng; Zhou, Jingli

    2005-11-01

    As Fibre Channel (FC) becomes the protocol of choice within corporate data centers, enterprises are increasingly deploying SANs in their data central. In order to mitigate the risk of losing data and improve the availability of data, more and more enterprises are increasingly adopting storage extension technologies to replicate their business critical data to a secondary site. Transmitting this information over distance requires a carrier grade environment with zero data loss, scalable throughput, low jitter, high security and ability to travel long distance. To address this business requirements, there are three basic architectures for storage extension, they are Storage over Internet Protocol, Storage over Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) and Storage over Dense Wavelength Division Multiplexing (DWDM). Each approach varies in functionality, complexity, cost, scalability, security, availability , predictable behavior (bandwidth, jitter, latency) and multiple carrier limitations. Compared with these connectiviy technologies,Coarse Wavelength Division Multiplexing (CWDM) is a Simplified, Low Cost and High Performance connectivity solutions for enterprises to deploy their storage extension. In this paper, we design a storage extension connectivity over CWDM and test it's electrical characteristic and random read and write performance of disk array through the CWDM connectivity, testing result show us that the performance of the connectivity over CWDM is acceptable. Furthermore, we propose three kinds of network architecture of SAN extension based on CWDM interface. Finally the credit-Based flow control mechanism of FC, and the relationship between credits and extension distance is analyzed.

  9. San Mateo County's Server Information Program (S.I.P.): A Community-Based Alcohol Server Training Program.

    ERIC Educational Resources Information Center

    de Miranda, John

    The field of alcohol server awareness and training has grown dramatically in the past several years and the idea of training servers to reduce alcohol problems has become a central fixture in the current alcohol policy debate. The San Mateo County, California Server Information Program (SIP) is a community-based prevention strategy designed to…

  10. Assessment of Goods and Valuation of Ecosystem Services (AGAVES), San Pedro River Basin, U.S./Mexico

    EPA Science Inventory

    A consortium of federal, academic, and non-government organizations (NGO) partners have established a collaborative research enterprise in the San Pedro River Basin to develop methods, standards, and tools to assess and value ecosystem goods and services. The central premise of e...

  11. 78 FR 29289 - Safety Zone; Big Bay Boom, San Diego Bay, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-20

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Big Bay Boom, San Diego Bay, San Diego, CA... Big Bay Boom Fireworks display from 8:45 p.m. to 10 p.m. on July 4, 2013. These proposed safety zones... Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking A....

  12. 78 FR 39610 - Safety Zone; Big Bay Boom, San Diego Bay; San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Big Bay Boom, San Diego Bay; San Diego, CA... Fourth of July Big Bay Boom Fireworks display on the evening of July 4, 2013. These temporary safety... as being available in the docket, go to http://www.regulations.gov , type the docket number in...

  13. 33 CFR 165.754 - Safety Zone: San Juan Harbor, San Juan, PR.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... remain in the safety zone unless authorized by the Captain of the Port, San Juan, Puerto Rico, or a... through the safety zone with a Coast Guard designated escort. (3) The Captain of the Port and the Duty Officer at Sector San Juan, Puerto Rico, can be contacted at telephone number 787-289-2041. The...

  14. 75 FR 51098 - Protection Island and San Juan Islands National Wildlife Refuges, Jefferson, Island, San Juan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... Register on August 14, 2007 (72 FR 45444), announcing our intent to complete a CCP/EA and inviting public... Fish and Wildlife Service Protection Island and San Juan Islands National Wildlife Refuges, Jefferson, Island, San Juan, Skagit, and Whatcom Counties, WA AGENCY: Fish and Wildlife Service, Interior....

  15. 78 FR 10062 - Safety Zone; Sea World San Diego Fireworks, Mission Bay; San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-13

    ... Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking A... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Sea World San Diego Fireworks, Mission Bay... establishing a safety zone on the navigable waters of Mission Bay in support of the Sea World San...

  16. The Economic Impact of San Juan College on San Juan County, New Mexico, 1991-92.

    ERIC Educational Resources Information Center

    Clark, Mary Jo

    A study was conducted of the economic impact of San Juan College (SJC) in Farmington, New Mexico, on businesses and employment in San Juan County during fiscal year (FY) 1991-92. The five components used to measure the college's tangible economic impact on the local community were SJC's total expenditures in FY 1991-92 used to buy goods and…

  17. 77 FR 46115 - Notice of Inventory Completion: San Diego Museum of Man, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-02

    ...The San Diego Museum of Man has completed an inventory of human remains in consultation with the appropriate Indian tribe, and has determined that there is a cultural affiliation between the human remains and a present-day Indian tribe. Representatives of any Indian tribe that believes itself to be culturally affiliated with the human remains may contact the San Diego Museum of Man.......

  18. 76 FR 14051 - Notice of Inventory Completion: San Francisco State University, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR National Park Service Notice of Inventory Completion: San Francisco State University, San Francisco, CA AGENCY: National Park Service, Interior. ACTION: Notice. Notice is here given in accordance with the Native American Graves Protection...

  19. 78 FR 29025 - Sea World San Diego Fireworks 2013 Season; Mission Bay, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-17

    ... FR Federal Register NPRM Notice of Proposed Rulemaking A. Regulatory History and Information The... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Sea World San Diego Fireworks 2013 Season; Mission Bay... establishing a safety zone on the navigable waters of Mission Bay in support of the Sea World San...

  20. 77 FR 42638 - Safety Zone: Sea World San Diego Fireworks, Mission Bay; San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    .... SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone: Sea World San Diego Fireworks, Mission Bay... establishing a safety zone on the navigable waters of Mission Bay in support of the Sea World San...

  1. 77 FR 60899 - Safety Zone; Sea World San Diego Fireworks, Mission Bay; San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-05

    ... DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking A... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Sea World San Diego Fireworks, Mission Bay... establishing a safety zone on the navigable waters of Mission Bay in support of the Sea World San...

  2. Una Visita al Viejo San Juan (A Visit to Old San Juan).

    ERIC Educational Resources Information Center

    Cabello, Victor; And Others

    Written in Spanish, this black and white illustrated booklet provides a tour of Old San Juan, Puerto Rico's oldest and most historic city. Brief historical information is provided on the Perro de San Jeronimo, a statue of a barking dog found in front of the Castillo; Plaza de Colon, a small plaza dedicated to Christopher Columbus; the Catedral de…

  3. The San Andreas Fault 'Supersite' (Invited)

    NASA Astrophysics Data System (ADS)

    Hudnut, K. W.

    2013-12-01

    An expanded and permanent Supersite has been proposed to the Committee on Earth Observation Satellites (CEOS) for the San Andreas Fault system, based upon the successful initial Group on Earth Observations (GEO) Geohazard Supersite for the Los Angeles region from 2009-2013. As justification for the comprehensive San Andreas Supersite, consider the earthquake history of California, in particular the devastating M 7.8 San Francisco earthquake of 1906, which occurred along the San Andreas Fault, as did an earthquake of similar magnitude in 1857 in southern California. Los Angeles was only a small town then, but now the risk exposure has increased for both of California's megacities. Between the San Francisco and Los Angeles urban areas lies a section of the San Andreas Fault known to creep continually, so it has relatively less earthquake hazard. It used to be thought of as capable of stopping earthquakes entering it from either direction. Transitional behavior at either end of the creeping section is known to display a full range of seismic to aseismic slip events and accompanying seismicity and strain transient events. Because the occurrence of creep events is well documented by instrumental networks such as CISN and PBO, the San Andreas Supersite can be expected to be especially effective. A good baseline level of geodetic data regarding past events and strain accumulation and release exists. Many prior publications regarding the occurrence of geophysical phenomena along the San Andreas Fault system mean that in order to make novel contributions, state-of-the-art science will be required within this Supersite region. In more recent years, the 1989 Loma Prieta earthquake struck adjacent to the San Andreas Fault and caused the most damage along the western side of the San Francisco Bay Area. More recently, the concern has focused on the potential for future events along the Hayward Fault along the eastern side of San Francisco Bay. In Southern California, earthquakes

  4. The morphology of strike-slip faults - Examples from the San Andreas Fault, California

    NASA Technical Reports Server (NTRS)

    Bilham, Roger; King, Geoffrey

    1989-01-01

    The dilatational strains associated with vertical faults embedded in a horizontal plate are examined in the framework of fault kinematics and simple displacement boundary conditions. Using boundary element methods, a sequence of examples of dilatational strain fields associated with commonly occurring strike-slip fault zone features (bends, offsets, finite rupture lengths, and nonuniform slip distributions) is derived. The combinations of these strain fields are then used to examine the Parkfield region of the San Andreas fault system in central California.

  5. Electrical resistivity variations associated with earthquakes on the san andreas fault.

    PubMed

    Mazzella, A; Morrison, H F

    1974-09-01

    A 24 percent precursory change in apparent electrical resistivity was observed before a magnitude 3.9 earthquake of strike-slip nature on the San Andreas fault in central California. The experimental configuration and numerical calculations suggest that the change is associated with a volume at depth rather than some near-surface phenomenon. The character and duration of the precursor period agree well with those of other earthquake studies and support a dilatant earthquake mechanism model. PMID:17833697

  6. Assessment of remaining recoverable oil in selected major oil fields of the San Joaquin Basin, California

    USGS Publications Warehouse

    Tennyson, Marilyn E.; Cook, Troy A.; Charpentier, Ronald R.; Gautier, Donald L.; Klett, Timothy R.; Verma, Mahendra K.; Ryder, Robert T.; Attanasi, E.D.; Freeman, P.A.; Le, Phoung A.

    2012-01-01

    The U.S. Geological Survey (USGS) recently completed an estimate of volumes of technically recoverable, conventional oil that could eventually be added to reserves in nine selected major oil fields in the San Joaquin Basin in central California. The mean total volume of potential oil reserves that might be added in the nine fields using improved oil-recovery technologies was estimated to be about 6.5 billion barrels of oil.

  7. California coastal processes study: Skylab. [San Pablo and San Francisco Bays

    NASA Technical Reports Server (NTRS)

    Pirie, D. M.; Steller, D. D. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. In San Pablo Bay, the patterns of dredged sediment discharges were plotted over a three month period. It was found that lithogenous particles, kept in suspension by the fresh water from the Sacramento-San Joaquin, were transported downstream to the estuarine area at varying rates depending on the river discharge level. Skylab collected California coastal imagery at limited times and not at constant intervals. Resolution, however, helped compensate for lack of coverage. Increased spatial and spectral resolution provided details not possible utilizing Landsat imagery. The S-192 data was reformatted; band by band image density stretching was utilized to enhance sediment discharge patterns entrainment, boundaries, and eddys. The 26 January 1974 Skylab 4 imagery of San Francisco Bay was taken during an exceptionally high fresh water and suspended sediment discharge period. A three pronged surface sediment pattern was visible where the Sacramento-San Joaquin Rivers entered San Pablo Bay through Carquinez Strait.

  8. Thermal regime of the San Andreas Fault near Parkfield, California

    NASA Astrophysics Data System (ADS)

    Sass, J. H.; Williams, C. F.; Lachenbruch, Arthur H.; Galanis, S. P., Jr.; Grubb, F. V.

    1997-12-01

    Knowledge of the temperature variation with depth near the San Andreas fault is vital to understanding the physical processes that occur within the fault zone during earthquakes and creep events. Parkfield is near the southern end of the Coast Ranges segment of the San Andreas fault. This segment has higher mean heat flow than the Cape Mendocino segment to the northwest or the Mojave segment to the southeast. Boreholes were drilled specifically for the U.S. Geological Survey's Parkfield earthquake prediction experiment or converted from other uses at 25 sites within a few kilometers of the fault near Parkfield. These holes, which range in depth from 150 to over 1500m, were intended mainly for the deployment of volumetric strain meters, water-level recorders, and other downhole instruments. Temperature profiles were obtained from all the holes, and heat flow values were estimated from 17 of them. For a number of reasons, including a paucity of thermal conductivity data and rugged local topography, the accuracy of individual determinations was not sufficiently high to document local variations in heat flow. Values range from 54 to 92 mW m-2, with mean and 95% confidence limits of 74±4 mW m-2. This mean is slightly lower than the mean (83±3) of 39 previously published values from the central Coast Ranges, but it is consistent with the overall pattern of elevated heat flow in the Coast Ranges, and it is transitional to the mean of 68±2 mW m-2 that characterizes the Mojave segment of the San Andreas fault immediately to the south. The lack of a heat flow peak near the fault underscores the absence of a frictional thermal anomaly and provides additional support for a very small resolved shear stress parallel to the San Andreas fault and the nearly fault-normal maximum compressive stress observed in this region. Estimates of subsurface thermal conditions indicate that the seismicaseismic transition for the Parkfield segment corresponds to temperatures in the range of

  9. Central line infections - hospitals

    MedlinePlus

    ... infection; CVC - infection; Central venous device - infection; Infection control - central line infection; Nosocomial infection - central line infection; Hospital acquired infection - central line infection; Patient safety - central ...

  10. Electromagnetic Imaging of Fluids in the San Andreas Fault

    SciTech Connect

    Martyn Unsworth

    2002-05-01

    OAK 270 - Magnetotelluric data were collected on six profiles across the san Andreas Fault at Cholame,Parkfield, and Hollister in Central California. On each profile, high electrical resistivities were imaged west of the fault, and are due to granitic rocks of the Salinian block. East of the fault, lower electrical resistivities are associated with rocks of the Fanciscan formation. On the seismically active Parkfield and Hollister segments, a region of low resistivity was found in the fault zone that extends to a depth of several kilometers. This is due to a zone of fracturing (the damaged zone) that has been infiltrated by saline ground water. The shallowest micro-earthquakers occur at a depth that is coincident with the base of the low resistivity wedge. This strongly suggests that above this depth, the fault rocks are too weak to accumulate sufficient stress for earthquake rupture to occur and fault motion is accommodated through aseismic creep.

  11. Solar Synoptic Maps from the San Fernando Observatory

    NASA Astrophysics Data System (ADS)

    Hodgson, John, II; Chapman, G.; Preminger, D.; Cookson, A.

    2011-05-01

    We are developing a set of synoptic image maps compiled from daily photometric images taken at the San Fernando Observatory. Our initial maps show the progression of solar features across the central meridian for approximately one solar rotation. The red continuum maps show the photometric contrast of solar features in the photosphere while the Ca II K-line maps show the same in the lower chromosphere. Comparing these maps with each other, and with those of other solar groups, will yield information regarding the evolutionary patterns of solar activity at different heights of the solar atmosphere. This is a first step toward a comprehensive set of synoptic maps covering the period from mid-solar cycle 22 in 1988 to the present. This work has been supported in part by NSF grant ATM-0848518.

  12. Late Glacial and Holocene Record of Hydroclimate in the San Luis Valley, Southern Colorado, USA

    NASA Astrophysics Data System (ADS)

    Yuan, F.; Koran, M.

    2012-12-01

    Lake sediments from the San Luis Valley, south-central Colorado, archive a detailed record of Late Glacial and Holocene climatic fluctuations in the southern Rocky Mountains. Together with radiometric dating analysis, measurements of grain size, magnetic susceptibility, total inorganic carbon (TIC), oxygen and carbon isotopic composition of the TIC fraction on sediment samples from San Luis Lake (at an average resolution of 60 years per sample) allow us to generate a sediment record of climatic change in the region spanning the last 16ka (1 ka=1000 cal yrs). This record documents the timing and duration of major climate episodes and trends, comparable to the existing paleoclimate records from the American Southwest. The Late Glacial record of San Luis Lake contains a big wet episode in the late part of the Mystery Interval (MI), a relatively dry climate during Bølling-Allerød (B/A) warm interval, and a relatively wet episode during the Younger Dryas (YD) interval, similar to the lake-level record found in the Estancia basin in central New Mexico. The early to middle Holocene record of d18O in the San Luis Lake parallels the calcite d18O record of Bison Lake in northern Colorado, documenting a history of significant change in precipitation seasonality across the northern boundary of the North American monsoon (NAM). The middle Holocene epoch is characterized by greater variations in magnetic susceptibility, d18O and d13C, suggesting the prevalence of wet, variable or transitional climate conditions. In contrast, the late Holocene climate is relatively dry, as indicated by more positive values of d18O in San Luis Lake. The results of this study reveal a complex history of climate evolution due to the interactions of two seasonally distinct precipitation regimes with mountainous landforms in the region.

  13. Diversity of Denitrifying Bacteria in the San Francisco Bay

    NASA Astrophysics Data System (ADS)

    Atluri, A.; Lee, J.; Francis, C. A.

    2012-12-01

    We compared the diversity of communities of denitrifying bacteria from the San Francisco Bay to investigate whether environmental factors affect diversity. To do this, we studied the sequence diversity of the marker gene nirK. nirK codes for the enzyme nitrite reductase which helps reduce nitrite to nitric oxide, an important step in denitrification. Sediment samples were collected spatially from five different locations and temporally during the four different seasons along a salinity gradient in the bay. After collecting samples and extracting DNA from them, we used PCR to amplify our gene of interest, created clone libraries for sequencing, and compared phylogenetic trees from the different communities. Based on several phylogenetic analyses on our tree and environments, we saw that denitrifying bacteria from the North and Central Bay form distinct spatial clusters; Central Bay communities are very similar to each other, while communities from the North Bay are more distinct from each other and from communities in the Central Bay. Bacteria from site 8.1M (Carquinez Strait) showed the most cm-scale spatial diversity, and there was the most species richness during the winter. All this suggests that diversity of communities of denitrifying bacteria may be affected by spatial and temporal environmental factors.

  14. 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

  15. Cacao use and the San Lorenzo Olmec

    PubMed Central

    Powis, Terry G.; Cyphers, Ann; Gaikwad, Nilesh W.; Grivetti, Louis; Cheong, Kong

    2011-01-01

    Mesoamerican peoples had a long history of cacao use—spanning more than 34 centuries—as confirmed by previous identification of cacao residues on archaeological pottery from Paso de la Amada on the Pacific Coast and the Olmec site of El Manatí on the Gulf Coast. Until now, comparable evidence from San Lorenzo, the premier Olmec capital, was lacking. The present study of theobromine residues confirms the continuous presence and use of cacao products at San Lorenzo between 1800 and 1000 BCE, and documents assorted vessels forms used in its preparation and consumption. One elite context reveals cacao use as part of a mortuary ritual for sacrificial victims, an event that occurred during the height of San Lorenzo's power. PMID:21555564

  16. Cacao use and the San Lorenzo Olmec.

    PubMed

    Powis, Terry G; Cyphers, Ann; Gaikwad, Nilesh W; Grivetti, Louis; Cheong, Kong

    2011-05-24

    Mesoamerican peoples had a long history of cacao use--spanning more than 34 centuries--as confirmed by previous identification of cacao residues on archaeological pottery from Paso de la Amada on the Pacific Coast and the Olmec site of El Manatí on the Gulf Coast. Until now, comparable evidence from San Lorenzo, the premier Olmec capital, was lacking. The present study of theobromine residues confirms the continuous presence and use of cacao products at San Lorenzo between 1800 and 1000 BCE, and documents assorted vessels forms used in its preparation and consumption. One elite context reveals cacao use as part of a mortuary ritual for sacrificial victims, an event that occurred during the height of San Lorenzo's power. PMID:21555564

  17. Salt Ponds, South San Francisco Bay

    NASA Technical Reports Server (NTRS)

    2002-01-01

    higher resolution 1000 pixel-wide image The red and green colors of the salt ponds in South San Francisco Bay are brilliant visual markers for astronauts. The STS-111 crew photographed the bay south of the San Mateo bridge in June, 2002. This photograph is timely because a large number of the salt ponds (more than 16,500 acres) that are owned by Cargill, Inc. will be sold in September for wetlands restoration-a restoration project second in size only to the Florida Everglades project. Rough boundaries of the areas to be restored are outlined on the image. Over the past century, more than 80% of San Francisco Bay's wetlands have been filled and developed or diked off for salt mining. San Francisco Bay has supported salt mining since 1854. Cargill has operated most of the bay's commercial salt ponds since 1978, and had already sold thousands of acres to the State of California and the Don Edwards National Wildlife Refuge. This new transaction will increase San Francisco Bay's existing tidal wetlands by 50%. The new wetlands, to be managed by the California Department of Fish and Game and the U.S. Fish and Wildlife Service, will join the Don Edwards National Wildlife Refuge, and provide valuable habitat for birds, fish and other wildlife. The wetlands will contribute to better water quality and flood control in the bay, and open up more coastline for public enjoyment. Additional information: Cargill Salt Ponds (PDF) Turning Salt Into Environmental Gold Salt Ponds on Way to Becoming Wetlands Historic Agreement Reached to Purchase San Francisco Bay Salt Ponds Astronaut photograph STS111-376-3 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

  18. Forecasting the Next Great San Francisco Earthquake

    NASA Astrophysics Data System (ADS)

    Rundle, P.; Rundle, J. B.; Turcotte, D. L.; Donnellan, A.; Yakovlev, G.; Tiampo, K. F.

    2005-12-01

    The great San Francisco earthquake of 18 April 1906 and its subsequent fires killed more than 3,000 persons, and destroyed much of the city leaving 225,000 out of 400,000 inhabitants homeless. The 1906 earthquake occurred on a km segment of the San Andreas fault that runs from the San Juan Bautista north to Cape Mendocino and is estimated to have had a moment magnitude m ,l 7.9. Observations of surface displacements across the fault were in the range m. As we approach the 100 year anniversary of this event, a critical concern is the hazard posed by another such earthquake. In this talk we examine the assumptions presently used to compute the probability of occurrence of these earthquakes. We also present the results of a numerical simulation of interacting faults on the San Andreas system. Called Virtual California, this simulation can be used to compute the times, locations and magnitudes of simulated earthquakes on the San Andreas fault in the vicinity of San Francisco. Of particular importance are new results for the statistical distribution of interval times between great earthquakes, results that are difficult or impossible to obtain from a purely field-based approach. We find that our results are fit well under most circumstances by the Weibull statistical distribution, and we compute waiting times to future earthquakes based upon our simulation results. A contrasting approach to the same problem has been adopted by the Working Group on California Earthquake Probabilities, who use observational data combined with statistical assumptions to compute probabilities of future earthquakes.

  19. A Case for Historic Joint Rupture of the San Andreas and San Jacinto Faults

    NASA Astrophysics Data System (ADS)

    Lozos, J.

    2015-12-01

    The ~M7.5 southern California earthquake of 8 December 1812 ruptured the San Andreas Fault from Cajon Pass to at least as far north as Pallet Creek (Biasi et al., 2002). The 1812 rupture has also been identified in trenches at Burro Flats to the south (Yule and Howland, 2001). However, the lack of a record of 1812 at Plunge Creek, between Cajon Pass and Burro Flats (McGill et al., 2002), complicates the interpretation of this event as a straightforward San Andreas rupture. Paleoseismic records of a large early 19th century rupture on the northern San Jacinto Fault (Onderdonk et al., 2013; Kendrick and Fumal, 2005) allow for alternate interpretations of the 1812 earthquake. I use dynamic rupture modeling on the San Andreas-San Jacinto junction to determine which rupture behaviors produce slip patterns consistent with observations of the 1812 event. My models implement realistic fault geometry, a realistic velocity structure, and stress orientations based on seismicity literature. Under these simple assumptions, joint rupture of the two faults is the most common behavior. My modeling rules out a San Andreas-only rupture that is consistent with the data from the 1812 earthquake, and also shows that single fault events are unable to match the average slip per event for either fault. The choice of nucleation point affects the details of rupture directivity and slip distribution, but not the first order result that multi-fault rupture is the preferred behavior. While it cannot be definitively said that joint San Andreas-San Jacinto rupture occurred in 1812, these results are consistent with paleoseismic and historic data. This has implications for the possibility of future multi-fault rupture within the San Andreas system, as well as for interpretation of other paleoseismic events in regions of complex fault interactions.

  20. San Marcos Astronomical Project and Doctoral Prospectus

    NASA Astrophysics Data System (ADS)

    Aguilar, M. L.

    2009-05-01

    The Universidad Nacional Mayor de San Marcos, UNMSM, in Lima, Perú, is the only Peruvian institution working for the peruvian astronomical development as a career since 1970. We are conforming a network with international friend astronomers to invite them as Visiting Lectures to assure the academic level for the future doctoral studies in the UNMSM. The Chancellor of UNMSM has decided that the Astronomical Project is a UNMSM Project, to encourage and advance in this scientific and strategical area, to impulse the modernity of Peru, the major effort will be the building of the San Marcos Astronomical Observatory, with a telescope of 1 meter aperture.

  1. Lower San Fernando corrugated metal pipe failure

    SciTech Connect

    Bardet, J.P.; Davis, C.A.

    1995-12-31

    During the January 17, 1994, Northridge earthquake, a 2.4 m diameter corrugated metal pipe was subjected to 90 m of extensive lateral crushing failure at the Lower San Fernando Dam. The dam and outlet works were reconstructed after the 1971 San Fernando Earthquake. In 1994, the dam underwent liquefaction upstream of the reconstructed berm. The pipe collapsed on the west side of the liquefied zone and a large sinkhole formed over the drain line. The failure of this drain line provides a unique opportunity to study the seismic response of buried drains and culverts.

  2. Aerial views of the San Andreas Fault

    USGS Publications Warehouse

    Moore, M.

    1988-01-01

    These aerial photographs of the San Andreas fault were taken in 1965 by Robert E. Wallace of the U.S Geological Survey. The pictures were taken with a Rolliflex camera on 20 format black and white flim; Wallace was aboard a light, fixed-wing aircraft, flying mostly at low altitudes. He photographed the fault from San Francisco near its north end where it enters by the Salton Sea. These images represent only a sampling of the more than 300 images prodcued during this project. All the photographs reside in the U.S Geological Survey Library in Menlo Park, California. 

  3. The San Francisco volcanic field, Arizona

    USGS Publications Warehouse

    Priest, S.S.; Duffield, W.A.; Malis-Clark, Karen; Hendley, J. W., II; Stauffer, P.H.

    2001-01-01

    Northern Arizona's San Francisco Volcanic Field, much of which lies within Coconino and Kaibab National Forests, is an area of young volcanoes along the southern margin of the Colorado Plateau. During its 6-million-year history, this field has produced more than 600 volcanoes. Their activity has created a topographically varied landscape with forests that extend from the Pi?on-Juniper up to the Bristlecone Pine life zones. The most prominent landmark is San Francisco Mountain, a stratovolcano that rises to 12,633 feet and serves as a scenic backdrop to the city of Flagstaff.

  4. 98. Street view, East San Antonio Ave., looking west northwest, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    98. Street view, East San Antonio Ave., looking west northwest, Guarantee Shoe Co. is 211 East San Antonio Ave. - South El Paso Street Historic District, South El Paso, South Oregon & South Santa Fe Streets, El Paso, El Paso County, TX

  5. 30. Photocopy of photograph (from National Park Service, San Francisco, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Photocopy of photograph (from National Park Service, San Francisco, California, 1930 (?) EXTERIOR, EAST SIDE OF MISSIONA AFTER RESTORATION, C. 1930 (?) - Mission San Francisco Solano de Sonoma, First & Spain Streets, Sonoma, Sonoma County, CA

  6. 27. Photocopy of photograph (from National Park Service, San Francisco, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. Photocopy of photograph (from National Park Service, San Francisco, California, Date unknown) EXTERIOR, SOUTH FRONT, DETAIL OF ENTRANCE AFTER RESTORATION, C. 1930 (?) - Mission San Francisco Solano de Sonoma, First & Spain Streets, Sonoma, Sonoma County, CA

  7. 13. Photocopy of photograph (from Golden Gate Museum, San Francisco, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Photocopy of photograph (from Golden Gate Museum, San Francisco, California, 1850's) EXTERIOR, VIEW OF CONVENTO BEFORE RESTORATION, 1850'S - Mission San Francisco Solano de Sonoma, First & Spain Streets, Sonoma, Sonoma County, CA

  8. 75 FR 71179 - Environmental Impact Statement: San Diego County, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... Federal Highway Administration Environmental Impact Statement: San Diego County, CA AGENCY: Federal... Environmental Impact Statement (EIS) will be prepared ] for a proposed highway project in San Diego County... Hovey, Environmental Analysis Branch Chief, California Department of Transportation, District...

  9. 7. Historic American Buildings Survey From Golden Gate Park San ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Historic American Buildings Survey From Golden Gate Park San Francisco, California Original: Ante 1860 Re-photo: February 1940 VIEW FROM SOUTH - Mission San Carlos Borromeo, Rio Road & Lausen Drive, Carmel-by-the-Sea, Monterey County, CA

  10. Utilization of geothermal energy in the production of fuel grade ethanol in the San Luis Valley, Colorado

    SciTech Connect

    Hewlett, E.M.; Erickson, M.V.; Walter, K.M.

    1981-10-01

    The San Luis Valley, a high alpine valley in south-central Colorado, is an area of known geothermal activity. The valley is a sparsely populated agricultural area whose principal crops are potatoes, beer barley, and wheat. In the surrounding mountains there are several lumber operations. This combination of a geothermal heat source and a biomass feedstock source makes the valley a candidate area for the production of fermentation ethanol. Therefore, a study was initiated to investigate the engineering, environmental, institutional and economic feasibility of utilizing geothermal energy for the commercial production of 76 to 189 million liters (20 to 50 million gallons) of fuel grade ethanol in the San Luis Valley.

  11. Multi-scale InSAR analysis of aseismic creep across the San Andreas, Calevaras,and Hayward Fault systems

    NASA Astrophysics Data System (ADS)

    Agram, P. S.; Simons, M.

    2011-12-01

    We apply the Multi-scale Interferometric Time-series (MInTS) technique, developed at Caltech,to study spatial variations in aseismic creep across the San Andreas, Calaveras and Hayward Faultsystems in Central California.Interferometric Synthetic Aperture Radar (InSAR) Time-series methods estimate the spatio-temporal evolution of surface deformation using multiple SAR interferograms. Traditional time-series analysis techniques like persistent scatterers and short baseline methods assume the statistical independence of InSAR phase measurements over space and time when estimating deformation. However, existing atmospheric phase screen models clearly show that noise in InSAR phase observations is correlated over the spatial domain. MInTS is an approach designed to exploit the correlation of phase observations over space to significantly improve the signal-to-noise ratio in the estimated deformation time-series compared to the traditional time-series InSAR techniques. The MInTS technique reduces the set of InSAR observations to a set of almost uncorrelated observations at various spatial scales using wavelets. Traditional inversion techniques can then be applied to the wavelet coefficients more effectively. Creep across the Central San Andreas Fault and the Hayward Fault has been studied previously using C-band (6 cm wavelength) ERS data, but detailed analysis of the transition zone between the San Andreas and Hayward Faults was not possible due to severe decorrelation. Improved coherence at L-band (24 cm wavelength) significantly improves the spatial coverage of the estimated deformation signal in our ALOS PALSAR data set. We analyze 450 ALOS PALSAR interferograms processed using 175 SAR images acquired between Dec 2006 and Dec 2010 that cover the area along the San Andreas Fault System from Richmond in the San Francisco Bay Area to Maricopa in the San Joaquin Valley.We invert the InSAR phase observations to estimate the constant Line-of-Sight (LOS) deformation

  12. Summary of suspended-sediment concentration data, San Francisco Bay, California, water year 2009

    USGS Publications Warehouse

    Buchanan, Paul A.; Morgan, Tara L.

    2012-01-01

    Suspended-sediment concentration data were collected by the U.S. Geological Survey in San Francisco Bay during water year 2009 (October 1, 2008–September 30, 2009). Optical sensors and water samples were used to monitor suspended-sediment concentration at two sites in Suisun Bay, one site in San Pablo Bay, two sites in Central San Francisco Bay, and one site in South San Francisco Bay. Sensors were positioned at two depths at most sites to help define the vertical variability of suspended sediments. Water samples were collected periodically and analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the output of the optical sensors so that a record of suspended-sediment concentrations could be derived. This report presents the data-collection methods used and summarizes, in graphs, the suspended-sediment concentration data collected from October 2008 through September 2009. Calibration curves and plots of the processed data for each sensor also are presented.

  13. Summary of suspended-sediment concentration data, San Francisco Bay, California, water year 2010

    USGS Publications Warehouse

    Buchanan, Paul A.; Morgan, Tara L.

    2014-01-01

    Suspended-sediment concentration data were collected by the U.S. Geological Survey in San Francisco Bay during water year 2010 (October 1, 2009–September 30, 2010). Turbidity sensors and water samples were used to monitor suspended-sediment concentration at two sites in Suisun Bay, one site in San Pablo Bay, three sites in Central San Francisco Bay, and one site in South San Francisco Bay. Sensors were positioned at two depths at most sites to help define the vertical variability of suspended sediments. Water samples were collected periodically and analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the output of the turbidity sensors so that a record of suspended-sediment concentrations could be computed. This report presents the data-collection methods used and summarizes, in graphs, the suspended-sediment concentration data collected from October 2009 through September 2010. Calibration curves and plots of the processed data for each sensor also are presented.

  14. Summary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2006

    USGS Publications Warehouse

    Buchanan, Paul A.; Lionberger, Megan A.

    2009-01-01

    Suspended-sediment concentration data were collected by the U.S. Geological Survey in San Francisco Bay during water-year 2006 (October 1, 2005-September 30, 2006). Optical sensors and water samples were used to monitor suspended-sediment concentration at two sites in Suisun Bay, one site in San Pablo Bay, two sites in Central San Francisco Bay, and one site in South San Francisco Bay. Sensors were positioned at two depths at most sites to help define the vertical variability of suspended sediments. Water samples were collected periodically and analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the output of the optical sensors so that a record of suspended-sediment concentrations could be derived. This report presents the data-collection methods used and summarizes, in graphs, the suspended-sediment concentration data collected from October 2005 through September 2006. Calibration curves and plots of the processed data for each sensor also are presented.

  15. State of stress near the San Andreas fault: implications for wrench tectonics

    SciTech Connect

    Mount, V.S.; Suppe, J.

    1987-12-01

    Borehole elongations or breakouts in central California show that the direction of regional maximum horizontal stress is nearly perpendicular to the San Andreas fault and to the axes of young thrust-related anticlines. This observation resolves much of the controversy over shear-stress magnitude in the crust and around the San Andreas fault specifically. A low shear stress of 10-20 MPa (100-200 bar) or less on the San Andreas fault, suggested by heat-flow and seismic observations, is compatible with a high regional deviatoric stress (100 MPa, 1 kbar) when the observed principal stress directions are considered. Therefore, the San Andreas fault is a nearly frictionless interface, which causes the transpressive plate motion to be decoupled into a low-stress strike-slip component and a high-stress compressive component. These observations suggest that standard concepts of transpressive wrench tectonics - which envisage drag on a high-friction fault - are wrong. The thrust structures are largely decoupled from the strike-slip fault.

  16. Geologic map of the Cochetopa Park and North Pass Calderas, northeastern San Juan Mountains, Colorado

    USGS Publications Warehouse

    Lipman, Peter W.

    2012-01-01

    The San Juan Mountains in southwestern Colorado have long been known as a site of exceptionally voluminous mid-Tertiary volcanism, including at least 22 major ignimbrite sheets (each 150-5,000 km3) and associated caldera structures active at 33-23 Ma. Recent volcanologic and petrologic studies in the San Juan region have focused mainly on several ignimbrite-caldera systems: the southeastern area (Platoro complex), western calderas (Uncompahgre-Silverton-Lake City), and the central cluster (La Garita-Creede calderas). Far less studied has been the northeastern San Juan region, which occupies a transition between earlier volcanism in central Colorado and large-volume younger ignimbrite-caldera foci farther south and west. The present map is based on new field coverage of volcanic rocks in seventeen 7.5' quadrangles in northeastern parts of the volcanic field, high-resolution age determinations for 120 new sites, and petrologic studies involving several hundred new chemical analyses. This mapping and the accompanying lab results (1) document volcanic evolution of the previously unrecognized North Pass caldera and the morphologically beautifully preserved but enigmatic Cochetopa basin, including unique features not previously described from ignimbrite calderas elsewhere; (2) provide evidence for a more rapid recurrence of large ignimbrite eruptions than previously known elsewhere; (3) quantify the regional time-space-volume progression from the earlier Sawatch magmatic trend southward into the San Juan region; and (4) permit more rigorous comparison between the broad mid-Tertiary magmatic belt in the western U.S. Cordillera and the type continental-margin arc volcanism in the central Andes.

  17. New paleoseismic data from the northern San Jacinto Fault Zone, southern California

    NASA Astrophysics Data System (ADS)

    Onderdonk, N.; McGill, S. F.; Marliyani, G. I.; Rockwell, T. K.

    2010-12-01

    -versa). We also note that the two most recent events at Mystic Lake overlap with the two most recent events at the Hog Lake paleoseismic site, 30 miles to the south along the San Jacinto Fault Zone on the Clark Fault. This observation suggests that either some large San Jacinto events may jump across the San Jacinto Valley releasing step-over that separates the northern and central fault segments, or that stress triggering along one segment causes the other to fail in close succession. We anticipate that further work at Mystic Lake will allow us to test these ideas and evaluate the relationships between rupture events along the San Jacinto Fault and the degree of connectivity between the San Jacinto and San Andreas faults.

  18. Tower details, sheet 16. San Bernardino Valley Union Junior College, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Tower details, sheet 16. San Bernardino Valley Union Junior College, Auditorium Building. Clock and finial details; tower roof plan. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 16, job no. 692. Various scales. July 15, 1937. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, July 24, 1937. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  19. Sections. Ceiling plan. San Bernardino Valley Union Junior College, Auditorium ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Sections. Ceiling plan. San Bernardino Valley Union Junior College, Auditorium Building. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 9, job no. 692. Scale 1/8 inch to the foot. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  20. Detail of proscenium opening. San bernardino Valley Union Junior College, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of proscenium opening. San bernardino Valley Union Junior College, Auditorium Building. Details of corbels and soffit; lettering detail for frieze. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet W.P.A. 2, job no. 692. Scale 3/4 inch to the foot. May 18, 1937. (no state stamp. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  1. Basement plan. San Bernardino Valley Union Junior College, Auditorium building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Basement plan. San Bernardino Valley Union Junior College, Auditorium building. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 2, Job no. 692. Scale 1/8 inch to the foot. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  2. Rose windows and other details. San Bernardino Valley Union Junior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Rose windows and other details. San Bernardino Valley Union Junior College, Auditorium Building. Rose window; front windows; drinking fountain alcove; proscenium arch; stage door. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 12, job no. 692. Various scales. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  3. Second floor plan. San Bernardino Valley Union Junior College, Auditorium ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Second floor plan. San Bernardino Valley Union Junior College, Auditorium Building. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 4, job no. 692. Scale 1/8 inch to the foot. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  4. Plot plan. San Bernardino Valley Union Junior College, Auditorium building. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Plot plan. San Bernardino Valley Union Junior College, Auditorium building. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 1, job no. 692. Scale 1 inch to forty feet. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  5. Fault-crossing P delays, epicentral biasing, and fault behavior in Central California

    USGS Publications Warehouse

    Marks, S.M.; Bufe, C.G.

    1979-01-01

    The P delays across the San Andreas fault zone in central California have been determined from travel-time differences at station pairs spanning the fault, using off-fault local earthquake or quarry blast sources. Systematic delays as large as 0.4 sec have been observed for paths crossing the fault at depths of 5-10 km. These delays can account for the apparent deviation of epicenters from the mapped fault trace. The largest delays occur along the San Andreas fault between San Juan Bautista and Bear Valley and Between Bitterwater Valley and Parkfield. Spatial variations in fault behavior correlate with the magnitude of the fault-crossing P delay. The delay decreases to the northwest of San Juan Bautista across the "locked" section of the San Andreas fault and also decreases to the southeast approaching Parkfield. Where the delay is large, seismicity is relatively high and the fault is creeping. ?? 1979.

  6. Radar image San Francisco Bay Area, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The San Francisco Bay Area in California and its surroundings are shown in this radar image from the Shuttle Radar Topography Mission (SRTM). On this image, smooth areas, such as the bay, lakes, roads and airport runways appear dark, while areas with buildings and trees appear bright. Downtown San Francisco is at the center and the city of Oakland is at the right across the San Francisco Bay. Some city areas, such as the South of Market district in San Francisco, appear bright due to the alignment of streets and buildings with respect to the incoming radar beam. Three of the bridges spanning the Bay are seen in this image. The Bay Bridge is in the center and extends from the city of San Francisco to Yerba Buena and Treasure Islands, and from there to Oakland. The Golden Gate Bridge is to the left and extends from San Francisco to Sausalito. The Richmond-San Rafael Bridge is in the upper right and extends from San Rafael to Richmond. Angel Island is the large island east of the Golden Gate Bridge, and lies north of the much smaller Alcatraz Island. The Alameda Naval Air Station is seen just below the Bay Bridge at the center of the image. Two major faults bounding the San Francisco-Oakland urban areas are visible on this image. The San Andreas fault, on the San Francisco peninsula, is seen on the left side of the image. The fault trace is the straight feature filled with linear reservoirs, which appear dark. The Hayward fault is the straight feature on the right side of the image between the urban areas and the hillier terrain to the east.

    This radar image was acquired by just one of SRTM's two antennas and, consequently, does not show topographic data, but only the strength of the radar signal reflected from the ground. This signal, known as radar backscatter, provides insight into the nature of the surface, including its roughness, vegetation cover and urbanization. The overall faint striping pattern in the images is a data processing artifact due to the

  7. 76 FR 12692 - San Juan National Forest Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... Forest Service San Juan National Forest Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The San Juan National Forest Resource Advisory Council (RAC) will meet in... comments should be sent to Attn: San Juan National Forest RAC, 15 Burnett Court, Durango, CO...

  8. 75 FR 48306 - San Juan National Forest Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-10

    ... Forest Service San Juan National Forest Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The San Juan National Forest Resource Advisory Council (RAC) will meet in... comments should be sent to Attn: San Juan National Forest RAC, 15 Burnett Court, Durango, CO...

  9. 76 FR 40876 - San Juan National Forest Resource Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-12

    ... Forest Service San Juan National Forest Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The San Juan National Forest Resource Advisory Council (RAC) will meet in... Sonoran Meeting Rooms. Written comments should be sent to Attn: San Juan National Forest RAC, 15...

  10. 27 CFR 9.130 - San Ysidro District.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... northerly drainage of San Ysidro Creek southeast for approximately 2,000 feet to the seasonal pond adjacent to Canada Road; (7) From the seasonal pond, the boundary follows the southerly drainage of San Ysidro... end of a seasonal pond on the San Felipe, Calif., U.S.G.S. map; (10) The boundary follows...

  11. 33 CFR 161.50 - Vessel Traffic Service San Francisco.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the San Joaquin River, as far north as the port of Sacramento on the Sacramento River. ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Vessel Traffic Service San... Movement Reporting System Areas and Reporting Points § 161.50 Vessel Traffic Service San Francisco. The...

  12. 33 CFR 161.50 - Vessel Traffic Service San Francisco.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the San Joaquin River, as far north as the port of Sacramento on the Sacramento River. ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vessel Traffic Service San... Movement Reporting System Areas and Reporting Points § 161.50 Vessel Traffic Service San Francisco. The...

  13. 33 CFR 161.50 - Vessel Traffic Service San Francisco.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the San Joaquin River, as far north as the port of Sacramento on the Sacramento River. ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Vessel Traffic Service San... Movement Reporting System Areas and Reporting Points § 161.50 Vessel Traffic Service San Francisco. The...

  14. 33 CFR 161.50 - Vessel Traffic Service San Francisco.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the San Joaquin River, as far north as the port of Sacramento on the Sacramento River. ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Vessel Traffic Service San... Movement Reporting System Areas and Reporting Points § 161.50 Vessel Traffic Service San Francisco. The...

  15. 33 CFR 165.754 - Safety Zone: San Juan Harbor, San Juan, PR.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... referenced use datum: NAD 83. (2) The waters around Liquefied Petroleum Gas ships departing San Juan Harbor... coordinates referenced use datum: NAD 83. (b) Regulations. (1) No person or vessel may enter, transit...

  16. San Francisco's New Zoo's Connections for Conservation.

    ERIC Educational Resources Information Center

    Routman, Emily

    2001-01-01

    Provides information on a redevelopment project at the San Francisco Zoo known as the New Zoo. The explicit goal of the project is to inspire a sense of caring and appreciation for wildlife that is the foundation of a conservation ethic. (DDR)

  17. 77 FR 20379 - San Diego Gas &

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-04

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission San Diego Gas & Electric Company v. Sellers of Energy and Ancillary Services Into Markets Operated by the California Independent System Operator Corporation and the...

  18. Persistence and Attrition at San Juan College.

    ERIC Educational Resources Information Center

    Moore, Nelle

    A project was undertaken at San Juan College, in New Mexico, to examine findings from several studies of student persistence and retention to shed light on factors influencing persistence at the college. The project took into account several definitions of persistence, including re-enrollment in the subsequent semester (semester to semester),…

  19. San Miguel High School: Focus and Preparation

    ERIC Educational Resources Information Center

    Principal Leadership, 2010

    2010-01-01

    The corporate internship program is a cornerstone of the education that students receive at San Miguel High School in Tucson, Arizona. Four students share one job, so each student works for a corporate partner outside of the school every fourth day. The money they earn is used to help defray the cost of their education, and the experience is…

  20. San Francisco, California: Solar in Action (Brochure)

    SciTech Connect

    Not Available

    2011-10-01

    This brochure provides an overview of the challenges and successes of San Francisco, CA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  1. High Tech Images. San Bernardino City Hall

    ERIC Educational Resources Information Center

    McCoy, Esther

    1974-01-01

    A part of San Bernardino's larger redevelopment plan, the new City Hall has helped revitalize the downtown core. The solar bronze glass-surfaced structure, called a 6-story street, is the shape of the street which was closed to form the site. (Author/MF)

  2. Student Tracking System, San Antonio College.

    ERIC Educational Resources Information Center

    Cherne, Ferne; And Others

    The Student Tracking System (STS) at San Antonio College is designed to increase retention of high risk students, and primarily students enrolled in developmental education courses. In addition to identifying students experiencing difficulty in the classroom, STS alerts educational support services personnel to these students, provides a system of…

  3. San Diego, California: Solar in Action (Brochure)

    SciTech Connect

    Not Available

    2011-10-01

    This brochure provides an overview of the challenges and successes of San Diego, CA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  4. Sans study of spinach CF 1-ATPase

    NASA Astrophysics Data System (ADS)

    Calmettes, P.; Girault, G.; Berger, G.; Galmiche, J. M.

    1989-01-01

    SANS experiments were performed on solutions of spinach chloroplast CF 1-ATPase in heavy water. Removal of the ɛ subunit partially activates the enzyme and further addition of dithiothreitol fully activates it. Molar masses and gyration radii values are given for these different conditions.

  5. Humanities at College of San Mateo.

    ERIC Educational Resources Information Center

    San Mateo Coll., CA.

    Descriptions are provided for the courses in the College of San Mateo's new Humanities program. As introductory material notes, these team-taught, interdisciplinary courses were designed to be taken independently in various combinations depending upon the student's major or interests. They carry three units of transferable credit and satisfy…

  6. Simulations of the 1906 San Francisco Earthquake

    SciTech Connect

    Rodgers, A; Petersson, A; Tkalcic, H

    2005-12-16

    Simulations of the Great 1906 San Francisco earthquake are being performed as part of the event's centenary. LLNL is participating in a large effort to study this event and possible consequences if the event were to happen today. This document is meant to describe our efforts to others participating in the project.

  7. SAN PEDRO VEGETATION MAP VECTOR DATA

    EPA Science Inventory

    This data set is a digital vegetation map of the San Pedro Riparian National Conservation Area and Babocomari River. The map was produced by manual interpretation of true-color, stereo aerial photography flown in November 2000. Standard U.S. Geological Survey Digital Orthophoto...

  8. SAN PEDRO VEGETATION MAP GRID DATA

    EPA Science Inventory

    This data set is a digital vegetation map of the San Pedro Riparian National Conservation Area and Babocomari River. The map was produced by manual interpretation of true-color, stereo aerial photography flown in November 2000. Standard U.S. Geological Survey Digital Orthophoto...

  9. Educational and Demographic Profile: San Francisco County

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    This profile uniquely presents educational and socioeconomic information for San Francisco County, nearby counties, and the state. It highlights the relationship between various factors that affect the economic well-being of individuals and communities. This information provides a framework for enhanced communication and collaboration between the…

  10. Educational and Demographic Profile: San Diego County.

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    This profile uniquely presents a variety of educational and socioeconomic information for San Diego County, nearby counties, and the state. The profile highlights the relationship between various factors that affect the economic well-being of individuals and communities. This presentation of information provides a framework for enhanced…

  11. Educational and Demographic Profile: San Mateo County.

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    This profile uniquely presents a variety of educational and socioeconomic information for San Mateo County, nearby counties, and the state. The profile highlights the relationship between various factors that affect the economic well-being of individuals and communities. This presentation of information provides a framework for enhanced…

  12. Educational and Demographic Profile: San Benito County.

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    This profile uniquely presents a variety of educational and socioeconomic information for San Benito County, nearby counties, and the state. The profile highlights the relationship between various factors that affect the economic well-being of individuals and communities. This presentation of information provides a framework for enhanced…

  13. Educational and Demographic Profile: San Bernardino County.

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    This profile uniquely presents a variety of educational and socioeconomic information for San Bernardino County, nearby counties, and the state. The profile highlights the relationship between various factors that affect the economic well-being of individuals and communities. This presentation of information provides a framework for enhanced…

  14. Are Fibre Channel SANs a Commodity?

    NASA Technical Reports Server (NTRS)

    Becker, Jeff; Jacob, Matt; Biegel, Bryan A. (Technical Monitor)

    2000-01-01

    The goal of this work is to evaluate the feasibility of putting together a Fibre Channel Storage Area Network with heterogeneous hardware running both open-source and commercial operating systems. Adherence to the Fibre Channel Specification is supposed to guarantee interoperability in such an environment. We also want to evaluate how difficult it might be to put together a SAN using open-source components. While all the commercial vendors provide Fibre Channel support, this comes at a cost, e.g., not only O/S and drivers, but usually an expensive support contract. The open-source model could lower the cost of building and maintaining a SAN. Of course, for this to be the case, the open-source platforms would have to provide the functionality to construct a SAN. We are assembling a Fibre Channel SAN from heterogeneous hardware (i386, alpha, sparc) running *BSD, Linux, Tru64, NT and Solaris operating systems. We are running several tests to investigate the level of Fibre Channel support provided by each OS. Our current testbed is specified in the table below. Currently, it only contains open-source platforms. We plan to add a PC running OpenBSD, as well as the following commercial systems: Sun Ultra 1/Solaris, DEC AlphaServer 4000/Tru64 Unix, Pentium Pro PC/Windows NT.

  15. San Jose, California: Solar in Action (Brochure)

    SciTech Connect

    Not Available

    2011-10-01

    This brochure provides an overview of the challenges and successes of San Jose, CA, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  16. San Geronimo de Taos (Taos Pueblo).

    ERIC Educational Resources Information Center

    Kauppinen, Heta

    1989-01-01

    This lesson plan introduces high school students to pueblo architecture. Students will learn about pueblo architecture and its cultural tradition; discuss architectural characteristics and aesthetics in San Geronimo de Taos; examine the pueblo as a living environment; explore adobe pueblo structure in clay; and study Hopi, Zuni, and Pueblo…

  17. Potamocorbula amurensis discovered in San Francisco Bay

    USGS Publications Warehouse

    Schemel, Laurence E.

    1989-01-01

    The small Asian clam, Potamocorbula amurensis, is now a major component of benthic communities in most areas of northern San Francisco Bay and some areas of South Bay. Because of its wide tolerance of salinity and other environmental variables and its high abundance in many areas, benthic ecologists believe this recent invasion may represent a major and permanent change in the bay system.

  18. Nathaniel Hawthorne Elementary School: San Antonio, Texas.

    ERIC Educational Resources Information Center

    American Educator, 1997

    1997-01-01

    Discusses the successful use of Core Knowledge Curriculum in one inner-city elementary school in San Antonio (Texas) that had previously reflected low student achievement, inconsistent attendance, and student behavioral problems. Improvements in these conditions as revealed through teacher observations are highlighted. (GR)

  19. San Antonio, Texas: Solar in Action (Brochure)

    SciTech Connect

    Not Available

    2011-10-01

    This brochure provides an overview of the challenges and successes of San Antonio, TX, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  20. The Third International San Francisco Book Fair.

    ERIC Educational Resources Information Center

    Kalmon, Winn; And Others

    Friends of Books and Comics presents its catalog of the Third International San Francisco Book Fair, a marketplace of alternative books, comics, and magazines. Nearly 200 alternative and small presses are listed alphabetically with address, telephone number, names of principal people involved, and a brief description of type and subject of…

  1. Educational and Demographic Profile: San Joaquin County

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    This profile uniquely presents a variety of educational and socioeconomic information for San Joaquin County, nearby counties, and the state. The profile highlights the relationship between various factors that affect the economic well-being of individuals and communities. This presentation of information provides a framework for enhanced…

  2. The San Joaquin Valley: 20 years later

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The history of irrigation development and the need for disposal of saline drainage water in the San Joaquin Valley was described to provide background for the drainage water disposal problem that resulted from the closure of the Kesterson Reservoir. A 5 year study developed in Valley alternatives fo...

  3. Desegregation in the South San Joaquin Valley.

    ERIC Educational Resources Information Center

    Serrano, Rodolfo G.

    Notably isolated from the large metropolitan centers by geography and predominantly agricultural in its economy, Kern County is California's third largest county in land area. About one-third of the county is situated on the flat valley floor at the extreme southern end of the San Joaquin Valley. The area relies heavily on Chicano and Black manual…

  4. San Joaquin Delta College Student Athlete Study.

    ERIC Educational Resources Information Center

    Lewis, Merrilee R.; Marcopulos, Ernest

    In spring 1988, a study was conducted of students who participated in college athletics at San Joaquin Delta College (SJDC) between 1983-84 and 1987-88. Data collected on each student athlete included ethnicity, sport, place of residence, initial and current reading level, total grade point average (GPA), GPA in athletics and physical education…

  5. Groundwater quality in the San Fernando--San Gabriel groundwater basins, California

    USGS Publications Warehouse

    Kulongoski, Justin T.; 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 San Fernando and San Gabriel groundwater basins constitute one of the study units being evaluated.

  6. Estimating Natural Flows into the California's Sacramento - San Joaquin Delta

    NASA Astrophysics Data System (ADS)

    Huang, G.; Kadir, T.; Chung, F. I.

    2014-12-01

    Natural flows into the California's Sacramento - San Joaquin Delta under predevelopment vegetative conditions, if and when reconstructed, can serve as a useful guide to establish minimum stream flows, restoration targets, and a basis for assessing impacts of global warming in the Bay-Delta System. Daily simulations of natural Delta flows for the period 1922-2009 were obtained using precipitation-snowmelt-runoff models for the upper watersheds that are tributaries to the California's Central Valley, and then routing the water through the Central Valley floor area using a modified version of the California Central Valley Groundwater-Surface Water Simulation Model (C2VSIM) for water years 1922 through 2009. Daily stream inflows from all major upper watersheds were simulated using 23 Soil Water Assessment Tool (SWAT) models. Historical precipitation and reference evapotranspiration data were extracted from the SIMETAW2 with the 4km gridded meteorological data. The Historical natural and riparian vegetation distributions were compiled from several pre-1900 historical vegetation maps of the Central Valley. Wetlands were dynamically simulated using interconnected lakes. Flows overtopping natural levees were simulated using flow rating curves. New estimates of potential evapotranspiration from different vegetative classes under natural conditions were also used. Sensitivity simulations demonstrate that evapotranspiration estimates, native vegetation distribution, surface-groundwater interaction parameters, extinction depth for groundwater uptake, and other physical processes play a key role in the magnitude and timing of upstream flows arriving at the Delta. Findings contradict a common misconception that the magnitude of inflows to the Delta under natural vegetative conditions is greater than those under the historical agricultural and urban land use development. The developed models also enable to study the impacts of global warming by modifying meteorological and

  7. ASTER Images San Francisco Bay Area

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This image of the San Francisco Bay region was acquired on March 3, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters about 50 to 300 feet ), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.

    Image: This image covers an area 60 kilometers (37 miles) wide and 75 kilometers (47 miles) long in three bands of the reflected visible and infrared wavelength region. The combination of bands portrays vegetation in red, and urban areas in gray. Sediment in the Suisun Bay, San Pablo Bay, San Francisco Bay, and the Pacific Ocean shows up as lighter shades of blue. Along the west coast of the San Francisco Peninsula, strong surf can be seen as a white fringe along the shoreline. A powerful rip tide is visible extending westward from Daly City into the Pacific Ocean. In the lower right corner, the wetlands of the South San Francisco Bay National Wildlife Refuge appear as large dark blue and brown polygons. The high spatial resolution of ASTER allows fine detail to be observed in the scene. The main bridges of the area (San Mateo, San Francisco-Oakland Bay, Golden Gate, Richmond-San Rafael, Benicia-Martinez, and Carquinez) are easily picked out, connecting the different communities in the Bay area. Shadows of the towers along the Bay Bridge can be seen over the adjacent bay water. With enlargement the entire road network can be easily mapped; individual buildings are visible, including the shadows of the high-rises in downtown San Francisco.

    Inset: This enlargement of the San Francisco Airport highlights the high spatial resolution of ASTER. With further enlargement and careful examination, airplanes can be seen at the terminals.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth

  8. 75 FR 8106 - Don Edwards San Francisco Bay National Wildlife Refuge, Alameda, Santa Clara, and San Mateo...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... Fish and Wildlife Service Don Edwards San Francisco Bay National Wildlife Refuge, Alameda, Santa Clara... located in Alameda, Santa Clara, and San Mateo Counties of California. We provide this notice in..., we initiate our process for developing a CCP for Don Edwards San Francisco Bay NWR in Alameda,...

  9. 77 FR 15799 - Notice of Intent To Repatriate a Cultural Item: San Francisco State University, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-16

    ... National Park Service Notice of Intent To Repatriate a Cultural Item: San Francisco State University, San... University, in consultation with the appropriate Indian tribes, has ] determined that the cultural item meets... affiliated with the cultural item may contact the San Francisco State University NAGPRA Program....

  10. 75 FR 81854 - Safety Zone; New Year's Celebration for the City of San Francisco, Fireworks Display, San...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-29

    ... Celebration for the City of San Francisco Fireworks Display. The temporary safety zone will extend 100 feet... will extend 1,000 feet from the nearest point of the barge during the fireworks display. This safety... feet from the San Francisco Ferry Building in San Francisco, CA. The fireworks display is...

  11. 33 CFR 165.1185 - Regulated Navigation Area; San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Regulated Navigation Area; San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin River, and connecting waters in California. 165.1185 Section 165.1185 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY...

  12. Ecology and management of savannas and semi-deserts of central Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation of western pampas of central Argentina comprises: caldera, local name of a savanna to woodland ecosystem dominated by Prosopis caldenia; short-grassland and dune-grassland. The area include the central La Pampa and southern San Luis provinces, following a western precipitation gradient fr...

  13. Geochronology and geology of late Oligocene through Miocene volcanism and mineralization in the western San Juan Mountains, Colorado

    USGS Publications Warehouse

    Bove, Dana J.; Hon, Ken; Budding, Karin E.; Slack, John F.; Snee, Lawrence W.; Yeoman, Ross A.

    2001-01-01

    This paper presents 25 new 40Ar/39Ar dates from the main calc-alkaline ash-flow sheets and related younger plutons of the western San Juan volcanic field, the ash-flow sheets of the Lake City caldera cycle, and veins and other altered rocks in the Lake City region. The goal of the study was to produce similar quality 40Ar/39Ar ages to those currently published for the eastern and central San Juan Mountains. These new data provide a much more precise chronological framework for interpreting durations of events and their relationship to mineralization than do previously published conventional K-Ar dates for the western San Juan Mountains.

  14. A case for historic joint rupture of the San Andreas and San Jacinto faults.

    PubMed

    Lozos, Julian C

    2016-03-01

    The San Andreas fault is considered to be the primary plate boundary fault in southern California and the most likely fault to produce a major earthquake. I use dynamic rupture modeling to show that the San Jacinto fault is capable of rupturing along with the San Andreas in a single earthquake, and interpret these results along with existing paleoseismic data and historic damage reports to suggest that this has likely occurred in the historic past. In particular, I find that paleoseismic data and historic observations for the ~M7.5 earthquake of 8 December 1812 are best explained by a rupture that begins on the San Jacinto fault and propagates onto the San Andreas fault. This precedent carries the implications that similar joint ruptures are possible in the future and that the San Jacinto fault plays a more significant role in seismic hazard in southern California than previously considered. My work also shows how physics-based modeling can be used for interpreting paleoseismic data sets and understanding prehistoric fault behavior. PMID:27034977

  15. A case for historic joint rupture of the San Andreas and San Jacinto faults

    PubMed Central

    Lozos, Julian C.

    2016-01-01

    The San Andreas fault is considered to be the primary plate boundary fault in southern California and the most likely fault to produce a major earthquake. I use dynamic rupture modeling to show that the San Jacinto fault is capable of rupturing along with the San Andreas in a single earthquake, and interpret these results along with existing paleoseismic data and historic damage reports to suggest that this has likely occurred in the historic past. In particular, I find that paleoseismic data and historic observations for the ~M7.5 earthquake of 8 December 1812 are best explained by a rupture that begins on the San Jacinto fault and propagates onto the San Andreas fault. This precedent carries the implications that similar joint ruptures are possible in the future and that the San Jacinto fault plays a more significant role in seismic hazard in southern California than previously considered. My work also shows how physics-based modeling can be used for interpreting paleoseismic data sets and understanding prehistoric fault behavior. PMID:27034977

  16. Floor plan and front elevation. San Bernardino Valley Union Junior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Floor plan and front elevation. San Bernardino Valley Union Junior College, Library Building. Also includes detail of concrete grille; sections QQ and TT; and detail of bulletin board. Howard E. Jones, Architect, San Bernardino, California. Sheet 2, job no. 315. Scales 1/8 inch to the foot (plan, elevation), 1/2 inch to the foot (sections), and 1/4 inch to the foot (bulletin board). No date given on sheet (probably March or April, 1927). - San Bernardino Valley College, Library, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  17. Mezzanine plan and north elevation. San Bernardino Valley Union Junior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Mezzanine plan and north elevation. San Bernardino Valley Union Junior College, library building. Also includes interior elevation of wall between windows, showing light receptacle and section through beam. Howard E. Jones, Architect, San Bernardino, California. Sheet 3, job no. 315. Scales 1/8 inch to the foot (plan, elevation) and 1/2 inch to the foot (interior elevation). No date given on sheet (probably March or April, 1927). - San Bernardino Valley College, Library, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  18. North & south elevations. San Bernardino Valley Union Junior College, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    North & south elevations. San Bernardino Valley Union Junior College, Classics Building. Also includes longitudinal sections through the boiler room, plan of chimney, elevations of counter in the bookkeeping room, and detail of trusses over the oral English room. Howard E. Jones, Architect, San Bernardino, California. Sheet 4, job no. 312. Scales 1/8 inch to the foot and 1/2 inch to the foot. February 15, 1927. - San Bernardino Valley College, Classics Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  19. SAN virtualization study and implementation based on FC switches

    NASA Astrophysics Data System (ADS)

    Yang, Yi; Cao, Mingcui; Luo, Zhixiang

    2005-11-01

    Currently the mainstream technology of SAN is SAN storage virtualization and its implementation. The switch-based storage virtualization embeds the virtualizer in the core of the storage networking fabric in an "intelligent switch" rather than an appliance or a host. This paper describes the SV-FC SAN switch's hardware and software architecture. The main aid of design and implementation the switch is to give a new way to realize FC-SAN storage virtualization. Storage virtualization modules are embedded in the switches firmware. The switch can provide simple and friendly interfaces for users to configure and manage the FC SAN.

  20. Floc Depositional Characteristics within the Sacramento-San Joaquin River

    NASA Astrophysics Data System (ADS)

    Manning, Andrew; Schoellhamer, David

    2015-04-01

    The Sacramento-San Joaquin River Delta (Delta) is where the rivers of the Central Valley of California merge to become the San Francisco Estuary. The rivers deliver sediment from the Central Valley watershed (approximately 96,000 km2) to the Delta. One of the major drivers of sediment transport and turbidity in the Delta is the supply of fine sediment from the watersheds, particularly the Sacramento River. Deposited sediment helps create and sustain the landscape in the Delta, including desirable habitats such as tidal marsh, shoals, and floodplains. Massive sediment supply during the period of hydraulic mining in the late 1800s caused deposition in Sacramento Valley rivers, the Delta, and San Francisco Bay. Today, a key management question is whether the existing Delta landscape can be sustained as sea level rises. The erosion and deposition processes are strongly dependent on the local sediment properties, particularly when cohesion and flocculation are important, as they are in the Delta. The U.S. Geological Survey (USGS) collects data that supports the development, calibration, and validation of numerical models of sediment transport and turbidity in the Delta. Research questions include: How much flocculation of sediment particles occurs in the Delta, and what are the settling velocities of the flocs? How do floc settling properties vary spatially and temporally? To address these questions, a Co-operative Agreement was established between the USGS and HR Wallingford (UK). This abstract presents preliminary findings from measurements of floc depositional properties throughout the Delta during 2010-2011. Individual floc properties and dynamics were measured with the LabSFLOC-1 instrument; a high resolution video-based device. Thirty-one floc population samples were obtained from 21 sites within the Delta. Flocculated particles were observed throughout the Delta including in freshwater. Suspended-sediment concentrations in the near-bed region ranged from 4-52 mg

  1. Near-field stress and pore pressure observations along the Carrizo Plain segment of the San Andreas fault in California

    SciTech Connect

    Castillo, D.A.; Hickman, S.H.

    1996-12-31

    Preliminary observations of wellbore breakouts from 9 wells drilled to depths approaching 5 km and located within 3-10 km of the San Andreas fault in the Carrizo Plain area indicate maximum principal stress orientations (SHmax) 30-40{degrees} from the fault trend, consistent with high shear stress resolved unto the fault. Analysis of stress orientation data from additional wells located >10 km from the fault confirm previous observations that SHmax stresses are at high angles to the fault trend, consistent with low shear stress on the San Andreas. We suggest that the overall variation in shear stresses resolved onto the fault may be depth dependent, with greater shear stress at shallower depths. Alternatively, these stress rotations observed in the vicinity of the San Andreas might also reflect the influence of local secondary faulting and folding, variations in lithology and/or slip heterogeneties associated with the 1857 M8+ Fort Tejon earthquake. Estimates of crustal pore pressure inferred from drilling mud-weights and drill-stem tests from wells in the vicinity (<10 km) of the San Andreas fault indicate near-hydrostatic conditions to depths of about 5 km. However, 20-30 km from the San Andreas fault and within the central portions of the southern San Joaquin Valley, crustal pore pressures approach 60% of the lithostatic load starting at about 3.5 km depth. Thus, our data close to the fault suggests that elevated fluid pressures within the fault zone, as proposed to explain the long-term low-strength of the San Andreas, either do not penetrate far into the adjacent crust and/or are confined largely to deeper portions of the fault zone.

  2. Near-field stress and pore pressure observations along the Carrizo Plain segment of the San Andreas fault in California

    SciTech Connect

    Castillo, D.A. ); Hickman, S.H. )

    1996-01-01

    Preliminary observations of wellbore breakouts from 9 wells drilled to depths approaching 5 km and located within 3-10 km of the San Andreas fault in the Carrizo Plain area indicate maximum principal stress orientations (SHmax) 30-40[degrees] from the fault trend, consistent with high shear stress resolved unto the fault. Analysis of stress orientation data from additional wells located >10 km from the fault confirm previous observations that SHmax stresses are at high angles to the fault trend, consistent with low shear stress on the San Andreas. We suggest that the overall variation in shear stresses resolved onto the fault may be depth dependent, with greater shear stress at shallower depths. Alternatively, these stress rotations observed in the vicinity of the San Andreas might also reflect the influence of local secondary faulting and folding, variations in lithology and/or slip heterogeneties associated with the 1857 M8+ Fort Tejon earthquake. Estimates of crustal pore pressure inferred from drilling mud-weights and drill-stem tests from wells in the vicinity (<10 km) of the San Andreas fault indicate near-hydrostatic conditions to depths of about 5 km. However, 20-30 km from the San Andreas fault and within the central portions of the southern San Joaquin Valley, crustal pore pressures approach 60% of the lithostatic load starting at about 3.5 km depth. Thus, our data close to the fault suggests that elevated fluid pressures within the fault zone, as proposed to explain the long-term low-strength of the San Andreas, either do not penetrate far into the adjacent crust and/or are confined largely to deeper portions of the fault zone.

  3. Inferences drawn from two decades of alinement array measurements of creep on faults in the San Francisco Bay Region

    USGS Publications Warehouse

    Galehouse, J.S.; Lienkaemper, J.J.

    2003-01-01

    We summarize over 20 years of monitoring surface creep on faults of the San Andreas system in the San Francisco Bay region using alinement arrays. The San Andreas fault is fully locked at five sites northwest from San Juan Bautista, the southern end of the 1906 earthquake rupture, that is, no creep (< 1 mm/yr) is observed. Likewise, the San Gregorio, Rodgers Creek, and West Napa faults show no creep. The measured creep rate on the Calaveras-Paicines fault from Hollister southward is either 6 or ??? 10 mm/yr, depending on whether the arrays cross all of the creeping traces. Northward of Hollister, the central Calaveras creep rate reaches 14 ?? 2 mm/yr but drops to ??? 2 mm/yr near Calaveras Reservoir, where slip transfers to the southern Hayward fault at a maximum creep rate of 9 mm/yr at its south end. However, the Hayward fault averages only 4.6 mm/yr over most of its length. The Northern Calaveras fault, now creeping at 3-4 mm/yr, steps right to the Concord fault, which has a similar rate, 2.5-3.5 mm/yr, which is slightly slower than the 4.4 mm/yr rate on its northward continuation, the Green Valley fault. The Maacama fault creeps at 4.4 mm/yr near Ukiah and 6.5 mm/yr in Willits. The central and southern segments of the Calaveras fault are predominantly creeping, whereas the Hayward, Northern Calaveras, and Maacama faults are partly locked and, along with the Rodgers Creek and San Andreas, have high potential for major earthquakes.

  4. A record of estuarine water contamination from the Cd content of foraminiferal tests in San Francisco Bay, California

    USGS Publications Warehouse

    VanGeen, A.; Luoma, S.N.

    1999-01-01

    A five-year dissolved Cd time series from San Francisco Bay and adjacent coastal water shows that the composition of surface water towards the mouth of the estuary is determined largely by the effect of coastal upwelling. Cd concentrations inside and outside the estuary (0.2-1.0 nmol/kg) increase as Cd-rich deep water is advected to the surface near the coast during spring and summer. On average, the mean Cd concentrations inside San Francisco Bay (0.54 nmol/kg) during 1991-1995 was significantly higher than outside (0.35 nmol/kg), however. Surface samples collected throughout San Francisco Bay confirm an internal Cd source unrelated to river discharge. The Cd content of the test of a benthic foraminifer (Elphidiella hannai) in a dated sediment core from San Francisco Bay was measured to determine if the water column Cd enrichments in San Francisco Bay could be related to the rapid development of the watershed. The method is based on the observation that the Cd/Ca ratio of carefully cleaned tests of foraminifera is, determined by the dissolved Cd content of overlying water at the time of test formation. Pre-industrial foraminiferal Cd/Ca ratios in the sediment core average 274 ?? 15 nmol/mol (n = 19) nmol/mol. Foraminiferal Cd/Ca ratios increased to 386 ?? 33 nmol/mol (n = 19) over the past several decades indicating a 40% increase in the mean Cd content of surface water in Central San Francisco Bay. We suggest that, in addition to Cd discharges into the estuary, indirect consequences of agricultural development in the Central Valley of California could have contributed to this increase. This new method to reconstruct estuarine contamination is not affected by some of the processes that complicate the interpretation of changes in bulk sediment metal concentrations.

  5. 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

  6. Sills of the San Rafael Volcanic Field, Utah

    NASA Astrophysics Data System (ADS)

    Gallant, E.; Connor, C.; Connor, L.; Richardson, J. A.; Wetmore, P. H.

    2014-12-01

    Substantial populations, such as Mexico City, Auckland, and Portland, are built within or near monogenetic fields, so it is important to understand both eruption precursors and magma plumbing systems in such areas. Directly observing the plumbing systems of this rarely witnessed eruption style provides valuable insight into the nature of magmatic transport and storage within the shallow crust, as well as the associated monogenetic eruptive processes. Within the San Rafael Desert of Central Utah is an exposed Pliocene complex of approximately 2000 mapped dikes, 12 sills, and 60 conduits eroded to a depth of 800 m below the paleosurface. A combination of airborne LiDAR (ALS), provided by NCALM, and terrestrial LiDAR (TLS) surveys are used to map the dip of 5 major sills within a 35 sq km area. The ALS provides a 1 m aerial resolution of exposed volcanic features and the TLS gives vertical measurements to cm accuracy. From these data we determine that the 5-25 m thick sills in this area dip approximately 1 to 6 degrees. Field observations show that steps in sills and related fabrics indicate flow direction in sills during emplacement and that sills normally propagate down dip in the Entrada sandstone host rock away from apparent feeder dikes and conduits. Some sills have foundered roofs, especially near conduits, suggesting that nearly neutrally buoyant magmas emplaced into sills along bed partings in the Entrada, differentiated, and in some cases flowed back into conduits. By volume, at 800 m depth in the San Rafael, nearly all igneous rock (approximately 90 percent) is located in sills rather than in dikes or conduits. These observations are consistent with geochemical models that suggest differentiation in shallow sills explains geochemical trends observed in single monogenetic volcanoes in some active fields. Deformation associated with sill inflation and deflation may be a significant precursor to eruptive activity in monogenetic volcanic fields.

  7. Fish and wildlife to determine endangered status of San Rafael Cactus

    SciTech Connect

    Not Available

    1986-09-01

    The US Fish and Wildlife Service has proposed to determine the endangered status of the San Rafael Cactus. Although the only known occurrences of the species do not appear to fall within the boundaries of the San Rafael Swell Special Tar Sands Area, nearby combined hydrocarbon leasing could be impacted. There are two known populations of Pediocactus despainii, about 25 miles apart and each containing 2000 to 3000 individuals. Both occur in central Utah (Emery County), mainly in areas administered by the Bureau of Land Management. This rare species is being sought be cactus collectors, one population is heavily impacted by recreational off-road vehicles, and approximately one-half of each population is in areas covered by oil and gas leases and/or mining claims for gypsum. If the species is determined to be endangered, then the Fish and Wildlife Service could define a critical habitat for its preservation.

  8. Analaysis of San Antonio River Floods Caused by Tropical Storm Erin

    NASA Astrophysics Data System (ADS)

    Elhassan, A.; Sharif, H.

    2008-12-01

    Tropical Storm Erin started as a depression on August 14 2007. It deepened rapidly to evolve into a tropical storm the morning of the 15th. It moved into Texas on the 16th with maximum sustained winds of 56 km/hr. The storm produced 2-10 inches over south central Texas on August 16-17, 2008. The heaviest rainfall fell within a 6-hour period with totals in excess of 7.5 inches, as observed by the WSR-88D radar in New Braunfels, near San Antonio, TX. Average precipitation over the summer provided sufficient moisture to cause Erin's precipitation to produce significant rapid runoff over portions of the San Antonio River. Radar rainfall data and a two-dimensional, physically-based, distributed-parameter hydrologic model were used to perform hydrometeorological analysis of this event. Hydrologic simulations on several sub-basins will be discussed.

  9. Predicting the vertical structure of tidal current and salinity in San Francisco Bay, California

    USGS Publications Warehouse

    Ford, Michael; Wang, Jia; Cheng, Ralph T.

    1990-01-01

    A two-dimensional laterally averaged numerical estuarine model is developed to study the vertical variations of tidal hydrodynamic properties in the central/north part of San Francisco Bay, California. Tidal stage data, current meter measurements, and conductivity, temperature, and depth profiling data in San Francisco Bay are used for comparison with model predictions. An extensive review of the literature is conducted to assess the success and failure of previous similar investigations and to establish a strategy for development of the present model. A σ plane transformation is used in the vertical dimension to alleviate problems associated with fixed grid model applications in the bay, where the tidal range can be as much as 20–25% of the total water depth. Model predictions of tidal stage and velocity compare favorably with the available field data, and prototype salinity stratification is qualitatively reproduced. Conclusions from this study as well as future model applications and research needs are discussed.

  10. Exploring the Power Output of Small Wind Turbines in Urban San Antonio, Texas

    NASA Astrophysics Data System (ADS)

    Casillas, Jose; Sperduti, Stephanie; Cardenas, Rosa

    2015-03-01

    The means of transporting power from a centralized power plant by transmission lines has several disadvantages. Electricity transmission and distribution networks are costly, require long planning processes and are unsightly to residents. These networks are also susceptible to natural disasters creating massive disruptions to consumers. For these reasons distributed power sources such as solar panels and small wind turbines are becoming a more desirable and viable means of energy production. We report on the status of a study to determine the maximum output power of small wind turbines in urban San Antonio, Texas. Wind speed data along with power measurements from small wind turbines in urban San Antonio will be reported. U.S. Department of Education Title V HSI-STEM and Articulation Award No. P031C110145.

  11. Central Italy

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Clouds and haze cover most of the Italian peninsula in this view of central Italy (41.5N, 14.0E) but the Bay of Naples region with Mt. Vesuvius and the island of Capri are clear. The Adriatic Sea in the background separates Italy from the cloud covered Balkans of eastern Europe and the Tyrrhenian Sea in the foreground lies between the Italian mainland and the off scene islands of Corsica and Sardinia. Several aircraft contrails can also be seen.

  12. Effects of flow diversions on water and habitat quality: Examples from California's highly manipulated Sacramento–San Joaquin Delta

    USGS Publications Warehouse

    Monsen, Nancy E.; Cloern, James E.; Burau, Jon R.

    2007-01-01

    We use selected monitoring data to illustrate how localized water diversions from seasonal barriers, gate operations, and export pumps alter water quality across the Sacramento-San Joaquin Delta (California). Dynamics of water-quality variability are complex because the Delta is a mixing zone of water from the Sacramento and San Joaquin Rivers, agricultural return water, and the San Francisco Estuary. Each source has distinct water-quality characteristics, and the contribution of each source varies in response to natural hydrologic variability and water diversions. We use simulations with a tidal hydrodynamic model to reveal how three diversion events, as case studies, influence water quality through their alteration of Delta-wide water circulation patterns and flushing time. Reduction of export pumping decreases the proportion of Sacramento- to San Joaquin-derived fresh water in the central Delta, leading to rapid increases in salinity. Delta Cross Channel gate operations control salinity in the western Delta and alter the freshwater source distribution in the central Delta. Removal of the head of Old River barrier, in autumn, increases the flushing time of the Stockton Ship Channel from days to weeks, contributing to a depletion of dissolved oxygen. Each shift in water quality has implications either for habitat quality or municipal drinking water, illustrating the importance of a systems view to anticipate the suite of changes induced by flow manipulations, and to minimize the conflicts inherent in allocations of scarce resources to meet multiple objectives.

  13. Carte du Ciel, San Fernando zone

    NASA Astrophysics Data System (ADS)

    Abad, C.

    2014-06-01

    An updated summary of a future large astrometric catalogue is presented, based on the two most important astrometric projects carried out by the Real Instituto y Observatorio de la Armada de San Fernando (ROA). The goal is to make a catalogue of positions and proper motions based on ROA's Cart du Ciel (CdC) and the Astrographic Catalogue (AC) San Fernando zone plates, and the HAMC2 meridian circle catalogue. The CdC and AC plates are being reduced together to provide first-epoch positions while HAMC2 will provide second-epoch ones. New techniques have been applied, that range from using a commercial flatbed scanner to the proper reduction schemes to avoid systematics from it. Only thirty plates (out of 540) remain to be processed, due to scanning problems that are being solved.

  14. Discovery Along the San Andreas Fault: Relocating Photographs From the 1906 Earthquake in San Francisco and San Mateo Counties

    NASA Astrophysics Data System (ADS)

    Grove, K.; Prentice, C.; Polly, J.; Yuen, C.; Wu, K.; Zhong, S.; Lopez, J.

    2005-12-01

    April of 2006 will mark the 100-year anniversary of the great 1906 San Francisco earthquake. This earthquake was important not only because of its human tragedy (thousands of dead or homeless people), but also because of its scientific significance. The 8.3 magnitude earthquake ruptured 430 km of the northern San Andreas fault (SAF) and lasted nearly one minute. Investigations after the earthquake led to discoveries that were the beginning of modern earthquake theories and measuring instruments. This was also one of the first large-scale natural disasters to be photographed. Our research group, which is part of the National Science Foundation funded SF-ROCKS program, acquired photographs that were taken shortly after the earthquake in downtown San Francisco and along the SAF in San Mateo County. The SAF photos are part of a Geographical Information System (GIS) database being published on a U.S. Geological Survey web site. The goal of our project was to improve estimates of photograph locations and to compare the landscape features that were visible after the earthquake with the landscape that we see today. We used the GIS database to find initial photo locations, and we then used a high-precision Global Positioning System (GPS) to measure the geographic coordinates of the locations once we matched our view to what we saw in a photo. Where possible, we used a digital camera to retake photos from the same position, to show the difference in the landscape 100 years later. The 1906 photos show fault zone features such as ground rupture, sag ponds, shutter ridges, and offset fences. Changes to the landscape since 1906 have included erosion and grading of the land, building of houses and other structures, and more tree cover compared to previous grassland vegetation. Our project is part of 1906 Earthquake Centennial activities; it is contributing to the photo archive that helps scientists and engineers who study earthquakes and their effects. It will also help the

  15. San Bernardino National Wildlife Refuge Well 10

    SciTech Connect

    Ensminger, J.T.; Easterly, C.E.; Ketelle, R.H.; Quarles, H.; Wade, M.C.

    1999-12-01

    The U.S. Geological Survey (USGS), at the request of the U.S. Fish and Wildlife Service, evaluated the water production capacity of an artesian well in the San Bernardino National Wildlife Refuge, Arizona. Water from the well initially flows into a pond containing three federally threatened or endangered fish species, and water from this pond feeds an adjacent pond/wetland containing an endangered plant species.

  16. Bismuth ochers from San Diego Co., California

    USGS Publications Warehouse

    Schaller, W.T.

    1911-01-01

    The chief points brought out in this paper may be briefly summarized as follows: (1) The existence of natural Bi2O3 has not been established. (2) Natural bismite or bismuth ocher, when pure, is more probably a bismuth hydroxide. (3) The bismuth ochers from San Diego County, California, are either a bismuth hydroxide or bismuth vanadate, pucherite, or mixtures of these two. (4) Pucherite has been found noncrystallin and determined for the first time in the United States.

  17. The San Joaquin Valley Westside Perspective

    SciTech Connect

    Quinn, Nigel W.T.; Linneman, J. Christopher; Tanji, Kenneth K.

    2006-03-27

    Salt management has been a challenge to westside farmerssince the rapid expansion of irrigated agriculture in the 1900 s. Thesoils in this area are naturally salt-affected having formed from marinesedimentary rocks rich in sea salts rendering the shallow groundwater,and drainage return flows discharging into the lower reaches of the SanJoaquin River, saline. Salinity problems are affected by the importedwater supply from Delta where the Sacramento and San Joaquin Riverscombine. Water quality objectives on salinity and boron have been inplace for decades to protect beneficial uses of the river. However it wasthe selenium-induced avian toxicity that occurred in the evaporationponds of Kesterson Reservoir (the terminal reservoir of a planned but notcompleted San Joaquin Basin Master Drain) that changed public attitudesabout agricultural drainage and initiated a steady stream ofenvironmental legislation directed at reducing non-point source pollutionof the River. Annual and monthly selenium load restrictions and salinityand boron Total Maximum Daily Loads (TMDLs) are the most recent of thesepolicy initiatives. Failure by both State and Federal water agencies toconstruct a Master Drain facility serving mostly west-side irrigatedagriculture has constrained these agencies to consider only In-Valleysolutions to ongoing drainage problems. For the Westlands subarea, whichhas no surface irrigation drainage outlet to the San Joaquin River,innovative drainage reuse systems such as the Integrated Farm DrainageManagement (IFDM) offer short- to medium-term solutions while morepermanent remedies to salt disposal are being investigated. Real-timesalinity management, which requires improved coordination of east-sidereservoir releases and west-side drainage, offers some relief toGrasslands Basin farmers and wetland managers - allowing greater salinityloading to the River than under a strict TMDL. However, currentregulation drives a policy that results in a moratorium on all

  18. Cenozoic evolution of San Joaquin basin, California

    SciTech Connect

    Bartow, J.A.

    1988-03-01

    The Neogene San Joaquin basin in the southern part of the 700-km long Great Valley of California is a successor to a late Mesozoic and earliest Tertiary forearc basin. The transition from forearc basin to the more restricted Neogene marine basin occurred principally during the Paleogene as the plate tectonic setting changed from oblique convergence to normal convergence, and finally to the initiation of tangential (transform) movement near the end of the Oligocene. Regional-scale tectonic events that affected the basin include: (1) clockwise rotation of the southernmost Sierra Nevada, and large-scale en echelon folding in the southern Diablo Range, both perhaps related to Late Cretaceous and early Tertiary right slip on the proto-San-Andreas fault; (2) regional uplift of southern California in the Oligocene that resulted from the subduction of the Pacific-Farallon spreading ridge: (3) extensional tectonism in the Basin and Range province, particularly in the Miocene; (4) wrench tectonism adjacent to the San Andreas fault in the Neogene; (5) northeastward emplacement of a wedge of the Franciscan complex at the west side of the Sierran block, with associated deep-seated thrusting in the late Cenozoic; and (6) the accelerated uplift of the Sierra Nevada beginning in the late Miocene. Neogene basin history was controlled principally by the tectonic effects of the northwestward migration of the Mendocino triple junction along the California continental margin and by the subsequent wrench tectonism associated with the San Andreas fault system. East-west compression in the basin, resulting from extension in the Basin and Range province was an important contributing factor to crustal shortening at the west side of the valley. Analysis of the sedimentary history of the basin, which was controlled to some extent by eustatic sea level change, enables reconstruction of the basin paleogeography through the Cenozoic.

  19. Dipping San Andreas and Hayward faults revealed beneath San Francisco Bay, California

    USGS Publications Warehouse

    Parsons, T.; Hart, P.E.

    1999-01-01

    The San Francisco Bay area is crossed by several right-lateral strike-slip faults of the San Andreas fault zone. Fault-plane reflections reveal that two of these faults, the San Andreas and Hayward, dip toward each other below seismogenic depths at 60?? and 70??, respectively, and persist to the base of the crust. Previously, a horizontal detachment linking the two faults in the lower crust beneath San Francisco Bay was proposed. The only near-vertical-incidence reflection data available prior to the most recent experiment in 1997 were recorded parallel to the major fault structures. When the new reflection data recorded orthogonal to the faults are compared with the older data, the highest, amplitude reflections show clear variations in moveout with recording azimuth. In addition, reflection times consistently increase with distance from the faults. If the reflectors were horizontal, reflection moveout would be independent of azimuth, and reflection times would be independent of distance from the faults. The best-fit solution from three-dimensional traveltime modeling is a pair of high-angle dipping surfaces. The close correspondence of these dipping structures with the San Andreas and Hayward faults leads us to conclude that they are the faults beneath seismogenic depths. If the faults retain their observed dips, they would converge into a single zone in the upper mantle -45 km beneath the surface, although we can only observe them in the crust.

  20. Examination of spotted sand bass (Paralabrax maculatofasciatus) pollutant bioaccumulation in San Diego Bay, San Diego, California

    PubMed Central

    2013-01-01

    The spotted sand bass (Paralabrax maculatofasciatus) is an important recreational sport and subsistence food fish within San Diego Bay, a large industrialized harbor in San Diego, California. Despite this importance, few studies examining the species life history relative to pollutant tissue concentrations and the consumptive fishery exist. This study utilized data from three independent spotted sand bass studies from 1989 to 2002 to investigate PCB, DDT, and mercury tissue concentrations relative to spotted sand bass age and growth in San Diego Bay, with subsequent comparisons to published pollutant advisory levels and fishery regulations for recreational and subsistence consumption of the species. Subsequent analysis focused on examining temporal and spatial differences for different regions of San Diego Bay. Study results for growth confirmed previous work, finding the species to exhibit highly asymptotic growth, making tissue pollutant concentrations at initial take size difficult if not impossible to predict. This was corroborated by independent tissue concentration results for mercury, which found no relationship between fish size and pollutant bioaccumulation observed. However, a positive though highly variable relationship was observed between fish size and PCB tissue concentration. Despite these findings, a significant proportion of fish exhibited pollutant levels above recommended state recreational angler consumption advisory levels for PCBs and mercury, especially for fish above the minimum take size, making the necessity of at-size predictions less critical. Lastly, no difference in tissue concentration was found temporally or spatially within San Diego Bay. PMID:24282672

  1. Examination of spotted sand bass (Paralabrax maculatofasciatus) pollutant bioaccumulation in San Diego Bay, San Diego, California.

    PubMed

    Loflen, Chad L

    2013-01-01

    The spotted sand bass (Paralabrax maculatofasciatus) is an important recreational sport and subsistence food fish within San Diego Bay, a large industrialized harbor in San Diego, California. Despite this importance, few studies examining the species life history relative to pollutant tissue concentrations and the consumptive fishery exist. This study utilized data from three independent spotted sand bass studies from 1989 to 2002 to investigate PCB, DDT, and mercury tissue concentrations relative to spotted sand bass age and growth in San Diego Bay, with subsequent comparisons to published pollutant advisory levels and fishery regulations for recreational and subsistence consumption of the species. Subsequent analysis focused on examining temporal and spatial differences for different regions of San Diego Bay. Study results for growth confirmed previous work, finding the species to exhibit highly asymptotic growth, making tissue pollutant concentrations at initial take size difficult if not impossible to predict. This was corroborated by independent tissue concentration results for mercury, which found no relationship between fish size and pollutant bioaccumulation observed. However, a positive though highly variable relationship was observed between fish size and PCB tissue concentration. Despite these findings, a significant proportion of fish exhibited pollutant levels above recommended state recreational angler consumption advisory levels for PCBs and mercury, especially for fish above the minimum take size, making the necessity of at-size predictions less critical. Lastly, no difference in tissue concentration was found temporally or spatially within San Diego Bay. PMID:24282672

  2. An overview of San Francisco Bay PORTS

    USGS Publications Warehouse

    Cheng, Ralph T.; McKinnie, David; English, Chad; Smith, Richard E.

    1998-01-01

    The Physical Oceanographic Real-Time System (PORTS) provides observations of tides, tidal currents, and meteorological conditions in real-time. The San Francisco Bay PORTS (SFPORTS) is a decision support system to facilitate safe and efficient maritime commerce. In addition to real-time observations, SFPORTS includes a nowcast numerical model forming a San Francisco Bay marine nowcast system. SFPORTS data and nowcast numerical model results are made available to users through the World Wide Web (WWW). A brief overview of SFPORTS is presented, from the data flow originated at instrument sensors to final results delivered to end users on the WWW. A user-friendly interface for SFPORTS has been designed and implemented. Appropriate field data analysis, nowcast procedures, design and generation of graphics for WWW display of field data and nowcast results are presented and discussed. Furthermore, SFPORTS is designed to support hazardous materials spill prevention and response, and to serve as resources to scientists studying the health of San Francisco Bay ecosystem. The success (or failure) of the SFPORTS to serve the intended user community is determined by the effectiveness of the user interface.

  3. Paleoseismic displacement history, Coachella Valley segment, San Andreas fault

    NASA Astrophysics Data System (ADS)

    Williams, P. L.

    2009-12-01

    This paper examines individual earthquake displacements and slip curves for the southern segment of the San Andreas fault. In prior work, detailed geomorphic slip evidence (features offset up to ~20 meters right-laterally) were inventoried along the southern 50 km (Bombay Beach to Thermal) of the Coachella Valley Segment (CVS). Compilation of that survey, and current work indicate that the latest 5 events produced moderate offsets, averaging 3-4 meters from Durmid Hill (adjacent to the Salton Sea) through the central Indio Hills (adjacent to Palm Desert). Streams exhibiting cumulative offset of 15 to 18 meters are interpreted to record five events, with locally higher values obtained in the southern Mecca Hills and central Indio Hills. Stream displacements of 21 to 24 and 25 to 28 meters have been documented at a small number of sites. The presence of larger values, and absence of intervening values, indicates these events likely were characterized by offsets larger than 3-4 meters. Addressing the contribution to total offset from fault creep is especially important to characterize slip-per-event on the CVS, since creep contributes up to 20 to 30% of the long-term slip rate there (Sieh and Williams 1990). While creep probably can't be discriminated from seismic offset in geomorphic study of multi-event fault offsets, the consistency of field evidence indicates that creep may be a neutral or minor factor in interpreting the offset record: i.e., the surface slip in a given earthquake cycle, while a sum of seismic + postseismic surface slip, approximates total seismogenic slip at depth. In the present open interval, for example, the strongest signal for prior event slip is ~3.5m. 1-1.5m of this is presumed to be postseismic creep (ibid). Thus the latest seismic surface slip was probably about 2-2.5m, and the latest seismogenic rupture (at depth) was probably in the range of 3-3.5 m, and 1-1.5m of this occurred as postseismic slip plus creep at the surface. Prior event

  4. High frequency radar measurements of tidal currents flowing through San Pablo Strait, San Francisco Bay

    USGS Publications Warehouse

    Maresca, Joseph W., Jr.; Padden, Robin R.; Cheng, Ralph T.; Seibel, Erwin

    1980-01-01

    High frequency (HF) radar measurements of the surface current averaged over the upper 0.5 m in San Pablo Strait were compared with current meter measurements of the subsurface current made at 9.4 m below mean lower low water (MLLW) over two 12.4-h tidal cycles. After averaging the radar and current meter data over two tidal cycles, a southerly (ebbing direction) surface current of 32 cm·s−1 was deduced from the radar measurements and a northerly (flooding direction) subsurface current of 7 cm·s−1 from the current meter measurements. This nontidal flow is maintained by freshwater discharge from the Sacramento–San Joaquin Rivers into Suisun and San Pablo Bays. The radar measurement technique provides quantitative estimates of the surface currents that previously were determined only from surface drifter studies.

  5. Space Radar Image of San Francisco, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a radar image of San Francisco, California, taken on October 3,1994. The image is about 40 kilometers by 55 kilometers (25 miles by 34 miles) with north toward the upper right. Downtown San Francisco is visible in the center of the image with the city of Oakland east (to the right) across San Francisco Bay. Also visible in the image is the Golden Gate Bridge (left center) and the Bay Bridge connecting San Francisco and Oakland. North of the Bay Bridge is Treasure Island. Alcatraz Island appears as a small dot northwest of Treasure Island. This image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on orbit 56. The image is centered at 37 degrees north latitude, 122degrees west longitude. This single-frequency SIR-C image was obtained by the L-band (24 cm) radar channel, horizontally transmitted and received. Portions of the Pacific Ocean visible in this image appear very dark as do other smooth surfaces such as airport runways. Suburban areas, with the low-density housing and tree-lined streets that are typical of San Francisco, appear as lighter gray. Areas with high-rise buildings, such as those seen in the downtown areas, appear in very bright white, showing a higher density of housing and streets which run parallel to the radar flight track. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (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: the L-band (24 cm), C-band (6 cm) and X-band (3cm). 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 studies, will give scientists clearer insights into those environmental changes

  6. 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.

  7. A Study of the San Andreas Slip Rate on the San Francisco Peninsula, California

    NASA Astrophysics Data System (ADS)

    Feigelson, L. M.; Prentice, C.; Grove, K.; Caskey, J.; Ritz, J. F.; Leslie, S.

    2008-12-01

    The most recent large earthquake on the San Andreas Fault (SAF) along the San Francisco Peninsula was the great San Francisco earthquake of April 18, 1906, when a Mw= 7.8 event ruptured 435-470 km of the northern SAF. The slip rate for this segment of the SAF is incompletely known but is important for clarifying seismic hazard in this highly urbanized region. A previous study south of our site has found an average slip rate of 17±4 mm/yr for the late Holocene on the San Francisco Peninsula segment of the SAF. North of the Golden Gate, the SAF joins the San Gregorio Fault with an estimated slip rate of 6 mm/yr. A trench study north of where the two faults join has produced an average late Holocene slip rate of 24±3 mm/yr. To refine slip-rate estimates for the peninsula segment of the SAF, we excavated a trench across the fault where we located an abandoned channel between the San Andreas and Lower Crystal Springs reservoirs. This abandoned channel marks the time when a new channel cut across the SAF; the new channel has since been offset in a right-lateral sense about 20 m. The measured amount of offset and the age of the youngest fluvial sediments in the abandoned channel will yield a slip rate for the San Francisco Peninsula segment of the SAF. We excavated a trench across the abandoned channel and logged the exposed sediments. Our investigation revealed channel-fill alluvium incised and filled by probable debris flow sediments, and a wide fault zone in bedrock, west of the channel deposits. The most prominent fault is probably the strand that moved in 1906. We completed a total-station survey to more precisely measure the offset stream, and to confirm that the fault exposed in the trench aligns with a fence that is known to have been offset 2.8m during the 1906 earthquake. We interpret the debris flow sediments to represent the last phase of deposition prior to abandonment of the old channel. We collected samples for radiocarbon dating, optically stimulated

  8. Arsenic in benthic bivalves of San Francisco Bay and the Sacramento/San Joaquin River Delta

    USGS Publications Warehouse

    Johns, C.; Luoma, S.N.

    1990-01-01

    Arsenic concentrations were determined in fine-grained, oxidized, surface sediments and in two benthic bivalves, Corbicula sp. and Macoma balthica, within San Francisco Bay, the Sacramento/San Joaquin River Delta, and selected rivers not influenced by urban or industrial activity. Arsenic concentrations in all samples were characteristic of values reported for uncontaminated estuaries. Small temporal fluctuations and low arsenic concentrations in bivalves and sediments suggest that most inputs of arsenic are likely to be minor and arsenic contamination is not widespread in the Bay.

  9. 3. Photographic copy of map. San Carlos Project, Arizona. Irrigation ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Photographic copy of map. San Carlos Project, Arizona. Irrigation System. Department of the Interior. United States Indian Service. No date. Circa 1939. (Source: Henderson, Paul. U.S. Indian Irrigation Service. Supplemental Storage Reservoir, Gila River. November 10, 1939, RG 115, San Carlos Project, National Archives, Rocky Mountain Region, Denver, CO.) - San Carlos Irrigation Project, Lands North & South of Gila River, Coolidge, Pinal County, AZ

  10. Roof and gridiron plans. San Bernardino Valley Union Junior College, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Roof and gridiron plans. San Bernardino Valley Union Junior College, Auditorium Building. Also includes tower plan drawings, and a drawing of roof plan at stage. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 6, job no. 692. Scales all 1/8 inch to the foot. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  11. First floor plan. San Bernardino Valley Union Junior College, Auditorium. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    First floor plan. San Bernardino Valley Union Junior College, Auditorium. Also includes six small detail drawings. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 3, Job no. 692. Scales 1/8 inch to the foot (main plan) and various scales for the details. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  12. Tower details, sheet 14. San Bernardino Valley Union Junior College, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Tower details, sheet 14. San Bernardino Valley Union Junior College, Auditorium Building. Plan and elevation of tower above sixth floor; section through stage ventilators; elevation, stage ventilators. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 14, job no. 692. Scale 3/4 inch to the foot. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  13. Elevations. San Bernardino Valley Union Junior College, Auditorium Building. West, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevations. San Bernardino Valley Union Junior College, Auditorium Building. West, south, east elevations, elevation of loggia, areaway railing detail. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 7, job no. 692. Scales 1/8 inch to the foot (elevations) and 3/4 inch to the foot (detail). March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  14. Elevations and sections. San Bernardino Valley Union Junior College, Auditorium ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Elevations and sections. San Bernardino Valley Union Junior College, Auditorium Building. North elevation; longitudinal section through entire building; north, east, and west elevations of foyer. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 8, job no. 692. Scale 1/8 inch to the foot. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  15. Foyer and entrance details. San Bernardino Valley Union Junior College, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Foyer and entrance details. San Bernardino Valley Union Junior College, Auditorium Building. Section through foyer showing ticket window; detail front entrance with tiling; rear of ticket window. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 13, job no. 692. Scale 3/4 inch to the foot. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  16. Third floor plan. San Bernardino Valley Union Junior College, Auditorium ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Third floor plan. San Bernardino Valley Union Junior College, Auditorium Building. Also includes one small detail drawing of ladder from fly gallery to grid iron. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 5, Job no. 692. Scales 1/8 inch to the foot (main plan) and 3/4 inch to the foot for the detail. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  17. Impulsive radon emanation on a creeping segment of the San Andreas fault, California

    USGS Publications Warehouse

    King, C.-Y.

    1985-01-01

    Radon emanation was continuously monitored for several months at two locations along a creeping segment of the San Andreas fault in central California. The recorded emanations showed several impulsive increases that lasted as much as five hours with amplitudes considerably larger than meteorologically induced diurnal variations. Some of the radon increases were accompanied or followed by earthquakes or fault-creep events. They were possibly the result of some sudden outbursts of relatively radon-rich ground gas, sometimes triggered by crustal deformation or vibration. ?? 1985 Birkha??user Verlag.

  18. Provenance and compositional analysis of marbles from the medieval Abbey of San Caprasio, Aulla (Tuscany, Italy)

    NASA Astrophysics Data System (ADS)

    Lezzerini, M.; Di Battistini, G.; Zucchi, D.; Miriello, D.

    2012-08-01

    A compositional study of twenty-two marble artefacts from the medieval Benedictine Abbey of San Caprasio at Aulla (North-western Tuscany, Central Italy) has been carried out. The mineralogical and petrographic analyses, the estimation of the maximum grain size of the calcite crystals, and the determination of carbon and oxygen stable isotopes support a provenance of most marbles from the Apuan Alps quarries (Italy). Only some marbles indicate a probable provenance from the islands of Paros and Thasos in the eastern Mediterranean area.

  19. The densest meteorite collection area in hot deserts: The San Juan meteorite field (Atacama Desert, Chile)

    NASA Astrophysics Data System (ADS)

    Gattacceca, Jérôme; Valenzuela, Millarca; Uehara, Minoru; Jull, A. J. Timothy; Giscard, Marlène; Rochette, Pierre; Braucher, Régis; Suavet, Clement; Gounelle, Matthieu; Morata, Diego; Munayco, Pablo; Bourot-Denise, Michèle; Bourles, Didier; Demory, François

    2011-09-01

    Abstract- We describe the geological, morphological, and climatic setting of the San Juan meteorite collection area in the Central Depression of the Atacama Desert (Chile). Our recovery activities yielded 48 meteorites corresponding to a minimum of 36 different falls within a 3.88 km2 area. The recovery density is in the range 9-12 falls km-2 depending on pairing, making it the densest among meteorite collection areas in hot deserts. This high meteorite concentration is linked to the long-standing hyperaridity of the area, the stability of the surface pebbles (> Ma), and very low erosion rates of surface pebbles (approximately 30 cm Ma-1 maximum). The San Juan meteorite population is characterized by old terrestrial ages that range from zero to beyond 40 ka, and limited weathering compared with other dense collection areas in hot desert. Chemical weathering in San Juan is slow and mainly controlled by the initial porosity of meteorites. As in the Antarctic and other hot deserts, there is an overabundance of H chondrites and a shortage of LL chondrites compared with the modern falls population, suggesting a recent (< few ka) change in the composition of the meteorite flux to Earth.

  20. Testing Total Ammonia Levels in the Sacramento- San Joaquin Valley Delta

    NASA Astrophysics Data System (ADS)

    Kaser, C.; Harris, A.; Miller, K.

    2014-12-01

    Northern California's Sacramento-San Joaquin Delta is surrounded by many agricultural fields, making is susceptible to increased ammonia levels from nutrient rich fertilizer runoff. Last year we noticed a large bloom of Water Hyacinth, an invasive species from South America, throughout many channels of the delta which led us to believe that there was an abundance of ammonia in the water. We hypothesized this with the prior knowledge that Water Hyacinth feeds on ammonia and thrives in places with high levels of ammonia in the water. Because there are no current regulation standards for ammonia levels in the Delta, we decided to test eight points around the delta to see whether or not the ammonia levels exceed regulatory standards of nearby waters. After determining the ammonia levels of each of our eight samples, we compared the data that we collected to the maximum levels of ammonia allowed in the Central San Francisco Bay, which is 0.16 ppm. We discovered that each point that we tested in the delta had ammonia levels much lower than 0.16 ppm. With these results we concluded that unusually high levels of ammonia is not a concern in the Sacramento-San Joaquin Delta.

  1. Oral health in prehistoric San Pedro de Atacama oases, Northern Chile.

    PubMed

    Oliveira, R E; Neves, W A

    2015-12-01

    After almost 2000 years of local development, including limited trading with neighboring ethnic groups, the societies that occupied the oases of San Pedro de Atacama, Northern Chile, became part of the trade web of the Tiwanaku empire, between 500 and 1000 CE. Archaeological evidence tends to support the idea that the period under the influence of the altiplano (high plane) empire was very affluent. Here we investigate the possibility that this affluence had a positive impact on the health status of the Atacameneans, using the oral health as an indirect indicator of quality of life. Dental decay, dental abscess, dental wear, linear enamel hypoplasia, periodontal disease and dental calculus were analyzed on 371 skeletons from 12 sites from San Pedro de Atacama oases. We believe that if, indeed, there were better biological conditions during the altiplano influence, this could have been caused by the access to a more diversified food intake promoted by the intensification of the trading network established by Tiwanaku in the central-south Andes, of which San Pedro de Atacama became an important node. PMID:26253130

  2. Depositional model for the San Andres Formation, Roberts unit, Wasson field, Yoakum County, Texas

    SciTech Connect

    Ginger, E.P. )

    1992-04-01

    The Permian San Andres reservoir at Roberts unit produces from approximately 250 ft of anhydritic dolostones. The reservoir interval, which is more than 500 ft below the top of the San Andres Formation, consists of fossiliferous and pelletal/peloidal dolowackestones and dolopackstones. They were deposited in a shallow-marine environment with local shoaling conditions. Toward the top of the reservoir, intertidal and supratidal deposits interfinger with the subtidal units and form the lateral and overlying seals. A sponge-bryozoan bank lithofacies is recognized within the subtidal deposits at Roberts unit. The banks consist of dolomitized mud-rich boundstones dominated by bryozoans, sponges, and crinoids. Interbedded fossiliferous dolowackestones, dolopackstones, and dolograinstones are common. The restricted nature of the San Andres in the western part of Roberts unit (i.e., shoreward of the banks) indicates that the banks baffled wave energy and inhibited current circulation on the platform, resulting in a mud-dominated, restricted lagoonal facies with very low faunal diversity. The sponge-bryozoan banks occur within a narrow belt across the central part of Roberts unit and continue into the adjacent Willard unit. Their distribution has a distinct northeast-soutwest trend that parallels the subjacent Abo shelf margin reef trend, suggesting that the Abo reef trend influenced subsequent bank development.

  3. Desaturation of Fatty Acids Associated with Monogalactosyl Diacylglycerol: The Effects of San 6706 and San 9785 1

    PubMed Central

    Lem, Nora W.; Williams, John P.

    1981-01-01

    The effects of two substituted pyridazinone herbicides, San 6706 and San 9785, on photosynthesis, dark respiration, and fatty acid metabolism were studied in mature leaf tissue of Vicia faba. Both San 6706 and San 9785 inhibited photosynthesis within 2 hours after initial exposure of leaf tissue to the chemicals although San 9785 was more effective in inhibiting photosynthesis than San 6706. Neither San 6706 nor San 9785 had any marked effect on dark respiration. Kinetic studies using 14CO2 indicated that synthesis of 18:3 esterified to monogalactosyl diacylglycerol (MGDG) was not completely inhibited by San 9785 up to 48 hours after feeding. Radioactivity was observed to accumulate in MGDG (digalactosyl diacylglycerol [DGDG] and sulpholipid [SL]) 18:2 at the expense of 18:3 but the specific radioactivity of MGDG 18:3 continued to increase throughout the experiment indicating only partial inhibition of MGDG 18:3 synthesis. No significant differences were observed in the metabolism of other fatty acids. The metabolism of fatty acids from leaf tissue was not affected by treatment with San 6706. The data indicate that there are at least two sites for 18:2 desaturation to form 18:3, one associated with MGDG in the chloroplast, which is inhibited by San 9785, and one or more sites not inhibited by San 9785. The fatty acid specific radioactivity data support the hypothesis that there is vectorial transfer of fatty acids from phosphatidyl choline to MGDG to produce the large quantities of MGDG 18:3 found in higher plant tissue. PMID:16662031

  4. Seismic mapping of shallow fault zones in the San Gabriel Mountains from the Los Angeles Region Seismic Experiment, southern California

    USGS Publications Warehouse

    Fuis, G.S.; Ryberg, T.; Lutter, W.J.; Ehlig, P.L.

    2001-01-01

    During the Los Angeles Region Seismic Experiment (LARSE), a reflection/refraction survey was conducted along a profile (line 1) extending from Seal Beach, California, northeastward to the Mojave Desert and crossing the Los Angeles and San Gabriel Valley basins and San Gabriel Mountains. In most shot gathers from the southern and central San Gabriel Mountains, clear secondary arrivals are seen that merge, or appear to merge, with first arrivals at three locations, including the location of the Vincent thrust fault, an exposed late Mesozoic/early Cenozoic megathrust. These secondary arrivals are interpretable as reflections in the shallow crust (<5 km depth) from a concave-upward interface that projects to the surface in the north near the Vincent thrust fault, is offset in its central part at the San Gabriel fault (an old branch of the San Andreas fault), and terminates in the south at 1 to 2 km depth at the southern mountain front. The velocity structure above and below this interface strongly suggests it is the Vincent thrust fault: intermediate velocities (6.2 km/s), consistent with mylonites overlying the Vincent thrust fault, are observed above it; lower velocities (5.8 km/s), consistent with the Pelona Schist underlying the Vincent thrust fault, are observed below it. Problems arise, however, in attempting to match this reflector to the exposed Vincent thrust fault, which is seen in outcrops east of line 1. The Vincent thrust fault is shallower than the reflector in most places. An unmapped structure (steep fault, monocline, or thrust fault) is required between line 1 and the outcrops that either drops the Vincent thrust fault down to the depths of the reflector or repeats the Vincent thrust fault beneath line 1 in the footwall of another thrust fault. An alternative interpretation of the reflector is a deep greenstone horizon within the Pelona Schist, although this alternative is not favored by the velocity structure. Copyright 2001 by the American

  5. Water resources of the Descanso Area, San Diego County, California

    USGS Publications Warehouse

    Duell, L.F., Jr.

    1990-01-01

    Hydrologic information was collected during water year 1988 (October 1987 to September 1988) to evaluate the effects of current pumping on groundwater levels in the Descanso area in south-central San Diego County. Water year 1988 was a period of near-normal precipitation and runoff. The groundwater system in the area consists of aquifers in the metamorphic and granitic bedrock and in the overlying regolith (weathered bedrock). Most wells penetrate both aquifers, but the regolith is the source of most water pumped from wells. Groundwater storage in 1988 was estimated to be 800 to 2,000 acre-ft in the regolith and 300 to 3,000 acre-ft in bedrock. Recharge to the groundwater system from infiltration of precipitation and streamflow was estimated to be about 1,000 acre-ft. Pumpage, which was estimated to be 170 acre-ft, had little effect on groundwater storage. Water levels in wells were nearly the same at the end of the water year as at the beginning. Groundwater quality generally was suitable for domestic uses. Concentrations of iron and manganese , although nontoxic, exceeded California maximum contaminant levels for domestic drinking water in some wells. (USGS)

  6. Origin and characteristics of discharge at San Marcos Springs based on hydrologic and geochemical data (2008–10), Bexar, Comal, and Hays Counties, Texas

    USGS Publications Warehouse

    Musgrove, MaryLynn; Crow, Cassi L.

    2012-01-01

    The Edwards aquifer in south-central Texas is a productive and important water resource. Several large springs issuing from the aquifer are major discharge points, popular locations for recreational activities, and habitat for threatened and endangered species. Discharges from Comal and San Marcos Springs, the first and second largest spring complexes in Texas, are used as thresholds in groundwater management strategies for the Edwards aquifer. Comal Springs is generally understood to be supplied by predominantly regional groundwater flow paths; the hydrologic connection of San Marcos Springs with the regional flow system, however, is less understood. During November 2008–December 2010, a hydrologic and geochemical investigation of San Marcos Springs was conducted by the U.S. Geological Survey (USGS) in cooperation with the San Antonio Water System. The primary objective of this study was to define and characterize sources of discharge from San Marcos Springs. During this study, hydrologic conditions transitioned from exceptional drought (the dry period, November 1, 2008 to September 8, 2009) to wetter than normal (the wet period, September 9, 2009 to December 31, 2010), which provided the opportunity to investigate the hydrogeology of San Marcos Springs under a wide range of hydrologic conditions. Water samples were collected from streams, groundwater wells, and springs at and in the vicinity of San Marcos Springs, including periodic (routine) sampling (every 3–7 weeks) and sampling in response to storms. Samples were analyzed for major ions, trace elements, nutrients, and selected stable and radiogenic isotopes (deuterium, oxygen, carbon, strontium). Additionally, selected physicochemical properties were measured continuously at several sites, and hydrologic data were compiled from other USGS efforts (stream and spring discharge). Potential aquifer recharge was evaluated from local streams, and daily recharge or gain/loss estimates were computed for several

  7. Landslide oil field, San Joaquin Valley, California

    SciTech Connect

    Collins, B.P.; March, K.A.; Caballero, J.S.; Stolle, J.M.

    1988-03-01

    The Landslide field, located at the southern margin of the San Joaquin basin, was discovered in 1985 by a partnership headed by Channel Exploration Company, on a farm out from Tenneco Oil Company. Initial production from the Tenneco San Emidio 63X-30 was 2064 BOPD, making landslide one of the largest onshore discoveries in California during the past decade. Current production is 7100 BOPD from a sandstone reservoir at 12,500 ft. Fifteen wells have been drilled in the field, six of which are water injectors. Production from the Landslide field occurs from a series of upper Miocene Stevens turbidite sandstones that lie obliquely across an east-plunging structural nose. These turbidite sandstones were deposited as channel-fill sequences within a narrowly bounded levied channel complex. Both the Landslide field and the larger Yowlumne field, located 3 mi to the northwest, comprise a single channel-fan depositional system that developed in the restricted deep-water portion of the San Joaquin basin. Information from the open-hole logs, three-dimensional surveys, vertical seismic profiles, repeat formation tester data, cores, and pressure buildup tests allowed continuous drilling from the initial discovery to the final waterflood injector, without a single dry hole. In addition, the successful application of three-dimensional seismic data in the Landslide development program has helped correctly image channel-fan anomalies in the southern Maricopa basin, where data quality and severe velocity problems have hampered previous efforts. New exploration targets are currently being evaluated on the acreage surrounding the Landslide discovery and should lead to an interesting new round of drilling activity in the Maricopa basin.

  8. Source rock maturation, San Juan sag

    SciTech Connect

    Gries, R.R.; Clayton, J.L.

    1989-09-01

    Kinetic modeling for thermal histories was simulated for seven wells in the San Juan sag honoring measured geochemical data. Wells in the area of Del Norte field (Sec. 9, T40N, R5E), where minor production has been established from an igneous sill reservoir, show that the Mancos Shale source rocks are in the mature oil generation window as a combined result of high regional heat flow and burial by approximately 2,700 m of Oligocene volcanic rocks. Maturation was relatively recent for this area and insignificant during Laramide subsidence. In the vicinity of Gramps field (Sec. 24, T33N, R2E) on the southwest flank of the San Juan sag, these same source rocks are exposed due to erosion of the volcanic cover but appear to have undergone a similar maturation history. At the north and south margins of the sag, two wells (Champlin 34A-13, Sec. 13, T35N, R4.5E; and Champlin 24A-1, Sec. 1, T44N, R5E) were analyzed and revealed that although the regional heat flow was probably similar to other wells, the depth of burial was insufficient to cause maturation (except where intruded by thick igneous sills that caused localized maturation). The Meridian Oil 23-17 South Fork well (Sec. 17, T39N, R4E) was drilled in a deeper part of the San Juan sag, and source rocks were intruded by numerous igneous sills creating a complex maturation history that includes overmature rocks in the lowermost Mancos Shale, possible CO{sub 2} generation from the calcareous Niobrara Member of the Mancos Shale, and mature source rocks in the upper Mancos Shale.

  9. 78 FR 77597 - Safety Zone; Allied PRA-Solid Works, San Diego Bay; San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-24

    ...The Coast Guard is establishing a temporary safety zone on the navigable waters of the San Diego Bay in support of a fireworks display on the evening of January 28, 2014. The zone is necessary to provide for the safety of the participants, crew, spectators, participating vessels, and other vessels and users of the waterway. Persons and vessels are prohibited from entering into, transiting......

  10. Chinanteco de San Juan Lealao, Oaxaca (Chinantec of San Juan Lealao, Oaxaca).

    ERIC Educational Resources Information Center

    Mexico Coll. (Mexico City)

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Chinantec, an indigenous language of Mexico spoken in San Juan Lealao, in the state of Oaxaca. The objective of collecting such a representative sampling of…

  11. Trique de San Juan Copala, Oaxaca (Trique of San Juan Copala, Oaxaca).

    ERIC Educational Resources Information Center

    Mexico Coll. (Mexico City)

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Trique, an indigenous language of Mexico spoken in San Juan Copala, in the state of Oaxaca. The objective of collecting such a representative sampling of the…

  12. 78 FR 57482 - Safety Zone; America's Cup Aerobatic Box, San Francisco Bay, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-19

    ... San Francisco, CA in support of 2013 America's Cup air shows. These safety zones are established to provide a clear area on the water for pilots to initiate maneuvers and also provide for the safety of... rule is effective as to persons with actual notice starting September 6, 2013. This rule is...

  13. 78 FR 38584 - Safety Zone; San Diego Symphony Summer POPS Fireworks 2013 Season, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-27

    ... FR Federal Register NPRM Notice of Proposed Rulemaking A. Regulatory History and Information The... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego Symphony Summer POPS Fireworks... Symphony Summer POPS Fireworks 2013 season. This safety zone is necessary to provide for the safety of...

  14. Otomi de San Andres Cuexcontitlan, Estado de Mexico (Otomi of San Andres Cuexcontitlan, State of Mexico).

    ERIC Educational Resources Information Center

    Lastra, Yolanda

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Otomi, an indigenous language of Mexico spoken in San Andres Cuexcontitlan, in the state of Mexico. The objective of collecting such a representative…

  15. 78 FR 34123 - Notice of Inventory Completion: San Francisco State University NAGPRA Program, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ... from site CA-PLA-9 in Placer County, CA. This notice is published as part of the National Park Service... site CA-PLA-9 in Placer County, CA, by San Francisco State University personnel in conjunction with... point. The age of site CA-PLA-9 is unknown, but the site is located within the historically...

  16. Existing Whole-House Solutions Case Study: Build San Antonio Green, San Antonio, Texas

    SciTech Connect

    none,

    2013-06-01

    PNNL, FSEC, and CalcsPlus provided technical assistance to Build San Antonio Green on three deep energy retrofits. For this gut rehab they replaced the old roof with a steeper roof and replaced drywall while adding insulation, new HVAC, sealed ducts, transfer grilles, outside air run-time ventilation, new lighting and water heater.

  17. 76 FR 46352 - Approval of Noise Compatibility Program for San Diego International, San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ... the navigable airspace and air traffic control systems, or adversely affecting other powers and... Monitoring System (ANOMS) was approved for purposes of part 150, (Approval of this measure does not obligate... Federal Aviation Administration Approval of Noise Compatibility Program for San Diego International,...

  18. Huave de San Mateo del Mar, Oaxaca (Huave of San Mateo del Mar, Oaxaca).

    ERIC Educational Resources Information Center

    Mexico Coll. (Mexico City)

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Huave, an indigenous language of Mexico spoken in San Mateo del Mar, in the state of Oaxaca. The objective of collecting such a representative sampling of…

  19. 77 FR 70891 - Safety Zone; Bay Bridge Construction, San Francisco Bay, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-28

    ...The Coast Guard is establishing a temporary safety zone in the navigable waters of the San Francisco Bay near Yerba Buena Island, CA in support of the Bay Bridge Construction Safety Zone from November 1, 2012 through July 31, 2013. This safety zone is being established to protect mariners transiting the area from the dangers associated with over-head construction operations. Unauthorized......

  20. College Success and the Black Male. San Jose City College, San Jose, California. Research Report #128.

    ERIC Educational Resources Information Center

    Carr, Percy; And Others

    In 1992, a study was conducted at San Jose City College (SJCC) and Evergreen Valley College (EVC), California, to examine the fourth semester persistence rates of black male students and to investigate the effect of SJCC athletic and athlete academic support programs on persistence. Study findings included the following: (1) new full-time (NFT)…

  1. 75 FR 28194 - Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-20

    ... Zone; San Clemente Island, CA in the Federal Register (74 FR 39584). We received one comment on the... joint statement from three commercial fishing organizations: the Sea Urchin Commission (CSUC), the...) Environmental Impact Statement (EIS)/Overseas EIS (OEIS) (Record of Decision, January 30, 2009) (74 FR...

  2. 77 FR 42649 - Safety Zone: Sea World San Diego Fireworks, Mission Bay; San Diego, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    ... FR Federal Register NPRM Notice of Proposed Rulemaking A. Regulatory History and Information The... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone: Sea World San Diego Fireworks, Mission...

  3. English Articulation between the San Francisco Unified School District and the City College of San Francisco. Youth Data Archive Issue Brief

    ERIC Educational Resources Information Center

    Gurantz, Oded

    2012-01-01

    San Francisco's Bridge to Success (BtS) initiative brings together the City and County of San Francisco, the San Francisco Unified School District (SFUSD), the City College of San Francisco (CCSF), and key community organizations to promote postsecondary success for underrepresented students. Various working groups, each comprised of staff from…

  4. [Health levels in San Andres Cholula].

    PubMed

    Alvarez Martinez, A; Corro Fernandez, G; Balmaceda, M

    1991-12-01

    In matters of health and curing, the community of San Andres Cholula in Puebla, Mexico, demonstrates a syncretism similar to religious syncretism. Perspectives on illness and health consistent with the traditional medical practices of curanderos coexist with modern medical practices. Curanderos and physicians often treat the same patients. A curandero's powers are viewed as a special gift transmitted by God or the saints during a dream. The curandero effects a cure not only through knowledge of the medicinal plants, rites, and ceremonies, but by understanding the context of the patient. The Western medical concept of disease emphasizes a biological model and technological control, to the detriment of mental, behavioral, and social factors and determinants. The traditional medical concept stresses the relationship of the individual to the social and ecological environment. Improvements in life expectancy in the developing countries in recent years have been attributed to improved levels of living or to importation of vaccination programs, antibiotics, and similar technologies from the developed countries. The vital register of San Andres Cholula records many deaths whose cause cannot be easily interpreted according to the World Health Organization International Classification of Diseases. It is clear, however, that the root cause of many deaths is malnutrition. The proportion of deaths caused by infectious diseases has declined in Mexico since 1940, but Puebla is still included among the states with the highest incidence. There are great regional and rural-urban mortality differentials in Mexico. In the past 50 years, the infant mortality rate has declined from 250 to 40/1000 live births in San Andres Cholula, more as a result of vaccination campaigns than of improved levels of living. 89% of children have been vaccinated, but the population still lives in about the same state of material comfort as it has for generations except that most households have televisions

  5. Neuroimaging Features of San Luis Valley Syndrome

    PubMed Central

    Whitehead, Matthew T.; Lee, Bonmyong

    2015-01-01

    A 14-month-old Hispanic female with a history of double-outlet right ventricle and developmental delay in the setting of recombinant chromosome 8 syndrome was referred for neurologic imaging. Brain MR revealed multiple abnormalities primarily affecting midline structures, including commissural dysgenesis, vermian and brainstem hypoplasia/dysplasia, an interhypothalamic adhesion, and an epidermoid between the frontal lobes that enlarged over time. Spine MR demonstrated hypoplastic C1 and C2 posterior elements, scoliosis, and a borderline low conus medullaris position. Presented herein is the first illustration of neuroimaging findings from a patient with San Luis Valley syndrome. PMID:26425383

  6. Subsurface Structure of San Leandro From the San Francisco Bay to the Hayward Fault

    NASA Astrophysics Data System (ADS)

    Goldman, M. R.; Catching, R. D.; Rymer, M. J.; Gandhok, G.; Steedman, C. E.

    2003-12-01

    The city of San Leandro, California is located in the eastern San Francisco Bay area between the Bay and the East Bay hills (Diablo Mountains). The major known tectonic structures in the immediate San Leandro area are the Hayward fault to the east and the San Leandro basin, a deep sedimentary basin, beneath the western side of the city. To better understand the San Leandro basin, its subsurface fault structures, and the effect of these structures on ground water and earthquake hazards, the U.S. Geological Survey acquired an approximately 10-km-long, high-resolution, combined reflection and refraction seismic imaging profile across the city in June 2002. The seismic profile originated within the waters of the San Francisco Bay and ended at the Hayward fault. Seismic sources were generated by a combination of 400-grain, Betsy-Seisgun blanks in 0.3-m-deep holes and 0.25-to-0.5-kg, buried explosions in 1.5-m-deep holes. The combined spacing of seismic sources was 5 m. The seismic data were recorded on an array of four 60-channel Geometrics Strataview seismographs, with 40-Hz single-element, vertical sensors spaced at 5 m. P-wave velocities range from about 800 m/s at the surface to greater than 2000 m/s at about 100 m depth. Prominent lateral low-velocity areas are evident at several locations along the profile. Reflection images show that the low-velocity areas are largely related to zones of faulting. Near-surface faults are observed on the reflection images, including southwest-dipping faults at the edge of the bay and near-vertical faults within the Hayward fault zone, but the most prominent fault occurs approximately 1 km east of the bay, where it bounds the ~1-km-deep San Leandro basin. Because the near-surface faults are observed within a few meters of the surface and because epicenters of small-magnitude earthquakes correlate with these faults, it is likely that they are active and represent potential hazards. The reflection and velocity images show that some

  7. 5. NORTHEAST SIDEELEVATION. Puente de la Marina, San LorenzoFlorida ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. NORTHEAST SIDE-ELEVATION. - Puente de la Marina, San Lorenzo-Florida & Cerro Gordo Neighborhoods, spanning Rio Grande de Loiza River at Narciso Varona-Suarez Street, San Lorenzo, San Lorenzo Municipio, PR

  8. 4. NORTHWEST APPROACHELEVATION. Puente de la Marina, San LorenzoFlorida ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. NORTHWEST APPROACH-ELEVATION. - Puente de la Marina, San Lorenzo-Florida & Cerro Gordo Neighborhoods, spanning Rio Grande de Loiza River at Narciso Varona-Suarez Street, San Lorenzo, San Lorenzo Municipio, PR

  9. 3. SOUTHEAST APPROACHELEVATION. Puente de la Marina, San LorenzoFlorida ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. SOUTHEAST APPROACH-ELEVATION. - Puente de la Marina, San Lorenzo-Florida & Cerro Gordo Neighborhoods, spanning Rio Grande de Loiza River at Narciso Varona-Suarez Street, San Lorenzo, San Lorenzo Municipio, PR

  10. A review of circulation and mixing studies of San Francisco Bay, California

    USGS Publications Warehouse

    Smith, Lawrence H.

    1987-01-01

    influenced by delta discharge, and South Bay, a tributary estuary which responds to conditions in Central Bay. In the northern reach net circulation is characterized by the river-induced seaward, flow and a resulting gravitational circulation in the channels, and by a tide- and wind-induced net horizontal circulation. A surface layer of relatively fresh water in Central Bay generated by high delta discharges can induce gravitational circulation in South Bay. During low delta discharges South Bay has nearly the same salinity as Central Bay and is characterized by tide- and wind-induced net horizontal circulation. Several factors control the patterns of circulation and mixing in San Francisco Bay. Viewing circulation and mixing over different time-periods and at different geographic scales causes the influences of different factors to be emphasized. The exchange between the bay and coastal ocean and freshwater inflows determine the year-to-year behavior of San Francisco Bay as a freshwater-saltwater mixing zone. Within the bay, exchanges between the embayments control variations over a season. Circulation and mixing patterns within the embayments and the magnitude of river-induced seaward flow influence the between-bay exchanges. The within-bay patterns are in turn determined by tides, winds, and freshwater inflows. Because freshwater inflow is the only factor that can be managed, a major study focus is estimation of inflow-related effects. Most questions relate to the patterns of freshwater inflow necessary to protect valuable resources whose welfare is dependent on conditions in the bay. Among the important questions being addressed are: --What quantity of freshwater inflow is necessary to prevent salt intrusion into the Sacramento-San Joaquin Delta, and what salinity distributions in the bay would result from various inflow patterns? --What quantity of freshwater inflow is sufficient to flush pollutants through the bay? Knowledge of circul

  11. Elevated time-dependent strengthening rates observed in San Andreas Fault drilling samples

    NASA Astrophysics Data System (ADS)

    Ikari, Matt J.; Carpenter, Brett M.; Vogt, Christoph; Kopf, Achim J.

    2016-09-01

    The central San Andreas Fault in California is known as a creeping fault, however recent studies have shown that it may be accumulating a slip deficit and thus its seismogenic potential should be seriously considered. We conducted laboratory friction experiments measuring time-dependent frictional strengthening (healing) on fault zone and wall rock samples recovered during drilling at the San Andreas Fault Observatory at Depth (SAFOD), located near the southern edge of the creeping section and in the direct vicinity of three repeating microearthquake clusters. We find that for hold times of up to 3000 s, frictional healing follows a log-linear dependence on hold time and that the healing rate is very low for a sample of the actively shearing fault core, consistent with previous results. However, considering longer hold times up to ∼350,000 s, the healing rate accelerates such that the data for all samples are better described by a power law relation. In general, samples having a higher content of phyllosilicate minerals exhibit low log-linear healing rates, and the notably clay-rich fault zone sample also exhibits strong power-law healing when longer hold times are included. Our data suggest that weak faults, such as the creeping section of the San Andreas Fault, can accumulate interseismic shear stress more rapidly than expected from previous friction data. Using the power-law dependence of frictional healing on hold time, calculations of recurrence interval and stress drop based on our data accurately match observations of discrete creep events and repeating Mw = 2 earthquakes on the San Andreas Fault.

  12. Wind resource assessment: San Nicolas Island, California

    SciTech Connect

    McKenna, E.; Olsen, T.L.

    1996-01-01

    San Nicolas Island (SNI) is the site of the Navy Range Instrumentation Test Site which relies on an isolated diesel-powered grid for its energy needs. The island is located in the Pacific Ocean 85 miles southwest of Los Angeles, California and 65 miles south of the Naval Air Weapons Station (NAWS), Point Mugu, California. SNI is situated on the continental shelf at latitude N33{degree}14` and longitude W119{degree}27`. It is approximately 9 miles long and 3.6 miles wide and encompasses an area of 13,370 acres of land owned by the Navy in fee title. Winds on San Nicolas are prevailingly northwest and are strong most of the year. The average wind speed is 7.2 m/s (14 knots) and seasonal variation is small. The windiest months, March through July, have wind speeds averaging 8.2 m/s (16 knots). The least windy months, August through February, have wind speeds averaging 6.2 m/s (12 knots).

  13. History of the Italian San Marco equatorial mobile range

    NASA Technical Reports Server (NTRS)

    Nesbitt, H. N.

    1971-01-01

    Events leading to the development of the San Marco Equatorial Range are presented. Included are background information leading to the cooperative space program between the United States and Italy, conceptual planning, training activities, equipment design and fabrication, and range utilization. The technical support provided the San Marco Program by Scout Project Office, and other NASA installations is described.

  14. 6. Photocopy of photograph, c. 1892. DISTANT VIEW OF SAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Photocopy of photograph, c. 1892. DISTANT VIEW OF SAN JUAN SMELTING AND MINING COMPANY WORKS WITH EXTANT SMELTER STACK AT LEFT. (Original print in possession of Strater Hotel, Durango, Colorado. Photographer unknown.) - San Juan & New York Mining & Smelting Company, Smelter Stack, State Route 160, Durango, La Plata County, CO

  15. San Ysidro High School: An Invincible Sense of Promise

    ERIC Educational Resources Information Center

    Principal Leadership, 2013

    2013-01-01

    Commitment to one another, determination to prove stereotypes wrong, and a strong belief in the power of education are the core values at San Ysidro High School in San Diego, California. The school serves 2,364 students in one of the poorest communities in the country. The community celebrates its predominately Mexican-American heritage and…

  16. 33 CFR 117.193 - San Leandro Bay.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false San Leandro Bay. 117.193 Section 117.193 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.193 San Leandro Bay. The drawspans...

  17. 33 CFR 117.193 - San Leandro Bay.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false San Leandro Bay. 117.193 Section 117.193 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.193 San Leandro Bay. The drawspans of the California Department of...

  18. 33 CFR 117.193 - San Leandro Bay.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false San Leandro Bay. 117.193 Section 117.193 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.193 San Leandro Bay. The drawspans...

  19. 33 CFR 117.193 - San Leandro Bay.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false San Leandro Bay. 117.193 Section 117.193 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.193 San Leandro Bay. The drawspans...

  20. 33 CFR 117.193 - San Leandro Bay.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Leandro Bay. 117.193 Section 117.193 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.193 San Leandro Bay. The drawspans of the California Department of...