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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Utilization requirements. A southern California Gas Company project SAGE report: Utilization requirements

Utilization requirements are given and comparisons made of two phase III SAGE (solar assisted gas energy) installations in California: (1) a retrofit installation in an existing apartment building in El Toro, and (2) an installation in a new apartment building in Upland. Such testing in the field revealed the requirements to be met if SAGE-type installations are to become commercially practical on a widespread basis in electric and gas energy usage.

Barbieri, R. H.↗
NASA NTRS1978

Public policy issues. A Southern California Gas Company project SAGE report

The use of solar energy to stretch our supplies of fossil fuels was investigated. Project SAGE (semi-automated ground environment) addresses itself to one application of this goal, solar assistance in central water heating systems for multifamily projects. Public policy issues that affect the rate of adoption of solar energy systems were investigated and policy actions were offered to accelerate the adoption of SAGE and other solar energy systems.

Barbieri, R. H.↗
NASA NTRS1977

Active and inactive faults in southern California viewed from Skylab

A number of prominent linears in basement terrane of the Peninsular Ranges appeared on Skylab images. In most cases, they were represented by straight or gently curved valleys; however, detailed field investigations have shown that several of these linears mark previously unmapped faults which form two distinct fault sets; one set trends northeast, the other west-northwest. No indications of recent movement were present on these faults which were truncated by seismically active, northwest trending fault zones such as the Elsinore and San Jacinto. Right-lateral separation is demonstrable on the northeast trending set.

Merifield, P. M.↗
NASA NTRS1979

Time-dependent gravity in southern California, May 1974 - Apr 1979

Gravity measurements were coordinated with the long baseline three dimensional geodetic measurements of the Astronomical Radio Interferometric Earth Surveying project which used radio interferometry with extra-galactic radio sources. Gravity data from 28 of the stations had a single reading standard deviation of 11 microgal which gives a relative single determination between stations a standard deviation of 16 microgal. The largest gravity variation observed, 80 microgal, correlated with nearby waterwell variations and with smoothed rainfall. Smoothed rainfall data appeared to be a good indicator of the qualitative response of gravity to changing groundwater levels at other suprasediment stations, but frequent measurement of gravity at a station was essential until the quantitative calibration of the station's response to groundwater variations was accomplished.

Whitcomb, J. H.↗
NASA NTRS1982

Retrofit energy conservation in residential buildings in southern California

The common energy conservation techniques (ECTs) that can be retrofit-installed into residential buildings are surveyed. The quantity of saved energy for heating and cooling attributable to each ECT is evaluated for three common modes of heating: natural gas heating at 60/therm; heating via heat pump at $1.20/therm; and electric resistance heating at $2.40/therm. In every case, a life cycle cost comparison is made between the long term revenue due to energy conservation and a safe and conventional alternative investment that might be available to the prudent homeowner. The comparison between investment in an ECT and the alternative investment is brought into perspective using the life cycle payback period and an economic Figure of Merit (FOM). The FOM allows for relative ranking between candidate ECTs. Because the entire spectrum of winter heating climates in California is surveyed, the decision maker can determine whether or not a considered ECT is recommended in a given climate, and under what conditions an ECT investment becomes attractive.

Turner, R. H.↗
NASA NTRS1985

Dislocation model for aseismic fault slip in the transverse ranges of Southern California

Geodetic data at a plate boundary can reveal the pattern of subsurface displacements that accompany plate motion. These displacements are modelled as the sum of rigid block motion and the elastic effects of frictional interaction between blocks. The frictional interactions are represented by uniform dislocation on each of several rectangular fault patches. The block velocities and fault parameters are then estimated from geodetic data. Bayesian inversion procedure employs prior estimates based on geological and seismological data. The method is applied to the Transverse Ranges, using prior geological and seismological data and geodetic data from the USGS trilateration networks. Geodetic data imply a displacement rate of about 20 mm/yr across the San Andreas Fault, while the geologic estimates exceed 30 mm/yr. The prior model and the final estimates both imply about 10 mm/yr crustal shortening normal to the trend of the San Andreas Fault. Aseismic fault motion is a major contributor to plate motion. The geodetic data can help to identify faults that are suffering rapid stress accumulation; in the Transverse Ranges those faults are the San Andreas and the Santa Susana.

Cheng, A.↗
NASA NTRS1988

Determination of convergence rates across the Ventura Basin, Southern California, using GPS and historical triangulation

Comparison of angles from historical triangulation observations dating as far back as 1932 with Global Positions System (GPS) measurements taken in 1987 indicates that rapid convergence may be taking place on decade timescales in the central and eastern part of the Ventura basin, an east-west trending trough bounded by thrust faults. Changes in angles over this time were analyzed using Prescott's modified Frank's method and in terms of a model which assumes that the regions to the north and south of the basin are rigid blocks undergoing relative motion. For the two block model, inversion of the observed angle changes over the last 28 years for the relative motion vector leads to north-south convergence across the basin of 30 + or - 5 mm/yr, with a left lateral component of 10 + or - 1 mm/yr in the Fillmore-Santa Paula area in the central part of the basin. The modified Frank's method yields strain rates of approximately 2 microrad/yr in both the east and central parts of the basin for measurements spanning the 1971 San Fernando earthquake. Assuming no east-west strain yeilds north-south compression of approximately 3.5 + or - .2 cm/yr. Comparison of triangulation data prior to the earthquake shows no strain outside the margin of error. The convergence rates determined by geodetic techniques are consistent with geologic observations in the area. Such large geodetic deformation rates, with no apparent near-surface creep on the major thrust, can be understood if these faults become subhorizontal at relatively shallow depths and if the subhorizontal portions of the faults are creeping. An alternative explanation of the large displacement rates might be that the pumping of oil in the vicinity of the benchmarks caused large horizontal motions, although it is unlikely that meter scale horizontal motions are due to oil withdrawal. These and other hypotheses are evaluated to better constrain the tectonics of this active region.

Donnellan, Andrea↗
NASA NTRS1987

Aseismic crustal deformation in the Transverse Ranges of southern California

Using geodetic data at a plate boundary, the subsurface displacements that accompany plate motion were modeled as the sum of rigid block motion and the elastic effects of frictional drag between blocks in a model consisting of 12 blocks and 27 rectangular fault patches. The block motion inferred from the geodetic data has the same order of magnitude as the geologic estimates, and for many faults the agreement was excellent. The model implies about 20 mm/y of crustal shortening normal to the trend of the San Andreas fault.

Cheng, Abe↗
NASA NTRS1992

Stress near geometrically complex strike-slip faults - Application to the San Andreas fault at Cajon Pass, southern California

A model is presented to rationalize the state of stress near a geometrically complex major strike-slip fault. Slip on such a fault creates residual stresses that, with the occurrence of several slip events, can dominate the stress field near the fault. The model is applied to the San Andreas fault near Cajon Pass. The results are consistent with the geological features, seismicity, the existence of left-lateral stress on the Cleghorn fault, and the in situ stress orientation in the scientific well, found to be sinistral when resolved on a plane parallel to the San Andreas fault. It is suggested that the creation of residual stresses caused by slip on a wiggle San Andreas fault is the dominating process there.

Saucier, Francois↗
NASA NTRS1992

An investigation of extensional tectonics of southern California

Geologic mapping and interpretation of Landsat TM imagery has filled in a significant gap in the geologic database for southwestern Arizona and southeastern California. The new data acquired, along with interpretation of existing data, forms the basis for a proposed reconstruction of late Tertiary faults in these regions. This reconstruction integrates available geological and geophysical data to define the eastern limit of deformation related to the San Andreas fault, and has significant implications for other recently proposed reconstructions of Tertiary deformation in the region. This progress in interpreting deformation during the last 10 Ma in the region forms a foundation for developing and testing models of older deformation in this region, including the initiation of San Andreas fault system, and the interaction of Early Miocene extension in the Basin and Range with the evolving San Andreas system.

Richard, Steven M.↗
NASA NTRS1991

Site comparison for optical visibility statistics in southern California

Negotiations are under way to locate an atmospheric visibility monitoring (AVM) observatory at Mount Lemmon, just north of Tucson, Arizona. Two more observatories will be located in the southwestern U.S. The observatories are being employed to improve a weather model for deep-space-to-ground optical communications. This article explains the factors considered in choosing a location and recommends Table Mountain Observatory as the location for another AVM facility.

Cowles, K.↗
NASA NTRS1995

Geologic investigations of a 'slip gap' in the surficial ruptures of the 1992 Landers earthquake, southern California

A 3-km-long gap in the dextral surficial rupture of the 1992 M(sub W) = 7.3 Landers earthquake occurs at the north end of a major fault stepover between the Johnson Valley and Homestead Valley faults. This gap is situated along a segment of the Landers rupture that has been modeled geophysically as having a deficit in average slip at depth. To better evaluate the nature of the slip gap, we document in detail the character and distribution of surficial rupture within it. Along the gap, is a northwest trending thrust fault rupture with an average of less than 1 m of northeast directed reverse-slip and nearly no oblique right slip. We interpret this rupture to be limited to the shallow crust of the northern end of the stepover and to have been the secondary result of dextral shear, rather than a mechanism of rigid-block slip-transfer from the Landers-Kickapoo fault. A zone of en echelon extensional ruptures also occurs along the slip gap, which we interpret as the secondary result of diffuse dextral shear that accommodated less than 0.5 m of west-northwest extension. These secondary ruptures represent a discontinuity in the surficial dextral ruptre of the Landers earthquake, which we propose resulted from the lack of a mature fault connection between the Johnson Valley and Homestead Valley faults. The rupture pattern of the slip gap implies a significant deficit in net surficial slip, which compares favorably with some geophysical models. Aspects of this rupture pattern also suggest a temporal sequence of rupture that compares favorably with geophysical interpretations of the dynamic rupture propagation.

Spotila, James A.↗
NASA NTRS1994

Increase in atmospheric CHF2Cl (HCFC-22) over southern California from 1985 to 1990

Column densities of CHF2Cl (HCFC-22) have been measured over Table Mountain Facility (TMF), Wrightwood, California (34.4 deg N) using the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier-transform infrared (FTIR) spectrometer. Between October 1985 and July 1990, the exponential column increase rate was (6.7 +/- 0.5)%/yr. Additionally, column measurements of CHF2Cl over McMurdo Sound, Antarctica (78 deg S) in September and October 1986 by the MarkIV FTIR spectrometer were used to derive a south-north interhemispheric ratio of (0.86 +/- 0.08). Model calculations investigated the feasibility of using CHF2Cl column measurements with a predicted global OH field to determine a globally averaged chemical lifetime for CHF2Cl, or equivalently, an estimate of the OH field using a predicted lifetime. The current uncertainty in historical CHF2Cl emissions is too large for CHF2Cl to be used to infer adequately either the lifetime or the OH field.

Irion, Fredrick W.↗
NASA NTRS1999

A Southern California Perspective of the April, 1998 Trans-Pacific Asian Dust Event

The Jet Propulsion Laboratory (JPL) coherent CO2 backscatter lidar has been in almost continuous operation since 1984 and has now accumulated a significant time-series database tracking the long-term and seasonal variability of backscatter from the atmospheric column above the Pasadena, Calif. locale. A particularly noteworthy episode observed by the lidar in 1998 was a particularly extreme instance of incursion by Asian-sourced dust during the closing days of April. Such events are not uncommon during the northern spring, when strong cold fronts and convection over the Asian interior deserts loft crustal material into the mid-troposphere whence it can be transported across the Pacific Ocean, occasionally reaching the continental US. However, the abnormal strength of the initiating storm in this case generated an atypically dense cloud of material which resulted in dramatically reduced visibility along the length of the Western Seaboard. These dust events are now recognized as a potentially significant, non-negligible radiative forcing influence. The progress of the April 1998 dust cloud eastward across the Pacific Ocean was initially observed in satellite imagery and transmitted to the broader atmospheric research community via electronic communications. The use of Internet technology in this way was effective in facilitating a rapid response correlative measurement exercise by numerous atmospheric observation stations throughout the western US and its success has resulted in the subsequent establishment of an ad hoc communications environment, data exchange medium, and mechanism for providing early-warning alert of other significant atmospheric phenomena in the future.

Tratt, David M.↗
NASA NTRS2002

The 1999 Hector Mine Earthquake, Southern California: Vector Near-Field Displacements from ERS InSAR

Two components of fault slip are uniquely determined from two line-of-sight (LOS) radar interferograms by assuming that the fault-normal component of displacement is zero. We use this approach with ascending and descending interferograms from the ERS satellites to estimate surface slip along the Hector Mine earthquake rupture. The LOS displacement is determined by visually counting fringes to within 1 km of the outboard ruptures. These LOS estimates and uncertainties are then transformed into strike- and dip-slip estimates and uncertainties; the transformation is singular for a N-S oriented fault and optimal for an E-W oriented fault. In contrast to our previous strike-slip estimates, which were based only on a descending interferogram, we now find good agreement with the geological measurements, except at the ends of the rupture. The ascending interferogram reveals significant west-sidedown dip-slip (approximately 1.0 m) which reduces the strike-slip estimates by 1 to 2 m, especially along the northern half of the rupture. A spike in the strike-slip displacement of 6 m is observed in central part of the rupture. This large offset is confirmed by subpixel cross correlation of features in the before and after amplitude images. In addition to strike slip and dip slip, we identify uplift and subsidence along the fault, related to the restraining and releasing bends in the fault trace, respectively. Our main conclusion is that at least two look directions are required for accurate estimates of surface slip even along a pure strike-slip fault. Models and results based only on a single look direction could have major errors. Our new estimates of strike slip and dip slip along the rupture provide a boundary condition for dislocation modeling. A simple model, which has uniform slip to a depth of 12 km, shows good agreement with the observed ascending and descending interferograms.

Sandwell, David T.↗