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We examine shear velocity anisotropy in the Yuha Desert, California using aftershocks of the 2010 M7.2 El Mayor-Cucapah earthquake. The Yuha Desert is underlain by a complex network of right- and left-lateral conjugate faults, some of which experienced triggered slip during the El Mayor-Cucapah earthquake. An automated method that implements multiple measurement windows and a range of bandpass filters is used to estimate the fast direction (ϕ) and delay time (δt) of the split shear waves. We find an average ϕ oriented approximately north-south suggesting it is primarily controlled by the regional maximum compressive stress direction. However, the spatial variability in ϕ reveals that the fault structures that underlie the Yuha Desert also influence the measured splitting parameters.We infer that the northeast- and northwest-oriented ϕ reflect shear fabric subparallel to the conjugate fault structures.We do not observe a simple correlation between δt and hypocentral distance. Instead, the observed spatial variation in δt suggests that near-source variation in anisotropic strength may be equal to or more important than effects local to the station. No temporal variation in splitting parameters is observed during the 70-day period following the main shock. In this region of complex faulting, we observe a spatially variable pattern of anisotropy that is both stress- and structurecontrolled. This study suggests that shear fabric can formeven along short, discontinuous fault strands with minimal offset. [ABSTRACT FROM AUTHOR]

A total of 1860 beach profiles were surveyed monthly from October 1995 to December 2003 at 29 control points along the coast of Rosarito (Baja California, Mexico). Sand volumes were estimated for the subaerial beach and related to deep-water wave records off California and nearshore waters at two localities off Rosarito. The spectral analysis of the sand volume time series revealed two main spectral peaks of 12- and 36-month periods. The latter cycle was identified for the first time along Rosarito beaches, showing a slightly larger amplitude on the beaches near the Federal Electricity Commission's breakwater and in the southern part of the study area. The contribution to sand movement produced by the annual cycle was 80 m3 m-1, while the transport induced by the 36-month cycle was 50 m3 m-1. The erosion and accretion cycle corresponded to winter and summer, respectively, but this pattern was inverted at two localities. The annual or seasonal cycle of sand volume change, defined in terms of the Dean number (Ω = Hs/wsT), is controlled by the seasonal wave pattern, while the inverted cycle is due to local changes in beach morphology and approach angle of breaking waves. The factor that accounted for this cycle is associated with interannual wave pattern variations and this, in turn, with ENSO events. [ABSTRACT FROM AUTHOR]

With levelized electricity costs (LEC) of 10–12 USCts/kWh the well-known SEGS (Solar Electric Generating Systems) plants in California are presently the most successful solar technology for electricity generation [Price and Cable (2001) Proc. ASME Int. Solar Energy Conf. Forum 2001]. The SEGS plants apply a two-circuit system, consisting of the collector circuit and the Rankine cycle of the power block. These two-circuits are connected via a heat exchanger. In the case of the Direct Steam Generation (DSG) in the collector field [Zarza et al. (2001) Proc. Solar Forum 2001, Washington], the two-circuit system turns into a single-circuit system, where the collector field is directly coupled to the power block. This renders a lower investment and higher process temperatures resulting in a higher system efficiency. Due to the lower investment and the higher efficiency a reduction of the LEC of 10% is expected when the DSG process is combined with improved components of the solar collectors [Zarza (2002) DISS Phase II Final Report, EU Contract No. JOR3-CT98-0277]. Within the European DISS (Direct Solar Steam) project the feasibility of the direct steam generation has been proven in more than 3700 operation hours. Steam conditions of 100 bar and 400 °C have been demonstrated. This paper presents the main scientific results of the DISS project that aims at the investigation and demonstration of the DSG process in parabolic troughs under real solar conditions. [Copyright &y& Elsevier]