Beginning in October 1976, a program of water-level monitoring of abandoned water wells was initiated in the Palmdale area with the purpose of identifying possible water-level changes premonitory to a major earthquake on the San Andreas fault.In October 1977, the program was extended southeastward along the rift zone to the Valyermo area.In November 1977, the monitoring of water wells along the San Jacinto fault was initiated with the expectation of experiencing a moderate size earthquake while monitoring was in progress.Currently about 35 wells are being monitored.Eight wells are monitored continuously with Stevens Type F recorders.The remaining wells are probed weekly, or in some cases semi-weekly or daily, PLATE Plate 1 Map showing earthquakes, observation wells and precipitation stations ..............
Desert regions are increasingly being put into use for a variety of purposes. The California Desert may be subjected to a number of energy technologies—particularly those related to harnessing solar energy—in the near future. In conjunction with past or other current disturbances, the fragmentation and pollution impacts of energy development could pose serious threats to the desert's fragile ecosystems. Land-intensive energy technologies, such as solar receivers and biomass crops, will mainly result in changes that disrupt natural habitats. If all feasible energy schemes came to fruition, we estimate that one-half of the California Desert's area would be devoted to energy production. Even for much lower estimates of energy development, most of the Desert's natural habitat would be fragmented in park areas. Based upon island geographic principles and conservation biology, loss of species would be inevitable. Some species are already threatened with extinction. Research is required to determine ways in which the Desert's natural resources—solitude, scenic vistas, wildlife, and insolation—can best be used to meet energy, recreation, and conservation, needs. In particular, research is required to estimate how successive small habitat losses would stress desert ecosystems.
The author has identified the following significant results. ERTS and Skylab images reveal a number of prominent lineaments in the basement terrane of the Peninsular Ranges, Southern California. The major, well-known, active, northwest trending, right-slip faults are well displayed; northeast and west to west-northwest trending lineaments are also present. Study of large-scale airphotos followed by field investigations have shown that several of these lineaments represent previously unmapped faults. Pitches of striations on shear surfaces of the northeast and west trending faults indicate oblique slip movement; data are insufficient to determine the net-slip. These faults are restricted to the pre-tertiary basement terrane and are truncated by the major northwest trending faults. They may have been formed in response to an earlier stress system. All lineaments observed in the space photography are not due to faulting, and additional detailed geologic investigations are required to determine the nature of the unstudied lineaments, and the history and net-slip of fault-controlled lineaments.
One of the photographic techniques which shows great promise as an aid in interpreting ERTS imagery is pseudocolor transformation. It is a process where each shade of gray in an original black-and-white image is seen as a different color in the transformation. The well known ERTS-1 MSS image of the Monterey Bay-San Francisco area was transformed using a technique which requires only two intermediate separations. Possible faults were delineated on an overlay of the transformation before referring to geologic maps. The results were quite remarkable in that all large active or recently active faults shown on the latest geologic map of California were interpreted from the image for all, or much, of their length. Perhaps the most interesting result was the Reliz fault. The fault is shown as covered; however, a lineation corresponding to the position of the fault is visible on the image. The usefulness of ERTS image in identifying recently active faults is demonstrable. Although the faults are also visible in the unenhanced image, they are clearly accentuated and more easily mapped on the pseudocolor transformation.
Kern Lake has served as a sink for drainage from the southern Sierra Nevada and, in lesser amounts, from the southern Temblor Range. Both areas contain significant uranium source rocks. The uranium content in Holocene Kern Lake sediments correlates best with the mud (silt and clay) fraction. It correlates less well with organic carbon. Biotite grains could account for much of the uranium in the sand fraction, and perhaps the silt fraction as well. The data suggest that fixation of uranium by adsorption on mineral grains is a dominant process in this lake system. Further work is required to determine the importance of cation-exchange of uranium on clays and micas and of organically complexed uranium adsorbed to mineral surfaces. These findings also raise the question of whether uranium transport down the Kern River occurs largely as uranium adsorbed to mineral surfaces.
