Filters: Tags: Quaternary International (X)
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Southern California relies heavily upon imported water from the Sacramento and Colorado river systems to augment local supplies and to mitigate the impacts of drought. In this paper a ‘perfect drought’ is defined as a prolonged drought that affects southern California, the Sacramento River basin and the upper Colorado River basin simultaneously. Examination of instrumental climate and discharge records shows that over the past century such perfect droughts do occur, but generally persist for less than five years. Perfect droughts that extend across all three areas are associated with anomalous upper-level high pressure off west coast and over western North America which is in turn associated with anomalously...
Geomorphologists have long recognized that eolian sand transport pathways extend over long distances in desert regions. Along such pathways, sediment transport by wind can surmount topographic obstacles and cross major drainages. Recent studies have suggested that three distinct eolian sand transport pathways exist (or once existed) in the Mojave and Sonoran Desert regions of the southwestern United States. One hypothesized pathway is eolian sand transport from the eastern Mojave Desert of California into western Arizona, near Parker, and would require sand movement across what must have been at least a seasonally dry Colorado River valley. We tested this hypothesis by mineralogical, geochemical and magnetic analyses...
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