TOPOGRAPHIC EFFECTS ON VENTIFACT DEVELOPMENT,MOJAVE DESERT,CALIFORNIA |
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| Authors: | Julie E Laity |
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| Institution: | Department of Geography , California State University, Northridge , Northridge, California 91330 |
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| Abstract: | I nvestigations into processes of ventifact formation in the east-central Mojave Desert, California confirm the importance of topography as a control in the location, orientation, and intensity of ventifact abrasion. Ventifacts in the region appear to be relict in nature and probably formed during a period that ended several thousand years ago. Comparison of groove orientations with available wind data shows that regional flow direction has not changed in the recent past. Although west to northwest winds are the most frequent and intense, and therefore dictate the regional erosion pattern, low to moderate southeasterly flow is recorded on ventifacts near the crests of hills owing to the effects of velocity acceleration. Two conditions that affect ventifact development are considered in this paper: (1) wind acceleration through topographic constrictions; and (2) wind acceleration up the windward flanks of hills. Constrictions in the Barstow-Bristol trough allowed velocity increases that resulted in ventifaction on 70–90 percent of all exposed cobbles and boulders. Velocity acceleration towards the crests of hills caused a marked increase in sand transport and resultant abrasion, as expressed by increases in groove and pit dimensions. Key words: Aeolian geomorphology, ventifacts, Mojave Desert, California.] |
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| Keywords: | Florida solar energy teleconnections ENSO AMO |
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