THE AVALANCHING OF GRANULAR SOLIDS ON DUNE AND SIMILAR SLOPES

AVALANCHING OR LANDSLIDES OCCUR ON SLOPES UNDERLAIN BY LOOSE GRANULAR SOLIDS IN RESPONSE TO A PARTICLE DEPOSITION- RATE GRADIENT WHICH STEEPENS THESE SLOPES TO STATES OF INSTABILITY. THE FREQUENCY, SIZE, AND BEHAVIOR OF LANDSLIDES THUS RELEASED ARE SHOWN THEORETICALLY TO DEPEND ON A PARTICLE DEPOSITION-RATE GRADIENT, THE PARTICLE CONCENTRATION AT THE TIME OF DEPOSITION, THE PARTICLE SIZE AND DENSITY, AND THE AVALANCHING MEDIUM. THEORETICAL AND EXPERIMENTAL STUDIES DESCRIBED EXPLORE THE MAIN FACTORS CONTROLLING THE FREQUENCY AND SIZE OF AVALANCHES OF GRANULAR SOLIDS, PRINCIPALLY AS OCCURRING ON SUCH BED FORMS AS RIPPLES, DUNES, GILBERT-TYPE DELTAS. EXPERIMENTS USING NATURAL SANDS, GLASS BEADS, AND NATURAL GRAINS IN VARIOUS MEDIA GAVE FAIRLY SATISFACTORY CONFIRMATION OF THE THEORY CONCERNING AVALANCHE FREQUENCY, UNDER THE SIMPLE CONDITIONS OF A SPATIALLY CONSTANT DEPOSITION-RATE GRADIENT. BECAUSE OF RELATIVELY VERY LOW SEDIMENT-SUPPLY RATES AVALANCHES ON SCREES BORDERING MOUNTAIN WALLS ARE VERY INFREQUENT. IN COMPARISON WITH AVALANCHES GENERATED ON AN EXPERIMENTAL DUNE-LIKE SAND BODY THE THEORY IS FULLY CONSISTENT WITH EXPERIENCE ONLY FOR MODERATE AND LARGE OVERALL SEDIMENT SUPPLY RATES.

  • Availability:
  • Supplemental Notes:
    • Vol 78, No 3, PP 326-351, 10 FIG, 3 TAB, 24 REF
  • Corporate Authors:

    University of Chicago Press

    1427 E. 60th Street
    Chicago, IL  United States  60637-2954
  • Authors:
    • Allen, J R
  • Publication Date: 1970-5

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Filing Info

  • Accession Number: 00235745
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 26 1970 12:00AM