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Aeolian Creep Transport: Theory and Experiment
Author(s) -
Wang Peng,
Zhang Jie,
Dun Hongchao,
Herrmann Hans J.,
Huang Ning
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl088644
Subject(s) - creep , aeolian processes , power law , mechanics , scaling , geology , saturation (graph theory) , flux (metallurgy) , steady state (chemistry) , geotechnical engineering , stress relaxation , statistical physics , geophysics , materials science , physics , thermodynamics , geomorphology , geometry , mathematics , statistics , chemistry , combinatorics , metallurgy
Abstract Aeolian sand transport drives geophysical phenomena, such as bedform evolution and desertification. Creep plays a crucial, yet poorly understood, role in this process. We present a model for aeolian creep, making quantitative predictions for creep fluxes, which we verify experimentally. We discover that the creep transport rate scales like the Shields number to the power 5/2, clearly different from the laws known for saltation. We derive this 5/2 power scaling law from our theory and confirm it with meticulous wind tunnel experiments. We calculate the creep flux and layer thickness in steady state exactly and for the first time study the relaxation of the flux toward saturation, obtaining an analytic expression for the relaxation time.