bonne question ! Je vous suggére de lire le chapitre 7 du papier de Paula Messina qui fait référence à l'effet des vents sur le déplacements des pierres:
http://geosun.sjsu.edu/paula/rtp/dissertation/chapter7.pdf
Voici quelques extraits:
"Thus relatively straight trails can be explained. Traces such as those produced by Amelia, Cynthia, Pamela (Figure 7.7, page 214); Jacki, Julie (Figure 7.8, page 210); and Helen (Figure 7.17, page 227) may indicate initial propulsion and relatively-straight movement caused by wind shear followed by ultimate entanglement within a whirlwind."
"The sliding rocks appear to record vortex activity, especially in the convoluted scribbles found at the ends of several trails"
Once set into motion, the rock may be propelled by wind speeds roughly half of those necessary to initiate activity (Bacon, Cahill and Tombrello, 1996).
Some trails are parallel to others that are in close proximity and generally strike from south to north, consistent with prevailing wind patterns, thereby suggesting wind as the motive force.
Il faut noter que les déplacements ne sont pas tous linéaires (voir les schémas du chap 7).
Cocolumbo
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