TY - JOUR
T1 - Self-similar growth of a bimodal laboratory fan
AU - Delorme, Pauline
AU - Voller, Vaughan
AU - Paola, Chris
AU - Devauchelle, Olivier
AU - Lajeunesse, Éric
AU - Barrier, Laurie
AU - Métivier, François
N1 - Publisher Copyright:
© Author(s) 2017.
PY - 2017/5/8
Y1 - 2017/5/8
N2 - Using laboratory experiments, we investigate the growth of an alluvial fan fed with two distinct granular materials. Throughout the growth of the fan, its surface maintains a radial segregation, with the less mobile sediment concentrated near the apex. Scanning the fan surface with a laser, we find that the transition between the proximal and distal deposits coincides with a distinct slope break. A radial cross section reveals that the stratigraphy records the signal of this segregation. To interpret these observations, we conceptualize the fan as a radially symmetric structure that maintains its geometry as it grows. When combined with slope measurements, this model proves consistent with the sediment mass balance and successfully predicts the slope of the proximal-distal transition as preserved in the fan stratigraphy. While the threshold-channel theory provides an order-of-magnitude estimate of the fan slopes, driven by the relatively high sediment discharge in our experimental system, the actual observed slopes are 3-5 times higher than those predicted by this theory.
AB - Using laboratory experiments, we investigate the growth of an alluvial fan fed with two distinct granular materials. Throughout the growth of the fan, its surface maintains a radial segregation, with the less mobile sediment concentrated near the apex. Scanning the fan surface with a laser, we find that the transition between the proximal and distal deposits coincides with a distinct slope break. A radial cross section reveals that the stratigraphy records the signal of this segregation. To interpret these observations, we conceptualize the fan as a radially symmetric structure that maintains its geometry as it grows. When combined with slope measurements, this model proves consistent with the sediment mass balance and successfully predicts the slope of the proximal-distal transition as preserved in the fan stratigraphy. While the threshold-channel theory provides an order-of-magnitude estimate of the fan slopes, driven by the relatively high sediment discharge in our experimental system, the actual observed slopes are 3-5 times higher than those predicted by this theory.
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U2 - 10.5194/esurf-5-239-2017
DO - 10.5194/esurf-5-239-2017
M3 - Article
AN - SCOPUS:85018892500
SN - 2196-6311
VL - 5
SP - 239
EP - 252
JO - Earth Surface Dynamics
JF - Earth Surface Dynamics
IS - 2
ER -