TY - JOUR
T1 - Morphology of Barchan Dunes on Earth and Mars
T2 - Classification and Scale-Invariance
AU - Sherman, Douglas J.
AU - Zhang, Pei
AU - Bae, Jinsu
AU - Butler, Robert J.
AU - Baas, Andreas C.W.
N1 - Publisher Copyright:
© 2024. The Author(s).
PY - 2024/10/1
Y1 - 2024/10/1
N2 - Morphological characteristics were measured for barchan dunes on Earth (2,686 dunes in 30 barchan fields) and Mars (720 dunes in 10 barchan fields) using satellite images. The data were used to (a) develop a new barchan classification system; (b) compare characteristics of barchans on Earth and Mars; and (c) assess whether barchans, in bulk, display allometric or scale-invariant characteristics. Dimensional metrics were obtained for the width and length of barchan bodies, the width and length of barchans including the horns, and the length of each horn. Dimensionless metrics were derived for the ratios of the body width to the width between the tips of the horns (width ratio), the length of the entire barchan to the length of the body (length ratio), and the length of the longer horn to the shorter horn (symmetry ratio). The width, length, and symmetry ratios were used to classify barchans into eight types and compare the characteristics of their distributions on the two planets. From this analysis, it was established that, statistically, barchans on Earth are distinctive from those on Mars based on the morphometrics, with terrestrial barchans being, on average, of smaller size and more often symmetrical, while Martian barchans more often have convergent horns that are short relative to the central dune body and are more often asymmetrical. The analysis further reveals that barchan planform morphology can be considered scale-invariant, and we argue that body width is the most appropriate measure representing barchan size.
AB - Morphological characteristics were measured for barchan dunes on Earth (2,686 dunes in 30 barchan fields) and Mars (720 dunes in 10 barchan fields) using satellite images. The data were used to (a) develop a new barchan classification system; (b) compare characteristics of barchans on Earth and Mars; and (c) assess whether barchans, in bulk, display allometric or scale-invariant characteristics. Dimensional metrics were obtained for the width and length of barchan bodies, the width and length of barchans including the horns, and the length of each horn. Dimensionless metrics were derived for the ratios of the body width to the width between the tips of the horns (width ratio), the length of the entire barchan to the length of the body (length ratio), and the length of the longer horn to the shorter horn (symmetry ratio). The width, length, and symmetry ratios were used to classify barchans into eight types and compare the characteristics of their distributions on the two planets. From this analysis, it was established that, statistically, barchans on Earth are distinctive from those on Mars based on the morphometrics, with terrestrial barchans being, on average, of smaller size and more often symmetrical, while Martian barchans more often have convergent horns that are short relative to the central dune body and are more often asymmetrical. The analysis further reveals that barchan planform morphology can be considered scale-invariant, and we argue that body width is the most appropriate measure representing barchan size.
KW - aeolian
KW - allometry
KW - bedform
KW - morphometrics
KW - shape
UR - http://www.scopus.com/inward/record.url?scp=85206890639&partnerID=8YFLogxK
U2 - 10.1029/2024JE008526
DO - 10.1029/2024JE008526
M3 - Article
AN - SCOPUS:85206890639
SN - 2169-9097
VL - 129
JO - Journal of Geophysical Research: Planets
JF - Journal of Geophysical Research: Planets
IS - 10
M1 - e2024JE008526
ER -