TY - JOUR
T1 - Complementary classifications of aeolian dunes based on morphology, dynamics, and fluid mechanics
AU - Courrech du Pont, Sylvain
AU - Rubin, David M.
AU - Narteau, Clément
AU - Lapôtre, Mathieu G.A.
AU - Day, Mackenzie
AU - Claudin, Philippe
AU - Livingstone, Ian
AU - Telfer, Matt W.
AU - Radebaugh, Jani
AU - Gadal, Cyril
AU - Gunn, Andrew
AU - Hesp, Patrick A.
AU - Carpy, Sabrina
AU - Bristow, Charles S.
AU - Baas, Andreas C.W.
AU - Ewing, Ryan C.
AU - Wiggs, Giles F.S.
N1 - Publisher Copyright:
© 2024 The Authors
PY - 2024/6/22
Y1 - 2024/6/22
N2 - Dunes form where winds blow over a bed of mobile sediment grains — conditions that are common in our solar system. On Earth, dunes abound in arid continental interiors and along sandy coastlines. Dune fields have also been recognized on Venus, Mars, Saturn's moon Titan, and Pluto. In response to the different boundary conditions and other environmental forcings, dunes adopt a rich diversity of shapes, sizes, and behaviors. Thus, people around the globe and over centuries have developed a rich vocabulary to describe dunes and their complexity. As a result, existing dune nomenclature often includes redundant terms with differing definitions across scientific communities. Previous studies have endeavored to link dune shape to environmental forcing, usually by means of correlation. Although instructive, correlation-based classifications can be misleading if not based on underlying mechanics or if dune morphogenetic classes are not uniquely defined. Here, we synthesize existing dune terminology and use the last two decades of research on dune morphodynamics to propose three complementary dune classification schemes based on: (1) descriptive dune geomorphology, (2) morphodynamic processes, and (3) fluid mechanics and physics of sediment transport. The first classification relates dune types to geomorphic setting, the presence or absence of vegetation or obstacles, and dune shape (including planform shape, and cross-sectional symmetry or asymmetry). Dune classes can be further subdivided where the direction of sand transport is known independently. The second classification relates dune types and shapes to bed properties (sand-covered vs partially starved bed) and wind forcing (directional variability or the relative strengths and directions of wind modes) that together influence dune dynamics (growth, migration, elongation) and select the dominant processes by which dunes are shaped and oriented relative to the resultant transport direction. The third classification relates, for different planetary environments, the range of possible dune sizes, from minimum to maximum wavelength, to fluid flow regime (rough or smooth) and the response of sediment flux, which influence the coupling between sand bed topography, fluid flow, and sediment transport. These characteristic lengths are useful scales for comparative geomorphology. The three classification schemes provide complementary information. Together, they form a unified framework for geomorphologists, sedimentologists, geographers, physicists, and others to describe windblown sand dunes on Earth and beyond through their shape, dynamics, and size as a response to winds and boundary conditions.
AB - Dunes form where winds blow over a bed of mobile sediment grains — conditions that are common in our solar system. On Earth, dunes abound in arid continental interiors and along sandy coastlines. Dune fields have also been recognized on Venus, Mars, Saturn's moon Titan, and Pluto. In response to the different boundary conditions and other environmental forcings, dunes adopt a rich diversity of shapes, sizes, and behaviors. Thus, people around the globe and over centuries have developed a rich vocabulary to describe dunes and their complexity. As a result, existing dune nomenclature often includes redundant terms with differing definitions across scientific communities. Previous studies have endeavored to link dune shape to environmental forcing, usually by means of correlation. Although instructive, correlation-based classifications can be misleading if not based on underlying mechanics or if dune morphogenetic classes are not uniquely defined. Here, we synthesize existing dune terminology and use the last two decades of research on dune morphodynamics to propose three complementary dune classification schemes based on: (1) descriptive dune geomorphology, (2) morphodynamic processes, and (3) fluid mechanics and physics of sediment transport. The first classification relates dune types to geomorphic setting, the presence or absence of vegetation or obstacles, and dune shape (including planform shape, and cross-sectional symmetry or asymmetry). Dune classes can be further subdivided where the direction of sand transport is known independently. The second classification relates dune types and shapes to bed properties (sand-covered vs partially starved bed) and wind forcing (directional variability or the relative strengths and directions of wind modes) that together influence dune dynamics (growth, migration, elongation) and select the dominant processes by which dunes are shaped and oriented relative to the resultant transport direction. The third classification relates, for different planetary environments, the range of possible dune sizes, from minimum to maximum wavelength, to fluid flow regime (rough or smooth) and the response of sediment flux, which influence the coupling between sand bed topography, fluid flow, and sediment transport. These characteristic lengths are useful scales for comparative geomorphology. The three classification schemes provide complementary information. Together, they form a unified framework for geomorphologists, sedimentologists, geographers, physicists, and others to describe windblown sand dunes on Earth and beyond through their shape, dynamics, and size as a response to winds and boundary conditions.
KW - Aeolian bedforms
KW - Desert, coastal, and planetary dune types
KW - Dune classification
KW - Fluid mechanics
KW - Geomorphology
KW - Morphodynamics
KW - Sediment transport
KW - Wind-blown landscapes
UR - http://www.scopus.com/inward/record.url?scp=85196553465&partnerID=8YFLogxK
U2 - 10.1016/j.earscirev.2024.104772
DO - 10.1016/j.earscirev.2024.104772
M3 - Review article
AN - SCOPUS:85196553465
SN - 0012-8252
VL - 255
JO - Earth-Science Reviews
JF - Earth-Science Reviews
M1 - 104772
ER -