Dune deformation in a multi‐directional wind regime: White Sands Dune Field, New Mexico

Abstract

As with most dune fields, the White Sands Dune Field in New Mexico forms in a wind regime that is not unimodal. In this study, crescentic dune shape change (deformation) with migration at White Sands was explored in a time series of five LiDAR‐derived digital elevation models (DEMs) and compared to a record of wind direction and speed during the same period. For the study period of June 2007 to June 2010, 244 sand‐transporting wind events occurred and define a dominant wind mode from the SW and lesser modes from the NNW and SSE. Based upon difference maps and tracing of dune brinklines, overall dune behavior consists of crest‐normal migration to the NE, but also along‐crest migration of dune sinuosity and stoss superimposed dunes to the SE. The SW winds are transverse to dune orientations and cause most forward migration. The NNW winds cause along‐crest migration of dune sinuosity and stoss bedforms, as well as SE migration of NE‐trending dune terminations. The SSE winds cause ephemeral dune deformation, especially crestal slipface reversals. The dunes deform with migration because of differences in dune‐segment size, and differences in the lee‐face deposition rate as a function of the incidence angle between the wind direction and the local brinkline orientation. Each wind event deforms dune shape, this new shape then serves as the boundary condition for the next wind event. Shared incidence‐angle control on dune deformation and lee‐face stratification types allows for an idealized model for White Sands dunes. Copyright © 2015 John Wiley & Sons, Ltd.

The Imprint of Vegetation on Desert Dune Dynamics

“…While not exact, a unidirectional approximation for both the dune migration direction and wind direction is reasonable. Wind speeds above threshold are strongly unimodal (from the Southwest) and the majority of dune migration occurs along these SW winds (Jerolmack et al, ; Pedersen et al, ). Previous research has identified three regions associated with differing sediment transport and dune dynamics (Figure ).…”

Interpreting Soft Sediment Deformation and Mass Transport Deposits as Seismites in the Dead Sea Depocenter

“…Soft‐sediment deformation is a disruption of unlithified sediments (Alsop et al, ; Owen et al, ; Van Loon, ) and is widely documented in both subaerial (McKEE et al, ; Moretti, ; Pedersen et al, ) and subaqueous environments (Avşar et al, ; Gladkov et al, ; Jiang et al, ; Sims, ). Commonly, the disturbances are triggered either by seismic shaking (Liu‐Zeng et al, ; Monecke et al, ; Sakaguchi et al, ; Sims, ; Strasser, Kölling, et al, ) or by nonseismic triggers, for example, tides (Greb & Archer, ), storm waves (Molina et al, ), floods (Li et al, ), and sediment overloads (Moretti et al, ; Moretti & Sabato, ).…”

Stratigraphic architecture resulting from dune interactions: White Sands Dune Field, New Mexico

“…() and Pedersen et al . (). All time‐series components were georeferenced and co‐registered in ESRI ArcMap ™ .…”

“…The crescentic dunes average 4·7 m in height (Baitis et al ., ), crestline length averages 247 m, dune spacing averages 136 m and crestline orientation is 345° (Ewing et al ., ), which is borderline transverse (classification of Hunter et al ., ) to the net resultant of the wind towards 065° (Reitz et al ., ; Jerolmack et al ., ). Crescentic dune behaviour consists of crest‐normal migration at ca 3·5 m yr −1 under strongly dominant south‐westerly winds, but there is also along‐crest migration of dune sinuosity to the south‐east because of a secondary mode of NNW winds (Pedersen et al ., ). A tertiary wind mode from the SSE gives rise to ephemeral crestal slipface reversals (Pedersen et al ., ).…”

“…Low‐relief bedforms occur superimposed on the stoss slopes of many of the crescentic dunes and are oriented approximately normal to the crestline trends of the host bedforms. The superimposed bedforms primarily migrate along‐crest in response to the NNW winds (Pedersen et al ., ). In the south‐central region of the dune field where this study is located (Fig.…”