Premium
The Bagnold Dunes in Southern Summer: Active Sediment Transport on Mars Observed by the Curiosity Rover
Author(s) -
Baker Mariah M.,
Lapotre Mathieu G. A.,
Minitti Michelle E.,
Newman Claire E.,
Sullivan Robert,
Weitz Catherine M.,
Rubin David M.,
Vasavada Ashwin R.,
Bridges Nathan T.,
Lewis Kevin W.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl079040
Subject(s) - bedform , aeolian processes , mars exploration program , geology , impact crater , sediment transport , orbiter , oceanography , geomorphology , sediment , astrobiology , physics , aerospace engineering , engineering
Orbiter‐based observations have demonstrated that active aeolian environments are ubiquitous across Mars. Here we examine one such environment, the Bagnold Dune Field in Gale crater, with repeat imaging campaigns conducted from Curiosity during southern summer. Images reveal widespread migration of aeolian impact ripples (up to 2.8 cm/sol), which is in stark contrast to the inactivity of similar bedforms during southern winter. The winds responsible for steady southwestward migration of ripples are consistent with predictions of regional‐scale flows that enter the crater from the north and interact with the topography of Mount Sharp but are not fully representative of all dune‐forming winds. Inferred friction speeds of 1.5 m/s needed to explain mobilization of bedforms are likely not being achieved, and thus, a majority of sediment transport may be taking place at subthreshold conditions. This hypothesis is further supported by sand flux estimates that suggest a low saltation flux environment within the dune field.