Other Dunes and Other Sand Deposits - Dune Worlds: How Windblown Sand Shapes Planetary Landscapes - page 92

Fig. 7.8 A ripples showing the
'echo' effect on Mars. The
innermost ripple follows the
shape of, but is standing off a
short distance away from, the
aerodynamic obstacle, a rock
named 'Stimpy'. Image from the
Sojourner rover on Sol 70 of its
mission. The blank line across
the image is where data were lost
during transmission between the
rover and the lander. NASA/JPL
image

Fig. 7.9 Nebkhas on the sebkha.
Small dunes forming in the lee of
salt-tolerant plants on the Chott
El-Djerid, in Tunisia. See also
snow dune in the lee of a tent in
Fig. 2.1 , and sand drifts in the lee
of boulders on Mars. Photo R.
Lorenz

7.9 Blowout Dune

on the original dune form on which the blowout developed,
but the blowout itself generally lacks a slip face. Blowouts
most often occur on dunes previously stabilized by vege-
tation, and the blowout forms where that stabilizing vege-
tation has been disrupted or destroyed, as by a localized fire.

Disruption of a dune surface by locally enhanced wind
scour and the alteration of any adjacent dune pattern
(Fig. 7.10 b). There may be one or more slip faces present