Abstract
Theoretical and field studies show that P-wave velocity increases continuously with depth in unconsolidated sands. Many analytical and empirical models have been proposed to account for this phenomenon in near-surface layers. This study presents five new uphole data sets acquired in sand dunes located in the Empty Quarter (Rub’ Al-Khali) Desert in southeastern Saudi Arabia. Furthermore, the study compares the following velocity-depth functions: constant-velocity, Al-Shuhail, and Liner by fitting them to these data sets in addition to the sand curve data set. The constant-velocity function estimates an average P-wave velocity equal to 641 m/s in the dunes with an average sum of squared errors
(SSE)
=
0.00101
. Liner’s velocity function estimates an average surface P-wave velocity = 450 m/s and an average porosity (
ϕ
)
=
38.33
%
in the dunes with an average
SSE
=
0.000133
. Al-Shuhail’s velocity function estimates an average surface P-wave velocity
=
25.78
m/s
and an average velocity-depth gradient
=
662
m
-
1
/
3
in the dunes with an average
SSE
=
0.0000877
.