D. H. Abbott, Robert W. Embley and M. A. Hobart

Correlation of shear strength, hydraulic conductivity, and thermal gradients with sediment disturbance; South Pass region, Mississippi Delta

Geo-Marine Letters( 1985), 5(2):113-119

Index Terms/Descriptors: Atlantic Ocean; deformation; engineering geology; failures; geothermal gradient; Gulf of Mexico; hydraulic conductivity; Louisiana; materials, properties; mathematical models; Mississippi Delta; North Atlantic; pore pressure; pressure; shear strength; slope stability; soil mechanics; South Pass; thermal conductivity; United States

Latitude & LongitudeN18°00'00'' - N30°04'00'' and W98°00'00'' - W80°30'00''N29°00'00'' - N33°00'00'' and W94°05'00'' - W89°00'00''


The degree of sediment disturbance in the South Pass area is correlated to the average hydraulic conductivity, shear strength, and thermal gradient. Hydraulic conductivity averages 18, 6, and 4 × 10−7 cm/s in the undisturbed, moderately disturbed, and most disturbed sediments, respectively. Shear strength also decreases with increasing disturbance, from 7.6 to 4.4 to 3.5 kPa. Excluding the four stations dominated by annual temperature variations, the remaining 19 thermal gradients correlate well with sediment disturbance. The average gradient is positive in all of the disturbed sediments (0.12 ± 0.07° C/m) and 0 in the undisturbed sediments (0.02 ± 0.05° C/m).