摘要：The quality of the ice core from Siple Dome, West Antarctica, varied widely, with significant fracturing below 400 m. Bubbly ice persisted to the ice–rock interface at 1004 m and constituted the brittle zone. The core has undergone minimal relaxation and has remained brittle and prone to fracturing more than 5 years after it was drilled. This behavior is attributed to unrelieved stresses from Kamb and Bindschadler Ice Streams (former Ice Streams C and D) flanking the dome. Melt layers were identified sporadically throughout the core, as were inclined layers tilted at angles that occasionally exceeded 10°. Structurally, the ice was characterized by extensive recrystallization including grain-size changes from 0.074 cm 2 at 59 m to >50 cm 2 at 992 m, and major transitions in c -axis fabrics. Unusual fabrics included vertical c -axis clusters superimposed on vertical girdles that may reflect vertical compression acting in conjunction with horizontal tension. The sudden appearance of a shear-type fabric at 700–800 m appears closely linked to the occurrence of abundant tephra particles embedded in the ice. The occurrence of dispersed sediment in the bottom 2 m is attributed to freeze-on of basal meltwater.
