Geologic controls on the West Antarctic Ice Sheet

• Main Author: Anandakrishnan, Sridhar
• Format: Other/Unknown Material
• Language: unknown
• Published: 1993
• Subjects: 46; Antarctic; Ross Sea; West Antarctic Ice Sheet; Byrd; Byrd Subglacial Basin; Antarc*; Ice Sheet; Ice Stream B; Ice Stream C
• Online Access: http://ntrs.nasa.gov/search.jsp?R=19930022711

The stability of the West Antarctic Ice Sheet is intertwined with its geologic history. The sub-ice geology and the possibility of active rifting and associated elevated heat-flux and volcanism might be determining factors in ice-sheet behavior. Seismic monitoring of natural events at the base of Ice Stream C reveals the presence of a young sedimentary basin beneath the ice stream. The sediments are presumed to be of glacio-marine origin, similar to those beneath Ice Stream B and in the Ross Sea. The young sediments are approximately 1/2 km thick at UpC camp, but thin abruptly southward to 100 m or less. We hypothesize the presence of a fault with a throw of 400 m to account for this (though we have not directly detected the fault), rather than invoking unrealistic basement dips. To extend these studies to critical inland regions, we suggest an expanded explosive-source seismic survey of the Byrd Subglacial Basin to determine the extent and character of the hypothesized rift basin. High-resolution seismic monitoring will detect layering in the sedimentary column, as well as possibly imaging faults directly.