This presentation examines the potential of a 4 year weekly National Ice Center (NIC) ice-chart dataset for regional- to continental-scale studies of sea-ice thickness and volume. The weekly ice-chart data are compared with in situ sea-ice thickness observations from the Antarctic Sea Ice Processes and Climate (ASPeCt) program during the 1995 to 1998 time period. Sea-ice thickness calculations from both datasets are computed. The ice-chart dataset is then temporally joined with spatially averaged in situ observations using a Geographic Information System (GIS). The uncertainties for both thickness and volume are obtained through individual calculations and the GIS processing. The evaluation shows that the weekly ice-chart thickness estimates correlate reasonably well with in situ observations during five voyages from May/June 1995, August 1995, May/June 1998, December 1998/January 1999 and December 1999/January 2000 at the Ross Sea basin scale. The comparison is being extended to the entire Southern Ocean. Along with the comparison, the ice-chart-derived weekly, monthly and seasonal averages will be shown to illustrate the annual growth and melt cycles and ice dynamics evident from the ice-chart-derived thickness and volume data.