IceCube as a three-dimensional air-shower array covers an energy range of the
cosmic-ray spectrum from below 1 PeV to approximately 1 EeV. This talk is a
brief review of the function and goals of IceTop, the surface component of the
IceCube neutrino telescope. An overview of different and complementary ways
that IceCube is sensitive to the primary cosmic-ray composition up to the EeV
range is presented. Plans to obtain composition information in the threshold
region of the detector in order to overlap with direct measurements of the
primary composition in the 100-300 TeV range are also described.Comment: 12 pages, 5 figures, presented at COSPAR, Bremen Germany, 2010
Accepted for publication in Advances in Space Research. Revised version adds
acknowledgmen