IceCube is a cubic-kilometer Cherenkov detector in the deep ice at the geographic South Pole. The dominant event yield is produced by penetrating atmospheric muons with energies above several 100 GeV. Due to its large detector volume, IceCube provides unique opportunities to study atmospheric muons with large statistics in great detail. Measurements of the energy spectrum and the lateral separation distribution of muons offer insights into hadronic interactions during the air shower development, for example, and can be used to test hadronic models. In addition, the surface detector IceTop provides information about the electromagnetic component of air showers. Together with muon measurements in the deep ice this can be used to derive the mass composition of cosmic rays.
We will present an overview of various measurements of atmospheric muons in IceCube, including the energy spectrum of muons between 10 TeV and 1 PeV. This is used to derive an estimate of the prompt contribution of muons, originating from the decay of heavy (mainly charmed) hadrons and unflavored mesons. We will also present measurements of the lateral separation distributions of TeV muons between 150 m and 450 m for several initial cosmic ray energies. In addition, studies on the seasonal variations of atmospheric muon fluxes in IceCube will be shown. Finally we will introduce new techniques to study the cosmic ray mass composition up to EeV energies. This hybrid approach uses muon measurements in the deep ice detector, together with information from the surface detector array.