  The Cherenkov radio pulse emitted by hadronic showers in ice is calculated
for showers of energies in the EeV range. This is obtained with three
dimensional simulations of both shower development and the coherent radio pulse
emitted as the excess charge develops in the shower. A Monte Carlo, ZHAireS,
has been developed for this purpose combining the high energy hadronic
interaction capabilities of AIRES, and the dense media propagation capabilities
of TIERRAS, with the precise low energy tracking and specific algorithms
developed to calculate the radio emission in ZHS. A thinning technique is
implemented and optimized to allow the simulation of radio pulses induced by
showers up to 10 EeV in ice. The code is validated comparing the results for
electromagnetic and hadronic showers to those obtained with GEANT4 and ZHS
codes. The contribution to the pulse of other shower particles in addition to
electrons and positrons, mainly pions and muons, is found to be below 1%. The
characteristics of hadronic showers and the corresponding Cherenkov frequency
spectra are compared with those from purely electromagnetic showers. The
dependence of the spectra on shower energy and high-energy hadronic model is
addressed and parameterizations for the radio emission in hadronic showers in
ice are given for practical applications.
