We discuss the reconstruction of neutrino flavor neutrino at a distant source in the very high en- ergy regime. This reconstruction procedure is relevant to the confirmation of detecting cosmogenic neutrinos, for example. To facilitate such a reconstruction, it is imperative to achieve effective flavor discriminations in terrestrial neutrino telescopes. We note that, for energies beyond few tens of PeV, a tau-lepton behaves like a track similar to a muon. Hence, while it is rather challenging to separate { \nu}{ \mu} from { \nu}{ \tau} in this case, one can expect to isolate { \nu}e from the rest by a distinctive shower signature. We present the result of flavor ratio reconstruction given the anticipated accuracies of flavor measurement in neutrino telescopes and current uncertainties of neutrino mixing parame- ters. It is shown that the further separation between { \nu}{ \mu} and { \nu}{ \tau} events does not improve the flavor reconstruction due to the approximate { \nu}{ \mu} - { \nu}{ \tau} symmetry.
Categories: hep-ph hep-ex