  Results from the IceCube Neutrino Observatory have recently provided
compelling evidence for the existence of a high energy astrophysical neutrino
flux utilizing a dominantly Southern Hemisphere dataset consisting primarily of
nu_e and nu_tau charged current and neutral current (cascade) neutrino
interactions. In the analysis presented here, a data sample of approximately
35,000 muon neutrinos from the Northern sky was extracted from data taken
during 659.5 days of livetime recorded between May 2010 and May 2012. While
this sample is composed primarily of neutrinos produced by cosmic ray
interactions in the Earth's atmosphere, the highest energy events are
inconsistent with a hypothesis of solely terrestrial origin at 3.7 sigma
significance. These neutrinos can, however, be explained by an astrophysical
flux per neutrino flavor at a level of Phi(E_nu) = 9.9^{+3.9}_{-3.4} times
10^{-19} GeV^{-1} cm^{-2} sr^{-1} s^{-1} ({E_nu / 100 TeV})^{-2}, consistent
with IceCube's Southern Hemisphere dominated result. Additionally, a fit for an
astrophysical flux with an arbitrary spectral index was performed. We find a
spectral index of 2.2^{+0.2}_{-0.2}, which is also in good agreement with the
Southern Hemisphere result.
