Abstract: The AMANDA-II high energy neutrino detector began operation at the South Pole in January, 2000 with the expectation of ushering in the era of multi-messenger astronomy. This detector was originally conceived to detect neutrinos with energies of the order of 1-10 TeV, although it is capable of detecting neutrinos over a much broader range of energies. Recently, a new technique has been developed to extend the sensitivity of the detector to neutrino energies as large as 10 PeV. I will summarize the results of a search for point sources of TeV-scale neutrinos and diffuse sources of neutrinos at the energy frontier.
New and radically different detectors are required to probe for fluxes of neutrinos at energies in excess of 10 PeV. One such idea is called ANITA, a balloon-borne telescope that can view areas as large as 1 million square kilometers. If all goes as planned, ANITA will be the first detector with the capability to measure the flux of neutrinos emitted by the interaction between high energy cosmic rays and cosmic microwave background photons. I'll try to explain why this measurement is important.