Abstract: In this seminar, we will discuss two studies in the context of the high-energy neutrino detection. First, we address the impact of tau appearance from high-energy muon and electron neutrinos interaction as they propagate through Earth. This component is predicted to be significantly larger than the atmospheric background, and it alters current and future neutrino telescopes’ capabilities to discover a cosmic tau-neutrino flux. Second, we explore the capabilities to detect neutrino-nucleon soft interactions induced by TeV-scale gravity with the next generation of radio telescopes. In this elastic regime, the commonly used method to measure the total cross section breaks down, so we explore new proxies.