There was a predecessor that proved the detector concept and eventually merged into IceCube: https://en.wikipedia.org/wiki/Antarctic_Muon_And_Neutrino_Detector_

There was a predecessor that proved the detector concept and eventually merged into IceCube: https://en.wikipedia.org/wiki/Antarctic_Muon_And_Neutrino_Detector_Array https://en.wikipedia.org/wiki/Antarctic_Muon_And_Neutrino_De... AMANDA observed atmospheric but not extra-terrestrial neutrinos.