Icecube neutrino detector a cubic kilometer in South Pole, traces energetic TeVs-PeVs neutrino signals by their cascades or better by their tracks inside its icy volume. Cascades, explosive
spherical showers in icy, are mostly for electron or tau or neutral current, tracks are made by muons. High energy tau tracks might show a birth place cascade and a second decay tau shower,
allowing a peculiar directional track. In general hundreds TeVs-PeVs Cascades show very poor directionality. Therefore they are nearly blind to disentangle the source event. Therefore we
suggest to neglect such cascades in future Gen-2 Icecube. Indeed the most interesting signals are the tens TeVs up to PeVs muon upgoing tracks, either born inside, HESE, or outside Icecube: the
trought going muon tracks. These ones are more abundant at ultra high energy (UHE) regimes because their interactions is outside the Icecube, mainly in the wider volume of dense rock around
and below the Icecube volume. Such several kilometers tracks offer the most energetic and precise neutrino astronomy. Moreover highest tens TeV or PeVs neutrinos become opaque to the
Earth radius. Therefore they are arriving mainly as up-going nearly horizontal tracks, because they are crossing only short Earth cords. In consequence we suggest an upgrade Muon Icecube
detector by a widest kilometers spaced concentric spiral array rings (around old Icecube), each arm nearly a kilometer far from the other, leading to the largest and widest array net (for any
given string number). Such wider (km) empty array volumes, like a sponge, may better amplify, almost quadratically, the observed mass volume, in comparision to a more dense but homogeneous
volumetric cubic one (at 240 or 330 meters distance among strings) as the Icecube Gen-2 project. In our first approximation one may obtain an increased cubic volume reaching about 50 times the kilometer Icecube array, by a shell like spiral volume or a honeycomb cell net, leading not to a few rare (hundred TeV energy) event a year but to many tens or even a hundred of such neutrino tracks each year, running toward a more statistical rich astronomy.