Earthquakes along the mid‐Arctic ridge radiate earthborne compressional and shear waves, which in turn excite the Arctic acoustic channel. These waterborne arrivals, calledTwaves, have been observed about 300 km from the source and apparently enter the acoustic channel by scattering of vertical rays into nearly horizontal ones by the Arctic ice canopy above the source. TheTwaves are acoustically energetic (up to 400 kJ), are of surprisingly long duration (up to 72 s at its 8‐dB down levels), have low‐frequency content (peaks in the 5–15‐Hz region), and have haystack spectra (4th power positive and negative dependence below and above the peak frequency, respectively). Characteristics of these sporadic noises are displayed for one event in a sonogram, in short time frequency spectra, in a time series, and in directional spectra. Directional analysis was accomplished with use of a large (∼1 km) two‐dimensional horizontal array. Speculations on duration of the observed events suggest that source depth, water‐column reverberation above the source, and source magnitude, including ‘‘rapid‐fire’’ multiple source excitations, could be the primary causes.