Sastrugi sea ice than on multiyear ice. First-year ice is smoother than multiyear ice, which allows the wind to pass uniformly over the surface without topographic obstructions. Except during the melt season, snow is dry and light in climates cold enough for sea ice, allowing the snow to be easily blown and create sastrugi parallel to the wind direction. The locations of sastrugi are fixed by March in the northern hemisphere and may be linked to the formation of melt ponds. Melt ponds are more likely to form in the depressions between zastrugi on first-year ice. Sastrugi Sastrugi, or zastrugi, are
Surface wave detection by animals (short bursts of amplitude less than 100μm which contain many frequencies between 5 Hz and 190 Hz and are of short duration, as when an insect just touches the water rather than moves continuously at the surface). The other is continuous wave stimuli, which will contain many frequencies and in the wild are generated by fallen prey struggling at the water surface. It has been pointed out that "A lineatus" and other surface feeding fish are able to locate prey even if the waveform is only in click form (just touching the surface once, as when surfacing for air or