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 and predictable waves, as dictated by surface tension and gravity. The water surface has a dampening effect which causes an abnormal dispersion pattern in which waves decrease in amplitude, speed and frequency with distance from the source. Short-wavelength (higher frequency) waves disperse faster than longer wavelength waves, resulting in higher frequencies at the front of the wave-train and lower frequencies at the tail; a fish detects this as a downward-sweeping frequency modulation. A vast amount of the research on surface wave detection has been done in the surface-feeding topminnow/killfish "Aplocheilus lineatus". Schwartz (1965) demonstrated that this species has exceptionally well-developed