Barotropic seiches in a perennially ice‐covered lake, East Antarctica

Abstract

This work contributes to a growing body of observations on currents and seiches in ice-covered lakes. Under-ice currents play an important role in the biology of ice-covered lakes, and are especially important for redistributing nutrients in perennially ice-covered, polar lakes. This manuscript provides evidence of barotropic seiches below a 4-m-thick ice cover with consistent 10.5-min periods in Lake Hoare in the McMurdo Dry Valleys of East Antarctica. The period of the seiche seasonally lengthened to 13 min following the arrival of summer melt. During winter, there is a strong relationship between surface winds >5 m s À1 and seiche activity, indicating that seiches are caused by flexural vibrations of the permanent ice cover. Our manuscript provides new information that will benefit those studying under-ice water movements. Firstly, Lake Hoare is much smaller and has a much thicker ice cover than previous studies. Secondly, our data include a much longer time-series. Lastly, our data cover an important period when the lake transitions from winter fast ice to summer floating ice.