The results of a detailed hydrological study of the Larsemann Hills Oases (East Antarctica) during field seasons of 2017 to 2019 are presented. The study investigates a variety of lakes’ hydrological regime and the characteristics of outburst floods resulting from the lakes’ water flowing through tunnels in the snow-ice dams. The hydrographs calculated by the mathematical modeling do not generally contradict the physical essence of the process of outburst flood formation.