The detection of liquid water by the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) at the base of the south polar layered deposits in Ultimi Scopuli has reinvigorated the debate about the origin and stability of liquid water under present-day Martian conditions. To establish the extent of subglacial water in this region, we acquired new data, achieving extended radar coverage over the study area. Here, we present and discuss the results obtained by a new method of analysis of the complete MARSIS dataset, based on signal processing procedures usually applied to terrestrial polar ice sheets. Our results strengthen the claim of the detection of a liquid water body at Ultimi Scopuli and indicate the presence of other wet areas nearby. We suggest that the waters are hypersaline perchlorate brines, known to form at Martian polar regions and thought to survive for an extended period of time on a geological scale at below-eutectic temperatures.

在Ultimi Scopuli的南极层状沉积物底部的火星高级地下探测和电离层探测雷达（MARSIS）对液态水的探测，重新激发了关于当今火星条件下液态水的起源和稳定性的争论。为了确定该地区的冰川下水范围，我们获取了新的数据，从而在研究区域内扩大了雷达覆盖范围。在这里，我们介绍并讨论通过基于通常应用于陆地极地冰盖的信号处理程序对整个MARSIS数据集进行分析的新方法所获得的结果。我们的结果加强了在Ultimi Scopuli检测到液态水体的主张，并表明附近存在其他潮湿区域。我们建议这些水是高盐高氯酸盐盐水，