Abstract

In December 2017, Centro de Estudios Científicos (CECs), conducted a survey at the Subglacial Lake CECs area, West Antarctica (79°15′S 87°34′W). The over snow survey used a deep-penetrating low-frequency radar system developed by CECs that was mounted on sledges pulled by snowmobiles allowing measuring near 260 km of the central West Antarctic plateau. The system is an impulse radar working at a central transmission frequency of 2 MHz having three main components: a 4 kV power transmitter that works at 1 kHz pulse repetition frequency (PRF); a digital acquisition system ADQ214, with an analog to digital converter working at 400 MHz of sample rate, with a resolution of 14 bits and 256 traces on average; and a dual-frequency GPS receiver used for georeferencing the whole system. Transmitter and receiver antennae were resistively loaded wire dipoles. The components were installed inside peli-cases, each one having its own power and solar-panel charging system, including batteries allowing 8 hours of a continuous survey. Each component was installed on sledges tied together forming a 140 m long convoy. The convoy was pulled by snowmobiles moving at 8–10 km h–1 surface velocity. Ice thickness up to ~2700 m was reached. The upper hundreds of meters of the internal structure of the ice were mapped in detail, permitting the identification of isochronous layers with a vertical resolution of ~40 m. A comparison with previous surveys (2010 and 2016) offers major improvements in performance and reliability.