The newly developed RECoverable Autonomous Sonde (RECAS) allows sampling and analysis of subglacial water while the subglacial lake remains isolated from the surface. The sonde was successfully tested in East Antarctica during the 2021–2022 field season: it reached the ice-sheet base at a depth of 200.3 m, sampled basal meltwater and measured its pressure, temperature, pH and conductivity and returned to the ice surface. The average downward penetration rate was 1.85 m h⁻¹, and the average upward penetration rate was 2.94 m h⁻¹. The successful test of a self-melting, recoverable probe in Antarctica marks further progress towards the clean exploration of subglacial water bodies.

Antarctic drilling projects provide critical information for investigating ice-sheet stability, reconstructing paleoclimate evolution, and characterizing subglacial geological structures through ice-core and bedrock recovery. Drilling site selection currently relies on high-resolution geophysical methods such as radio echo sounding and active-source seismic methods; however, radar imaging near the ice–bedrock interface is limited by electromagnetic attenuation, while active-source seismic methods in polar regions are constrained by logistical complexity and high cost. To address these limitations, this study proposes a passive integrated imaging approach that integrates P-wave responses and vertical-component Rayleigh-wave information retrieved from continuous ambient noise recordings near drilling sites using seismic interferometry. Based on their distinct propagation characteristics, signal selection and processing workflows are developed to jointly image near-surface firn structure, ice-sheet thickness, and subglacial bedrock structure. Application to the Princess Elizabeth Land drilling project in East Antarctica demonstrates that high- signal-to-noise-ratio P-wave responses and vertical-component Rayleigh-wave signals can be retrieved from as little as 24 h of ambient noise data, while stacking the full 20-day record further suppresses incoherent noise and yields more reliable imaging of the ice–bedrock interface. These results indicate that passive seismic imaging provides a rapid, cost-effective, and environmentally friendly complement for drilling site selection and operational support.

There are numerous subglacial lakes in Antarctica, typically covered by thick ice sheets. Qilin subglacial lake is one of the largest subglacial lakes in Antarctica, lying beneath approximately 3600 m of ice. The exploration of this unique environment is of considerable scientific importance. Recoverable Autonomous Sonde (RECAS) has been proposed for exploring Qilin subglacial lake. However, drilling into the lakes with such probe may be impeded by volcanic ash or small rock clasts within the ice sheet. In addition, RECAS is incapable of withstanding the extreme hydrostatic pressure existing in the Qilin subglacial lake. To address these challenges, the thermal head of RECAS was redesigned and fabricated. Compared with the original RECAS thermal head, the updated thermal head has extra water circulation unit. Laboratory test validated that the redesigned RECAS thermal head can operate at water pressures of up to 40 MPa. Moreover, its rate of penetration (ROP) improved by 21.1 % in clean ice, by 41.1 % in dust-laden ice, and by 253.4 % in ice with debris-rich ice. The updated RECAS thermal head is expected to be utilized to drill Qilin Subglacial Lake in the coming Antarctic work season.

There are numerous subglacial lakes in Antarctica, typically covered by thick ice sheets. Qilin subglacial lake is one of the largest subglacial lakes in Antarctica, lying beneath approximately 3600 m of ice. The exploration of this unique environment is of considerable scientific importance. Recoverable Autonomous Sonde (RECAS) has been proposed for exploring Qilin subglacial lake. However, drilling into the lakes with such probe may be impeded by volcanic ash or small rock clasts within the ice sheet. In addition, RECAS is incapable of withstanding the extreme hydrostatic pressure existing in the Qilin subglacial lake. To address these challenges, the thermal head of RECAS was redesigned and fabricated. Compared with the original RECAS thermal head, the updated thermal head has extra water circulation unit. Laboratory test validated that the redesigned RECAS thermal head can operate at water pressures of up to 40 MPa. Moreover, its rate of penetration (ROP) improved by 21.1 % in clean ice, by 41.1 % in dust-laden ice, and by 253.4 % in ice with debris-rich ice. The updated RECAS thermal head is expected to be utilized to drill Qilin Subglacial Lake in the coming Antarctic work season.