Seismic Acquisition, Modelling, and Data Analysis of Antarctic subglacial lakes

Abstract. Subglacial lakes are crucial for studying life evolution, ice sheet dynamics, and climate change. Lake Qilin, located in the Princess Elizabeth Land region of East Antarctica, is the second largest subglacial lake discovered in Antarctica. Studying its microbial communities and biogeochemical cycles provides valuable insights into Earth's life evolution and the search for extraterrestrial life. To advance this research, China plans to conduct clean drilling and water sampling in Lake Qilin from 2025 to 2027. Additionally, during the 41th Chinese National Antarctica Research Expedition, active-source seismic exploration will be conducted to obtain high-resolution imaging, guiding drilling site selection. This study provides theoretical support for these efforts by developing a representative velocity model for subglacial lakes, simulating wavefields to characterize seismic responses, processing simulated data to identify processing challenges, and evaluating acquisition systems to determine the optimal survey geometry for Lake Qilin exploration. The results demonstrate that, in addition to primary reflections, multiples and guided waves will prominently develop in the seismic wavefield. Conventional seismic data processing of multiples introduce false coherent events, complicating seismic interpretation. Furthermore, the full-coverage acquisition system is identified as the optimal approach for the Lake Qilin exploration. To validate our simulation results, seismic data from Thwaites Glacier were processed and analyzed, and the results aligning well with part of our simulations, thus confirming the accuracy of the theoretical framework.