남극 빙저호 탄성파 탐사 = Seismic Survey for the Subglacial Lake in Antarctica

국문 초록 (Abstract)

극지연구소는 남극 데이비드 빙하에 위치한 D2 빙저호의 규모와 호수 주변 빙하 하부 지질구조 조사를 위해 국내 최초 남극 빙하지역에서 탄성파 탐사를진행하였다. 탄성파 탐사는 남극 장보고 과학기지와 내륙 진출 루트 인프라를 활용하여 2019-20 남극 하계시즌에 1차 탐사에 착수, 빙하 아래 존재하는호수의 확인과 구조의 파악이 가능한 광역적 탐사자료를 확보하였다. 이후 남극 내륙 빙원에서의 환경적 상황과 기후조건에 의해 도출되어진 다양한 문제점을 보완하고 호수 아래 퇴적층 확인이 가능하도록 수신기와 음원 배열을 개선하여 2021-22 남극 하계시즌 2차 탐사를 실시하였다. 이 때 폭약 용량을 기존 400 g에서 1,600 g으로 늘리고, 막대형 수신기를 48채널에서 96채널로 확장, 중합 수를 1에서 4 또는 8로 증가시킴으로써 호수 아래 퇴적구조의확인이 가능한 정밀탐사를 진행하였다. 또한 열수 시추기를 사용해 시추공에 폭약을 설치 후 충분한 시간을 두어 장약된 시추공이 단단하게 얼어붙도록하는 등 다방면에서 자료의 품질 향상을 위한 노력을 기울였다. 그 결과 빙하 아래 호수의 규모와 구조적 특징 및 퇴적층 확인이 가능하며 최적의 열수시추 위치를 선정할 수 있는 충분한 정보가 담긴 고품질의 탄성파 자료를 확보할 수 있었다. 빙저호 탄성파 자료는 남극 내륙 빙저호 연구의 기초 정보를제공하고 향후 남극 내륙 내 다른 빙하 하부 구조 조사와 차기 빙저호 연구에 중요한 참고 자료로 활용될 수 있을 것으로 기대한다.

다국어 초록 (Multilingual Abstract)

The Korea Polar Research Institute (KOPRI) conducted Korea’s first seismic survey of an Antarctic glacier to investigate the size and subsurface structure of subglacial lake D2 beneath the David Glacier. The initial seismic survey was conducted during the 2019-2020 Antarctic summer season, utilizing infrastructure from the Jang Bogo Station and the Korean inland route (K-Route). This survey confirmed the existence of a subglacial lake and provided comprehensive data for preliminary structural analysis. Based on these findings, a second seismic survey was conducted during the summer of 2021-2022. In this survey, we employed a methodology to address the environmental challenges of the Antarctic inland ice sheet and to enhance detection resolution for subglacial lake sedimentary structures. In the second survey, the explosive charge was increased from 400 g to 1,600 g, the number of rod-type receiver channels was expanded from 48 to 96 channels, and the fold number was increased from 1 to 4 or 8, improving data quality and clarity. In addition, 25-30 m hot-water drilling was used to position explosives within the boreholes, which were then allowed to freeze solidly to maximize energy transmission efficiency. These high-quality seismic data enabled precise delineation of the subglacial lake’s size, structural features, and underlying sedimentary layers, thereby providing critical information for selecting optimal sites for further hot-water drilling. This dataset establishes foundational resources for Antarctic subglacial lake research and will support future studies on subglacial lake dynamics and structural analyses across Antarctica.

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