2025_programme: Hydroacoustic Observation of the 2022 Fimbul Ice Shelf Calving Event and Iceberg D-31 Formation

• Day: June 16, Monday
    Location / Time: A. TERPSIHORI at 12:00-12:20
• Last minutes changes: -
• Session: 04. Comprehensive Nuclear-Test-Ban Treaty Monitoring, and its Civil and Scientific Applications
  Organiser(s): Georgios Haralabus, Mario Zampolli, Tiago Oliveira, Mark Prior
  Chairperson(s): Georgios Haralabus, Tiago Oliveira
• Lecture: Hydroacoustic Observation of the 2022 Fimbul Ice Shelf Calving Event and Iceberg D-31 Formation
  Paper ID: 2125
  Author(s): Shiyan Wei, Yanming Yang, Hailin Ruan
  Presenter: Shiyan Wei
  Abstract: Ice shelf calving plays a significant role in driving sea level rise. Therefore, long-term monitoring of ice break-up on ice shelves and icebergs in Antarctica is essential. Detection and localization of acoustic signals emitted by ice rifting and calving in Antarctica, using the hydrophones of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System (IMS) hydroacoustic stations, could be an efficient way to monitor the disintegration of the Antarctic ice shelves. This presentation analyses hydroacoustic signals from the Fimbul Ice Shelf on the Princess Martha Coast of Antarctica recorded at CTBT-IMS hydrophone station HA04, which is located in the Southern Indian Ocean. The ice shelf events are located by estimating the back-azimuth of the signals arriving at H04 station and the distance to the sound source based on the frequency characteristics. A 3D parabolic equation (PE) model is then used to propagate the sound in the ocean for approximately 3700 km further to the hydrophone station. The source levels are derived from the recorded levels at each hydrophone, corrected for the transmission loss between the event and hydrophone locations. In addition, a reconstruction of the calving, colliding and fracturing process of iceberg D-31 is achieved by integrating satellite Synthetic Aperture Radar (SAR) and hydroacoustic observations. Our study shows that the CTBT IMS hydrophone stations provide valuable insights into the dynamics of ice shelves, especially for ice breaks of small volume.
• Corresponding author: Dr Shiyan Wei
  Affiliation: Third Institute of Oceanography, Ministry of Natural Resources (TIO)
  Country: China