2023_programme: Hydroacoustic signals from Kermadec and Chilean submarine earthquakes recorded at CTBT-IMS station HA03

• Session: 03. Comprehensive Nuclear-Test-Ban Treaty Monitoring and its Civil and Scientific Applications
  Organiser(s): Georgios Haralabus, Mario Zampolli and Peter Nielsen
• Lecture: Hydroacoustic signals from Kermadec and Chilean submarine earthquakes recorded at CTBT-IMS station HA03
  Paper ID: 1934
  Author(s): Oliveira Tiago, Metz Dirk, Zampolli Mario, Haralabus Georgios
  Presenter: Oliveira Tiago
  Abstract: In addition to monitoring the oceans for signs of nuclear explosions, the International Monitoring System (IMS) hydroacoustic data have been used for a broad range of civil and scientific applications, including studies of submarine earthquakes. This presentation analyzes low-frequency (2 to 25 Hz) hydroacoustic signals from Kermadec and Chilean submarine earthquakes recorded at CTBT-IMS hydrophone station HA03. This station is located in the Juan Fernández Islands (Chile, South-East Pacific Ocean) at approximately 8800 km and 800 km from the epicenters of the Kermadec and Chilean earthquakes, respectively. HA03 is composed of two hydrophone arrays located about 15 km north (H03N) and 15 km south (H03S) of Robinson Crusoe Island to account for the acoustic shadow produced by Juan Fernández islands. The Dase ToolKit - Graphical Progressive Multi-Channel Correlation (DTK-GPMCC) program was used to estimate the arrival times and back azimuth of the recorded hydroacoustic signals. Different arrivals within the duration of the earthquake signals were identified. A discussion is provided on the characteristics of the arrivals detected at H03N and H03S for the different Kermadec and Chilean submarine earthquakes. Furthermore, reflected propagation paths induced by bathymetric features along the path from the epicenters to H03N and H03S are discussed.
• Corresponding author: Mr Tiago Oliveira
  Affiliation: Comprehensive Nuclear-Test-Ban Treaty Organization
  Country: Austria
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