UACE2017 Proceedings: Identification of changes in the acoustic environment of the Indian Ocean using long term trend analysis on CTBTO data collected at Cape Leeuwin

• Session:
  Comprehensive nuclear test-ban treaty monitoring
• Paper:
  Identification of changes in the acoustic environment of the Indian Ocean using long term trend analysis on CTBTO data collected at Cape Leeuwin
• Author(s):
  Kostas Sotirakopoulos, Peter Harris, Stephen Robinson, Lian Wang, Valerie Livina
• Abstract:
  Continuous monitoring of deep ocean sound can be used for the identification of loud short term noise events occurring within the greater vicinity of monitoring locations. At the same time analysis of data coming from such monitoring stations has the potential to reveal less pronounced longer term changes in the oceans’ acoustic environment. The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has developed a network of monitoring stations including a number of hydro-acoustic recorders located in all major oceans. Many of these recorders have been continuously capturing low frequency deep ocean sound for more than a decade providing ideal datasets for long term analysis. In this paper multiband regression analysis is performed on time series of daily sound pressure levels extracted from datasets coming from the three hydrophone recorders at Cape Leeuwin’s monitoring station in Australia. The aim is the examination of trends in the recordings that might indicate changes in the Indian Ocean’s acoustic environment. Bootstrap resampling of the regression residuals is used as a non-parametric approach to computing the uncertainties associated with the trend estimates. Also, time series of average sound pressure levels extracted from the original recordings are used to identify a number of natural seismic events occurring many kilometres away from the station.
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Contact details

• Contact person:
  Mr Kostas Sotirakopoulos
• e-mail:
  
• Affiliation:
  MIO
• Country:
  United Kingdom