During SnT19 we presented our work on defining the sources of hydroacoustic signals in the Indian ocean and looked at how the IMS can contribute to SDG 14. During the analysis we only managed to process three months of data from IMS HA04, HA08 and HA01. This time, we processed more than 12 months of non-stop data from those same stations. Data processing was performed using PMCC method with standard parameters for hydroacoustic signal detections. For each station we separated the detections into two main categories. The first category is the detections which remains present during the entire processing period. The second category is detections that requires further investigations, such as volcanos, land slide, breaking ice, cyclones and life below water. Constant detection was observed at stations H01W, H08S, H04N, respectively, between azimuth 140 and 250; azimuth 27 to 35 and 150 to 200; azimuth 0 to 100. We observed that those signals may come from tectonic events and ice breaking. For life below water it is still hard to say if we have detected any but this is included in NDC Madagascar’s perspective.
This work is the fruit of researches and recommendations following the SnT2019. We brought updates and new approach especially for detection association.