Table 3 Classification and labelling system for blue and fin whale sounds in the SORP library of annotated recordings.
Label | Call Type | References | Description |
|---|---|---|---|
Bm-Ant-A | Antarctic blue whale unit A | A constant frequency tone between 28 and 25 Hz (depending on the year) without other units | |
Bm-Ant-B | Antarctic blue whale unit AB | Antarctic blue whale unit A tone followed by partial or full inter-tone downsweep (unit B) | |
Bm-Ant-Z | Antarctic blue whale z-call; (AKA 3 unit vocalisation) | Antarctic blue whale 'z-call' with upper tonal unit A and lower tonal unit C present (and downswept unit B either present or absent) | |
Bm-D | Blue whale FM (AKA D-calls) | Any downswept frequency modulated calls from blue whales. Typically, but not always, longer in duration and lower in frequency than FM calls from fin and minke whales | |
Bp-20 Hz | Fin whale 20 Hz pulse | 20 Hz fin whale pulse without substantial energy at higher frequencies | |
Bp-20Plus | Fin whale 20 Hz pulse with energy at higher frequencies (e.g. 89 or 99 Hz components) | Fin whale 20 Hz pulse including secondary energy at higher frequencies (e.g. upper frequency peak near 80–100 Hz) | |
Bp-Downsweep | Fin whale FM calls (AKA ‘high frequency’ downsweep; AKA 40 Hz pulse) | Frequency modulated, usually downswept calls believed to be produced by fin whales. Usually, but not always shorter in duration and slightly higher in frequency than FM calls produced by blue whales | |
Unidentified | Unidentifiable sounds | Not applicable | Any transient biological sound that could not be confidently identified as any of the above classifications. This included sounds that could potentially be biological, but were substantially different than the above classifications. It also included FM downsweeps where the analyst was not certain whether they were blue whale D calls or fin whale downsweeps |
