Body: <p>I often have to deal with spectrograms similar to the one below, I have some ideas as to what the different signatures might come from but I still have some doubts. Do you have any idea as to what that might be.</p>
  <p>I suspect the low frequency (100Hz) signal to be hydrophone noise, but the higher frequency signal seems to high to be blue whales.</p>
  <p>Some context: This spectrogram is from a tagged elephant seal out at sea in the southern Indian Ocean. He is drifting passively (ie sleeping) at 100m depth.</p>
  <p>Any help would be appreciated :)</p>
  <p><a href="https://i.sstatic.net/nSJrmzPN.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/nSJrmzPN.png" alt="Beautiful spectrogram" /></a></p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-06-03T16:18:44.493Z
Comments.Text: yes indeed @Noil
Comments.UserDisplayName: Anatoole
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-06-11T14:36:10.840Z
Comments.Text: Could there be humpback whales in the area?
Comments.UserDisplayName: selene
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-06-12T09:43:17.757Z
Comments.Text: @selene Yes. Humpbacks or Southern right whales
Comments.UserDisplayName: Anatoole
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-06-12T15:20:37.433Z
Comments.Text: I am not an expert on low frequency whale sounds, but the variety and frequency of a few hundred Hz could maybe be humpback whales. Can you add some info about the season and more specifically the location to your question? A quick google search of 'humpback whale song southern indian ocean' gave me this paper that might be useful [Murray et al. 2012](https://onlinelibrary.wiley.com/doi/full/10.1111/j.1748-7692.2011.00484.x?casa_token=0GYKpYsB3L8AAAAA%3AyOzK-KWA6ejAdmmuvs8GB1RSFOxzgUKJhMDMnZhRdrc8qYvcRlB05F4l-8x2Re_DPorwkweCU91Wsrc)
Comments.UserDisplayName: selene
Tags: <hydrophone><call-identification>
Title: Unknown underwater acoustic sound source
ThreadText: # Unknown underwater acoustic sound source
  
  (Asked by: username_0 on 2024-06-03)
  
  I often have to deal with spectrograms similar to the one below, I have some ideas as to what the different signatures might come from but I still have some doubts. Do you have any idea as to what that might be.
  
  I suspect the low frequency (100Hz) signal to be hydrophone noise, but the higher frequency signal seems to high to be blue whales.
  
  Some context: This spectrogram is from a tagged elephant seal out at sea in the southern Indian Ocean. He is drifting passively (ie sleeping) at 100m depth.
  
  Any help would be appreciated :)
  
  [![Beautiful spectrogram](https://i.sstatic.net/nSJrmzPN.png)](https://i.sstatic.net/nSJrmzPN.png)
  
  **Tags:** hydrophone, call-identification
  
  > **Comments:**
  > **username_0**: yes indeed @Noil  
  > **username_1**: Could there be humpback whales in the area?  
  > **username_0**: @username_1 Yes. Humpbacks or Southern right whales  
  > **username_1**: I am not an expert on low frequency whale sounds, but the variety and frequency of a few hundred Hz could maybe be humpback whales. Can you add some info about the season and more specifically the location to your question? A quick google search of 'humpback whale song southern indian ocean' gave me this paper that might be useful [Murray et al. 2012](https://onlinelibrary.wiley.com/doi/full/10.1111/j.1748-7692.2011.00484.x?casa_token=0GYKpYsB3L8AAAAA%3AyOzK-KWA6ejAdmmuvs8GB1RSFOxzgUKJhMDMnZhRdrc8qYvcRlB05F4l-8x2Re_DPorwkweCU91Wsrc)  
  
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  ## 0 answers
  
  