Spectrogram of 493 signals at a time I have been working with some seismic data and recently submitted a paper to a journal.

My seismic data has 493 traces: each trace are 8300 seconds long with sampling frequency of 2000 Hz.

One of the reviewers is asking me to generate a frequency spectrogram at the time= 2000s for all signals. My knowledge about the spectrogram is that you can only do it for one signal and there should be a time window to run the frequency analysis on. How can I do it? 

Here are more detail about my problem:
These 493 traces recorded vibration around a cable in a oil producing horizontal well. The traces are 16ft away from each other along the well. The idea of the publication was to assess the spectrogram for traces  on a specific location that was the target for hydraulic fracturing. The figure below is the spectrogram of one of the traces (signals) close to the target zone. Note that there are 492 other traces and all of them have the same number of samples, frequency, and length. All these traces recorded vibration for the entire 8300secon. The question is how I could generate spectrogram of all 493 traces for example at 2000 second.
Here is the wording of the reviewer: "I welcome the addition of a spectrogram showing many channels at one particular time interval."
The paper is accepted, But I think it's better to address the reviewer's comment. I will appreciate your name in my acknowledgment.
"I welcome the addition of a spectrogram showing many channels at one
  particular time interval."


If you don't want to include it, or don't have enough space, it is always worthwhile to put them in a supplementary file, attached to the journal, or separately on the Internet. I suggest the reviewer is looking for an onset phenomenon, and it would be easy to generate a few crops in  time interval $[1500-2500]$ side-by-side, potentially for only a tenth of your data (about 50 signals).