How do you know when the Kraken is near?

Excuse me, but could you elaborate on how one might discern the proximity of the Kraken? Is there a specific set of signs or omens that have been historically associated with its approach? Alternatively, do experts in the field rely on more scientific methods, such as tracking underwater seismic activity or monitoring changes in ocean currents, to predict the Kraken's movements? I'm genuinely curious to understand how one goes about identifying the presence of such a legendary creature.