I'm open to an explanation. But, I think a lot of the effect of the animation is created by the dots representing the whale and ships being huge. In reality the dots would be tiny and almost never come into visible range of each other.
I don't think the animation type influences the information in a misleading way and I think that the suggested effect is real.
Whales use sound to gather information about their surroundings rather than sight. So it isn't about visibility range, but rather about auditory range. In addition, sound travels at a different speed under water (I don't know how it affects the range).
The movie 'The last Giants' [1] is a documentation about the whales in the Strait of Gibraltar. While I don't think it is a particular good movie (too emotional), I think the basic information presented, gives a good impression of how whales are affected by modern ships. It is cruel.
Thats not the point. I’m sure whales can hear the doppler shifts just as easily—or even easier—then we. And I’m sure they can deduce the direction and speed of a vessel just as well. And I’m sure being in the line of attack of something really big and really fast moving is just as stressful for a whale as it is for us.
Shipping noise can travel much further underwater than through the air. If the effect being shown is real then I wouldn't be shocked if sound were the culprit.
For scale, the latitude lines are drawn at 0.2 degree increments, i.e. 12 nautical miles or 22 km apart (1 degree of latitude - or 1 degree of longitude if and only if you're at the equator - is 60 nautical miles).
On twitter they say it is an indicator of speed. If sound is the main culprit in deterring the whale from the natural pattern, then it makes sense for a faster moving ships to have a more dramatic visual weight. That is a whale should be just as stressed of hearing something loud come at it with a high speed as we would be at seeing something big come at us on high speed.
