Whales use sound to navigate so the extra loud sonar blinds and scares them. They swim to get away and end up on the beach or maybe have lingering physical damage causing distress and eventually death. I don’t know if this is the case with the sonar mapping here, but I’m hoping the marine biologists are looking into it.

I am not a marine biologist, but I think of it this way: Imagine you are walking outside, minding your own fucking business, and are suddenly accosted by a sound so loud it bursts your ear drums and blinds you. You would run to get away from the sound, but being unable to use your ears or eyes to navigate your escape, you could run into traffic or off a cliff, or some other dangerous situation.