Oh yes! It’s absolutely true that underwater geography can steepen the wave front and amplify the height, sometimes by orders of magnitude. The deep water height of a tsunami wave is often a lot different from what you will see at the coastline.
An entertaining anecdote from the pre- smartphone era:
I sailed to the site near Chenega bay where the earthquake wiped out the village in 1958. We got permission from the elders at the Chenega bay village to land at the island, and it was extremely humbling to see the high water mark from the coastline, and to see the wreckage of boats far, far up on mountainsides.
I’m not a big believer in supernatural stuff, and there are plenty of alternative explanations, but it still freaks me out a bit that the photos we took (aside from the digital ones) did not develop any images of the village site. It was white as if it had been overexposed, even in the case of 1/2 frames. On both disposable cameras. Other photos from the same day, taken in other directions, turned out fine. The digital camera fell overboard in 500 fathoms, so we lost those photos the next day.
As for how exactly this could happen in any reasonable version of events, I’ve got nothing. I guess sometimes chance events line up just right to make for a good story.
Interestingly, there are big tidal bores frequently in Turnagain arm, with 1-3m being common. I’ve seen people surfing it with wetsuits in the ice cold water, getting a run of several miles lol.
> Interestingly, there are big tidal bores frequently in Turnagain arm, with 1-3m being common. I’ve seen people surfing it with wetsuits in the ice cold water, getting a run of several miles lol.
That’s going on the bucket list! How dangerous is it? If you biff it and get caught by the wave can you just dive under the wavefront and come up behind it like on a beach?
I don’t know much about the dangers involved, but it isn’t (or wasn’t, AFAIK) a big attraction… so maybe it’s crazy or dangerous? I’m not sure. Or it might be because the water is so cold that hypothermia and death is inevitable in less than an hour? Or because there probably is no realistic chance of rescue if something goes wrong?
At any rate, there was enough people willing to try that I saw it a couple of times, and TBF I think windsurfing isn’t too unusual in the arm now. But there is also trees and stuff in the tidal bores sometimes, so maybe debris is a big problem or the area is too shallow to be safe.
But, if it’s doable, I’m sure it would be memorable!