[HELP] Macross/Robotech "Super Tsunami" - How bad was it really?

[Black Aeronaut]

Okay, so I've been hearing all kinds of things about how the American West Coast was utterly devastated by a super tsunami that swept out from where the SDF-1 Macross space folded out along with South Ataria Island and a decent chunk of the Pacific Ocean.

And yet, later on, we see that Minmei's home town of Yokohama is just fine.

Wut.

No really, what the hell?

Because here, this map shows where South Ataria Island (actually South Iwo Jima in real life) is actually located.

   

So, how the hell is the West Cost screwed over six ways to Sunday, but Yokohama is just fine?  Was this yet another one of Harmony Gold's bending of the facts or did someone legit not do their homework?

Or, more importantly, can such an event even spawn such a huge tsunami?  Because, IIRC, tsunamis are caused by shifts in the tectonic plates that adjust the relative depths of the sea floor on either side of the faultline.  And I would think that would be shifting a helluva lot more volume of sea water than what got taken with the SDF-1.

So.... help?

[itsune9tl]

The Displacement wave from the Abbreviated Launch Sequence had an Inherent Vector from Kinetic transfer of energy to the Liquid Abatement Medium. Yokohama did get hit by a lesser Wave from the recovery cycle.

[Norgarth]

had to look up where Yokohama was
https://www.google.com/maps/place/Yokoha...39.6380256
the wave wouldn't be able to slam straight into Yokohama, it would have to bounce off of a headland or two on the way into the bay to hit the actual city, which would reduce the power of the wave.

[Black Aeronaut]

If you saw a post here before, it was erroneous on my part. I forgot to convert cubic meters to cubic kilometers. Back in a moment with corrected figures.

[itsune9tl]

I'm saying that West coast America got hit by the initial Bow Wave from the Space fold jump.  There is a reason Why the Zentradi were shocked by the fortress performing a fold maneuver so close to the planets surface.  It wasn't just possible damage to the ship, nor the sizable piece of real estate they took with them.

The Fold took all displaced mass that and drew a line in the direction of the fold. This created an amplified wave greater than the suddenly missing island could account for, and it had a direction it was moving in.

[Black Aeronaut]

Okay, it probably was as bad as implied... But I'm a little unsure at this point because the figures are just that wild.

So, SDF-1 takes a 50km diameter hemisphere out of the Pacific.

Formula for volume of a sphere is supposed to be (4/3)πr^3=V For a 50km sphere (25km radius), divided in half, that comes to about 65.5 Thousand km^3.

I would like to use the Tohoku Tsunami (the one that caused the Fukushima Nuclear Disaster) as a basis for comparison, but while I can find data that says that areas of the ocean floor shifted vertically by 7 to 10 meters, absolutely none of them happen to mention how large these areas are - merely utterly maddening hints such as "an area 180km in length 60km off the east coast of Japan".

Are there any maps that show how much of the sea floor shifted and to what degree?

[Black Aeronaut]

I'm saying that West coast America got hit by the initial Bow Wave from the Space fold jump.  There is a reason Why the Zentradi were shocked by the fortress performing a fold maneuver so close to the planets surface.  It wasn't just possible damage to the ship, nor the sizable piece of real estate they took with them.

The Fold took all displaced mass that and drew a line in the direction of the fold. This created an amplified wave greater than the suddenly missing island could account for, and it had a direction it was moving in.

I was under the impression that their shock was due to the audacity of performing a space fold from so deep within a planet's gravity well...  which we saw the results of shortly thereafter.

Also, I was under the impression that dimensional folds have little to no effect on local space, save for the arrival and departure points.  Are you saying that there was a gravity fluctuation along the path of the fold?  Because if this is a thing, then that would make dimensional folds a very hazardous method of FTL that would necessitate relatively short jumps with painstakingly calculated paths that avoid any and all possible celestial objects in their way.

[classicdrogn]

Sorry, I don't recall anything about a tsunami being involved. But, we see a passenger liner fold out from maybe a kilometer up when Myung heads to Earth in Macross Plus, and there's no gravity wave or whatever involved. I think there might have been seagulls flying around it that were undisturbed, though that could easily be my memory playing tricks. Granted, that's thirty-ish years after SDFMTV, but it's still the first-generation copied fold drives, it's not until Frontier another two decades on that they start taking it to new ground with the gate-style entry/exit and fold quartz enhanced experimental models.

[Valles]

AFAIK, the 'super tsunami' theory is not canon at all, but the result of fans with more scientific information - both via expertise from their day jobs and internet sources - doing math that the original creators hadn't considered. I'm pretty sure that it's original to a particular Robotech fic that sends a set of characters back in time from the Sentinels era, but there may be an earlier antecedent that I'm not aware of.

[ECSNorway]

This is kinda necro-ish, but I was rereading the fic in question recently.

One big thing that they came up with in discussion there was the point that the fold took the island with.

So what was left under it?

Answer: It wasn't just water displacement, it was the massive underwater volcanic eruption caused by the fold suddenly ripping the cap off of the magma chamber under the island.

[classicdrogn]

What is the fic? I don't think I've ever read it.

[Black Aeronaut]

What is the fic? I don't think I've ever read it.

I forget myself.  IIRC, it was a Robotech fic rather than Macross, though, and was really getting into the whole Robotech Masters thing that Harmony Gold cooked up because Rick, et al, had all been Peggy Sued back to the day the SDF-1 launched.  Yes, even Roy.  And Max and Millia.

I have to say, the implications about Millia being where she's at with what she knows... and the signs of her meddling that are already appearing, have been interesting.

[Black Aeronaut]

This is kinda necro-ish, but I was rereading the fic in question recently.

One big thing that they came up with in discussion there was the point that the fold took the island with.

So what was left under it?

Answer: It wasn't just water displacement, it was the massive underwater volcanic eruption caused by the fold suddenly ripping the cap off of the magma chamber under the island.

Daaaaayyyyyyuuuuuuummm...

I hadn't thought of that.  But holy hana, that'd do it alright!

More rationally: I strongly suspect that this would rival the foretold Yellow Stone Super Caldera eruption they've been worrying about.

[ECSNorway]

The fic was "Second Chances" by ajw.
https://www.tthfanfic.org/Story-30800/aj...hances.htm

And yeah, it's Robotech-based rather than Macross, but it's the only story I've seen that addresses the issue.

(One butterfly I liked: The tsunami killed off Senator Russo, the douchecanoe who was responsible for most of the idiotic UEG decisions in the Macross arc. Like telling the public that everyone on the SDF-1 or in Macross City was dead due ot terrorists and that there was no alien invasion going on....)

[classicdrogn]

Huh, TTH sayus I've read the first few chapters... but I don't remember it at all. Such hardships, how ever will I endure reading it anew? Thanks!