[Jan-Poo]

Originally Posted by Kylon99

Oh, no... if you mean by 'what caused' it you mean why was the explosion set off in the first place... I'd say that was part of what we were meant to find out. EP7 tells us it's something Beatrice planned for... and the why is in why she even thought of that. Supposedly. I'm not too sure she really intended for all of the deaths, similar to AuraTwilight... but... I have to consider the possibility her hands aren't as clean as I thought they were.

But if you mean 'what caused it' as in... who flipped the switch or ignited the fuse, etc... then... I don't believe that's relevant. All we know is someone did and the bomb did go off. The meat is in why Yasu (if it was her) set it up that way...

Uh no I'm talking of what caused the crater. Whether it's a carefully planned set of explosives displaced in an incredibly complex maze of tunnels, a single huge bomb placed below the Mansion, a nuclear bomb, a meteor, a landslide a volcano or an alien attack... that's what I want to know.

Additionally I'm not sure that we can confirm that Beatrice actually planned that explosion.

Originally Posted by Kylon99

Well not if the police became aware of the TNT used to trigger the event. And, the TIPS say that Erika may have become involved in the Rokkenjima Explosion Incident, not that she had to have been blown up directly by the bomb. So, if the landslide was natural (say due to the amount of rain) then they wouldn't have said that; they'd say Rokkenjima Landslide Incident. But if they could detect (say the residue of) the TNT and determined that, since it was probably all over the place thanks to 900T going off... then they would probably call it an Explosion Incident.

Despite the fact that what you suggest should be called implosion and not explosion. Your explanation raises important issues.
As you said if this is what happened the only way it could be known as an explosion is if the police actually noticed the TNT residue and made it public.

Then how come it was considered an accident?
Kylon, you said it yourself. You'd need tunnels all around the place and you'd need explosives set in strategic points. Something like what you suggest can't possibly happen "naturally" or by "chance". And yet it is obvious that the official explanation is that no one is responsible, it's just an accident, it's not a crime.

It doesn't match.

Even if you suggest the official explanation is that the japanese military during the war created that system as a way to self-destruct the island (which I fail to see it plausible), the public opinion would still consider the Japanese military and the government responsible for such a blunder.

Originally Posted by Kylon99

<-- this picture though shows a big round circle though. Is it from the anime? By the way, the way it's drawn, it looks like Toraian is right at the center...

the first picture is from the anime, the second picture is something I made to give an idea of the kind of damage the island suffered.
Well to be honest... I exaggerated a bit... considering the distance between the Mansion and the Kuwadorian is 2km. the crater should be a little smaller than that, but I think it gives the general idea.

Originally Posted by Kylon99

Anyways, Ripple Rock is my example of setting charges smartly rather than somehow consolidating 900T of TNT in one spot and just hoping it blows up the way you want. (Which as you've shown, won't.) And the result is to shear a mountain, a mass larger than Rokkenjima, so there's still plenty of TNT left to play with after... for things that you really do want to vaporize and blow up...

I gotta imagine someone surreptitiously asked some demolitions experts on how to do things... say, a mercenary group called the Yamainu.... :3

Emphasis on "smartly".

Anyway I'm aware that rocks and desert do not work in the same way and that rock blow more nicely than sand.

But that still doesn't explain the huge disparity between 104 kilotons and 0,9 kilotons.