Torsional rigidity in fishtanks during earthquakes

[DarkXerox]

So after seeing photos of a number of damaged reef tanks in Japan and given the industry trend to avoid bracing such as frames, euro-bracing, etc., I was wondering if anyone had actually looked into failure rates of tanks during earthquakes based on construction materials and design type?

In addition the effects of splashing onto equipment such as external Vortech pumps or controllers that frameless aquaria would be subject to could be a factor in damage.

Given that these types of aquaria were not around much during the heavy earthquakes (Loma Prieta in 89 and the Northridge in 94), I'm curious to see if anyone has heard of tank failures (not attributed to a lack of restraint systems) recently during a large earthquake?

 

[syrinx]

I certainly wouldn`t want a hard plumbed drilled tank system in a earthquake! I doubt tank manufacturers would ever change the way they build- but with effort I am sure a custom tank could be designed. Where I stay in haiti is about 2 miles from the epicenter of the eathquake there last year. The water in the pool came out in a tidal wave10 feet tall- and emptied 3/4 of the inground pool in one slosh. The pool itself suffered no damage. The reason I bring this up is to show that in a earthquake even container remaining intact, doesn`t guarantee much.