Hello all, having experienced a couple of small tremors in my new home town in the East Bay, I've been giving this issue some thought indeed. Someone with a little more experience in physics can correct me if I get this wrong, but I would imagine the two big forces we're concerned with are inertia and friction, and how our tanks respond to the energy input from the quake. The short version is that inertia is what makes the water slosh, and friction keeps the tank on the stand and the stand in one place on the floor. Someone mentioned in an earlier post that one of their tanks moved nearly 2" on its stand during a quake, which means that the force of the quake was sufficient to overcome the friction between tank and stand and shift the tank by that much. I know that under normal circumstances I cannot shift any of my tanks when they are full, so you can imagine how much force was being applied to that tank and stand during the quake. If your tank and stand are both fixed to the wall, the only way the force of the quake can be expressed is through water motion, and as mike mentioned that force might burst the seams of the tank, or if nothing else there will be a lot more sloshed water than if the stand alone is anchored. It seems that anchoring the stand is done with an eye towards keeping the stand and tank from toppling, since the principle of dissipating energy via tank movement would also apply to stand movement(though certainly you'll lose much more water if the tank falls over!). It was either posted here or on the Krib that someone had installed "bumpers" on their stands to keep the tank itself from shifting all the way off, which I think is probably a better choice than anchoring the tank to the wall with strapping. So, do any real physicists out there want to add to my science? It's been a while since I took physics... Cheers from the fault zone, Sarah LeGates --- Mike & Diane Wise <firstname.lastname@example.org> wrote: > Daniel, > > If the tank were firmly anchored, I'd worry about the sides > bursting due to the > pressure of > "sloshing" water. If the tank can move, "give" a little, I'd expect > there to be > less stress on the glass. Just a thought. Hmm. Aquarium air bag > (like in > automobiles)?? I wonder if there's a market there? :-) > __________________________________________________ Do You Yahoo!? Get email at your own domain with Yahoo! Mail. http://personal.mail.yahoo.com/ ------------------------------------------------------------------------- This is the apistogramma mailing list, email@example.com. For instructions on how to subscribe or unsubscribe or get help, email firstname.lastname@example.org. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!