I have thought about this a lot. I grew up hearing about the San Andreas Fault. Have you ever heard of Cascadia Subduction zone? No one knew of its existence 45 years ago. I only learned of it last year. It's a every ones worst nightmare. This lady won a Pulitzer Prize writing about it.
https://www.newyorker.com/magazine/2015/07/20/the-really-big-one
When Cascadia makes its next big move, it will be devasting to the Pacific Northwest. Unfortunately, I live in the southern end of the Cascadia Subduction zone. An earthquake at 9+ on the Richter scale going on and on for more than 5 minutes is not going to leave much standing. Even if we happen to survive the earthquake, if the resulting tsunami is 200' high, we will be 25' under water

I thought about bolting down our stand, but it's not going to do any good if my entire house is collapsed, and I'm pretty sure it will not be standing. WHEN the big one happens, I will lose my fish. I hope that I survive.
In my area, earthquake and fire are the biggest threats. Our neighborhood received training on what to do in a disaster. Scary stuff. FEMA is well aware of the devastating consquences of Cascadia going off. When it happens, relief supplies will be flown to a little airstrip 20+ miles inland, instead of the real airport in town (Crescent City). I thought that was strange, until I remembered that the resulting tsunami will wipe out the town completely.
When the big one happens, our best laid plans could be for nothing. I have a 20 KW generator. Immediately after a disaster, we have to check for leaking propane lines and turn the tank off...no generator. Thinking of getting a solar generator. I could stock up 6 months of food and water to survive, but I could lose it all if a major fire happened before the big earthquake. Learning about Cascadia has made me a survivalist/mini-prepper.
Fingers crossed that our house doesn't collapse, and the 15,000 pounds of water weight in the tank will keep it from sliding off the stand. I can't think of a way to secure a big acrylic tank. So sure our house won't survive that keeping survival supplies in the house would be counter productive.
Check out that New Yorker article, if you want to read a horror story that is going to happen. . do a search on Cascadia Subduction zone. It is scary...Portland and Seattle wiped out..I-5 corridor wiped out..power grid wiped out for many months, coastal communities completely destroyed....the San Andreas is a baby compared to the devastation that Cascadia is going to cause. The predictions say "IMMINENT" for Cascadia.
Yes, I've thought about monster tanks in earthquake zones.