Earthquakes, speaker stands, and Snell E

Here's a different sort of question for you. I have a pair of Snell EIII speakers, and they sit on stands custom-made for the speakers. The stands are triangularly-shaped; the speaker sits on two points in front, and one in back. This means that the speaker is unstable if moved in the direction of 10 or 2 o'clock. I relocated to LA, and I'm trying to decide how to keep my speakers from falling over during an earthquake. I've at least two options. First, there are 2 holes in each stand through which I could put a screw into the bottom of the speaker (the speakers have a base and the screw wouldn't enter the cabinet) and screw the speakers to the stands. My worry here is that it would change the dampening effect of the stands--cabinet vibrations would transfer through the screw to the stand.

The other option is the unconventional one. I can place unopened tennis ball cans under the rear two corners. Tennis ball containers, when unopened (they're vacuum sealed) are quite resiliant. They give, but not very much. So these would be "airbags" for my speakers, deflecting the speaker back away from 10 or 2 o'clock if they moved that way.

I've also noticed that the stands on 4 spikes dampen vibrations from quakes--the dampening works from the ground-up, as well. So this might be a consideration.

I've just discovered the community here, and I'm glad that I found you. I purchased my system in 1991 with my high school summer job money, and it is 15 years later that I finally have a bit of money that I can spend on audio gear (10 years of college and graduate school and then finding employment as a teacher will do this sort of thing). So, I really appreciate how much information is here, and how helpful people are.

Thanks!

Matt