We've tried this before with the even more powerful shock wave from the eruption of Krakatoa back in 1883. Didn't convince anybody.
Hmmm - we RE'ers should have worked a bit harder on that one.
If the FE is infinite (or at least VERY large) - then the sound waves would have radiated outwards like ripples on a pond - and never came back a second and subsequent time.
If the FE is finite (or perhaps if the claim is that the Ice Wall is somehow able to reflect these seismic waves - then the regular interval of the repeat would depend on how close you were to the edge/Ice-Wall.
If you were close to the thing that's reflecting the wave, then you'd get a trace like:
--------|----|-------------------|----|-------------------|----|-------------------|----|
...where the first blip was the wave going OUTWARDS - and the second would be the reflection from the nearby ice wall...then a long delay while it travels all across the world, reflects off of the opposite side and returns again.
What was actually recorded was a REGULAR 36 hour repeat:
--------|------------|------------|-----------|------------|------------|-----------|--------
...which can't be explained by something reflecting the wave back again unless you happened to be in the center of the FE.
(In fact, if you do throw a rock into a circular pond - but don't hit it dead-center - then the off-center ripples interfere with each other and rapidly degenerate into chaotic ripples with no obvious pattern...so the FE wouldn't sustain more than maybe one or two repeats of the effect before it all turned into mush.)
So - I believe that the Krakatoa and Tsar Bomba effects would have been VERY different in an FE world...either one detection of the ripple - then nothing (if there is no reflection of the seismic wave because the FE world is infinite) - or those distinctive paired detections if the event happened in the exact center of the world - or a couple of those paired detections and then mush if the event was off-center.
No possible FE model can explain regular 36 hour repetitions of the seismic wave.