That is very cool. The sound reminds me of what I often hear in the second(s) before a large quake. Though since
"the waves of energy behind an earthquake are actually too slow for human ears to detect"
I guess what I hear is the quake (those waves?) rumbling stuff as it comes towards me. Always reminds me of when i used to live a few feet from a railroad track.
From: "Lin Kerns firstname.lastname@example.org [geology2]" <email@example.com>
To: Geology2 <firstname.lastname@example.org>
Sent: Tuesday, February 21, 2017 12:19 PM
Subject: [Geology2] This is what the sonic boom of an earthquake looks & sounds like (Video)
Posted by: coyote <email@example.com>