On my last cruise to Alaska, we passed slowly by the Mendelssohn (spelled wrong) glacier and was told that the Indians called the glacier white thunder. It was constantly booming as the ice cracks and then in a few minutes you looked up and down the length of the glacier and would find it calving. Usually you found it when it hit the water. Sometimes you would be lucky and see a large calving from the top to the bottom...been doing that booming for as long as the glacier was in existence. The glacier is 6 miles long, but the ship was placed so you could see the full 6 miles. Then it moved closer so as to turn around...It sounded exactly like booming thunder...
Early one misty autumn morning in NM, when I was doing the mountain man thing, I was sipping coffee and reading, and I felt a rumble under my feet, and then a terrific crash, like a car had hit a telephone pole...
Then nothing for a while.
Then it happened again. The rumble followed by the crash...
I went outside, and through the fog, I saw two of the ranch's bulls, pacing off to about 100 yards apart, and then run into each other, butting heads.
Those were big bulls. Even though I shared a pasture with them, I avoided them.
Nature makes some strange noises and sensations. And sometimes, you don't have a clue what they are, until you understand what is going on.
It's a wonderful world we live in.
/johnny