Here is a thought: The difference between the two grooves could be just the difference in the recorded signal in these grooves. The microphonia look like close to only a sine signal while Mark's picture could be featuring a pink noise or dense classical orchestra passage.
Just imagine a graph of your woofer displacement in your loudspeaker vs. time - it would look very jagged in the second case. Also, note higher frequencies are recorded with more amplitude than lower ones on vinyl which will make it look stranger.
Just imagine a graph of your woofer displacement in your loudspeaker vs. time - it would look very jagged in the second case. Also, note higher frequencies are recorded with more amplitude than lower ones on vinyl which will make it look stranger.