Earthquakes at 10.0 kilometers deep? Man made or naturally occurring? Telsa's technology?

Has anyone ever wondered about the earthquakes that are only 10.0 kilometers deep? I have been observing the usgs for years and am always amazed that there are tons of earthquakes at 10.0 kilometers around the world, but never like 20.0, 40.0, or any other even number. It has always been 10.0. For example today's 10.0 kilometer earthquakes:

M 5.0 - 42km E of Dehloran, Iran

DYFI? - I
Time
2014-08-17 10:47:19 UTC-04:00
Location
32.659°N 47.715°E
Depth
10.0km

M 5.2 - Mid-Indian Ridge

DYFI? - I
Time
2014-08-17 12:04:48 UTC-04:00
Location
20.777°S 68.428°E
Depth
10.0km

M 4.7 - 13km ESE of Xiluodu, China

DYFI? - III
Time
2014-08-17 05:11:45 UTC-04:00
Location
28.151°N 103.703°E
Depth
10.0km

Just wondering sometimes if these were manmade. I believe the big one in Haiti a couple of years ago was at 10.0 as well. Just thought I would post this to see of anyone else has info on this subject or observed the same!
[link to earthquake.usgs.gov]