Was also looking at USGS, often see -km values for sonic booms bit typically they are called out as such. Same goes for mining blasting. Is depth measured from sea level? Could some depths actually be very shallow? Area of quakes is fairly high altitude even in the valley.
Live in SoCal, did not see a single Biden yard sign or bumper sticker until after the election then saw a couple bumper stickers. Saw lots of Clinton stuff at previous election everywhere. Kern should be a target for you. Orange and even LA look super suspicious to me based on pure observation.