Maybe an earthquake fag can answer. Two earthquakes in Carson, CA last night USGS location information changed sometime last night. The epicenters moved, actually traded location and the first larger earthquake is now being reported at the site of the aftershock. The original larger earthquake epicenter moved a street down and is under a church now but is being reported as the aftershock location. I don't remember seeing this before but maybe I haven't paid that much attention. Pics related, single zoomed out earthquake pic I grabbed last night right after the initial 4.3.
https://earthquake.usgs.gov/earthquakes/map/?currentFeatureId=ci39812479&extent=33.79959,-118.29629&extent=33.85649,-118.24238&listOnlyShown=true&list=false