Likely this is just the iron deposits from your well casing and pipes. The shaking mechanically dislodged/transported and are now concentrated in the water until everything flushes. Or possibly during the quake liquifaction moved some unwanted sediments into the developed well cone. What shawnee Acres said is correct and when a new well goes in pumping the well is a normal procedure to clear the water. In your case you would be redeveloping an established well by pumping to remove and thus improve water quality.
To check if this is iron....just add some iron-out to the water and see if the red goes bye-bye. Do not water your stock with that tho! There is no upper limit for iron concentration in well water for livestock becasue there is no toxicity assoc'ed with iron concentration in well water for livestock.
Tho rare on occassion I have seen/heard after an event that old/unknown septic contaminates find their way into well water. This tends to be nasty looking water and not the typical iron red coloring.
If in doubt call a water quailty firm and boil that water before used for humans.
It seems to be clearing up a bit...Ive been running it for awhile and it's definitely clearer than it was last night. If it doesnt get much better, i'll definitely call the water quality firm and see what they say!
Charlie Brown (1994 bay TB X gelding)
White Star (2004 grey TB gelding)