Interesting article describes a largish slow moving spring near San Andreas fault (SAF).
A San Andreas fault mystery: The 'slow-moving disaster' in an area where the Big One is feared
Quote:
A muddy spring mysteriously has begun to move at a faster pace through dry earth — first 60 feet over a few months, and then 60 feet in a single day, according to Imperial County officials.
It’s near the Salton Sea and moving along the path of the SAF.