Groundwater upwelling at Hotcake Slough - Main study site No flash player has been set up. Please select a player to play Flash videos. Video not playing? Update your browser or download the video clip Chas Jones discusses groundwater upwelling around his study site. Process Observed: Open WaterGroundwater Upwelling Date Process Observed: Saturday, March 31, 2012 Galleries: Hotcake Slough - Main Gallery