CHRIS PAOLA / SCIENCE PHOTO LIBRARY CHRIS PAOLA / SCIENCE PHOTO LIBRARY
Geological research tank. Braided streams flowing over sediment to the sea (at right) in an experim- ental basin. This 6.5-by-13-metre tank models how sediment layers are laid down by river and ocean currents. Its computer-controlled floor is slowly lowered so stratified sediment builds up over the equivalent of millions of years. This occurs as gravel, which lies below the rubber sheet on which the substrate forms, is run out through 432 funnels at the base of the tank. Uneven removal of gravel means parts of the floor can be altered by just 100 micrometres to model different tectonic activity. Photographed at the St Anthony Falls Laboratory at the University of Minnesota, USA.
Model release not required. Property release not required.