Made up of rock and mineral particles that are larger than clay but smaller than sand. Individual silt particles are so small that they are difficult to see. To be classified as silt, a particle must be less than .005 centimeters (.002 inches) across. Silt is found in soil, along with other types of sediment such as clay, sand, and gravel.
The Daily Mail reports that silt release is a normal and safe procedure that dam operators carry out every year. Three specialised holes in the dam release 30 million tonnes of silt downstream. The process, which has moved 90 million tonnes of silt over the past 13 years, attracts brave onlookers for a glimpse of this ominous yet beautiful dam safety procedure.
[Via: Rocket News/ Image credit: @DDN Japan]