CC.1 Density and Layering in Fluids
ESSENTIAL TO KNOW
- Fluids are separated by gravity to form layers, each layer having lower density than the layer below it.
- Less dense fluids rise through more dense fluids.
- More dense fluids sink through less dense fluids.
- A fluid is neutrally buoyant when the fluid above has lower density and the fluid below has higher density.
- A neutrally buoyant fluid will spread horizontally to form a layer.
- A fluid in which each higher layer is of lower density than the layer below it is stably stratified. There are no density-driven vertical motions within such a stably stratified fluid.
- The depth range in a fluid within which there is a marked vertical gradient of density is called a “pycnocline.” A pycnocline inhibits vertical mixing between fluid above and below the pycnocline layer.