Milankovitch Cycles and Glaciation
First published: 2017
Brief summary
Teaching resource linking orbital cycles with glaciation and paleoclimate evidence.
Article
The linked SERC resource documents a laboratory flume demonstration of how a low-head dam alters water flow and coarse sediment transport. Before installation, shallow flowing water carries bed material through the channel with relatively uniform transport.
Installing the dam creates deeper, slower, subcritical flow upstream and faster flow over and below the structure. Because the upstream velocity decreases, the water can no longer carry the same coarse sediment load and deposition begins behind the dam.
Sediment accumulates until the channel bed rises enough for flow velocity and transport to increase again. Downstream, sediment supply is interrupted while flowing water continues to remove material, producing scour and the “hungry water” effect associated with sediment-starved reaches below dams.
The demonstration also shows changes in hydraulic conditions when the downstream gate is adjusted, including the appearance and drowning of a hydraulic jump. The resource concerns sediment continuity, deposition and scour around a low-head dam rather than orbital climate cycles or glaciation.
Source details and credits
- Source / publisher: SERC / Carleton
- Source type: Teaching resource
- URL type: WWW
- Credits: SERC / Carleton
- URL: https://serc.carleton.edu/details/files/19075.html