Physics of Lava Flows
photo
provided by USGS
The way that lavas flow is dependent on many factors including: viscosity, rheologic properties, temperature and composition. Many studies have been completed to determine how lavas will act when sitting on a sloping surface. It has been determined by Hulme in 1974 that a lava must create a critical thickness, t, before it will flow. His findings can be expressed as:
Figure
1 (Francis, 1993)
Using this relationship the velocity at which a lava will flow down a slope can be determined using:
