Segment V1.1: Mt. St. Helens Eruption

(Related to Textbook Chapter 1 - Introduction)

Some flows, especially those associated with various natural phenomenon, are of a very large physical size. Such large-scale flows often involve the motion of a considerable amount of material.

The eruption of Mt. St. Helens in 1980 involved the motion of an extremely large amount of material—liquid, gas, and embedded solid material. Although the overall characteristic length of this flow is several thousands of feet (the plume reached to a height of 15 miles), there is considerable smaller scale flow involved as well. The smaller, detailed turbulent mixing and swirling within the volcanic plume are clearly visible.