Nuée Ardente

Synonyms

Pyroclastic flow

Definition

Nuée Ardente is a “glowing cloud” of superheated (often incandescent) particles and gases formed by the collapse of an explosive eruption column.

Discussion

Nuée Ardente is an old term that has been largely replaced by “pyroclastic flow” or more recently “pyroclastic density current” (PDC) (cf. Sulpizio et al., 2008). The name Nuée Ardente is derived from observations of Mount Pelée in 1902 (cf. Fisher and Heiken, 1982). Pyroclastic flows (and surges) are extremely hazardous and destructive processes that can have a number of origins (Nakada, 2000). The most well known are those that originate from the collapse of a rising eruption column. This collapse is usually instigated by a change in the eruption velocity caused by changing vapor/particle concentrations at the vent. If the expansion of the gas content of the erupting column can no longer support the lower ballistically expelled parts of the column, it will collapse. The collapse produces a...