fumasse

Fumasse is a term that appears in some volcanological and historical literature to describe a plume of smoke and fumes issuing from a volcanic vent or, more generally, from a burning surface. The word derives from the Latin fumus (smoke) and is cognate with the French fumée and the Italian fumassa; in contemporary English texts the term is uncommon, and sources typically use volcanic plume, ash plume, or smoke plume instead.

In volcanology, fumasse refers to the visible gassy component of an eruption, comprising water vapor, volcanic gases such as carbon dioxide and sulfur dioxide, and fine ash particles suspended in air. It forms a column or cloud that may rise from hundreds to thousands of meters, and its behavior depends on eruption dynamics, particle size, and atmospheric conditions. Fumasse is distinct from lava flows and pyroclastic density currents, though it often accompanies explosive activity. Persistent fumasse can lead to air quality issues and ash deposition over broad areas, impacting nearby communities and infrastructure.

Monitoring fumasse involves ground-based observation, fixed cameras, and remote sensing instruments; aviation safety relies on plume height estimates and ash concentration measurements using LiDAR, radar, spectrometers, and satellite data.

Outside volcanology, the term has historical usage to describe smoke produced by fires or industrial processes. In modern usage, these contexts more often employ generic terms such as smoke or fumes, while fumasse remains a niche or historical descriptor within volcanology. See also fumarole, volcanic plume, and air quality monitoring.