What is a swift-moving cloud of purnice and ash?

A swift-moving cloud of pumice and ash is commonly known as a volcanic ash plume, which forms during explosive volcanic eruptions. This cloud consists of tiny rock fragments, volcanic glass, and gas that are ejected into the atmosphere, often rising to significant heights. The rapid movement of the cloud is driven by the force of the eruption and prevailing winds, posing hazards to air travel, human health, and the environment. These clouds can spread over large distances, affecting air quality and climate.