In volcanology, the feather, or eruptive cloud is a cloud of tephritis and gas that is formed in a downward direction with respect to an erupting volcano. The vertical column of gas and material rising directly above the mouth takes the name of the eruptive column.
The eruptive clouds can be dragged by winds for thousands of miles, usually extending over an ever larger area as the distance from the source increases. Within a few days, larger eruptive clouds can do all around the globe.
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