Unlike some of its perpetually active neighbors on the Kamchatka Peninsula, Raikoke Volcano on the Kuril Islands rarely erupts. The small, oval-shaped island most recently exploded in 1924 and in 1778.
The dormant period ended around 4:00 a.m. local time on June 22, 2019, when a vast plume of ash and volcanic gases shot up from its 700-meter-wide crater. The dramatic event was captured from space by astronauts aboard the International Space Station.
In the image above we see the volcanic plume rising in a narrow column and then spreading out in a part of the plume known as the ‘umbrella region’. That is the area where the density of the plume and the surrounding air equalize and the plume stops rising. [source]