colonne

CONT: [Essais nucléaires]. Baker [explosion sous-marine] demeure à ce jour l'une des explosions les plus impressionnantes de par la masse d'eau projetée en l'air, la colonne atteignit plus de 2 kilomètres de haut et souleva ainsi plus d'un million de mètres cube d'eau.

CONT: Mushroom clouds are formed by many sorts of large explosions under earth gravity, though they are best known for their appearance after nuclear detonations. ... While it rises, air is drawn into it and upwards (similar to the updraft of a chimney), producing strong air currents known as ""afterwinds"", while inside the head of the cloud the hot gases rotate in a toroid shape. When the detonation itself is low enough, these afterwinds will draw in dirt and debris from the ground below to form the stem of the mushroom cloud.
CONT: [Nuclear tests]. The rapid formation of the cloud was dramatic - the stem shot up into the air like the Geneva fountain, developed the typical mushroom head, and then seemed to penetrate it and keep on going.