Eruption column dynamics are controlled mainly by the balance between thermal energy ejected from the vent and the work done during transportation of ejected material and entrained air through atmospheric stratification.
The flash is consistent with a cosmic explosion called a γ-ray burst, produced by a tightly collimated 'jet' of ejected material that was probably observed from a direction other than the axis of the jet.
Less common pyroclastic landforms include maars, low-relief craters often filled with water and surrounded by a rim of ejected material that was probably formed by explosive interaction of magma and groundwater; and tuff rings and tuff cones, which are landforms built of compacted pyroclastic deposits.
Neither do they have an apron of ejected material, another classic impact trait.
When clouds of ejected material and energy from the sun hit Earth's donut-shaped magnetic field, some of it is deflected, but the rest is shunted toward the ground near the magnetic poles.
The volume of ejected material from Hawaiian eruptions is less than half of that found in other eruptive types.
The estimated mass of the cloud is only a small part of the 50 100 Earth masses of ejected material.
In 2009, LCROSS sent a 2300 kg impactor into a permanently shadowed polar crater, and detected at least 100 kg of water in a plume of ejected material.
Velocities of ejected materials may become supersonic in the surrounding atmosphere, as evidenced by the observation of shock waves (e.g., Nairn, 1976).
When this threshold is reached, the quantity of ejected ash drastically increases together with the diameters of the pits (which may arrive to tens of meters in diameter).
When the cloud moves horizontally at a height of 6 8 km, the mass fraction of the ejected material decreases to <0.05 because of air entrainment (Fig. 2(h)).
